Magazine 2015 by NIsthul G

Vision of the Mechanical Engineering department Transforming young minds into motivated, quality aware and environment - conscious technocrats. Mission of the Mechanical Engineering department Educating the students to excel professionally by: Providing facilities and environment conducive to a high quality education. Cultivating the spirit of entrepreneurship, applied research and responding effectively to the needs of the industry. Emphasizing the values of leadership, contributing to economic development, protecting the environment and improving the quality of human life. PEOs of Mechanical Engineering Department After 3 to 5 years of completion of the graduation, our graduates will be able to: PEO 1 – Enhance Professional Capability – They will apply mathematical, scientific and engineering principles for analyzing and solving mechanical engineering problems. PEO 2 – Excel Technically and Foster Continued Learning – They will be competent to design and develop meaningful solutions for efficient utilization of man, machine, money and materials, using modern techniques and tools and nurture continuous learning. PEO 3 – Address Social, Ethical and Environmental Concerns – They will deal with social, ethical and environmental concerns in technological advancements. PEO 4 – Enrich Essential Management Skills – They will augment management skills along with teamwork and effective communication for successful completion of engineering projects. Programme Outcomes 1. Apply knowledge of mathematics, science and engineering fundamentals to the conceptualization of science and engineering models. 2. Identify, analyze, formulate and research literature to interpret data for Mechanical Engineering problems using first principles of mathematics and engineering sciences. 3. Design solutions for Mechanical Engineering problems and develop systems, components or processes that meet specified requirements 4. Conduct investigations, analyses and interpretation of data and synthesis of information to arrive at valid conclusions to complex Mechanical Engineering problems 5. Demonstrate skills to select and apply modern engineering tools, understanding the constraints, using appropriate techniques 6. Demonstrate understanding of the societal and legal issues and the consequent responsibilities relevant to engineering practice. 7. Understand the impact of engineering solutions in an environmental context and demonstrate knowledge of and need for sustainable development. 8. Follow professional ethics with consequent responsibilities relevant to norms of engineering practice. 9. Perform effectively as an individual, and as a member or leader in diverse teams, in multidisciplinary settings as well 10. Communicate technical ideas effectively with the engineering community and society by oral and written means. 11. Manage a project effectively, understanding the limitations of general business practices including risk and finance management 12. Engage in independent and life-long learning to meet global technological challenges

Mechanical Engineering Department of Saintgits College of Engineering have immense pleasure to unveil the fourth edition of Technical magazine for the academic year 2014-2015, presenting high quality works in an accessible medium for use in teaching and future research. This magazine is a small step towards emphasizing the values of leadership, contributing to economic development, protecting the environment and improving the quality of human life. The magazine organizing committee extend deep hearted gratitude to our Principal, Head of the Department, College management and beloved colleagues for their support, cooperation, constructive suggestions and healthy criticism with a view to enhance the utility of the magazine.

June 2015

Mechanical Engineering Department

CONTENTS

Sl.No.

TOPIC

PAGE No.

LOOP HEAT PIPE Githin V Sam, Jesvin Sam, Jethin Babu, Jithin Victor

A NOVEL METHOD FOR SPACE COOLING FROM AUTOMOBILE ENGINE EXHAUST Jesti n James, Jomy Jose, Anoop Vi jayan, Boney Thomas Varghese

PHOTOVOLTAIC DRIVEN THERMOELECTRIC REFRIGERATOR FOR CAR HEAT DISSIPATION DURING SUNNY DAYS Ashiq Georgi Abraham, Bobby Jacob, Davie George Vinu, Dean John Vinu

EXHAUST GAS WASTE HEAT RECOVERY AND UTILIZATION SYSTEM IN IC ENGINE Alvin P Koshy, Bijoy K Jose Jeffin Easo Johnson, K Navaneeth Krishnan, Bijeesh P

STUDY, DESIGN AND OPTIMIZATIONOF TRIANGULAR FINS Abel Jacob, Gokul Chandrashekhara, Jerin George, Jubin George

STEAM TURBOCHARGING Abhijith P, Akhilesh Rajan, Cyril Soji Thomas, Kevin George Jacob

REFORM THE PERFORMANCE OF A BILLET QUALITY BY REDUCING ITS DEFECTS AT SAIL-SCL KERALA LIMITED Abdul Haseeb NC, Alex P Jacob, Arvind Kumar, Dibin Vincent

UNDERWATER SEARCH AND RESCUE DEVICE Amjith K, Arundas V H, Harikrishnan M, Jeevan Sebastian CAPILLARY WATER PROVISION SYSTEM FOR IRRIGATION Philip Jacob Perakathu, Joju Thomas K, Kiran Thomas, Dheeraj M, Christin Thomas ANALYSIS OF EVAPORATIVE COOLER AND TUBE IN TUBE HEAT EXCHANGER IN INTERCOOLING OF GAS TURBINE Bibin Varkey, G Rahul Krishna, Akhil George Kurian, Adharsh S, Aswin Zachariah

CFD ANALYSIS OF A 24 HOUR OPERATING SOLAR REFRIGERATION ABSORPTION TECHNOLOGY Arunkumar. H, Benson P Sunny, Arun George, Jesbin Antony

EXPERIMENTAL INVESTIGATION OF PERFORMANCE AND EMISSION CHARACTERISTICS OF HYBRID FUEL ENGINE Nirmal Chandran, Blessen Sam Edison, Christy Binu, Godwin Geo Sabu, Jobin K Abey

SIX STROKE ENGINE Aarush Joseph Sony, Carol Abraham, Boney Mammen Ajith P Kurian, Prof. Sajan Thomas

A STUDY ON THE MECHANICAL PROPERTIES OF NATURAL FIBRE HYBRID COMPOSITE MATERIALS P.Sivasubramanian, Dr.M.Thiruchitrambalam

FLUE GAS LOW TEMPERATURE HEAT RECOVERY SYSTEM FOR AIRCONDITIONING Nirmal Sajan , Ruben Philip , Vinayak Suresh , Vishnu M , Vinay Mathew John

SEMI AUTOMATED COCONUT TREE CLIMBER Rahul V, Sameer Moideen CP, Sebin Babu, Vineeth VP, Nikhil Ninan

HIGH ALTITUDE AIR FLOW REGULATION FOR AUTOMOBILES Arun K Varghese, Saran S, Shaiju Joseph, Sherin George, Sreelal M

MULTISTAGE EPICYCLIC LUG WRENCH Nevin G Ninan, Nithin George, Salu Zachariah, Shinu Baby, Aju Zachariah Mani

101

REGENERATIVE SHOCK ABSORBER Tobin Thomas, Nidhin Abraham Mammen, Sethu Prakash S, Steve John, Varughese Punnoose Kochuparackal

105

AN ASSESSMENT ON DESIGN PARAMETERS AND VIBRATION CHARACTERISTICS OF BOILER FEED PUMP FOR AUXILIARY POWER CONSUMPTION Nikhil Abraham , Sachin Chacko , Sethu Sathyan , Sreenath K G , Parvathy Venugopal

110

LEVER DRIVEN BICYCLE Mebin Mathew, Natheem Nasar, Rahul Mohan M, Vijaya Krishnan R, Er. K C Joseph

117

SEMI-ACTIVE SUSPENSION FOR TWO WHEELERS Sanoop Soman, Sherry Shaji, Vipin T Thomas, Vishnu E.M, Arun K Varghese

120

DESIGN AND FABRICATION OF HAND PUMP OPERATED WATER PURIFICATION SYSTEM USING REVERSE OSMOSIS Nikhil Jacob Zachariah, Vimal P Sunil, SachinTomy, Vijith K

126

AN EXPERIMENTAL ANALYSIS ON SYNERGETIC EFFECT OF MULTIPLE NANOPARTICLE BLENDED DIESEL FUEL ON CI ENGINE Sajunulal Franc, Roshith Oommen George, Sachin Jacob James, Mathew John

131

MODELING AND ANALYSIS OF NONPNEUMATIC TYRES WITH HEXAGONAL HONEYCOMB SPOKES Vinay T V, Kuriakose J Marattukalam, Sachu Zachariah Varghese, Shibin Samuel, Sooraj Sreekumar

136

POWERLESS AIR CONDITIONING WITH INTEGRATED WATER HEATING Nishin Asharaf , Nicku Abhraham , Sajin Chacko , Shijo George , Tom Mathew

142

DESIGN AND ANALYSIS OF 3D BLADES FOR WELLS TURBINE Shyjjo Johnson,, Srriirram S Kumarr,, Tom B Thachuparrambiill,, Viivek Joseph John ,, G.Anil Kumar

148

DESIGN AND ANALYSIS OF HEAT EXCHANGER FOR AUTOMOTIVE EXHAUST BASED THERMOELECTRIC GENERATOR [TEG] Rakesh Rajeev, Richu Lonappan Jose, Rohan Mathai Chandy, Thomas Lukose, Er.Nandu S

152

SOLAR DISTILLATION Ken Toms Pothen,NevinSaju Varghese, Nidhish Thomas Jacob, Sachin Mathew, Nikhil Ninan

158

Loop Heat Pipe Githin V Sam, Jesvin Sam, Jethin Babu, Jithin Victor

Abstract: Loop heat pipes (LHPs) are two phase heat transfer devices that use evaporation and condensation of a working fluid to transfer the heat and use the capillary force developed in fine porous wick to circulate the fluid. They possess all the main advantages of conventional heat pipes, but owing to the original design and special properties of the capillary structure are capable of transferring heat efficiency for distances up to several meters at any orientation in the gravity field, or to several tens of meters in a horizontal position. They do not require any electrical energy for heat transport because of the absence of any mechanical moving parts. The main objective of this project is to fabricate a 2m long loop heat pipe for efficient transfer of heat. The main parts include a wick, a heater block, an accumulator, 2m long copper wire and a condenser. An external fan was introduced to speed up the natural condensation process. The wick was made with copper with 0.3 mm micro drilled pores. The working fluid used is ethanol. After fabricating the model, the pipe was completely filled with ethanol and temperature readings were noted using a temperature sensor at two different positions. A good agreement was reached between the two values.

LHPs can be kept lower than in the conventional HPs. The wicks in the LHPs develop high capillary pressures that are used to operate against gravity and can also be used to increase the horizontal distance for heat transport. The heat losses from vapor and liquid lines to ambient air and due to the pressure losses in the single-and two-phase fluids in the vapor and liquid lines. Figure 1 shows the layout of loop heat pipe.

Unlike conventional heat pipes, the wick structure used in the LHPs should not have excessively high effective thermal conductivity to avoid heat leaks to the liquid present in the compensation chamber. It should be noted that there is a need for compromise between back conduction problem and the desire for good thermal conductivity of wick to promote efficient heat exchange in the evaporating zone

I.INTRODUCTION Loop heat pipes (LHPs) are two-phase heat transfer devices. It uses the evaporation and condensation of a working fluid to transfer the heat from one point to other. Capillary forces are developed in the fine porous wicks which helps to circulate the fluid. It does not require electrical power because they have no moving mechanical parts. The pressure loss at the wick in the Loop Heat Pipes can be kept lower than in the conventional HPs. The wick is made of copper instead of PTFE (polytetrafluoroethylene) and has pores of size 0.3mm. Loop Heat Pipes are similar to heat pipes but have the advantage of being able to provide reliable operation over long distance. They can transport a large heat load over a long distance with a small temperature difference. Different designs of Loop Heat Pipes ranging from powerful, large size LHPs to miniature LHPs (micro loop heat pipe) have also been developed and successfully employed in a wide sphere of applications both ground based as well as space applications. Compared with conventional Heat Pipes (HPs), which also use capillary forces to circulate the working fluid, the LHPs can transport heat over longer distances. In the conventional Heat pipes, vapor flows through the center of the pipe from an evaporation area to a condensation area, while liquid flows through the wick, which is located in the inner surface of the entire pipe, from the condensation area back to the evaporation area. Therefore, if the distance needed for heat transport becomes longer, the length of the wick and the entire pipe also become longer. In contrast, in the LHPs, the wick is located only in the evaporator. Therefore, if the distance needed for the heat transport becomes longer, the length of the wick does not change. Because of this difference, the pressure loss at the wick in the

II. COMPONENTS A Copper Tube:

Fig. 2: Copper Tube

Copper tube is most often used for supply of hot and cold tap water, and as refrigerant line in HVAC systems. There are two basic types of copper tubing, soft copper and rigid copper. Copper tubing is joined using LPG welding. Copper offers a high level of corrosion resistance, but is becoming very costly. The vapor line consist of copper tube

` of 0.7in diameter and the liquid line consist of copper tube having 0.5in diameter.

D Accumulator: An accumulator is an apparatus by means of which energy can be stored. A GI moulded accumulator is used to store the working fluid which is ethanol.

B Fan: A mechanical fan is a machine used to create flow within a fluid, typically a gas such as air. The fan consists of a rotating arrangement of vanes or blades which act on the fluid. The rotating assembly of blades and hub is known as an impeller, a rotor, or a runner. Usually, it is contained within some form of housing or case. This may direct the airflow or increase safety by preventing objects from contacting the fan blades. Most fans are powered by electric motors, but other sources of power may be used, including hydraulic motors and internal combustion engines. Fans produce flows with high volume and low pressure (although higher than ambient pressure), as opposed to compressors which produce high pressures at a comparatively low volume. A fan blade will often rotate when exposed to a fluid stream, and devices that take advantage of this, such as anemometers and wind turbines, often have designs similar to that of a fan.

E Heater: Heaters are appliances whose purpose is to generate heat. Such a system contains a boiler, furnace, or heat pump to heat water, steam, or air. The heat can be transferred by convection, conduction, or radiation. Heaters exist for various types of fuel, including solid fuels, liquids, and gases. Another type of heat source is electricity, typically heating ribbons made of high resistance wire. This principle is also used for baseboard heaters and portable heaters. In loop heat pipes,GI ceramic injection moulded heater is used to heat the ethanol.

C Condenser:

Fig. 4: Heater

F. Wick: Fig. 3: Condenser In systems involving heat transfer, a condenser is a device or unit used to condense a substance from its gaseous to its liquid state, typically by cooling it. In so doing, the latent heat is given up by the substance, and will transfer to the condenser coolant. Condensers are typically heat exchangers which have various designs and come in many sizes ranging from rather small (hand- held) to very large industrial-scale units used in plant processes. For example, a refrigerator uses a condenser to get rid of heat extracted from the interior of the unit to the outside air. Condensers are used in air conditioning, industrial chemical processes such as distillation, steam power plants and other heat-exchange systems. Use of cooling water or surrounding air as the coolant is common in many condensers.Natural convection air cooled condenser of dimension 9â&#x20AC;?x9â&#x20AC;? fin type is used. The fins are made of Aluminium. Fig. 5: Wick

` 0.5in diameter copper tube with 0.3mm holes drilled onto the tube acts as the wick. The capillary forces developed in these pores give the required pressure difference to cause the ethanol flow.

The open end of the wick was welded to the accumulator. The accumulator is made of Galvanized iron. The other end of the wick was welded to 2m copper tube which formed the vapor line. The open end of the wick was welded to the accumulator. The accumulator is made of Galvanized iron. The other end of the wick was welded to 2m copper tube which formed the vapor line. At the end of the vapor line, 9*9 inch condenser with aluminum fins was kept.

G. Ethanol: Commonly referred to as the drinking alcohol or spirit. It is the principal type of alcohol found in alcoholic beverages. III. METHODLOGY Prior to fabrication, model was first designed in CATIA and analysed in ANSYS FLUENT (figure 6) to find out the thermal efficiency. After obtaining the appropriate design, the required materials were purchased and fabrication initiated.

Fig. 8 Filling Heat Pipe with Ethanol This causes phase change of the vapour ethanol to liquid. From the condenser to the accumulator, a copper tube of 0.5 inch diameter acts as the liquid line. An injection moulded heater was attached to the accumulator. The entire model was build up on cast iron frame. After assembling the entire model, leak test was conducted by using R-22 and soap solution. After conducting leak test, it was filled with ethanol as shown in figure 8 and sealed. After filling with ethanol, the entire pipe sections were insulated using thermo wool and thermo foam in order to prevent heat from escaping from the tube. The finished model is shown below.

Fig. 6: Analysis of Wick The wick was initially fabricated by micro drilling 0.3mm holes into the copper tube. The wick is shown in figure 5. One end of the pipe was closed by Gas welding. The wick of diameter 0.6inch was inserted into copper tube of diameter 0.7 inch and Gas welded

Fig. 9: Fabricated Model Fig. 7: Micro Drilling

` IV. RESULTS AND DISCUSSIONS

the heat loads. The pressure loss across the liquid line was much larger than those across the wick or the vapor line. To simplify the layout of the LHP, the outside diameters of the liquid line was made smaller as compared to vapor line. This emphasizes that when LHPs are designed for a long distance heat transport, it is important to take into account the pressure loss across the liquid line.

A Temperature Measurement on Two Metre Long Loop Heat Pipe: After the fabrication process was completed, the process of measuring the temperature at various locations throughout the LHP was carried out. Temperature was measured with the help of two temperature measuring sensors. The first sensor was placed at the starting of vapor line in order to measure the heater temperature. The second sensor was placed at the endof the vapor line.

V. CONCLUSIONS A two metre long Loop Heat Pipe was designed in CATIA and different parts were analysed using ANSYS FLUENT. After analysis we found out that higher efficiency was observed with the new wick design. Unlike the conventional heat pipe which has the wick present throughout the pipe, here the wick is present only at the beginning of the heat pipe. After making the appropriate alterations in the design, the model was fabricated with ethanol as the working fluid. The capillary forces developed in the fine porous wick helps to circulate the working fluid, thereby eliminating the need for electrical energy as there are no mechanical moving parts. Temperature was measured using two temperature sensors and it was found to be approximately equal at any point in the vapor line. A good agreement was reached between the two values. High efficiency was obtained above 60°c..

Fig. 10: Temperature Sensor Readings

REFERENCE [1]Mitomi and Hosei Nagano, “Long distance loop heat pipe for effective utilization of energy”. International Journal of Heat and Mass Transfer, Vol. 77, pp.777–784, (2014).

It was found that both the temperature readings were approximately close which implies that the capillary structure of the wick material enabled the hot vapor to travel through a distance of 2m through an ordinary copper tube. Two temperature readings are shown in the figure. The heater temperature was 62°C and the temperature at the end of the vapor line was 60°C.

[2]Maydanik, “Loop heat pipes”.Applied Engineering, Vol. 25, pp. 635–657, (2005).

Thermal

[3]Pastukhov and, Yu.F. Maidanik and C.V. Vershinin and M.A. Korukov, “Miniature loop heat pipes for electronics cooling”.Applied Thermal Engineering, Vol. 23, pp. 1125– 1135, (2003).

B.Pressure Losses over Long – Distance LHPs:

Fig. 11: Calculated Pressure Loses Figure 11 shows the calculated distributions of the pressure losses for the LHP. The figure shows that the wick, vapor line, and the liquid line had the largest pressure losses at all

A NOVEL METHOD FOR SPACE COOLING FROM AUTOMOBILE ENGINE EXHAUST Jestin James, Jomy Jose, Anoop Vijayan, Boney Thomas Varghese Abstract: High altitude performance is a major concern for automobiles. Due to lack of air density and pressure at high altitude the mass flow rate to engine drops considerably with altitude. This in turn will affect the volumetric efficiency of the engine. This is an area of great concern for Indian road conditions. The Indian road condition varies from sea level to around 6000m. Thus the engine performance varies drastically will altitude. We had considered flow through the inlet manifold for a four cylinder turbocharger diesel engine at low and high rpm. At lower rpm at around 1500 the turbocharger boost pressure will negligible, thus the engine will be in natural aspiration. Now at this normal running condition the mass flow to engine drops considerably with altitude. Now for a speed of around 2500 rpm there is sufficient flow to around 3000m and then drops. The flow pattern for a single cylinder in open condition has analyzed to find the average mass flow for different altitude.

Fig. 1: Counter-flow vortex tube

. This type of vortex tube is used in applications where space and equipment cost are of high importance.

I. INTRODUCTION The vortex tube is a mechanical device that separates single compressed air stream into cold and hot streams. It consists of nozzle, vortex chamber, separating cold plate, hot valve, hot and cold end tube without any moving parts. In the vortex tube, when works, the compressed gaseous fluid expands in the nozzle, then enters vortex tube tangentially with high speed, by means of whirl, the inlet gas splits in low pressure hot and cold temperature streams, one of which, the peripheral gas, has a higher temperature than the initial gas, while the other, the central flow, has a lower temperature. Vortex tube has the following advantages compared to the other commercial refrigeration devices: simple, no moving parts, no electricity or chemicals, small and light weight, low cost, maintenance free, instant cold air, durable, temperature adjustable. Therefore, the vortex tube has application in heating gas, cooling gas, cleaning gas, drying gas, and separating gas mixtures, liquefying natural gas, when compactness, reliability and lower equipment cost are the main factors and the operating efficiency becomes less important.

Fig. 2: Uniflow Vortex tube

The mechanism for the uni-flow tube (Figure 2) is similar to the counter-flow tube. A radial temperature separation is still induced inside, but the efficiency of the uni-flow tube is generally less than that of the counter-flow tube. Although the vortex tube effect was known for decades and intensive experiments and correlative investigation had been carried out, the mechanism producing the temperature separation phenomenon as a gas or vapor passes through a vortex tube is not fully understood yet. Several different explanations for the temperature effects in the vortex tube have been offered.

There are two types of the vortex tube. II. RESEARCH METHODOLOGY In current scenario the air condition system is run by a part of engine power. In our methodology, we use exhaust power by using a vortex tube for making refrigeration effect. The above figure 3 is the schematic diagram of the proposed project. The engine exhaust is connected to a turbine which is coupled to a compressor. As the turbine rotates, compressor coupled to it rotate and air is drawn from outside .This compressed air is given to the inlet of a vortex tube. In vortex

(1) Counter flow (2) Uni-flow. Both of these are currently in use in the industry. The more popular is the counter-flow vortex tube (Figure 1). The hot air that exits from the far side of the tube is controlled by the cone valve. The cold air exits through an orifice next to the inlet. On the other hand, the uni-flow vortex tube does not have its cold air orifice next to the inlet.

tube, the compressed air is entering tangentially through the nozzle near the cold end.

TABLE I DIMENSIONAL DATA FOR VORTEX TUBE EFFECTIVE LENGTH

300 mm

INLET DIAMETER

2 mm

TOTAL DIAMETER

10 mm

COLD OUTLET DIAMETER

5 mm

NUMBER OF NOZZLES

Fig. 3: Schematic of the proposed project

The escape of gases through cold end is prevented by a diaphragm. Thus the air moves towards the hotter side. A throttle body is placed at the hot end to control the cold fraction. A part of air which is rippled back by the throttle body flows back through the core. During this reversed vortex flow energy is given to the outer vortex and thereby getting a cold stream of air at the core. From the values obtained from the journal a suitable vortex tube is modelled using SOLIDWORKS. A six inlet vortex tube is opted for the system. Fig. 5: The model designed in CATIA V5

Fig. 6: Temperature to L/D ratio graph

Fig. 4: Proposed 6 inlet vortex tube model

A. Analysis:

Figure 6 shows the graph that relates between temperature and L/D ratio. It was based on the experimental data from the journal â&#x20AC;&#x153;Experimental study and CFD analysis on Vortex tube by Kalal.M. It was found that the optimum condition for vortex tube was when the L/D ratio stays between 20 and 55. The temperature separation decreases for L/D ratio above 55 and below 20.

Inlet is given tangentially. Diaphragm prevents the escape of inlet air directly. Six inlets are given to sustain the vortex motion. Properties at the inlet are usually obtained from experimental data, analysis, or estimation. It is very rare that all the boundary conditions required are available from experiment. Quantities of primary importance here are the velocity components normal and tangential to the inlet. In

axisymmetric flows, the swirl component must also be known. The counter flow vortex-tube type generally has an entrance block with an orifice and a control valve. Compressed gas enters the vortex tube tangentially through one or more nozzles. Most experiments provide inlet data such as pressure, temperature to and mass flow rate just before the nozzle. Unfortunately, they cannot be used as input data for computations which need the data at the nozzle exit stage. Little is known about the static pressure, temperature Tin, and velocity Vn, at the nozzle outlet. Those values may be obtained by extrapolation from their experimental profiles inside the tube to the nozzle exit location. Thus, this practice is adopted for the velocities; the total temperature at the nozzle exit is obtained by assuming an adiabatic nozzle, so that the total energy is conserved throughout the nozzle. Note that the static pressure values inside the flow field are calculated relative to the value at a reference point, for which measurement is available. Density at the inlet is calculated from the continuity equation

III. RESULT AND DISCUSSIONS A.Temperature Plot:

1) Meshing: Fig. 7: Temperature plot after analysis

The partial differential equations that govern fluid flow and heat transfer are not usually amenable to analytical solutions, except for very simple cases. Therefore, in order to analyze fluid flow, flow domains are split into smaller sub domains (made up to geometric primitives like hexahedra and tetrahedra in 3D and quadrilaterals and triangles in 2D). The governing equations are then discretized and solved inside each of these subdomains. Typically one of the methods is used to solve the approximate version of the system of equations: finite volumes, finite elements, or finite differences. Care must be taken to ensure proper continuity of solution across the common interfaces between two subdomains, so that the approximate solutions inside various portions can be put together to give a complete picture of fluid flow in the entire domain. The subdomains are often called elements or cells, and the collection of all elements or cells is called a mesh or grid. The origin of the term mesh (or grid) goes back to early days of CFD when most analysis were 2D in nature. For 2D analyses, a domain split into elements resembles a wire mesh, hence the name.

Fig. 8: Temperature contour at a plane

The contours of the air stagnation temperature are shown at Figure 8. The area of minimal energy is around the tube axis near the inlet nozzles. The area of maximal gas energy is near the hot outlet ring. The radial differential of the stagnation temperature peaks at the inlet nozzles section. This physical picture is confirmed by the measurements of the stagnation temperature in counter flow vortex tubes. B. Pressure Plot:

TABLE II MESHING SPECIFICATIONS OF VORTEX TUBE SL. NO

SPECIFICATIONS

NODES

19223

ELEMENTS

97609

TYPE OF MESHER

TRIANGULAR SURFACE MESHER.

According to the results of numerical simulations the following qualitative explanation of the Ranque-Hilsch effect seems to be reasonable. Expanding from inlet nozzle stream of compressed air transforms into highly intensive swirl flow with significant radial pressure gradient (data on pressure distribution are shown at Figure 10). The flow is turbulent, and turbulent eddies can travel in the tube cross-section to the

center of tube as well as to the peripheral layers. Microvolumes of fluid traveling from the central core of the vortex to its peripheral area with relatively higher pressure are compressed with corresponding heating. Fluid micro volumes moving to the center of the tube are expanding with cooling. The higher values of initial gas pressure will intensify all the processes responsible for energy exchange and increase the cooling ability of the vortex tube. Numerical analysis results are consistent with original experimental data of R.Hilsch for similar geometry vortex tube.

From the studies conducted we also plan to conduct a further study regarding the application of our technology in the practical air conditioning and radiator cooling unit. V. ACKNOWLEDGMENT The authors would like to acknowledge the support of Mechanical Engineering Department of Saintgits College of Engineering for conducting the present investigation REFERENCE [1] N.F. Aljuwayhel, G.F. Nellis, S.A. Klein, “Parametric and internal study of the vortex tube using a CFD model”, International Journal of Refrigeration, Vol. 28, 2005, pp. 442-450. [2] P. A. Ramakrishna, M. Ramakrishna, R. Manimaran, “Experimental Investigation of Temperature Separation in a Counter-Flow Vortex Tube”, Journal of Heat Transfer, Vol. 136, 2014, pp. 082801-1-6. [3] Kalal M., Matas R, Linhart J., “Experimental Study And CFD Analysis On Vortex Tube”, International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, HEFAT2008, 2008, pp. KM1 1-8

Fig. 9: Pressure plot for the vortex tube

Fig. 10: Pressure contour for the vortex tube IV. CONCLUSIONS In the light of the journals, the modeling of the vortex tube was conducted and based upon the analysis we reached at the conclusion that the system can be used as an ideal replacement for the conventional air conditioning unit in automobiles. The proposed system adheres to all conventional rules and is more economic than the normal automobile air conditioning unit. Through the proposed system we can reduce the engine load to a certain extend causing the engine to work at a better pace and performance than the normal engine.

PHOTOVOLTAIC DRIVEN THERMOELECTRIC REFRIGERATOR FOR CAR HEAT DISSIPATION DURING SUNNY DAYS Ashiq Georgi Abraham, Bobby Jacob, Davie George Vinu, Dean John Vinu Abstract— This project outlines the implementation of photovoltaic driven refrigerator in cars powered from solar panels with a battery bank. People normally don‟t tend to park cars under the sunlight during afternoon time as it causes great discomfort to the person when entering the vehicle after sometime. In order to prevent this thermoelectric module is placed to dissipate the heat that gets built up in the car cabin. This thermoelectric module is powered using nonconventional method, i.e. using solar energy. Hence not using any energy produced by the engine. This method do not cool the cabin but keep it maintained at an optimum temperature.

Different from conventional refrigeration systems, thermoelectric refrigeration, based on the Peltier effect, does not require any compressor, expansion valves, absorbers, condensers or solution pumps. Moreover, it does not require working fluids or any moving parts, which is friendly to the environment and results in an increase in reliability. Thermoelectric refrigeration replaces the three main working parts with: a cold junction, a heat sink and a DC power source. The Peltier effect is a temperature difference created by applying a voltage between two electrodes connected to a sample of semiconductor material. This phenomenon can be useful when it is necessary to transfer heat from one medium to another. Solar energy is the most low cost, competition free, universal source of energy as sunshine's throughout. This energy can be converted into useful electrical energy using photovoltaic technology.

Fig. 1.1 Peltier Module

The peltier module (Fig. 1.1) was discovered by a French watchmaker during the 19th century. It is described as a solid state method of heat transfer generated primarily through the use of dissimilar semiconductor material (P-type and N-type). A typical thermoelectric module is composed of two ceramic substrates that serve as a housing and electrical insulation for P-type and N-type (typically Bismuth Telluride) elements between the substrates. Heat is absorbed at the cold junction by electrons as they pass from a low energy level in the p-type element, to a higher energy level in the n-type element. At the hot junction, energy is expelled to a thermal sink as electrons move from a high energy element to a lower energy element. A module contains several P-N couples that are connected electrically in series and thermally in parallel.

INTRODUCTION

In the automobile industry, existing air-conditioning system give arise to numerous problems such as pollution to environment (CFC emission), increase in the usage of fuel and decreased engine performance. Moreover, the current airconditioning system is not capable to be used during the parked session. The conventional air conditioning system consumes much energy of the engine, when the car parked in sun is cooled. This scenario could be subdued by the introduction of thermoelectric device as an alternating cooling option for car interior. By using this option pollution, fuel usage and decreased engine performance can be prevented since the latter option was in the bracket of „Go Green‟ region. Basically, the thermoelectric device known as peltier module is a semiconductor based heat pump, where heat is absorbed from one side and dissipated on the opposite side of the module.

Previously, thermoelectric devices were used in for medical devices, sensor technology, cooling integrated circuits. The peltier module usually rated according to its capacity on heat removal, waste heat and maximum system temperature difference for a specified DC voltage and applied current. Another important characteristic of peltier module is the polarity of the heat removal changes when the direction of applied current changes, thus it is potential to cool or warm an

Battery

object within same configuration, with respect to the polarity of the current. When considering usage of these peltier modules, it is necessary to analyze the performance of the module over the heat removal rate. From a manufacturer data sheet of peltier module known as TE Technology, Inc, It is necessary to maintain the system temperature difference with respect to required heat removal in order to maintain the COP performance of the peltier module. Thus, in this project the development of the heat sinks must be considered to fulfill performance requirement. In the context of heat sink resistance, the leading materials that possess high thermal conductivity is copper and aluminum.

We use lead acid battery for storing the electrical energy from the solar panel for lighting the street. Where high values of load current are necessary, the lead-acid cell is the type most commonly used. The lead acid cell type is a secondary cell or storage cell, which can be recharged. The charge and discharge cycle can be repeated many times to restore the output voltage, as long as the cell is in good physical condition. However, heat with excessive charge and discharge currents shortens the useful life to about 3 to 5 years for an automobile battery. Of the different types of secondary cells, the lead-acid type has the highest output voltage, which allows fewer cells for a specified battery voltage.

When considering peltier cooling with copper or aluminum heat sinks, of course it will cost in high price for the fabrication of the prototype but since this manner of cooling could overcome some disadvantages of existing compressorbased cooling, it is still worth of the price.

Advantages

1.1 COMPONENTS AND DISCRIPTON When the car is parked during sunny days, the car cabinet get heated up. The thermoelectric module is powered using a solar panel. The battery is recharged by solar panels and the power is consumed by thermoelectric module from the battery. The temperature sensor is provided in the cabinet to measure the temperature inside the cabinet. A relay circuit is provided along with a microcontroller to cut off the supply from battery to thermoelectric module as the temperature goes below a certain value in the cabinet, thus maintaining a definite temperature.

•

Low cost

•

Long life

•

High reliability

•

High overall efficiency

•

Low discharge

•

Minimum maintenance Temperature Sensor

Temperature is the most-measured process variable in industrial automation. Most commonly, a temperature sensor is used to convert temperature value to an electrical value. Temperature Sensors are the key to read temperatures correctly and to control temperature in industrials applications. A large distinction can be made between temperature sensor types. Sensors differ a lot in properties such as contactway, temperature range, calibrating method and sensing element. The temperature sensors contain a sensing element enclosed in housings of plastic or metal. With the help of conditioning circuits, the sensor will reflect the change of environmental temperature. In the temperature functional module we developed, we use the LM34 series of temperature sensors. The LM34 series are precision integrated-circuit temperature sensors, whose output voltage is linearly proportional to the Fahrenheit temperature. The LM34 thus has an advantage over linear temperature sensors calibrated in degrees Kelvin, as the user is not required to subtract a large constant voltage from its output to obtain convenient Fahrenheit scaling.

Fig. 1.2 Schematic Layout

The major components are, 1.

Battery

Temperature sensor

Microcontroller unit

Solar panel

Thermo electric cooler

Relay drive

Microcontroller Unit The alcohol sensor senses the alcohol contents of the particular room/vehicle. This sensing signal is given to the microcontroller unit. When the current voltage is below the setted voltage, the output from the microcontroller activates the relay to function the alarm unit.

Solar Panel

one high power TEC selected for the cooling system. Bigger hot side heat sinks have to be selected accurately based its calculated thermal resistances for best cooling efficiency. With a single TEC, one hot side and a cold side heat sink a smaller personal TEC cooler which gives comfort can be fabricated and can be installed on roof for individual cooling by changing the airflow and some mechanical or electronics section modification, the TEC air cooling for car can be used for heating applications too.

The most useful way of harnessing solar energy is by directly converting it into electricity by means of solar photovoltaic cells. Sunshine is incident on Solar cells, in this system of energy Conversion that is direct conversion of solar radiation into electricity. Thermo Electric Cooler Using a combination of the Seebeck, Thomson and Peltier effects, cooling occurs when electricity flows through materials and specific junctions. Classic thermoelectric work, but with very low efficiency. The reason is simple. Heat will flow through any material, and does not require electrons to do so. So as soon as one side becomes colder than the other, then natural conduction will seek to equilibrate the two sides.

Advantages Simple in construction Compact and reliable This system is noiseless in operation Its operate in battery Maintenance cost is low

Thermoelectric coolers (TECs) employ the Peltier effect, acting as small, solid-state heat pumps. The TECs are ideally suited to a wide variety of applications where space limitations and reliability are paramount. The TECs operate on DC current and may be used for heating and cooling by simply reversing the direction of the DC current. Thermoelectric coolers (TECs) are solid-state heat pumps that have no moving parts and do not require the use of harmful chemicals.

II. MODELLING AND FABRICATION A solid works model is designed using the above heat load calculation, The size of windshield=18cm×38cm The size of back glass=10cm×18cm The area of side glass= 4(10cm×15cm)

Relay Drive A relay is an electro-magnetic switch which is useful if you want to use a low voltage circuit to switch on and off a light bulb (or anything else) connected to the 220v mains supply. WORKING PRINCIPLE A Thermoelectric Air cooling for car prototype was designed and built which can be used for personal cooling inside the car. Six TECs were used for achieving the cooling with a DC power supply through car battery. It had been shown from testing results that the cooling system is capable of cooling the air when recirculating the air inside the car with the help of blower. TEC cooling designed was able to cool an ambient air temperature from 32°C to 25.8°C. Cooling stabilizes within three minutes once the blower is turned ON. The system can attain a temperature difference of set target which was 7°C. Accomplishing the set target establish the success of the project. All the components in the project had been tested individually and the results were found to be positive.

Fig. 2.1 Front View

The prototype can be made compact by selecting as single TEC of higher power (.i.e. of 200W or more). It can be done by choosing a better cold side heat sink that has twisted channels or pipes for circulating the air for a longer time. As an alternative for normal axial fan used in this project, if a blower fans is selected, the cooling system would provide better airflow. Even as shown in the appended figure we can mount no of TEC cooling in Roof, Floor, Seat, Door, front dashboard with proper insulation. Well-known TEC brands (.i.e. Melcor, FerroTEC etc) must be chosen if there is only

Fig. 2.2 Side View

Fig. 2.6 Body With Glass Windows

Fig. 2.3 Top View Fig. 2.7 Temperature Sensor and Relay

Fig. 2.8 Peltier Module (Cold Side)

Fig. 2.4 Isometric View

Fig. 2.9 Solar Panels

2.1 FABRICATION Based on design model the outer frame was designed using an angle bar. Then a sheet metal of 20 gauge was used to cover the frame made from mild steel. To make the structure arc welding was used. A glass of 4mm thickness with the dimension windshield=18cm×38cm, back glass=10cm×18cm, side glass= 4(10cm×15cm) was incorporated. Then for insulation, the inside of the cabin was covered with 12mm thick thermocole. A 60 Watts Peltier module was placed on the lower part of the cabin such that the hot side lies outside the cabin and the cold side lies inside it. Heat sinks with fan are attached to both hot side and cold side.

Fig. 2.10 Peltier Module (Hot Side)

Fig. 2.11 Fabricated Model Fig. 2.5 Main Frame

III. EXPERIMENTS AND RESULTS Temperaturere

EXPERIMENTS The scale down model of cabin was placed under direct sunlight with absence of refrigeration system and measured the amount of heat accumulated between 12:00 pm to 1:00 pm for each 15 minutes in the cabin using temperature sensor. Then the thermoelectric module was switched on and the relay circuit temperature was set to 28˚C. Then using temperature sensor, reading for each 15 minutes was taken between 2:00 pm to 3:00 pm in order to obtain the rate of cooling.

50 45 40 35 30 25 20 15 10 5 0 2:00pm 2:15pm

Then the temperature change with respect to time was plotted.

2:30pm 2:45pm 3:00pm

Fig. 3.2 With Refrigeration System

RESULTS

IV. CONCLUSION

From the first experiment conducted without using refrigeration system it can be seen that the temperature inside the cabin begins to rise slowly with time since the entire volume of air inside the cabin gets heated up. After a certain period of time the temperature increases rapidly because of the accumulation of heat due to the thermal insulation of the cabin. Towards the end of the experiment the rate of increase in temperature becomes fairly constant. The graph was plotted for the temperature variation for 15 minutes intervals as shown in Fig. 3.1.

The scaled down version of the car cabin was fabricated from the design calculation. Experiments with and without using the refrigeration system was conducted on the model and the results were compared. Heat load accumulated in the cabin was reduced using this refrigeration method. The temperature inside the cabin was brought down to ambient condition and maintained by means of a relay drive. The thermoelectric system being compact gives a low maintenance cost. The energy used to run the refrigeration system is provided by nonconventional method i.e., using solar energy. As the system contains no moving parts it is reliable and produces no noise.

REFERENCES

[1] “ASHRAE Handbook of Fundamental, American Society of Heating”, Refrigerating, and Air Conditioning, Atlanta, GA, 1988.

Temperat

ure

44 42

[2] Mohammad A.F., and Majid B., “Comprehensive Modeling of Vehicle Air Conditioning Loads Using Heat Balance Method”, SAE Technical Paper 2013-01-1507, 2013, doi: 10.4271/2013-01-1507.

40 38 36

[3] Khurmi R.S. and Gupta J.K., “Refrigeration and Air conditioning”, Eurasia Publishing house Ltd.

12:00pm 12:15pm 12:30pm 12:45pm 1:00pm Fig. 3.1 Without Refrigeration System

From the second experiment conducted using the thermoelectric refrigeration system it can be seen that the temperature inside the cabin begins to fall slowly with time since the entire volume of air inside the cabin needs to be cooled. After a certain period of time the rate of cooling slightly increases and as a result the temperature inside the cabin is maintained at ambient condition. The graph was plotted for the temperature variation for 15 minutes intervals as shown in Fig. 3.2.

Exhaust Gas Waste Heat Recovery and Utilization System in IC Engine Alvin P Koshy, Bijoy K Jose Jeffin Easo Johnson, K Navaneeth Krishnan, Bijeesh P

Abstract: Most of the heat energy released from the fuel of an internal combustion engine is wasted to the environment. This is a serious issue in this world of depleting fuels. So an effort is made to recover the heat wasted from the exhaust gas of an internal combustion engine. If the heat wasted out through the exhaust gas is utilized, we can improve the efficiency of the engine to some extent. There are a lot of research works in the field of waste heat recovery systems. Many succeeded in their own methodologies. We hereby attempt to recover the waste heat from the exhaust gas and use the heat energy recovered to improve the efficiency of the internal combustion engine. For the same we studied the exhaust gas temperature of a four stroke diesel engine at various RPM. The exhaust gas temperature at 4000 RPM has got the maximum temperature. So a recovery system for a constant RPM of 4000 is designed. The recovery system consists of a shell and tube heat exchanger and a uniflow steam engine which is coupled to the main engine. The coupled steam engine improves the efficiency of the main engine by lowering the frictional power at the power stroke and idle stroke of the main engine. The initial cost of the system is high due to the additional recovery system. But in the long run the system proves to be profitable

II. METHODOLOGY         

The heat energy released to the exhaust gas in engines of various cubic capacities is analyzed. Engine suitable for this system is selected. The amount of heat in exhaust gas is calculated. Suitable heat exchanger type is selected. Numerical designing of heat exchanger is done. The different parts of the heat exchanger are modeled using CATIA. The volume of steam chamber required is calculated. The power developed from the steam chamber is calculated. The software analysis of the heat exchanger and the steam chamber are done using ANSYS. III. MAIN WORK PROCEDURE

The main work procedure consists of the following steps: 1) Engine selection. 2) Waste heat calculation. 3) Selection of heat exchanger. 4) Design and analysis of heat exchanger. 5) Design and analysis of steam cylinder. 6) Calculation of power developed from recovered heat

I.INTRODUCTION In this age of globalization there is a decreasing availability of fossil fuels. So there is a need of conserving it for the future generations. In normal IC engines, a major part of fuel energy is wasted through exhaust gas, cooling water and other losses. We know that a normal IC engine is only 30 to 40 %. This means that the rest of the 70 to 60 % of the heat is lost as waste to the environment. But we know from the basic law of thermodynamics we cannot tap 100% of the available energy. But if we synthesis a method to tap the lost heat from the sink and formulate a method to increase the efficiency of the IC engine, it would be worth for the future generation. We could tap this lost heat by many ways and utilized it for many purposes. In this project we used a heat exchanger to tap the heat. This heat is further used to increase the efficiency of the engine with the help of a steam. The steam engine cylinder used is considered as an extra cylinder which working together with the other cylinders of the engine whose efficiency is to be increased. The steam engine used gives additional power to the whole system. This additional power decreases the frictional power of the system thereby increasing the efficiency of the IC engine .

Fig. 1: Schematic Representation of the System

A. Engine Selection:

Field analysis and literature study on different engines of various cubic capacity from 150cc to 1500cc were conducted. We studied the temperature of exhaust gas from these engines and found that the temperature is too low for low capacity engines. Temperature is sufficiently high of about 700°C in engines of higher capacities. Also, the mass flow rate of the exhaust is higher in large engines. Finally we selected 1573cc diesel engine.

Since we have to run a steam engine which works with the pressure of the steam, it should be critically noted that the heat exchanger selected should be on with minimum pressure drop. Also, the function of our heat exchanger is to transfer the heat from the exhaust gas to the working fluid, and the working fluid has to be vaporized and superheated when coming out from the heat exchanger. Based on the requirements, we studied the characteristics of the available types of heat exchangers and found out that horizontal shell and tube heat exchanger with counter flow arrangement is the best suited one for our application.

Engine specification: Engine type : inline 4 cylinder Bore : 75mm Stroke : 89mm Displacement : 1573cc Compression ratio : 18 Rated power : 80bhp@4000rpm

D. Design Considerations: The working is fed to the heat exchanger at a pressure of 10bar and the heat exchanger designed should provide steam at the outlet of shell with pressure drops within allowable limit. The exhaust gas is fed to the tube at a pressure of 5bar. Designing of the heat exchanger is usually done on the basis of certain assumptions.

We also checked the exhaust gas temperature from the engine when it is working under various rpm, i.e. from 1000rpm to 4000 rpm. Here we also found that the temperature is high when the engine speed is 4000 rpm.

There is no heat transfer between the fluid streams and the outside environment. There are no leakages from the fluid streams to each other or to the environment. No heat is generated or lost via chemical or nuclear reactions, mechanical work or other means. There is no heat conduction along the length of the heat transfer surface, only in the direction of the normal of the surface. Fluid flow rates are equally distributed throughout the whole cross-sectional areas of flow. Where temperature distribution transverse to the flow direction is relevant, any fluid flow can be considered either completely mixed or completely unmixed. Properties of fluids are constant inside the heat exchanger. Overall heat transfer coefficient is a constant at all locations of the heat exchanger. Initial assumption that overall heat transfer coefficient U = 150 W/m2. Negligible fouling resistance occur in the heat exchanger

Table-1: Exhaust Gas Properties at Various Engine Speeds ITEM Engine Speed(rpm) Engine Power (kW) Exhaust temperature(K) Exhaust mass flow rate(g/s) B.

1000 14.9 801.5 18.7

CONTENT 2000 3000 50.2 70.8 862.4 890.8 59.6 83.3

4000 84.8 900.5 108

Heat Content of Exhaust Gas:

We measured the temperature of the exhaust gas from the engine at 4000rpm. We obtained the mass flow rate of exhaust gas at this rpm as 0.108kg/sec. The specific heat capacity of exhaust gas is 1.185kJ/kgK. So heat duty of exhaust gas at 4000rpm is calculated as: Qmax = ṁex cpex ∆T = 0.108*1.185*(737-30) = 90.4kW Where, ṁex

Heat Exchanger Selection:

E. Designing Procedure: The process of sizing a heat exchanger will inevitably be an iterative one. To calculate the area one has to have at least an estimate of U, once an area is calculated on the basis of the estimate (or guess), the geometry of the heat exchanger will be known so that a better estimate of U can be calculated, leading to a better estimate of the area, therefore some change in geometry, requiring a new value of U to be calculated, and so on.

= mass flow rate of exhaust gas

cp = specific heat ∆T = temperature difference= inlet temperature of exhaust – inlet Temperature of working fluid This is the maximum heat that can be transferred from exhaust gas to the cooling fluid.

Processes taking place in heat exchanger: Heating working fluid from 30 to 179.9

Vaporization of the working fluid at 179.9 Superheating of the working fluid to 205 .

determined: for example the required heat transfer area from NTU in a sizing problem, or fluid outlet temperatures from ε in a rating problem.

Since these stages occur • •

Calculation of mass flow rate of working fluid: We know the maximum heat transferred from the working fluid. We also know the processes happening to the working fluid. So the flow rate of working fluid can be calculated by the following steps.

• •

To increase temp of WF

•

• • • • •

= ṁwf cpwf ∆T = ṁwf ×4.18 × (179.9 – 30) = 626.528 ṁwf

Find out the mass flow rate of working Finding out the temperature of exhaust gas after each phase Finding out the value of heat capacity ratio R; Based on the value of R from standard graph between ε - NTU, take values of NTU for maximum effectiveness. Take estimated value of U for shell and tube heat exchanger for doing initial iteration Calculate the area required Fix standard tube and shell diameters Find out the number of tubes required Fix the number of tubes as specified by s standards Assume single pass and find out the velocity and Reynolds number for exhaust flow

To vaporize Table-2: Heat Exchanger Design Specifications Q2

= ṁwf hfg

PROPERTY Effectiveness Total heat exchange area Tube pitch Tube inner diameter Tube outer diameter Shell inner diameter No of tubes No of passes No of baffles

= 2013.6 ṁwf To superheat Q3

= ṁwf cpwf ∆T = ṁwf × 2.085×(205-179.9)

= 52.335 ṁwf Qmax = Q1 + Q2 + Q3

VALUE 76.3 18.27m2 1 inch square pitch 12.2mm 19.1mm 438.15mm 150 6 11

IV. MODELLING OF HEAT EXCHANGER

90.481= ṁwf × (626.582+2013.6+52.335) = ṁwf 2692.5155

Parts of the heat exchanger is designed and made using CATIA. The major parts of heat exchanger are:

ṁwf = 0.03360kg/sec

• • • • •

1) ε- NTU Method: The ε-NTU method of heat exchanger analysis is based on three dimensionless parameters: the heat exchanger effectiveness ε, ratio of heat capacity rates of the fluid streams CR, and number of transfer units NTU. ε is a function of heat duty and/or outlet temperatures and NTU a function of heat transfer area. Functions correlating the three dimensionless parameters to each other exist for a variety of flow arrangements. Use of the ε-NTU method starts by solving two of the dimensionless parameters from what is known about the situation, and then using the correct ε -NTU relationship to find the third. From that value and defin of the third dimensionless parameter one then solves what needs to be

Tube Shell Front end head Rear end head Tube Plate

Fig. 5: Tube Plate Fig. 2: Front End Head

Fig. 3: Rear End Head Fig. 6: Tube

Fig. 4: Shell Fig. 7: Tubes Assembled in Tube Plate

Fig. 8 Fully Assembled Heat Exchanger Fig. 11: Strain in Font End Head V. ANALYSIS OF HEAT EXCHANGER COMPONENTS

Fig. 12: Stress Distribution in Shell Fig. 9: Stress Distribution in Front End Head

Fig. 13: Stress Distribution in Tube From the above analysis done in ANSYS R15.0, we could understand that the maximum stress on the parts is much lesser than the yield strength of the material made. Hence the design is safe.

Fig. 10: Deformation in shell

From the above analysis we could clearly understand that the design safe with a very high factor of safety. VI THEORETICAL ANALYSIS OF THE STEAM ENGINE A Steam Engine Cylinder Design Assumptions:. The cylinder is one of the main parts of the steam engine. The design of steam engine requires certain assumptions. The main assumption is that the working fluid cut off percentage. Another assumption is that the stroke length is fixed to obtain a particular bore for the steam engine. This is to provide the steam engine with the stroke length as that of the IC engine stroke length. So a stroke length of 0.0889 m is assumed for the steam engine. The cut off of the working fluid is at 50% of the cylinder volume. Thus with these assumptions we could determine the volume of the steam chamber required

Fig. 14: Cam Follower Displacement Diagram

B Volume of the Steam Chamber Volume flow rate of working fluid = volume flow rate of steam chamber × cut off Mass flow rate, m = 0.0313 kg/sec 3

Density of steam, ρ = 4.529 kg/m

Fig. 15: Cam Profile

This is the required cam profile that is used to produce the required displacement of the valve. D Theoretical Analysis of Steam Engine: The analysis is carried out on the assumption that the steam engine is having an efficiency of 15%. The assumption is on the basis that normal steam engine efficiency ranges from 10 to 20%. IC engine is operating0 at 4000 RPM and at full load. The gross power output from the steam chamber is calculated as follows. Recovered heat = 68.15 kW Power output = 68.15*0.15 = 10.2225 kW Power loss due to pump = vΔp = 7.094×10-3× 9×105 kW = 6.3846 kW This is the power loss from pump. The gross power = 10.2225-6.3846 = 3.8379 kW

Hence the required volume of the steam engine cylinder 3

is 213cm . C. Cam Design: The cam profile is designed such that the cut off of the working fluid is at 50%. The lift of the valve is 4.5mm which is 45 deg.

E. Strokes in Engine Cylinders:

VII. CONCLUSIONS

Table-2: Strokes in Engine Cylinders CYLINDER NUMBER

STROKES

5 (Steam cylinder)

This is a novel mechanism which improves the performance of the engine. The power of the engine increases from 80 kW at 4000 RPM to 81.91895 kW. The thermal efficiency increases from 37.3% to 38.19%.There is a decrease in the bsfc by 5.28 g/kWhr. The initial cost of the recovery mechanism is very high. But this becomes economic in long run. The analysis is carried out theoreticallybut there may be differences when it is experimentally analyzed. The low value of the recovered heat is due to the small engine that we took. The improvement in the performance of the engine is due to the fact that the power developed by the mechanism is utilized to decrease part of the frictional power of the engine.

Where, S = suction stroke C = compression stroke P = power stroke E = exhaust stroke

VIII. FUTURE SCOPE The recovery mechanism should be experimentally analysed. An organic working fluid may be used in place of water. The experiment may be conducted in big engines which may be more effective than small engines. The experiment may be conducted at various RPM and loads. A recovery mechanism should be developed for engines working at various RPM and loads.

F. Improvement in Engine Performance: 1) Variation in Thermal Efficiency: Thermal efficiency, of the IC engine = 37.3%

ACKNOWLEDGEMENT The authors would like to acknowledge the support of Mechanical Engineering Department of Saintgits College of Engineering for conducting the present investigation

We also know brake power = 80 KW (Mass of fuel/sec) × Calorific value of diesel = 214.477 kW New brake power = bp of IC engine + (bp of steam engine)/2 = 80+1.91895 = 81.91895 kW Increase in thermal efficiency = 0.8947%

REFERENCE 1] Jianqin Fu, Jingping Liu, Yanping Yang, Chengqin Ren, Guohui Zhu- “A new approach or exhaust energy recovery of internal combustion engine ”, Applied Energy, 2013, pp.150-159.

2) Variation in Brake Specific Fuel Consumption:

[2] J.S. Jadhao, D.G. Thombare- “Review ofn exhaust gas recovery for I>. engine”, Applied Energy, 2013 . [3] Kiran K. KattaMyoungjin Kim- “Exhaust heat co generation using phase change for heavy duty vehichles ”Applied Energy, 2007.

Brake specific fuel consumption, bsfc of the IC engine = 225 g/kWhr

Fuel consumption for unit time for 80 KW = 18000 g/hr

[4] Q.A Kern – “Process heat transfer”

The new bsfc = 219.72 g/kWhr

[5] C P Kothandaraman, S Subramanyan – “Heat and mass transfer data book “

There is a decrease in bsfc = 5.28 g/kWhr

STUDY, DESIGN AND OPTIMIZATION OF TRIANGULAR FINS Abel Jacob, Gokul Chandrashekhara, Jerin George, Jubin George

Abstract: Extended surfaces commonly known as fins, offer an economical and trouble free solutions in many situations demanding natural convection heat transfer. Heat sinks in the form of fin arrays horizontal and vertical surfaces used in variety of engineering applications, studies of heat transfer and fluid flow associated with such arrays are of considerable engineering significance. The main controlling variable generally available to designer is geometry of fin arrays. Considering the above fact natural convection heat transfer from triangular fin arrays have been investigated experimentally and theoretically. Fin optimization is useful to go through the exercise of optimizing a fin in order to achieve the high rate of heat transfer per volume of fin material. The result of this optimization provides general guidelines relative to the dimensionless characteristics of a well- designed fin.

for a parabolic profile is only slightly greater than that for the triangular profile, its use can scarcely be justified in view of its larger manufacturing costs. II. RESEARCH METHODOLOGY Model is a Representation of an object, a system, or an idea in some form other than that of the entity itself. Modeling is the process of producing a model; a model is a representation of the construction and working of some system of interest. A model is similar to but simpler than the system it represents. One purpose of a model is to enable the analyst to predict the effect of changes to the system. On the one hand, a model should be a close approximation to the real system and incorporate most of its salient features. On the other hand, it should not be so complex that it is impossible to understand and experiment with it.

I. INTRODUCTION Fins are extended surfaces often used to enhance the rate of heat transfer from the engine surface. Fins are generally used on the surface which has very low heat transfer coefficient. Straight fins are one of the most common choices for enhancing better heat transfer from the flat surfaces. The rate of heat flow per unit surface area is directly proportional to the added heat conducting surface. The major heat transfer takes place in two modes i. e. by conduction or by convection. Heat transfer through fin to the surface of the fin takes place through conduction whereas from surface of the fin to the surroundings takes place by convection. Further heat transfer may be by natural convection or by forced convection. Due to the high demand for lightweight, compact, and economical fins, the optimization of the fin size is of great importance. The removal of excessive heat from system components is essential to avoid the damaging effects of burning or overheating. Therefore, the enhancement of heat transfer is an important subject in thermal engineering. The study of convective heat transfer originates from humanâ&#x20AC;&#x2122;s desire to understand and predict the amount of energy which is observed through any fluid flow as an energy transferring mediums. The science of convection is an interdisciplinary field which connects two earlier sciences, Heat Transfer and Fluid Mechanics. The rectangular fin is widely used, probably, due to simplicity of its design and itâ&#x20AC;&#x2122;s less difficult in manufacturing process. However, it is well-known fact that the rate of heat transfer from a fin base diminishes along its length. The optimum profile has been determined which may be circular or parabolic depending upon the consideration of with or without the idealization of length of arc. On the other hand, a triangular fin is attractive, since, for an equal heat transfer, it requires much less volume (fin material) than a rectangular profile. Nevertheless, since heat transfer rate per unit volume

Fig. 1: Isometric View of Single Fin

Figure 1 shows the isometric view of a Single Fin. A good model is a judicious tradeoff between realism and simplicity. Simulation practitioners recommend increasing the complexity of a model iteratively. An important issue in modeling is model validity. Model validation techniques include simulating the model under known input conditions and comparing model output with system output. Generally, a model intended for a simulation study is a mathematical model developed with the help of simulation software.

Fig. 2: Array of Fins Showing the Pitch Selected

The figure 5 shows the updated mesh obtained for the array of triangular fins with l/d ratio = 2. In order to increase the accuracy of the convergence graph, the relevance centre was chosen of fine type instead of coarse type. The total number of nodes and elements are shown in Table 1 below.

A. Meshing:

Fig. 3: Mesh of Array with l/d ratio = 1

L/D RATIO

NUMBER OF NODES

NUMBER OF ELEMENTS

35151

179456

1.5

35992

183262

36403

184240

III. RESULT AND DISCUSSIONS After the generation of mesh and assigning of load and constraints next step is to run the simulation for the model. This proceeds for the analyzing the steady-state heat transfer process and finally obtain the required result contour of temperature.

The figure 3 shows the updated mesh obtained for the array of triangular fins with l/d ratio = 1. In order to increase the accuracy of the convergence graph, the relevance centre was chosen of fine type instead of coarse type. The total number of nodes and elements are shown in Table 1 below.

Fig. 4: Mesh of Array with l/d ratio = 1.5

The figure 4 shows the updated mesh obtained for the array of triangular fins with l/d ratio = 1.5. In order to increase the accuracy of the convergence graph, the relevance centre was chosen of fine type instead of coarse type. The total number of nodes and elements are shown in Table 7.1 below.

Fig. 6 temperature contour for single fin with l/d ratio = 1

The resultant figure 6 shows the variations of temperature along length of fin with triangular extensions. It can be interpreted that the maximum value of temperature is found to be at 6.980Ă&#x2014;102 K; while the minimum value of temperature is found to be at 3.00Ă&#x2014;102 K. The source temperature from engine block was assumed to be 690K and the air temperature was taken as 300k. Fig. 5: Mesh of Array with l/d ratio = 2

The resultant figure 8.2 shows the variations of pressure along length of fin with triangular extensions. It can be interpreted that the maximum value of pressure is found to be at -1.466×101 Pa.; while the minimum value of pressure is found to be at 9.902×101 Pa.

The resultant figure 9 shows the variations of pressure along length of fin with triangular extensions. It can be interpreted that the maximum value of pressure is found to be at -1.466×101; while the minimum value of pressure is found to be at 9.902×101 Pa. Now we take single fin of L/D ratio = 2 (i.e. ratio of length of fin to width of fin is 1.5). We analyze the pressure and temperature contour formation of the fin when the source temperature is set as 690k and atmospheric pressure is taken as 1× Pa. Then we find the heat transfer rate from the fin.

Fig. 7: Pressure Contour for Single Fin with L/D Ratio = 1

Fig. 10: Temperature Contour for Single Fin with L/D Ratio = 2

The resultant figure 10 shows the variations of pressure along length of fin with triangular extensions. It can be interpreted that the maximum value of pressure is found to be at -1.466×101 Pa; while the minimum value of pressure is found to be at - 9.902×101 Pa.

Fig. 8: Temperature Contour for Single Fin with L/D Ratio = 1.5

Fig. 11: Pressure Contour for Single Fin with L/D Ratio = 2

The resultant figure 11 shows the variations of pressure along length of fin with triangular extensions. It can be interpreted that the maximum value of pressure is found to be at -1.466×101 Pa; while the minimum value of pressure is found to be at - 9.902×101 Pa.

Fig. 9: Pressure Contour for Single Fin with L/D Ratio = 1.5

The resultant figure 12 shows the variations of pressure along length of array of fins with triangular extensions. It can be interpreted that the maximum value of pressure is found to be at -1.466×101 Pa and the minimum pressure is found to be at - 9.902×101 Pa.

It can be interpreted that the maximum value of temperature is found to be at 6.980×102 K; while the minimum value of temperature is found to be at 3.00×102 K. The source temperature from engine block was assumed to be 690K and the air temperature which was taken as the input to measure convective heat transfer wsas given a value on 300 K.

Fig. 14: Temperature contour for an array of fins with pitch 50and l/d ratio = 2

Fig. 12: Temperature Contour for an Array of Fins with Pitch 50and L/D Ratio = 1.5

Now we analyze the heat transfer rate of an array of fins with pitch 50mm (i.e., distance between two corresponding points on adjacent fins is 50mm) and L/d ratio = 1.5 (i.e. ratio of length of fin to width of fin is 1.5). We analyze the pressure and temperature contour formation of these fins when the source temperature is set as 690k and atmospheric pressure is taken as 1×Pa.

Fig. 15: Pressure Contour for an Array of Fins with Pitch 50 and L/D Ratio = 2

The resultant figure 15 shows the variations of pressure along length of array of fins with triangular extensions. It can be interpreted that the maximum and minimum value of pressure is found to be at 1.000×105 Pa.

Fig. 13: Pressure Contour for an Array of Fins with Pitch 50 and L/D Ratio = 1.5

The resultant figure 13 shows the variations of pressure along length of array of fins with triangular extensions. It can be interpreted that the maximum value of pressure is found to be at -1.466×101 Pa and the minimum pressure is found to be at - 9.902×101 Pa. The resultant figure 14 shows the variations of temperature along an array of fins with triangular extensions.

Fig. 16: Residual graph for Single Fin with L/D Ratio = 1

The resultant figure 16 shows residual graph of convergence of temperature and pressure and values of

continuity equation for single fin with L/D ratio = 1. The values converges after 1000 iterations to a value close to

The source temperature from engine block was assumed to be 690K and the air temperature which was taken as the input to measure convective heat transfer was given a value on 300 K.

Fig. 17: Residual graph for Single Fin with L/D Ratio = 1.5 Fig. 19: Temperature contour for an array of rectangular fins with pitch 50and l/d ratio = 2

The resultant figure 8.12 shows residual graph of convergence of temperature and pressure and values of continuity equation for single fin with L/D ratio = 1.5. The values converges after 1000 iterations to a value close to

Fig. 20: Pressure contour for an array of rectangular fins with pitch 50and l/d ratio = 2

Fig. 18: Residual graph for Single Fin with L/D Ratio = 2

The resultant figure 18 shows residual graph of convergence of temperature and pressure and values of continuity equation for single fin with L/D ratio = 2. The values converges after 1000 iterations to a value close to The resultant figure 19 shows the variations of temperature along an array of fins with rectangular extensions. It can be interpreted that the maximum value of temperature is found to be at 6.980×102 K; while the minimum value of temperature is found to be at 2.98×102 K.

The resultant figure 20 shows the variations of pressure along length of fin with rectangular extensions. It can be interpreted that the maximum value of pressure is found to be at 3.837×10-2 Pa; while the minimum value of pressure is found to be at - 1.365×100 Pa

IV. CONCLUSIONS From the result it is clear that as the l/d ratio increases, the heat transfer also increases up to a certain limit. It is clear that as the pitch of the fins increases the heat transfer to a maximum value and then decreases. In comparison to the conventional fin (rectangular), rate of heat transfer of proposed fin is increased by 28.7%.Triangular fins provide about 5 % to 13% more enhancement of heat transfer as compared to conventional fins. Heat transfer through fin with triangular extensions higher than that of fin with other types of extensions. The effectiveness of fin with triangular extensions is greater than other extensions. V. ACKNOWLEDGMENT The authors would like to acknowledge the support of Mechanical Engineering Department of Saintgits College of Engineering for conducting the present investigation. REFERENCE [1] Tri Lam Ngo et al, Heat transfer and pressure drop correlations of micro channel heat exchangers with S-shaped and zigzag fins for carbon dioxide cycles. [2] .GiulioLorenzini et al, Constructed design of Tâ&#x20AC;&#x201C;Y assembly of fins for an optimized heat removal. [3] GiulioLorenzini et al,Numerical analysis on heat removal from Y shaped fins: Efficiency and volume occupied for a new approach to performance optimization.

STEAM TURBOCHARGING Abhijith P, Akhilesh Rajan, Cyril Soji Thomas, Kevin George Jacob Abstract: A new concept of steam turbocharging is proposed in this project which finds a solution for the major disadvantages of conventional turbocharging systems. In conventional turbocharging system the turbocharger starts operating only after certain engine rpm. The back pressure generated at the engine exhaust is also high in conventional systems. These disadvantages are being solved in this proposed project. The major objectives of this project are to achieve a target boosting pressure of 1.5 bar at the engine inlet, to reduce the backpressure at the engine exhaust and to increase the operating range of turbocharger. The IC engine exhaust energy is used to generate steam and then drive the turbine. Part of steam expansion power is used to drive air compressor. The heat exchanger and turbine are designed and simulated and the performance is analyzed. The results show that IC engine power can be increased by increasing the inlet boosting pressure. The analysis shows that in steam turbocharging system, the turbocharger starts working at 1000 rpm and has less exhaust back pressure compared to ordinary turbocharger.

II. RESEARCH METHODOLOGY The proposed concept of steam turbocharging is based on Rankine steam cycle. As said earlier in steam turbocharging thermal energy of exhaust gas is used instead of pressure energy. The exhaust thermal energy is recovered using heat transfer and this energy is used to generate effective work using a turbine. Finally, the output power of the turbine is used to run a compressor. Figure 1 shows the schematic diagram of steam turbocharging system. As shown in Figure 1, the steam turbocharging system consists of, valve, water tank, pump, heat exchanger, steam turbine, and air compressor, etc. Among these components, valve is used to adjust the mass flow rate of working medium water, while pump is used to control the pressure through the cycle. A motor is coupled to the transmission shaft connecting turbine and compressor to control the energy flow in the cycle. The modes of operation of motor are described as follows. (a) Driving the air compressor: at lower rpm of engine speed, the steam turbine does not work instantly and air compressor is driven by the motor to obtain target boosting pressure; since at low speeds the exhaust energy is less both motor as well as steam turbine is used to run the compressor (b) At higher engine speeds the turbine power generated is greater than required power to run the compressor so this energy is used to generate electricity from the motor. Both the air compressor and motor is run by steam turbine so the extra energy generated by the turbine is converted to electrical energy by motor. The steam turbocharging system shown in Figure 1 is an open steam power cycle system, which can be also designed as a closed system based on its application. In closed system the water used in the cycle is used again and again whereas in open system it is used only during a single cycle. Since there is no condenser and condensation in open cycle system it is comparatively simple. The cost of open cycle system is also less when compared to closed cycle system. Steam turbocharging based on open cycle has its major application in steam power plants. The working medium that is water must be available in plenty. Steam turbocharging based on closed system has wider applications since the working medium is recycled throughout the cycle. It can me both used in stationary as well as mobile applications such as in automobile and marine engines. This paper mainly deals with open cycle system and the working principle of both systems are moreover same.

I. INTRODUCTION The power performance and fuel economy of an Internal Combustion(IC) engine can be increased by boosting the intake pressure. By increasing the intake boosting pressure the BMEP also increases which leads to higher thermal efficiency. By increasing the boosting pressure the engine displacement can also be downsized. Exhaust turbocharging is most widely used method when compared to other boosting pressure technologies. Exhaust turbocharging is a method of Exhaust Energy Recovery (EER) in which the energy of the exhaust gas is used to run a turbine which in turn runs a compressor and boost the intake air to IC engine and thus improves its performance. In conventional exhaust turbocharging systems used in diesel engines only a part of the exhaust energy can be used efficiently the rest of the exhaust energy is wasted. This is because the exhaust gas contains mainly of thermal energy than pressure energy. In exhaust turbocharging an additional back pressure is also created which leads to less volumetric efficiency of the IC engine and more work during the exhaust stroke. Therefore some of the exhaust energy recovered is used to overcome this pumping loss. At low speeds of IC engine the exhaust energy may be less than the pumping loss, so at lower speeds the target boosting pressure may not be achieved. So exhaust turbocharging is not the best method to recover the exhaust energy or boost the intake pressure. Here we introduce a new concept which utilizes IC engine exhaust thermal energy to boost intake pressure. Since it is based on steam power cycle it is named as Steam Turbocharging, which is more effective when compared to IC engine exhaust turbocharging.

ITEM ENGINE TYPE DISPLACEME NT (L) COMPRESSION RATIO RATED POWER (KW/RPM)

CONTENT INLINE FOUR CYLINDER 1.573 18 80/4000

Table 2 Theoretically Calculated Compressor Specification ENGINE RPM 1000 MASS FLOW RATE

0.0158757

POWER REQUIRED (KW)

0.82

Fig.1.Schematic Diagram of Steam Turbocharging

2.1 MODELLING 2.1.1 DESIGN PROCEDURE OF COMPRESSOR A compressor is designed to produce 1.5 bar boosting pressure at the engine intake. To achieve that boosting pressure we have designed a compressor using the following formula. The analysis is carried out at the engine speed of 1000 rpm.

Fig 2 Compressor Chart of Selected Compressor

Where, m in is the mass flow rate of intake gas; C P is the constant pressure specific heat of intake gas; T1 and T2 are the intake gas temperature at the inlet and outlet of compressor, respectively. P1 and P2 are the intake gas pressure at the inlet and outlet of compressor, respectively; r is the specific heat ratio of intake gas. Îˇcom is the isentropic efficiency of compressor. The power required by the compressor is thus calculated from the above equation. By analyzing the results we came to a conclusion that garret 1544 turbocharger compressor will produce the desired pressure boosting.

Fig.3. Proposed Turbocharger Compressor

Fig 3 is the picture of the turbocharger compressor we selected after the calculations. From the compressor chart in Fig 2 we can see that this compressor meets our requirements. 2.1.2 DESIGN PROCEDURE OF HEAT EXCHANGER The exhaust gas from the engine is supplied to a heat exchanger in this proposed project. The energy of the exhaust gas is used to convert pressurized water to steam. The steps involved in designing a heat exchanger are:

Table 1 Basic Parameters of Test Engine

Step 1. The thermal and physical properties of hot and cold fluid is obtained and these properties are calculated at mean temperature. Step 2. From energy balance equation obtain the energy transferred to heat exchanger. Step 3. The value of overall heat transfer coefficient is assumed a approximate value (Uo, assm). The assumed value of Uo can be obtained from heat and mass transfer data book. Step 4. Determine required number of shell and tube passes (p, n). Step 5. Calculate area of heat transfer (A) required. Step 6. Select material of tube, select the tube diameter, its wall thickness and length of tube (L). Also calculate the number of tubes. Step 7. Determine type of shell and tube exchanger. Select the tube pitch (Pt), decide inside shell diameter (Ds) that can accommodate the calculated number of tubes (n). Step 8. Assign fluid to shell or tube side.

2.1.3 DESIGN OF REACTION TURBINE FOR POWER GENERATION The pressurised water which is fed into the heat exchanger is turned to steam by using the exhaust gas energy from engine. The steam at 5 bar pressure from the outlet of heat exchanger is directly fed to a reaction turbine to generate power required to run the compressor. The design of reaction turbine is done using ANSYS Vista RTD software. The geometry of turbine blade is generated using vista RTD and it is developed using BladeGEN of ANSYS. The analysis of the turbine blade is done using ANSYS Fluent 15. The model of the turbine blade developed through Vista RTD is shown in the Figure 5.

In the designed heat exchanger the value of heat transfer coefficient is assumed to be 150 W/m2. The exhaust gas is passed through the tube side and the pressurized water is passed through the shell side. Table 3 Theoretical Design Values of Heat Exchanger

ITEM AREA OF HEAT EXCHANGER NO OF TUBES OUTSIDE DIAMETER OF TUBE INSIDE DIAMETER OF TUBE NO OF PASSES SHELL DIAMETER LENGTH OF HEAT EXCHANGER EXHAUST GAS TEMPERATURE AT 1000 RPM EXHAUST MASS FLOW RATE AT 1000 RPM

CONTENT 0.2802 30

Fig.5. Turbine Blade Geometry

Figure 5 shows the geometry of turbine blade which is designed using Vista RTD. The envelop over the blade geometry shows the flow path or control volume. The blade is so designed that the steam gets expanded to a pressure of 1 bar at the outlet of the turbine.

31mm 25.4mm 2 28.62 cm

III. RESULT AND DISCUSSIONS

118cm

The heat exchanger and turbine analysis were done on ANSYS Fluent 15.0. The results are shown below:

801.1 K 0.087 kg/s

Fig 6 Tube side Temperature Distribution

The Figure 6 shows the temperature distribution of tube side fluid. The temperature of exhaust gas at tube inlet is around 801K and when it comes out of heat exchanger its

Fig.4. Solidworks Model of Designed Heat Exchanger

pressure of steam from heat exchanger outlet was found to be 423K at 4.7 bar pressure. This steam is expanded through a steam turbine and the analysis result showed that the steam expanded to a pressure of 1 bar, thus a total power of 0.86kW was generated by the turbine which is sufficient to run the compressor and the pump which pressurizes the water at heat exchanger inlet. From the analysis we found that the temperature at shell inlet is 303 K and shell outlet is 430 K. The maximum force acting on turbine blade is 0.36885 MPa.

temperature decreases to 450K. Figure 7 shows the shell side temperature distribution of same heat exchanger. In the shell side water enters at around 303K and leaves at around 423K as steam. The water is supplied to the heat exchanger at a pressure of 5bar using a pump. Figure 8 shows the contours of static pressure in a turbine blade. The steam enters at a pressure of 4.7 bar and expands to around 1 bar pressure. There are a total of 9 blades in the runner designed to generate required power.

IV. CONCLUSIONS From the analysis it was found that even at 1000 rpm engine speed, the power required to run the compressor is generated by the turbine thus a boosting pressure of 1.5 bar is produced at the engine inlet. By using this proposed system, the turbocharger starts to operate at 1000 rpm, thus the major disadvantage of existing turbocharger systems is solved. Since this system uses exhaust gas temperature, more thermal efficiency is obtained in steam turbocharging. In steam turbocharging system, since the exhaust gas is directly fed to a heat exchanger and not to the turbine as in conventional systems, the exhaust back pressure is considerably reduced. This increases the volumetric efficiency of the engine. The heat exchanger doesn’t hinder the flow of exhaust gas through it, thus the exhaust gas experiences less resistance when flowing through the heat exchanger. The engine air inlet pressure is maintained at 1.5 bar pressure in this proposed system, which increases the volumetric efficiencies as well as the overall efficiencies of the test engine. By supplying air at this pressure, the combustion takes place completely inside the engine and more power is developed, thus it is seen that by using steam turbocharging system all major disadvantages of conventional turbocharging systems is solved.

Fig 7 Shellside Temperature Distribution

Fig 8 Contours of Static Pressure in Turbine Blades

Acknowledgment The authors would like to acknowledge the support of Mechanical Engineering Department of Saintgits College of Engineering for conducting the present investigation.

[1]

Fig 9 Forces on Turbine Blade

[2]

During the analysis of heat exchanger, it was found that there is a pressure drop of 300 Pa and the outlet temperature and

REFERENCES Jianqin Fu, Jingping Liu, Yong Wang, Banglin Deng, Yanping Yang, Renhua Feng, Jing Yang. “A comparative study on various turbocharging approaches based on exhaust gas energy recovery” Applied Energy, Vol. 113, PP 248-257, 2014. Fu JQ, Liu JP, Yang YP, Ren CQ, Zhu GH. “A new approach for exhaust energy recovery of internal combustion engine: steam turbocharging”. Appl Therm Eng , Vol. 52, PP 150–9, 2013.

[3]

Hung TC, Shai TY, Wang SK. “A review of organic Rankine cycles (ORCs) for the recovery of low-grade waste heat” Appl Energy, Vol 6: 66PP 1– 7, 1997.

[4]

He MG, Zhang XX, Zeng K, Gao K. “A combined thermodynamic cycle used for waste heat recovery of internal combustion engine” Appl Energy, Vol 36:682,PP 1–9,2011.

REFORM THE PERFORMANCE OF A BILLET QUALITY BY REDUCING ITS DEFECTS AT SAIL-SCL KERALA LIMITED Abdul Haseeb NC, Alex P Jacob, Arvind Kumar, Dibin Vincent

Abstract: The development of continuous casting to produce semifinished products is now so far advanced that almost any grade of steel can be continuously cast, and in the most appropriate cross section for further shaping. High quality finished products can only be produced by using defect free billet. The removal of defects is either performed selectively by removing the specific defect. Our Project is based on industrial research, refers to the possibility of defining and cataloguing the surface defects specific to the semi-finished products continuously cast, in order to discover the generating source and to take the proper measures to prevent and remedy them where appropriate. We studied the various processes in the industry and done a project to improve the quality of billets, and thereby reducing the major loss of the company. The main problem faced by the industry is the defects caused during casting of the billets. The defectives can only be reused as scrap, which is the major loss of the industry. Root causes of these defects and solutions recommended are analysed for each case. We suggested a field mixing technology for the mixing of molten metal in correct proportion so that it reduces about 75% of its defects. Also we suggested other methods to improve the quality of billets.

II.

INDUSTRIAL PROFILE

Steel industry in India is on an upswing of the strong global and domestic demand. Indiaâ&#x20AC;&#x;s rapid economic growth and soaring demand by sectors like infrastructure, real estate and automobile, at home and abroad, has put Indian Steel Industry on the global map. According to the latest report by International Iron and Steel Institute (IISI), Indian steel Industry is organized in three categories i.e. the main producer and major producers have integrated iron ore and coal/gas for production of steel. The main producers are TATA steel, SAIL, and RINL while the other major producers are ESSAR, ISPAT and JVSL. The secondary sector is dispersed and consist of (1) Backward linkage from about 120 sponge iron producers that use iron ore and non-coking coal. (2) Approximately 650 mini blast furnaces, electric arc furnaces, induction furnaces and energy optimizing furnaces that use iron ore, sponge iron and melting scrap to produce steel. (3) Forward linkage with 650 re-rollers that roll out semis into finished steel products for consumer use SAIL, the largest public sector corporate entity have invested large amount for up gradation of technology and equipment at their integrated steel plants at Bhilai, Durgapur, Rorkela, Bokaro&Burnpur. SAIL become largest manufactures of steel in India and one of the top 10 steel makers in the world. Large scale modernization and renovation programs have helped SAIL to keep itself abreast of the developments in steel technology and to translate the same to its steel plants so as to move with the time.

INTRODUCTION

Steel is fundamentally an alloy of iron and carbon; with the carbon content varying up to 1.5%.The carbon is distributed throughout the mass of the metal, not as elemental or free carbon but as a compound (chemical combination) with iron. If however, the carbon is increased above 1.5%; a stage soon arrives when no more carbon can be contained in the combined state and any excess must be present as free carbon (graphite)cast iron.

In order to meet the gap in demand for wire roads, rounds and structureâ&#x20AC;&#x;s a new integrated steel plant was established in Vizag styled as RashtriyaIspat Nigam Ltd in 1992 with the capacity of 2 million tonnes finished steel.

Therefore, for a material to be classed as steel there must be no free carbon in its composition. The importance of carbon in steel lies not in its relative volume but in its remarkable influence on the internal structural changes and mechanical properties which occur when steel is heated and subsequently cooled by various methods.

The private sector integrated steel plant of the TATA viz, Tata Iron & Steel Ltd at Jamshedpur which was having a capacity of 2.5 million tonnes of saleable steel established a new Hot Strip Mill with a capacity of one million tonnes.

Carbon steels are predominantly pearlitic in the cast rolled or forged conditions. The constituents of hypoeutectoid steels (steel containing from and below 0.87%carbon) are therefore ferrite and pearlite and hypereutectoid steels from and above 0.87% cementite and pearlite.

Three major in the secondary sector, who have leaped forward to expand though electric arc furnace route and consolidate their position through technological excellence were ESSAR group viz, ESSAR Gujarat Ltd the largest manufacturers of hot briquetted iron, a substitute for steel scrap

in steel making, has its three module plants in Hazira, Gujarat with a capacity with a capacity of 1.75 million tonnes. The Jindal Organization comprises of 4 steel manufacturing companies viz, Jindal Strip Ltd, SAW pipes Ltd, Jindal Iron and Steel Ltd. The Nippon DenroIspat Ltd, the flagship company of the group has their plants near Nagpur manufacturing about 4 tonnes of steel.

new technology enables to have a product of superior strength and other mechanical properties at lesser cost of production by simply controlling the cooling regime and pattern. „TMT‟ Bars have become a style statement in the construction industry notwithstanding the huge cost benefit and also the superior quality. „TMT‟ bats assume all the more importance considering that most parts of India falls within seismic zones 3, 4 &5. It would rather be better to term this process also passes off in the market. „An insight into TMT‟ will be beneficial to avoid catastrophic results.

Other steel majors who have consolidated postions by putting up new facilities or enhanced such facilities through modernization programs during the eriod were Lloyds steel, Bhushan steel, Bellary steel, Malavika steel, Bhuvalka steel etc.

III.

The use of EAF allows steel to be made from a 100% scrap metal feedstock commonly own as cold ferrous feed to emphasize the fact that for an EAF, scrap is a regulated feed material. The primary benefit of this is the large reduction in specific energy (energy per unit weight) required to produce the steel. Another benefit is flexibility while blast furnaces cannot vary their production by much and never stopped, EAF can be rapidly started and is never stopped allowing the steel mill to vary production according to demand.

INDUSTRIAL PROFILE

SAIL-SCL KERALA LTD is the only mini steel plant in Kerala. The company was originally promoted in the joint sector between the Kerala Steel Industrial Development Corporation Ltd (KSIDC) and a private entrepreneur in 1969. SCL set up its mini steel plant in 1972 with installed capacity of 3700 tonnes p.a. which was subsequently enhanced to 55000 tonnes p.a. The company commenced commercial production in September 1973.

Government of Kerala has entered into a JV with SAIL. Incorporating the superior technology of SAIL the company has recently entered into the market of the latest quality constructional steel called TMT Bars

The steel produced here is strictly conforming to BIS specification falling under Mild, Medium Carbon and Spring Steel qualities and is cast into 100 mm sq. Billets. The billets are further rolled and converted into constructional steel of various sections at rolling mills and marketed by SCL.

1) 3.2.1 Features:  Resists fire Withstands temperature up to 600°C.  Resist corrosion

SAIL-SCL Kerala LTD is the best option in construction Steel. The company is going ahead with its ambitious expansion program including installation of TMT Rolling Mill. At present SCL is producing 100x100 mm sq. Steel through electric arc furnace route and continuous casting technology. The billets produces in the plant are converted into constructional steel items of different specifications.

The TMT process for superior strength and anticorrosive properties.  Earthquake resistance The soft ferrite-pearlite core enables the bar to bear dynamic and seismic loading.  Malleability TMT bars are most preferred because of their flexible nature.  Enables welding They have fine welding features.  Bonding Strength External ribs running across the entire length the TMT bar give superior bonding strength between the bar and the concrete.

A. Grade BIS License: During refining, samples are analysed in the laboratory and the process is controlled according to the samples. Steel produces in the plant is every time subjected to the most stringent and uncompromising quality control tests. The company being holder of „A‟ Grade BIS specification, quality control section is equipped with imported Optical Emission Spectrometer capable to analyse 30 elements of steel. Casting is made after analysing the quality of liquid metal.

Cost-Effective A high yield strength, stress ration and better elongation value give you great savings.

B. TMT Bars:

IV. HISTORY OF THE COMPANY

In the mid 1980‟s there was revolution in the steel technology. The invention of thermal and temporal processes for rolled steel products including long and flats came into practice. Before the mechanical properties of strength, malleability, corrosion resistance etc. used to control by controlling raw material combination of additives like Mn, Si, and Cu etc. This

SAIL-SCL KERALA LTD is located in 40 acres of land at Feroke in Kozhikode district Kerala. Steel Complex Ltd was incorporated on 12th December 1969 with a view to setting off regional imbalance in the supply of

essential raw materials, that is steel for construction of building in the state of Kerala. The company was originally promoted In the joint sector by Kerala State Industrial Development Corporation (KSIDC) and the private entrepreneur Mrs.Jifri.

be discharged of this responsibility. The bench gave the following directions. GOK to give necessary clearance for the companyâ&#x20AC;&#x2122;s proposal submitted to them by 31.05.2004.This should be fully tied up rehabilitation package for which SBI has also agreed.

SCL set up its mini steel plant in 1972 with installed capacity of 37000 tonnes. The company commenced commercial production of mild, medium, carbon and spring steel billets of 100mm square in September, 1973 as part of rehabilitation package. KSIDC raised its shareholding in SCL to more than 5% and thus SCL became the subsidy of KSIDC in 1979.

GOK to extend bank guarantee to the SBI by 31.03.2004. if the guarantee is not made available to SBI within the stipulated time frame, the bench will not hesitate in conforming the winding up of the company.

In 1983 SCL undertook expansion scheme by adding the 3rd electric arc furnace by which the production capacity was raised to 55000 tonnes p.a. the operation of the company then improved and SCL earned substantial profits during 1984 to 1986.

The company will ensure that the interest of workers including revision of wages / payments of workers dues is also including in the rehabilitation package to be submitted by the company. V. DESCRIPTION OF EQUIPMENTS A Furnace:

In July 1986 SCL took over Malabar steel Re Rolling Mill (p) Ltd. (MSRM) located at Malappuram district. In the year 1994, Government of Kerala took over SCL from KSIDC and the status continues. A. History of the Unit with BIFR: Steel Complex Ltd. become a sick industrial company for the first time and made reference to BIFT u/s 12(1) of SICA 1985. At the first hearing held on 5th JANUARY, 1993, IDBI was appointed as Operating Agency (OA) to the rehabilitation prospects of SCL. SCL submitted a proposal involving takeover of SCL by Government of Kerala from KSIDC and GOK to bring in 7.5 Cr out of which Rs. 3 Cr as additional equity and the balance Rs. 4.5 Cr as loan carrying Interest @ 13.5% p.a. the order came in to effect from 23.05.1995. The Government took over the SCL as per G.O(MS) No.6/94IP, Dated 05.01.1996.

The furnace comprises a cylindrical refractory lined shell with dished bottom and domed roof. The shell is mounted on chassis which also carries a back frame with roof suspension beams, electrode masts, winch units for electrode arms etc. The chassis with the furnace shell and the back frame is carried on two toothed rackers for tilting forward and backward. The separate mounting of the back frame ensures that the torque and stresses set up by roof on electrode movements are transmitted directly to the chassis and have no effect on the frame shell

B. Modified Sanctioned Scheme: The scheme modified 03.01.1997 at the time of review the board declared the scheme as failed and ordered change of management with the view to consider an opportunity for rehabilitating the company as the last chance. Even if IDBI (A) as submitted advertisements for change of management were issued, but there were no response to advertisements within the stipulated period. Finally on 18.11.2003 BIFR issued, considering the sick industrial company viz. Steel Complex Ltd is not likely to make its material all financial obligations and losses within the reasonable time while meeting all its financial obligations and that the company as a result of it is not likely to become viable. In future it is just and equitable that the sick industrial Co M/s Complex Ltd should be wound up in terms of section 20/1 of the act a hearing of the interested personal was fixed on 24.01.2004. After hearing the interested parties and considering the submission made at the hearing and the bench noted that henceforth SBI will be the O>A and IDBI will

The furnace is powered by a specially constructed transformer. The electrode movement is controlled electrically by a set of sensitive amplifiers. Tilting of the furnace is carried out hydraulically while the electrode clamps and the slag door are operated pneumatically. The maximum capacity of furnace after fresh lining is 10 ton. After every taping the capacity will be increased up to 15 ton. Bottom portion of the furnace is lined with DBM ramming material. It contains high percentage of magnesium oxide. It can withstand high temperature. After every tapping some portion of ramming material gets damaged. For repairing the

damaged of the bottom ramming material is fettled in the furnace bottom.

driving motor. The amplidynes are arranged to balance the arc voltage against the arc current through suitable increase on the arc voltage. The DC motors of the winch units are specially designed to have low movement of inertia for quick response.

The roof rings are supplied so that when one is in operation on the furnace the other may be bricked ready for used. They are of water cooled type and supported by four links attached to the roof lift beams. A platform is provided over the roof brick work to enable the operation to carry out any adjustment necessary to electrode clamps and fit new electrode as required

All the three electrodes are simultaneously controlled by a control switch. Each electrode can be individually controlled by hand through a control switch. The electrode control in the second and their furnaces had been changed to static regulations with thyristor control for better and efficient performance of the arc.

The roof suspension beam assembly together with the roof is suspended at four points and is lifted by two hydraulic cylinders mounted on the back of the structure. One vertical pivot pin is provided and secured to the chassis. The back structure carrying the roof lifting mechanism rotates about the pivot pin supported on the rollers which moves on a track concentric with its pivot pin. Rotation of the back structure and consequently swinging of the roof is carried out by double acting cylinder.

E. Con- Cast Machine: The continuous billet caster is a to strand machine. The two sectors being identical in design and operation except for handling left or right where necessary to facilitate parallel installation. The main structure of the installation provided support for the raised casting platforms, ladle support, tundish preparation are, and mould and tundish supports. An extension to the structure below the casting floor level provided plat for an emergency ladle positioned to receive the overflow of half metal from the slag box which is positioned on the casting floor. The mould oscillation mechanism is mounted on cross support beams below the casting operation together with alarm and failure indication is provided at the casting floor .Local control of cast at each mould is provided from pendant control box suspended from the back support structure. Access to the main and subsidiary floor level is by stairways having suitable hand rails. An integral steel walled enclosure forms the spray chamber in which the two spray roller aprons are located. A winch assembly is provided for handling the roller aprons.

Electrode arms are of tubular steel sections and carry the water cooled copper tubes to the electrode clamps. The electrode arms are bolted to the cross head which moves on electrode masts mounted on the back structure. The electrode clamps are made of none magnetic heat resisting steel. Water cooled copper inserts are included in the clamps for carrying current to electrode. The clamps are operated by pneumatic cylinder and operating lever. B.

Transformer:

Transformer is of the core type and constructed especially re-inforced windings to withstand heavy current fluctuations in furnace operation. For controlling the input power the arc tapping provisions are made primary windings of the transformer enabling section of ten different voltages ranging from 90 to 250 volt. In the secondary for selecting different voltages in the secondary an off load tap charger is also incorporated in the transformer. The transformer is of oil forced water cooled. C.

A straightener assembly mounted at ground level provides the drive and straightening effect for each strand. It also provides the drive for the dummy bar when re stranding the machine The discharge section of the machine consists of a pre-cut off roller table, a cutting area, discharge roller table and cooling bed. A dummy bar assembly housed in a receiver assembly provides the means of withdrawing the strand from the mould at the start of casting. Cutting of the strand into billets is affected at the cutting station, the billets are cut into required dimensions with help of portable oxy-acetylene equipment.

Reactor:

The transformer is provided with a series of reactor included in the main tank. The reactor has topping brought on the top of the transformer tank the selection of the reactor tapping corresponds to the reactor tapping corresponding to the reactor tapping corresponding to the voltage tapping are to be made for the stability of the charge material and the fault level of the supply system. For overall electrically efficiency minimum amount reactance should be chosen.

The billet pieces are transported along the discharge table until they contact end stops, pushers then move the billets sideways on the cooling beds at the ends of discharge table. A hydraulic power pack provides the pressure to operate the pusher and dummy bar receiver and cylinder. Control of the discharge sequence is from a discharge control desk mounted on a platform in the discharge area. A multi control center is positioned in the discharge area and these housed in a ventilated enclosure. The enclosure is divided

D. Electrode Control: The electrodes are regulated by a motor set comprising three amplidynes mounted on a common bed plate with a

into two rooms, the other rooms housing the hydraulic power pack. A cooling water system supplies water under pressure to the mould and to the spray chamber and discharge table. The water cools the molten metal in the mould and further solidifies the strand in the spray apron during casting process. The water is also used to cool the equipment.

The size of mould section is 100mm square

Fig. 3: Mould Tube

Length â&#x20AC;&#x201C; 800mm Taper- 0.9%/m 4m radius Weight of the mould assembly- 430 kg H. Foot Rolls: When using tapered and chromium plated mould tubes the foot rolls prevented the lower part of mould tubes from wearing out excessively and allows on the other hand an easy dummy bar insertion. These rolls must be strictly parallel to mould side wall. The casting radius template can be used for checking these points. The rape seed oil is fed to the various oiler plate outlets by means of an oil-pump through separate feed lines. Optimum mould cooling is achieved with a water velocity between 5 & 7m/s in the water gap formed by the mould tube and water jacket.

Fig. 2: Continuous Casting

F. Mould: Mould consists of essentially two parts. The mould tube is made up of copper and water jackets. The mould tubes is fixed to the key plate and mounted in the water jacket so that it can freely expand downwards. Water seals are fitted at both ends. An oiler plate is mounted on the top plate, attached to the bottom of water jacket are rolls adjustable and excenters. For each section size, it is recommended to have assembled water jackets and copper tubes ready as spares inorder to reduce mould changing time.

I. Hydraulic Power Unit: The hydraulic power unit is a package assembly used to provide the power to operate the pusher and dummy bar receiver rams. The package consist of a storage tank which forms the support two electric motors each driving a vane type hydraulic pump. Four solenoid operated selector valves are also mounted on brackets secured to the tank and govern the operation of the pusher and dummy bar receiver rams of each strand. The tank is floor mounted on corner feet. Fluid level is monitored by a level switch. A minimum quantity of hydraulic fluid must be in the tank before the waters can be started and if the level falls below the minimum during operation the motors are automatically tripped. Slight level gauges are fitted on two sides and combined filler cap and breather is fitted temperature regulator maintains the fluid temperature within a range by governing the flow through water cooler. Fillers are fitted on the suction side of each pump and a shut off walls allows either pump to pressurize one or both strand circuits. A selectable pressure gauge assembly enables either circuits pressure to be indicated

G. Mould Tubes: They are made of phosphorous deoxidized electrolytic copper with a hardness of 70-90 kg/mmÂ˛. They are tapered and chromium plated. When mounting the mould tube care must be taken that its position is exactly central in the water jackets inorder to ensure uniform cooling water gap on all four sides. The bottom water seal should not be over tightened to such a degree that it prevents the tube from expanding longitudinally. Prior to casting with a new assembly the mould table and at the top and bottom seals. A slight leakage from the bottom seal is not very serious provided it does not wet the dummy bar head during driving and does not become worse on subsequent casts. No water leakage of the top seal can be tolerated. It is always a good practice to check the prepared mould for leakage immediately prior to every casts.

The power pack is connected to the ram by metal pipes and couplings and flexible hoses are connected to the moving parts. The hoses are just wire reinforced and have asbestos as outer covering to protect them from hot metal. Thermal over load relays protect the electric motors and initiate an arm signal at the main control panel if an over load condition occurs. The alarm is also actuated by the low level float switch in the tank.

opposite to the spout enables the tundish to be emptied into the slag box. The inside of the shell is lined with the refractory brick, retained in position by plates welded to the side plates. The tundish nozzles are made of zirconium silicates. The diameter of nozzle is 13.7mm. The nozzle should be set in the small amount of fine grain mortar of high Al2O3 quality into the nozzle bricks and subsequently dried. The bricking of tundish should be composed of three layer safety lining, wear lining and protection layer. The ladle pouring point is subjected to heaviest wear. A brick quality of 70% Al2O3is therefore recommended for this area. In order to eliminate tundish pre heating proprietary lining tiles can be fitted over the work lining.

J. Dummy Bar: Dummy bar is of articulated construction consisting of a dummy bar head and a series of links, interconnected by pins and culminating in a tail link. The dummy bar provides the mean of sealing the bottom of the mould at the start of the cast and of withdrawing the strand through spray roller apron to the withdrawal assembly and the dummy bar receiver. The dummy bar head and link are connected by pins. The pin passes through bushes in the link and is retained in position by spring steel roll pins. The tail link from the end of the dummy bar, the link is drilled to facilitate the attachment of a shackle if required for handling purposes. K. Insertion of Dummy Bar: The dummy bar is introduced into the mould tube by means of driving rollers in the pinch roll unit. In the mould the dummy bar head has to be dry otherwise an explosion may occur at the start of cast. Under normal condition pre-heating is not necessary, since the head will still be warm from the previous cast. If the head is wet, it must be dried before entering the mould. The dummy bar head must be introduced 100mm into the mould tube for casting. The sealing method is to be temporarily a length of asbestos chord firmly into the gap between the head and the mould face. The dummy bar head sealing must be covered by nail nips. Dummy bar length is 7440mm and weight is 516kg

Fig. 4: Tundish in Continuous Casting

N. Ladle: Ladle is a large vessel to hold the liquid metal with a capacity of 12 to 15 ton. It is made with steel and is lined with high alumina refractory bricks. Three layers are provided at the bottom and two layers at the side. It carriers the molten metal from the furnace to the con-cast mould. Ladle is opened by means of hydraulically operated slide gate system which is fitted at the bottom portion of the ladle. The nozzle diameter of the ladle is 24mm.

L. Mould Oscillation: The mould is supplied b an oscillation assembly consisting of an oscillation arm actuated by a drive assembly. The mould is located on a secured to a top plate bolted to the oscillation arm. Mould cooling water pipes are connected to the underside of the plate. The mould oscillation is used to prevent the sticking of the solidified crust, the mould oscillate within the direction with a higher speed than casting speed. M. Tundish: The tundish is positioned in the tundish car to receive molten metal from the ladle and to transfer it to two mould assemblies through refractory nozzle. One tundish is provided to serve two moulds. The tundish basically comprises a fabricated metal shell in cooperating an overflow spout, a lid and two pouring holes. Lifting brackets, welded each corner provide sling attachment points. A lifting eye fitted to the side

Fig. 5: Ladle

O. Ladle Pre Heater:

collected in the hot water sump near to the con-cast machine. From this it is pumped to the cooling tower. By means of 20 HP turbine pump. This is collected in the cold sump. The mould water pumped from the cold sump is circulated through the mould jacket during casting and is returned back to the hot sump. From this it is pumped to the cooling tower through a 10 HP pump, furnace cooling water is pumped from the furnace and is collected in a tray from where it is collected at the hot sump by gravity flow. It is pumped to the cooling tower with a 10 HP pump. This is collected in the cold sump. This cycle is repeated.

Ladle pre heater is generally used for removing the moisture from the ladle, to avoid formation of gas reaction with the liquid melt. Most modern steel making ladle need to be preheated to 950 to 1050. Ladle pre heated are manufactured in both horizontal and vertical types. SCL have two horizontal type ladle pre heater. A horizontal ladle pre heater is designed to fire horizontally. Ladle will be positioned opposite to the flame direction with a minimum gap between the burner and the burner firing will be focused on the side wall of the ladle. In ladle pre heaters the flame will be positioned in such away to slide on the ladle side wall to ensure the faster heating to 900 in order to compensate the heat loss, when the molten metal is poured into the ladle. In SCL air-oil ladle pre heater is used.

VI. COMMERCIAL STEEL MAKING PROCESSESS The modern steel making industry is about 150 years old. It began with Bessemer process of steel making. Steel making has been dominated by LD (Linz-Donawitz) process of steel making or in the form of any of its modifications since the 1950â&#x20AC;&#x;s. the modified version of LD in the form of combined blowing process or the hybrid process of steel making in any form are the dominant process of steel making currently in use.

Fig. 6: Ladle Preheater

P. Sub-Station: They receiving electrical supply at 110KV level from K.S.E.B. They are equipped with two 110KV/11KV transformers of 15MVA and 12.5MVA respectively. The above transformers are arranged for independent working. Secondary supply of 11KV is bought to 11KV bus bar arranged inside the sub-station control room. For the present, all the three furnace load of 5MVA transformer secondary by arrangement of the bus couplers with interlock systems all these load could be changed to the 12.5MVA transformers 11KV secondary bus bar. The different furnace load are head by 11KV 3Phase underground cables they are equipped with all types of circuit breaker including gas circuit breaker, air circuit breaker for the efficient control an protection of the loads on the bus bar.

Fig. 7: LD Process

The various major types of steel making processes are: A. Basic Bessemer process: In this process the molten pig iron is held in a vessel with perforated bottom called a converter. Cold air or oxygen enriched blast is forced through the metal refining is completed in about 20 minutes and taking it into account the time for charging, tapping etc. a tap to tap time of about 35 to 40 minutes are required. This is an autogeneous process, i.e. No external heat is needed.

Q. Pump House: Steel manufacturing process requires plenty of cooling water for cooling the furnace and con-cast machine. Pump house consist of three separate cooling water pumps for storing furnace cooling, mould cooling and spray cooling water. For pumping cold water from cold sump to various equipment as well as the overhead storage tank 50 HP pump are used. After circulating the spray water through the casting machine, it is

Fig. 8: Bessemer converter

Fig. 10: Electric Arc Furnace Cross Section

Open Hearth Process. VII. ELECTRIC ARC FURNACE PROCESS

In this process, the furnace is a fairly shallow basic lined vessel. It is heated by either fluid and or gaseous fuels using the heat regeneration principle so as to attain steel making temperatures of about 1600 celsius. In the modern practice charge is a mixture of scrap and molten pig iron.

Electric arc furnace is used for steel making in SAIL-SCL KERALA. The electric arc furnace looks more like a sauce pan covered from top with an inverted saucer. The electrodes are inserted through the cover from top. The furnace unit consists of the following parts. 1) Furnace body - the shell, the hearth, the walls, the doors, etc… 2) Gears for furnace body movement. 3) Roof and roof lift arrangement. 4) Electrodes, their holders and support. 5) Electrical equipment‟s - transformer, cables, electrode control, mechanism etc… The furnace shell is a welded or riveted steel plate construction and has a cylindrical sauce pan like shape. The spherical bottom furnace is the universally accepted model since it is stronger. The furnace body needs to be tilted through 45 degree on the tapping side and 15 degree on the slagging side. The tilting gear is hydraulic or electric, but usually hydraulic gears are used. The electrodes are made up of graphite and are capable of carrying current at high density. Their sizes are of 300mm diameter and of length 1-3m. The furnace capacity is about 1012 tons. The electrode is a costly material and hence its consumption during the operation should be minimum, So as to run the electric arc furnaces, large transformers are required.

Fig. 9: Open Hearth Process

Electric Arc Process:

In this process, a three electrode arc furnace is used. The steel making temperature is maintained by an electric arc struck between the electrodes and the metallic charge. This process is very similar to the open hearth in charging and refining and several hours are needed to heat. This is the only process where in either oxidizing or reducing conditions can be maintained during refining, since the furnace does not possess its own ambient oxidizing atmosphere. The high cost of electrical energy makes this process costly.

VIII. DEFECT ANALYSIS The defect can be defined as any deviation from the appearance, form, size, macrostructure or provided in the technical standards. Defects are detected at the billets reception, by checking their surface quality on the inspection

beds, or by checking the macrostructure of the test samples. A defect is not always the result of a single case. Often, the defect is the result of multiple interacting causes, depending on a variable number of parameters. Similar defects, as â&#x20AC;&#x153;appearanceâ&#x20AC;?, may have one or more different causes, and apparently different defects may have one or more common causes. Therefore, there are often found several defects on the same billet. The defects arising from the steel continuous casting can be classified as follows: surface defects, internal defects, form defects, mechanical defects and deviations from the prescribed chemical composition of steel. The two primary defects that are commonly seen in billet casting at SAIL-SCL Ltd are surface defects and internal defects. Fig. 11: Pin holes on the surface of a billet observed by magnifying glass

A. Surface Defects Surface defects are those defects that are seen on the external surface of the billets. Surface defects can be longitudinal mid face and corner cracks, transverse mid face and corner cracks, and deep oscillation marks. Surface defects in continuous cast products need expensive, time consuming surface grinding, and in severe cases, even downgrading or rejection. Among the surface defects the dominant once are longitudinal casting cracks and lateral casting cracks.

Pinholes, often referred to as surface blow holes, occur sporadically an over large areas can affect all cast piece areas. In many cases, they only become visible after mechanical processing, but they are always visible to naked eye. They are primarily found on the outside of the cast piece or just below the surface of cast pieces made of cast iron with lamellar graphite, nodular graphite and vermicular graphite and in malleable iron casting and steel casting. Pin holes can appear in various forms, from spherical blisters with a bare metal surface or covered with small graphite skins to large, irregularly shaped cavities accompanied by slags or occurrences of oxidation.

1) Longitudinal Casting Cracks

3) Star Crack:

Fig. 8.1.1: Longitudinal Crack

These cracks form at the initial moment of crystallization. They usually appear at corners of faces of billets. It is because the outer crest of billets which is uneven in thickness and detached from the mould owing to shrinkage, fails to withstand the ferrostatic pressure of molten metal. They form in the direction of extracting the strand from the mould. Fig. 12: Star crack

2) Pin Holes:

They are very fine, being visible only on scale free surfaces. For removing the defect, the surfaces are locally grinded (if the cracks are not too deep).The causes that give rise to star cracks are the intense local cooling, which induce local tensions, and the presence of copper at the austenitic grain limit.

Pin holes are observed often for semi-killed steels cast with casting powder. It can give a place to defects in the final product if there is an important number in a small area or if they penetrate deep in the billet.

4) Transverse Crack

1) Intercrystalline Cracks

Fig. 13: Transverse Crack observed by magnifying glass Fig. 15: Intercrystalline Crack

Transverse cracks, although not always detect in the inspection of billets, may also give place to serious defect in the rolled products andare rarely seen in round profiles they appear due to the tensions on the longitudinal direction of strand. If they are not deep, they are grinded (deviations within the permissible prescribed limits for diameter and ovality).

Cr-Ni steels with nickel greater than 4% of its composition and other complex alloyed steels are especially prone to form intercrystalline cracks. These cracks are formed due to internal stress appearing in billet due to different rates of cooling of outer and deeper layers, inhomogeneity in metal composition resulting in that the metal in dendritic axis and interdendritic spaces pass through the critical point at different time, sulphide and aluminium nitride which segregate at grain boundaries weaken the cleavage between the grains. Formation of cracks begins from the end of crystallization and may proceed for a rather long time during storage of billets in cold state. These cracks at the axis of billet can cause lamination in the fracture of alloy steel. Intercrystalline spider shaped cracks at the billet axis can be welded by rolling with high reduction ratio.

5) Transverse Depressions

2) Internal Blow Holes: Fig. 14: Transverse Depression

The transverse depressions are formed in the transverse direction and may cyclically occur in relation to the strand length. The width of the depressions may cover some oscillation marks, and the depth can reach several mm. The peritectic steels with low Carbon percent and high percent of Manganese and the stainless steels are sensitive to the formation of this type of defect, due to the much larger contractions occurred during solidification. The depressions precede the occurrence of the longitudinal shrinkage cracks and the marginal internal cracks (subcutaneous). The material that presents this type of defect is locally and cyclically grinded, to check the presence of subcutaneous fissures. The macro sample is taken. B.

Fig. 16: Blow Holes

This defect is due to the high gas content or improper deoxidation of metal before tapping, a moist launder, and ladle or bottom plates. This can be seen as spongy structure in the cross section. Blowholes are cavities in the outer surface or in the subcutaneous zone of the billet, located at few tenths of millimetres from the stand surface. They have a diameter of 3 mm and a length (depth) that can reach up to 25 mm. Usually they contain CO, relatively low H2 and Ar, and they are often associated with inclusions.

Internal Defects:

Internal defects are those defects which normally occur inside the surface of the billet. These defects occur mainly due to the varying metal composition and also due to improper mixing of molten metal.

3) Flakes: Appear in billets during cooling, as the volumes of internal voids diminish upon thermo-mechanical treatment of

billet, the pressure of molecular hydrogen increases. And when, this exceeds the strength of steel, the metal fractures internally and forms flakes. They are also promoted by internal stresses caused by structural transformations in a chemically heterogeneous billet or fast cooling of billet. Flakes can cause sudden failures of parts operating under variable loads. 4) Shrinkage Porosity:

IX. ROOT CAUSE ANALYSIS A. Longitudinal Casting Cracks: The longitudinal cracks are formed due to the uneven removal of the heat in the mould and therefore, the uneven increase of the strand crust causing transverse tensions that lead to the strand cracking if the crust is not strong enough (uneven primary cooling). Another major reason for longitudinal cracks is turbulent flow of metal and a meniscus level variation in the mould. If secondary cooling is too intense or uneven cracks are formed. Advanced wear of the mould that leads to a different thermal conductivity coefficient also leads to formation of cracks. High casting temperature, great strand extraction speed, and inappropriate behaviour of the casting powder also are some of the reasons forcrack formation. B.

Pinholes:

Formation of pinholes is mostly related to evolution of gases resulting from casting powder decomposition during casting and can be enhanced by high oxygen activity in the liquid steel. Normal figures for lubrication rate are 20 to 30 gm/min, depending on powder properties, billet size and casting speed. C. Fig. 17: Different Pores Seen on Billet

Star Crack:

The causes that give rise to star cracks are the intenselocal cooling, which induce local tensions, and the presence of copper at the austenitic grain limit. They appear at 500 â&#x20AC;&#x201C; 600 ÂşC due to thermal stresses if the ductility of material is too low.

Shrinkage defects occur when feed metal is notavailable to compensate for shrinkage as the metal solidifies. Shrinkage defects can be split into two different types: open shrinkage defects and closed shrinkage defects. Open shrinkage defects are open to the atmosphere, therefore as the shrinkage cavity forms air compensates. There are two types of open air defects: pipes and caved surfaces. Pipes form at the surface of the casting and burrow into the casting, while caved surfaces are shallow cavities that form across the surface of the casting. Closed shrinkage defects, also known as shrinkage porosity, are defects that form within the casting. Isolated pools of liquid form inside solidified metal, and they are called hot spots. The shrinkage defect usually forms at the top of the hot spots. They require a nucleation point, so impurities and dissolved gas caninduce closed shrinkage defects. The defects are broken up into macroporosity and microporosity (or microshrinkage), where macroporosity can be seen by the naked eye and microporosity cannot.

D. Transverse Crack: Transverse crack can be caused by the thermal stresses due to the uneven solidification of the crust and the additional stress due to turbulent flow in the meniscus, also due to meniscus level variation and presence of segregations which cool more slowly and weaken the austenitic grain boundaries. Friction of the strand in the mould at higher casting speeds.They also appear when the melt flow between the mould wall and crust decreases. The edge friction increases with the viscosity of the powder used) or in the cylinder segments.Transverse cracks can form in the mould or during strengthening. When they are located in any corner, they are likely to be formed due to tensile effort related to sticking, this can be worsen by deep oscillation marks When the cracks are present only in the corner belonging to inner radius, they could be formed by tensile efforts during strengthening. This is common when corner temperature is within low ductility range.

Shrinkage porosity is mainly observed in high carbon alloy steel and steels of high viscosity. Temperature and fluidity of metal diminish during the cost of teeming. Shrinkage porosity represents a gap of material, visible in the cross section at the end of a bar. It can be removed by cutting the end of the bar, and the defective portion is rejected. The causes that produce this defect are high casting temperature, high extraction speed and intense secondary cooling.

E. Transverse Depressions: B. The transverse depressions can be caused by the steel level fluctuation in the mould, by the too large quantity of melted flux, located in the space between the mould wall and the strand, and by the turbulent steel flow at the sub-meniscus level.

Pinholes:

To minimize pinhole formation it is important not only to check if lubrication rate is within the usual range, but also verify if the powder distribution in the transverse section is homogeneous. Good distribution of casting powder is very important and to avoid excessive use of lubrication in corners. Also proper mixing of molten metal is required to avoid pinholes from casting. DINESH DEKATE et.al [9]

F. Intercrystalline Cracks: Intercrystalline cracks form due to the internal stresses appearing in billet due to different rates of cooling of outer and deeper layers. In addition to this inhomogeneity in metal composition resulting in that the metal in dendritic axes and interdendritic spaces pass through the critical points at different time also result in these kind of cracks. Sulphide and nitride which segregate at grain boundaries weaken the cleavage between the grains.

Star Crack:

Star cracks can be prevented by the correct adjustment of the spray nozzle holes and the right correlation between the spray flow and the casting speed (automatic flow control). By providing a uniform layer (film) of melted casting powder between the strand

G. Internal Blow Holes: The major reason for internal blow holes are insufficient deoxidation of steel, Moisture present in the casting powder.Also by increasing the quality of the casting powder and quantity and uniformity of its distribution. The variation of the steel level in the mould and the existence of moisture in the refractory lining of the tundishcan cause internal blow holes. The presence of argon entered in the mould during the injection of argon for filling the nozzle may also result in internal blow holes.

and the mould we can reduce star cracks to an extent.The cooling of the strand with a moderate intensity when it leaves the mould, to avoid the increase of the thermal stress and the development of cracks.ERIKA MONICA POPA et.al [7] D. Transverse Crack: A sound approach to solve the problem is to set proper secondary cooling to avoid the dangerous temperature range in the corners during strengthening. Air-water mist cooling provides more uniform cooling in both casting and transverse directions,and hence avoids cracks by minimizing the localized temperature fluctuations caused by the undercooling and overcooling associated with water droplet spray jets.ERIKA MONICA POPA et.al [7], DINESH DEKATE et.al [9]

H. Shrinkage Porosity: The density of a metal in molten state is less than its density in the solid state. Therefore, when a metal changes phase from the molten state to the solid state, it always shrinks in size. This shrinkage takes place when the casting is solidifying inside a mould. At the centre of thick sections of a casting, this shrinkage can end up as many small voids known as „shrinkage porosity‟. If the shrinkage porosity is small in diameter and confined to the very centre of thick sections it will usually cause no problems. However, if it is larger in size, or joined together, it can severely weaken a casting. It is also a particular problem for castings which need to be gas tight or watertight‟.

E. Transverse Depressions: They can be remedied by controlling the steel level fluctuation in the mould, by using a mould with parabolic taper, by using a powder lubricant with suitable viscosity and melting rate, by minimizing the turbulence and surface agitation, optimizing the position of the input nozzle and its support.However, each oscillation cycle createsa transverse depression in the solidifying shell at the meniscus, called an oscillation mark. Pressure from interaction with the flux rim at the meniscus can deepen these marks. Unsteady level fluctuations and surface waves due to turbulence can disturb formation of these marks, creating surface defects, such as ripples or depressions in the final product.ERIKA MONICA POPA et.al [7]

X. PREVENTION METHODS A. Longitudinal Cracks: These cracks can be minimized by supplying rigid stream of metal strictly at the axis of billets, by increasing the perimeter of the mould. They can be also reduced by retarding the teeming rate as well as by enhancing the viscosity of molten metal by changing its metal composition. Another effective method is to use square mould with concave surface.S. KUMAR et.al [2]

F. Intercrystalline Cracks: Out of the major defects we analysed in our project, the main reason for the formation of defects in the continuous cast billet at SAIL-SCL KERALA Ltd is due to the improper mixing of molten metal.

These types of cracks can be minimized by proper mixing of the molten metal, lowering the sulphur level, by applying high reduction ratio and by heating the top of the moulds so as to minimize the rate of heat transfer and improve the supply of metal to the axial portion of the billet. Proper mixing of molten metal is required to avoid these kinds of cracks. Transferhot billets soon after complete solidification to soaking pits and control the temperature of molten metal and rate of teeming so as to ensure good filling of shrinkage voids. LIFENG ZHANG et.al [1]

XI. FIXED MIXER In SAIL-SCL KERALA Ltd there is no adequate means for mixing of molten metal. Due to the arcing of electrodes in the furnace,pulses are generated inside the furnace. These pulses cause a slight motion to the molten metal.

G. Internal Blow Holes: Internal Blow holes can be prevented by following methods

For providing an additional mixing to the molten metal we suggested the idea about field mixing. If we can supply a three phase or two phase frequency converter, a rotating magnetic field can be generated, whose variation inside the steel produces eddy current. These current interacting with the magnetic field generates a force. This will result in the occurrence of a torque that induces the molten metal to rotate.

1) Sufficient de-oxidation of steel by using dry materials and additives. 2) Protection of ladle and tundish.

The solidification begins from the mould region. So it is best to set up such a kind of field mixer above or around the mould in the continuous casting machine.

3) use of dry casting powder (and preheated, if possible). 4) Possibly choosing a casting powder compatible with the steel grade. 5) Temperature and casting speed(and, of course, a good correlation between the casting power quantity and the casting speed). 6) Controlling the steel level fluctuations in the mould, to prevent the steel to flow over the casting powder and to embed it, controlling the nozzle immersion depth, use of nozzles free of defects. 7) Avoiding the high casting temperatures. 8) Maintaining the argon debit below the critical value, to avoid the capture of argon bubbles by the meniscus and the development of slag foaming around the nozzle. BRIAN G. THOMAS et.al [8], S. Kumar et.al [2] H. Shrinkage Porosity: The general technique for eliminating shrinkageporosity is to ensure that liquid metal under pressure continues to flow into the voids as they form. The mold walls should be routinely tapered to match the steel shrinkage in order to minimize air gap formation. Proper mixing of molten metal is recommended to avoid Shrinkage defects. Maintaining the change in temperature within the established limits and a good correlation between the casting speeds and cooling regimes shrinkage porosity can be eliminated. And also reduction of the casting speed, reduction of the cooling intensity, maintaining the water flow at the established minimum limit can reduce shrinkage porosity.RAJESH RAJKOLHE et.al [5]

Fig. 18: Design of Field Mixer

XII. CONCLUSIONS The requirement of steel is increasing rapidly in every corner of engineering work. So it is necessary to make improvements in the steel we are using. In our project work different casting defects are analysed. By referring different journal papers causes and their remedies are listed for each defect.These will help the qualitycontrol department of SAIL-

SCL KERALA Ltd for the analysis of casting defectsand also improve the productivity and yield of casting. So by adopting these techniques, the SAIL-SCL KERAL Ltd can produce better quality billets.

[9] Dinesh Dekate, Prof. B.D. Deshmukh, SarangKhedkar “Study and Minimization of Surface Defects on Bars and Wire Rod Originated in Continuous Cast Billets” ISSN: 2249-6645 Vol.3, Issue.2, March-April. 2013 pp-736-738

ACKNOWLEDGMENT The authors would like to acknowledge the support of Mechanical Engineering Department of Saintgits College of Engineering for conducting the present investigation. REFERENCES [1] Lifeng Zhang (Dr.), Brian G. Thomas (Prof.) “Inclusions In Continuous Casting Of Steel” XXIV National Steelmaking Symposium, Morelia, Mich, Mexico, 26-28, Nov.2003, pp. 138-183. [2] S. Kumar, I.V. Samarasekera, J.K. Brimacombe, “Mould thermal response and formation of defects in the continuous casting of steel billets––laps and bleeds” Iron and Steelmaker (1997) 53–69 [3] S. Kumar, B.N. Walker, I.V. Samarasekera, J.K. Brimacombe “Chaos at the meniscus––the genesis of defects in continuously cast steel billets” 13th PTD Conference Proceeding, 1993, pp. 119–141

[4] Alexander V. Lotov, George K. Kamenev, Vadim E. Berezkin , KaisaMiettinen“Optimal control of cooling process in continuous casting of steel using a visualization-based multi-criteria approach” Applied Mathematical Modelling 29 (2005) 653–672 [5] Rajesh Rajkolhe, J. G. Khan “Defects, Causes and Their Remedies in Casting Process” International Journal of Research in Advent Technology, Vol.2, No.3, March 2014 E-ISSN: 2321-9637 [6] Dr D.N.Shivappa1, Mr Rohit, Mr.Abhijit Bhattacharya “Analysis of Casting Defects and Identification of Remedial Measures” International Journal of Engineering Inventions ISSN: 2278-7461, Volume 1, Issue 6 (October2012) PP: 01-05 [7] Erika Monica POPA, Imre KISS "Assessment of surface defects in continuously cast steel” ACTAQ TECHNICA CORVINIENSIS-Bulletin of Engineering Tome IV (2011). ISSN 2067- 3809 [8] Brian G. Thomas “Modeling of Continuous-Casting Defects Related to Mold Fluid Flow” 3rd Internat. Congress on Science & Technology of Steelmaking, Charlotte, NC, May 9-12, AIST, Warrendale, PA, 2005, pp. 847-861.

UNDERWATER SEARCH AND RESCUE DEVICE Amjith K, Arundas V H, Harikrishnan M, Jeevan Sebastian Abstract: Third leading cause of unintentional death of total world population is drowning. Mostly, rescue attempts ends in failure mainly because of the due to long search time because of the absence of suitable and affordable aid which helps in searching .Current models of underwater drone are used in ocean are not used in local streams. Main disadvantages of the current models are that, they are designed for high cost, complex design etc. In the analysis it was found that the proposed design withstands the operation conditions of an underwater drone. It achieves stable equilibrium in fully merged condition. And it was found that the drone can achieve a speed up to .9m/s in the flow and work comfortably at a depth of 1km by using fiber glass body. The design also allows the installation of more gadgets like sonar and other devices. In the future application or as an extension of the project the drone can be used for many other purposes like under water exploration, useful tool for fishermen etc.

A. Design of Body: While designing our body our aim was to design a body which enhance maneuverability, has optimum strength, good stability, low drag, and good repairability. We have designed such a body. The parts and complete assembly are show below; B. Propeller Design: For designing our propeller we first fixed the diameter of our propeller with comparing to body size and the thrust required to propel it. Pitch of our device was calculated from our desired maximum speed. Our propeller is designed to have constant angle of attack throughout the length of blade. The main propeller helps in vertical motion of the device and the sub motors which rotate mutually opposite direction are use for forward motion and turnings.

I. INTRODUCTION We conducted a study on various underwater activities done by humans. It was found that most of these activities either involves direct human involvement or are costly. From these conclusions we thought of a new model of an underwater drone which is both economical and easy to use. The main purpose of this design was initially concentrated for search purposes which in future can be used for rescue operations also, provided, some modifications being done. In this paper we discussed about a novel model which is most suitable for local streams with low cost and ease of manoeuvring. The design consists of one main propeller for up and down movement and 2 sub propellers providing the front and rotational movement. Each propeller is powered by separate DC geared motor. Proposed body is made up of fibre glass. CATIA is used to design the model and analysis is done with ANSYS. Main parameters of the design are stability, balancing, manoeuvrability and structural strength of the drone.

Fig. 1: Shape of Standard Aerofoil

Standard aerofoil 2032C-il-20-32C AEROFOIL, because it has maximum coefficient of lift is 0.7 at zero angle of attack.

II. ANALYTICAL METHOD For designing our drone we assumed some values for its pay load, buoyancy, weight and maximum speed. The aim was to design our drone which satisfies our assumption. The values which we assumed are: Pay load of 19.6 N (2 kgf) Body weight assumed as 58.8 N (6 kgf) Buoyant force assumed as 117.6 N (12 kgf) Maximum speed limited to 0.9 m/s For designing our drone we divided the work into four categories they were, design of body, design of propeller, balancing and stability and electrical and control unit.

Fig. 2: Main Propeller Analysis Using MRF

Ansys Fluent to analyze the propeller. We used Moving Reference Frame (MRF) method to analyze the propeller. MRF method is a method used to analyze rotating bodies. Here the area shown in blue is the velocity inlet and area shown in red is pressure outlet. The condition tested is in still water so the inlet velocity is set to zero. Area shown in Yellow is the reference frame which we analyzed. C. Balancing and Stability: 1) Fully Submerged Body: In a fully submerged rigid body, for example a submarine, both centres are always in the same place relative to the body,

E. Calculation of Centre of Gravity: Center of Gravity is the point in a body where the gravitational force may be taken to act. Center of Gravity is found from CATIA directly.

barring possible shifts in the cargo. If the centre of gravity does not lie directly below the centre of buoyancy, but is displaced horizontally, for example by rotating the body, the direction of the moment will always tend to turn the body so that the centre of gravity is lowered with respect to the centre of buoyancy. The only stable equilibrium orientation of the body is where the centre of gravity lies vertically below the centre of buoyancy. Any small perturbation away from this orientation will soon be corrected and the body brought back to the equilibrium orientation, assuming of course that dissipative forces (friction) can seep off the energy of the perturbation, for otherwise it will oscillate.

Fig. 6: Result: Centre of Gravity

F. Shaft Axis: It is another point where forces acting on the system.

Fig. 3: Stable Equilibrium Condition

D.Calculation of Center of Buoyancy: Center of Buoyancy is the center of the gravity of the volume of water which a volume displaces. Center of buoyancy is found from CATIA by replacing the hollow body to solid body and defining the solid as water. The center of gravity of the obtained shape is the center of buoyancy of the actual volume Fig. 7: Result: Shaft Axis

Here from the three results it is clear that center of gravity below the center of buoyancy, which is the actual condition of stable equilibrium in the fully merged condition. Center of gravity and center of buoyancy coincide in same axis and center of buoyancy is 2.7 mm above center of gravity. Also the balancing condition is satisfied in this case. That is if all forces acting in the system pass through the same axis there will not be any unbalanced couples in the system. Center of gravity, shaft axis and center of buoyancy coincide in same axis satisfies the condition. Therefore the system is in stable equilibrium and in a balanced condition.

Fig. 4: Defined Shape to Find Center of Buoyancy

III.RESULTS The analysis of main propeller sub propellers, were done on Ansys Fluent using MRF method. Structural analysis of propellers was also done. The drag was calculated. Structural analysis of body was conducted. Structural analysis of motor casing was also done. The results obtained are mentioned below. A.CFD Analysis of Main Propeller: For the analysis of main propeller results are calculated at 2000rpm using MRF method. The main propeller CFD analysis is shown below. Fig. 5: Result: Centre of Buoyancy

Fig. 8: Velocity Stream Line

It was found that no vortex was formed. This indicates that the design of propeller is safe. The pressure contour of the main propeller is also shown below.

Fig. 11: Pressure Contour of Sub Propellers

The following results were obtained from the analysis Sub propeller thrust calculated from MRF method is 24.009969 N Sub propeller torque calculated from MRF method is 0.589641 Nm No vortex formation has been observed C. Structural Analysis of Propellers: Structural analysis of propeller was done and it is seen that aluminium alloy with a yield strength of 2.8 Ă&#x2014; N/ is the best suited material for propeller. By giving a load of 250N, the FOS for main propeller obtained was 1.125.The maximum force generated was found to be 221.29 N from the force report of the main propeller but in the structural analysis of the propeller a load greater than the maximum is applied so that it can accommodate any additional force acting on the system. The FOS will be a greater than 1.125 if the load applied was 221.29 N.

Fig. 9: Front View of Pressure Contour

Fig. 10: Back View of Pressure Contour

From the pressure contour it is clear that pressure acts on back side. In our design the main propeller is used to sink the device. So more pressure will act on back side. The main results obtained from MRF analysis of main propeller is given below. Main propeller thrust calculated from MRF method is 221.29607 N. Main propeller torque calculated from MRF method is 3.8204994 Nm. No vortex formation has been observed.

Fig. 12: Stress Analysis of Main Propeller

It can be seen that the stress is distributed equally and so the design is safe. For the sub propeller we gave a load of 25N and we got a FOS of 8.

B. CFD Analysis of Sub Propeller: CFD analysis on sub propellers were done and the pressure contour obtained is given below.

Fig. 13: The Stress Analysis of Sub Propeller

It can be seen that the stress is distributed equally on propeller and so that the design is safe.

F. Body Cover Alone: From this graph it is seen that at a depth of 1km a deformation of 3mm will occur to body cover. This is also not desirable.

D.3.4 Drag Calculation of Propeller: The vertical drag and transverse drag was calculated at a speed of .9 m/s. The maximum vertical drag was found to be equal to 48.429 N. The vortex flow was minimum.

Fig. 17: Pressure Contour When Body Cover Alone

G.Combination of Base Structure and Body Cover: It is seen that 0.9 mm deformation will occur to this combination at a depth of one kilometre. It is a safe condition. Combination gives only total deformation of 0.9 mm which can be assumed to be safe as 0.9 mm deformation cannot produce a crack on 3 mm thick body cover.

Fig. 14: Pressure Contour of Vertical Drag

The maximum transverse drag was found to be 5.49 N from CFD analysis. It was also found that the vortex formation is minimum. Pressure contour obtained is given below.

Fig. 15: Pressure Contour of Horizontal Drag

The structural analysis of body was conducted and the following results were obtained. Base structure Aluminium with yield strength of 9.5x N/ . Body cover fiberglass of Polyester and Chopped Strand Mat Laminated 30% E- glass with yield strength of 10x N/ . Pressure loaded is 1MPa which is approximately equal to the pressure at one kilometre depth.

Fig. 18: Deformation Contour When Base Structure and Body Cover

H.3.8 Structural Analysis of Motor Casing: Structural analysis of motor casing was done. The deformation graph obtained is given below.

E. Deformation Analysis: 1) Base Structure Alone: From the results, it is seen that a deformation of 8mm will happen to the base structure at one kilometre depth. This is an undesired condition since the thickness of our material is 3cm only.

Fig. 19: Stress Contour of Motor Casing

The results obtained are given below. Material used is polyethylene of yield strength with 2.5x N/ . With load of 250 N we get a FOS of 8.22. IV. CONCLUSION Stability of a fully merged body depends upon the relative position of the center of gravity and center of buoyancy. Here in this model we get center of gravity below the center of

Fig. 16: Pressure Contour When Base Structure Alone

[5] ANSYS Fluent 12.0 Theory Guide, ANSYS Inc,. 2009.

buoyancy, which is the actual condition of stable equilibrium in the fully merged condition. Center of gravity and center of buoyancy coincide in same axis and center of buoyancy is 2.7 mm above center of gravity. Also the balancing condition is satisfied in this case. That is if all forces acting in the system pass through the same axis there will not be any unbalanced couples in the system. Center of gravity, shaft axis and center of buoyancy coincide in same axis satisfies the condition. Normal speed of current under water devices like spray glider as small as 23 cm/s and normal divers of international standards are about 0.7 m/s. In this novel model designed from results it shows that it can achieve a speed up to 0.9 m/s for both vertical and transverse motion. The analysis was conducted at depth of 1 km from the surface of the water for analysing the structural strength of the main frame, body cover, main and the sub propeller and motor casing. CFD analysis shows body can withstand up to pressure of one kilometer depth. Drag for both vertical and transverse motion has been calculated and found to be less than that of the thrust actually given by the propeller. So the motion is not greatly disturbed by the drag force acting. Also vertical drag found to be less than that of the transverse drag because of the reason that exposed area on the transverse face. V.FUTURE SCOPE (1) Base model containing wired control which can be improvised to wireless model. (2) An improvised model can be used for rescuing purposes without a diver also. (3) Use various devices such as SONAR to help in missions. (4) Further improvisation in the design or addition of gadgets can make device work for other application efficiently. (5) It can be used in defence systems, under water construction, underwater exploration etc. REFERENCES [1] Weijia Fua and Lia, Haojie Wanga, “Numerical Simulation of Propeller Slipstream Effect on A Propellerdriven Unmanned Aerial Vehicle,” Engineering Analysis with Boundary Elements, Vol. 31, pp. 150 – 155, 2012. [2] Gerasimos K. Politis, “Simulation of unsteady motion of a propeller in a fluid including free wake modelling,” Engineering Analysis with Boundary Elements, Vol. 28, pp. 633–653, 2004. [3] Juraci Nóbrega, “Simple Calculation of Boat Propeller,” International Journal of Engineering and Innovative Technology (IJEIT), Vol. 2, pp. 150 – 155, 2013. [4] Serkan Ekinci, “A Practical Approach for Design of Marine Propellers with Systematic Propeller Series,” Brodo gradnja Vol. 62, pp. 255, 2011. [5] Benny Lautrup, Physics Of Continuous Matter, Vol. 3, pp. 41-56.

Capillary Water Provision System for Irrigation Philip Jacob Perakathu, Joju Thomas K, Kiran Thomas, Dheeraj M, Christin Thomas

has been observed that for different plants the root pressure varies from about 33 Pa to about 0.6 MPa. So for this study we are taking two root pressures. First we take a root pressure of 33 Pa which is least and can study the effect of smallest pressure plants in our designed system. Secondly we take an intermediate root pressure range 2.5 kPa, which is the root pressure of grape vines. Study and analysis are done for both cases and different heights up to which water can rise has been determined.

Abstract: Water provision system using capillary action is a restoration propagation operation. The capillary action occurs due to the combined effect of three phenomenaâ&#x20AC;&#x2122;s namely cohesion, adhesion, and surface tension. This is a low cost approach to supply an efficient and continuous source of moisture to plants. A variety of materials can be used to construct this system. In this study, a system has been designed and water is allowed to reach the root of plants through capillary action. For the betterment of water transfer, a porous material is embedded into the system. Using this system water can be provided to a certain height without the aid of mechanical devices like motor and pump. This method can be used to provide water to small plants and also to large plants in their initial growing stages. This largely helps in reducing wastage of water and helps in efficient use of water especially in water scarce regions. This system can be modified for more applications in the future.

II. MATERIALS AND METHODS In this method glass tubes having different diameters were taken and dipped in a container having water. So that the water level rises in each tube vary according to its diameter which can be clearly seen. Capillary Tubes of Varying Diameters:

Keywords: Capillarity, Surface Tension

I. INTRODUCTION For the improved use of water in agriculture several techniques have been implemented. One such technique is the method of using capillary irrigation systems. Capillary action or wicking is the ability of a liquid to flow in narrow spaces without the assistance of, and in opposition to, external forces like gravity. The effect can be seen in the drawing up of liquids between the hairs of a paint-brush, in a thin tube, in porous materials such as paper, in some non-porous materials such as liquefied carbon fiber, or in a cell. It occurs because of inter- molecular force between the liquid and surrounding solid surfaces. If the diameter of the tube is sufficiently small, then the combination of surface tension which is caused by cohesion within the liquid and adhesive forces between the liquid and container act to lift the liquid. In short, the capillary action is due to the pressure of cohesion and adhesion which cause the liquid to work against gravity. The water provision system using the capillary action is a restoration propagation operation. It gives a constant and steady supply of moisture to the root zones of plants from the bottom up. In this study we use porous materials like tissues for the betterment of capillary action .the porous material is stacked within the pipe and the porous medium is provided till the roots. It was found that water is rising through the porous material due to the effect of root pressure. The design and analysis have been done and the prototype has been made and found that water is reaching the root outlets, the height of rise depends on root pressure of selected plants. From various dataâ&#x20AC;&#x2122;s collected it

Fig. 1: Capillary Tubes of Varying Diameter The glass tubes used in the study are having diameters of different values. Figure 5.1 shows glass tubes of different diameters. This includes capillary tubes with diameter 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, and 5 mm respectively. When these tubes are dipped with its one end within a container having water, it is observed that the level of water rise in each tube is different. This is because of the varying diameter of the tube. It can be clearly inferred from the figure 2 that the tube with the least diameter is supporting the highest water rise, when compared with the other tubes. And the tube with the largest diameter is giving the least rise.

branch pipe which of smaller diameter so that water will be raised from the main line to the top section of the branch pipe through capillary action. Small holes have been provided at the top of the branch pipe so that the water can be provided to outside and when a plant root comes in contact with the porous material, it will takes in the required amount of water from the wet paper towel.

Fig. 2: Varying level of water in capillary Major problems resulting in this method is that: the water rise though it is been obtaining, but the rise is in the millimetre range only. This will not help in producing an efficient water provision system. Porous Material within the Capillary Tube:

Fig.4: Prototype of the proposed system

To overcome the problem faced in the first method i.e., the low water rise in the tube, a porous material is been used by stacking within the tube. Due to easy availability and to make economic, paper towel is been used in this case. Sponge can also be used. The water rise through a porous material will be much higher as compared to the rise in a capillary tube. This is due to the better adhesiveness between the two mediums. So, when this porous material is used within the glass tube then the resultant rise of water within the tube will be much higher as compared to that in the first case. This helps in attaining the study objective of providing water to more height which can be used for irrigation purposes.

Thus, through the system the main objective of developing an efficient water provision system using capillary action was obtained. This largely helps in reducing the water usage in plants, reduces labour, reduce total cost involved. III. DESIGN AND ANALYSIS Design using Solidworks: Figure 5 shows the designed water provision system for 5 cm height. The water inlet and outlet are given as the opening and ending portion of bottom main pipe. The branch pipes which are place at different heights are stacked with porous medium, and the outlets which were given on the branch pipes are the outlet to the roots.

Fig. 3: Porous Material Stacked Within Capillary Tube Porous Material within PVC Pipe: Fig.5 : Designed model

In order to overcome the problems faced in the above methods, a system of a pipe made some other material within which porous material is been kept to achieve the desired functional system. Pipe made of any recycled materials or other low cost material can be used. In this method a PVC pipe was used. But with its use the rise of water through it cannot be obtained as that in the case of capillary tubes. For achieving that, the porous material has been kept within the tube. This helps water to rise through the tube.

Analysis using ANSYS: Velocity and pressure analysis were carried out using ANSYS FLUENT. This analysis is mainly done in order to find out up to what height water can rise through the porous material due to capillary action for the root pressure considered 1). Analysis For Root Pressure (-33 Pa) For Various Heights: The analysis for different heights has been done and the results for different heights have been shown below. The

In this, water is been filled in the larger pipe which is the main line. While the porous material was kept within the

boundary conditions given are inlet and outlet of main pipe as 1 atm, root outlet pressure as â&#x20AC;&#x201C;33 Pa and porosity of medium as 0.8. From the analysis it was found out that water can rise up to a height of 7.5 cm for a root pressure of -33 Pa. The velocity and pressure contour for different heights of 2.5 cm, 5 cm and 7.5 cm is shown in the Figures 6, 7 and 8 respectively. Fig. 8: Velocity and Pressure contour for height 7.5 cm From the velocity and pressure contour for 7.5 cm height shown in the Figure 8 above it can be clearly inferred that water is reaching the farthest root outlet with a much lower velocity when compared with the root outlet at the beginning. From the pressure contour it is clear that the upward pressure is not as high as the above two cases. The maximum height water can be provided using root pressure 33 Pa is 7.5 cm. For plants with root pressure more than -33 Pa water will easily move up and will be capable of obtaining water from more depth. 2). Analysis For Root Pressure (-2.5 Kpa) With Various Heights:

Fig. 6: Velocity and Pressure contour for height 2.5cm

The analysis for different heights has done and the results were shown below. The boundary conditions given are inlet and outlet of main pipe as 1 atm, root outlet pressure as â&#x20AC;&#x201C;2.5 kPa and porosity of medium as 0.8. From the analysis the maximum possible height is 2 m.

Figure 6 show that water is reaching all the root outlets uniformly with a uniform velocity. The pressure contour shows that the upward pressure acting on the system decreases from bottom to top. There for it can be inferred that there is upward force acting throughout the pipes from bottom to the root outlets.

Velocity and pressure contours for heights 1.5 m and 2 m are shown in the Figures 9 and 10 respectively. For both the heights the velocity with which water reaching each root outlet was uniform. The pressure reduces from bottom to the root outlets, therefore an upward pressure is acting from bottom up.

From the velocity and pressure contour for 5 cm height shown in Figure 7 it can be inferred that water is not reaching all the root outlets in a uniform manner. As the distance of the root outlet from the main pipe increases the ease with which water reaching the outlet reduces.

Fig. 9: Velocity and pressure contour for height 1.5 m

Fig. 7: Velocity and Pressure contour for height 5 cm

Fig. 10: Velocity and pressure contour for height 2 m

RESULTS AND CONCLUSIONS The study, design and analysis of water provision system using capillary action have been carried out in this study. From the analysis carried out using ANSYS, it can be concluded that the height to which water can rise through the tube depends on the root pressure of the plant under consideration. Therefore this system can be effectively used for providing water needed for their growth. For plants with root pressure higher than the designed system, water intake will be possible. In the case of small plants, the root pressure was found to be higher. This enables the use of the proposed system in nurseries. The system has several advantages over conventional drip irrigation system which are: the cost involved is much less compared to the other. Fabrication is simpler and the maintenance involved is very less. Since PVC pipes are used in the current project it has life time of about 10-15 years. The porous material used has to be renewed once in 3 or 4 months. The system design is very simple compared to the conventional drip irrigation system. With this system water required for the plants is supplied effectively. This helps in reducing the water requirement and also helps in avoiding the use of motors and pumps as in conventional irrigation systems. Thus the system developed helps in attaining more profit. In addition to the advantages proposed above, the system can be used for research purposes for determining the exact usage of water by the plants. By the use of hybrid porous materials the efficiency of the system may be further improved. The system may be adopted in water scarce areas thereby helping in achieving continuous irrigation purposes.

REFERENCES [1] Sperry et al., “Spring Filling of Xylem Vessels in Wild Grapevine,” Plant Physiol, Vol.83, 1987, pp .414-417. [2] Beuther et al., “Characterization of Absorbent Flow Rate in Towel and Tissue,”.Journal of Engineered Fibers and Fabrics, Vol.5, Issue 2, 2010, pp. 1-7. [3] Githinji et al., “Physical and hydraulic properties of inorganic amendments and.modeling their effects on water movement in sand-based root zones,” Irrig Sci, Vol.29, 2010, pp. 65-77. [4] Zhong Feng et al., “Experimental Study on effects of magnetization on surface.tension of water”, Procedia Engineering, Vol.26, 2011, pp. 501–505. [5] Ityel et al., “An artificial capillary barrier to improve root-zone conditions for .horticultural crops: response of pepper, lettuce, melon, and tomato,” Irrig Sci, ..Vol.30, 2012, pp.293–301.

Analysis of Evaporative Cooler and Tube in Tube Heat Exchanger in Intercooling of Gas Turbine Bibin Varkey, G Rahul Krishna, Akhil George Kurian, Adharsh S, Aswin Zachariah

Abstract: In this project a study is conducted by using an evaporative cooler and a tube in tube heat exchanger for intercooling. In an evaporative cooler the water absorbs heat from the stream of the flowing air in order to change its phase and then evaporate, thus providing a net cooling effect to the incoming stream of compressed air. A typical tube in tube heat exchanger may be used to reduce the temperature of the flowing stream of gases. In our study we calculated the reduction in work done by the compressor for a particular flow rate of air through the system for both evaporative cooler and tube in tube heat exchanger. Calculations were made for different flow rates of cooling water and corresponding graphs were plotted.

I. INTRODUCTION A major portion of the power developed by the gas turbine is utilized by the compressor. It can be reduced by compressing air in two stages with an intercooler between the two. First of all the air is compressed in a low pressure compressor as a result the pressure and temperature of air is increased. Now the air is passed through an intercooler which reduces the temperature of the compressed air to its original temperature, but keeping the pressure constant. After that the compressed air is once again compressed in the high pressure compressor. Now the compressed air is passed through the heating chamber and then through the turbine. In this project we are going to analyses the evaporative cooler and counter flow tube in tube heat exchanger as an intercooler. Evaporative coolers are used with gas turbines to increase the density of the combustion air, thereby increasing power output. The air density increase is accomplished by evaporating water into the inlet air, which decreases its temperature and correspondingly increases its density. The water vapor passes through the turbine, causing a negligible increase in fuel consumption. In an evaporative cooler, cold water is sprayed to the incoming hot gases. The water absorbs some of the heat from the stream of the flowing gases in o rder to change its phase and then evaporate, thus providing a net cooling effect to the incoming stream of gases. It is very important to understand the velocity at which water is sprayed to the flowing gases. Knowing the velocity at which one gets the minimum air temp at outlet one can design the equipment by calculating the water mass flow rate. A heat exchanger is a piece of equipment built for efficient heat transfer from one medium to another.

A typical tube in tube counter flow heat exchanger is used to reduce the temperature of air stream from low pressure compressor. Water may be flown in the outer tube and air stream in the inner tube would lead the air to get cooled and a net increase in the density of air entering the high pressure compressor. Air Outlet Backflow Temperature Gauge Pressure Percentage of Water

Pressure outlet 581 K 0 Pa 100%

The main objective is to investigate the process of intercooling using evaporative cooler and tube in tube heat exchanger in gas turbines. The objectives involve to design an evaporative cooler and tube in tube counter flow heat exchanger for intercooling and to find the outlet temperatures. It also includes the work required for compression at various flow rates of cooling water. II. ANALYTICAL METHOD

First of all the atmospheric air enters the low pressure compressor at 300K (T1) and is compressed isentropically. Assuming the compression ratio of the low pressure compressor as 10 the outlet temperature T 2 is found using the relation, (Equation 1) Now using the outlet temperature of the low pressure compressor the outlet temperature T 3 of the intercooler is found by the analysis of intercooler. The cooling occurs at constant pressure. Analysis is done for evaporative cooler and counter flow tube in tube heat exchanger using Ansys Fluent 14.Thus we obtained the outlet temperature of the intercoolers.

Using the outlet temperature of the intercooler the outlet temperature of the high pressure compressor T 4 is found using the relation. Boundary Condition Air inlet Velocity inlet Temperature 581 K Velocity 1m/s Percentage of 0% water

(Equation 2) Finally the work done by the compressor is calculated using the equation

IV. MODELING THE COUNTER FLOW TUBE IN TUBE HEAT EXCHANGER

(Equation 3) III. MODELLING THE EVAPORATIVE COOLER

The counter flow tube in tube heat exchanger was modeled using the CAD software. The dimensions of the equipment are, air Stream Diameter is 10cm, Air stream length is 20cm Water Velocity inlet inlet Temperat 300K urePercentag 0.01% e of water Velocity 15m/s,50m/s,70m/s,100m/s, 200m/s and 250m/s and Water Annulus diameter is 12cm.

150m/s,

Fig. 2: Solid works model of evaporative cooler

The Evaporative cooler was modeled using the CAD software. The diameter of the air passage and water spray inlet are 10cm and 1 mm respectively, length of the air passage is 20 cm. The model was imported to the Design Modeler module of Ansys Fluent. The fluid and solid domains were defined and the named surfaces were created. Fig. 3: Solid Works model of counter flow tube in tube heat exchanger

The model was opened in the Meshing module of Ansys and the model was meshed with default settings. The mesh obtained can be found out that the Model was meshed with hexahedral elements. This can be found from the fact that the shape of the mesh is triangular in shape. The concentration of smaller elements near the water inlet tubes tells that the program has identified the salient points and has made the necessary mesh correction. The mesh elements size is 37357m and nodes number is 193567. Fluent uses for CFD analysis. The defined material is a mixture of Water liquid and Air. The cell zone condition is then selected using this mixture.

As per the dimensions the model was created. The model was imported to the Design Modeler module of Ansys Fluent. The fluid and solid domains were defined and the named surfaces were created. The model was opened in the Meshing module of Ansys and meshed with default settings. The mesh obtained tetrahedral elements. This can be found from the fact that the shape of the mesh is rectangular in shape. The concentration of smaller elements near the water inlet tubes conveys the salient points are identified and has made the necessary mesh correction, the obtained number of mesh elements is 2976 and number of nodes is 2563. We read the previously created mesh file in Fluent. We define the material as a mixture of liquid water and air. The cell zone condition is then selected using this mixture. The inner tube is set as air and the outer tube is set as water. The boundary condition we set has been tabulated below.

Table-2: boundary condition of evaporative cooler Water inlet Temperature Percentage of water

Velocity inlet 300K 0.01%

V. RESULT The analysis of both evaporative cooler and counter flow tube in tube heat exchanger, were done on Ansys Fluent. The temperature contour for various flow rate of water was obtained from the analysis. Using this the work done by the compressor was calculated for both evaporative cooler and counter flow tube in tube heat exchanger. The results obtained are mentioned below for both the case.

Fig. 6: Temperature Contour for Water Velocity 250m/S B. Tabulated Results of Evaporative Cooler Table-3: Results of evaporative cooler The table 3 where T1 is constant throughout the process of 300K and T2 is maintained at temperature of 581K,the table comprises of the temperatures at inlet and outlet of low

A. Results of Evaporative Cooler: The temperature contours are taken in the CFD Post to get the outlet temperature of the evaporative cooler. The mass flow rate of air stream is kept constant and different

Water velocity m/s

Air Outlet Backflow Temperature Gauge Pressure Percentage of Water

Pressure outlet 581 K 0 pa 100% temperature contours are obtained by varying the inlet velocities of the cooling water in evaporative cooler. The inlet velocities of cooling water for which the temperature contours were obtained are 15m/s, 50m/s, 70m/s, 100m/s, 150m/s, 200m/s and 250m/s

đ?&#x2018;&#x2021;3

đ?&#x2018;&#x2021;4

Work done (KJ)

(K)

0 15 50 70 100 150 200

581 533 514 511 499 491 481

1365.35 1252.55 1207.9 1200.85 1172.65 1153.85 1130.35

1069.61 1004.55 978.79 974.73 958.47 947.62 934.07

250

469

1102.15

917.81

pressure and high pressure compressors with variation of velocity at cooling water inlet. Table also shows work required by the compressor while using the evaporative ecooler at different velocities of cooling water. C. Performance Curves for Evaporative Cooler:

Fig. 4: Temperature Contour for Water Velocity 15m/s

Fig. 7: Outlet Temperature of Evaporative Cooler Vs Velocity of Water Figure 7 shows the variation of temperature at evaporative cooler outlet with variation in cooling water inlet velocity. The

Fig. 5: Temperature Contour for Water Velocity 50m/S

graph shows that the evaporative cooler outlet temperature decreases with increase in cooling water inlet velocity.

Fig. 10: Temperature Contour for Water Velocity 0.1m/S Fig. 8: Work Done Vs Velocity of Water Figure 8 shows the variation of work done by the compressor with variation in cooling water inlet velocity in case of the evaporative cooler. From the graph it can be inferred that work done by the compressor reduces with increase in cooling water inlet velocity D. Results of Counter Flow Tube in Tube Heat Exchanger: The temperature contours are taken in the CFD Post to get the outlet temperature of the tube in tube counter flow heat exchanger. The mass flow rate of air stream is kept constant and different temperature contours are obtained by varying the inlet velocities of the cooling water in the outer tube. The inlet velocities of cooling water for which the temperature contours were obtained are 0.01m/s, 0.1m/s, 0.5m/s, 1m/s, 10m/s, 15m/s, 20m/s, 25m/s and 150m/s.

Fig. 11: Temperature Contour for Water Velocity 150m/S E. Tabulated Results of Counter Flow Tube in Tube Heat Exchanger:

Fig. 9: Temperature Contour for Water Velocity 0.01m/S

Table-4: results of counter flow tube in tube heat exchanger Water velocity

đ?&#x2018;&#x2021;3

đ?&#x2018;&#x2021;4

(K)

m/s

Work

done

(KJ)

150

453.8

1066.43

897.20452

453.8

1066.43

897.20452

452.5

1063.375

895.4425

446.1

1048.335

886.76794

439

1031.65

877.1446

434.5

1021.075

871.0453

0.5

434.2

1020.37

870.63868

0.1

433.7

1019.195

869.96098

0.01

433.7

1019.195

869.96098

Fig. 13: Work Done Vs Velocity of Water Figure 13 shows the variation of work done by the compressor with variation in cooling water inlet velocity in case of the tube in tube counter flow heat exchanger. From the graph it can is clear that work done by the compressor increases with increase in cooling water inlet velocity. VI. CONCLUSION A major portion of the power developed by the gas turbine is utilized by the compressor. It can be reduced by compressing air in two stages with an intercooler between the two compressors. This method has been proved to increase the efficiency the entire gas power cycle. Evaporative cooler and tube in tube heat exchanger is analyzed in the project. Calculations and results show that the use of an intercooler to the power circuit decreases the work required for compression in power generation process. Calculations were made for different flow rates of the cooling water keeping the mass flow rate of air stream constant. It was seen from the graph that the work required for compression decreases with increase in mass flow rate in the evaporative cooler whereas work required for compression decreases with increase in mass flow rate in case of tube in tube heat exchanger.

The table 4,in which T1 is same through out of 300K, and T2 follows a constant temperature of 581K, the gives the temperatures at inlet and outlet of low pressure and high pressure compressors with variation of velocity at cooling water inlet. Table also shows work required by the compressor while using a tube in tube counter flow heat exchanger at different velocities of cooling water.

F. Performance Curves for Counter Flow Tube in Tube Heat Exchanger:

VII. ACKNOWLEDGMENT The authors would like to acknowledge the support of Mechanical Engineering Department of Saintgits College of Engineering for conducting the present investigation. VIII. REFERENCE [1] Ali Marzouk, Abdalla Hanafi, G. F., and Klein, S. A., â&#x20AC;&#x153;Thermo Economic Analysis of Inlet Air Cooling In Gas Turbine Plantsâ&#x20AC;?,Journal of Power Technologies, Vol. 93(2), pp. 90â&#x20AC;&#x201C;99, 2013.

Fig. 12: Outlet Temperature of Evaporative Cooler Vs Velocity of Water

[2] R S Johnson, â&#x20AC;&#x153;The Theory and Operation of Evaporative Coolers for Industrial Gas Turbine Installationsâ&#x20AC;?, Journal of Heat Transfer, Vol. 1, pp.1â&#x20AC;&#x201C;9, 1988

Figure 12 shows the variation of temperature at the outlet of tube in tube counter flow heat exchanger with variation in cooling water inlet velocity. The graph shows that the evaporative cooler outlet temperature decreases with increase in cooling water inlet velocity.

. [3] Gregory F Nellis, John M, â&#x20AC;&#x153;Effectiveness NTU Relation for a Counter Flow Heat Exchanger subjected to an external heat transferâ&#x20AC;?, Journal of HeatTransfer, Vol. 127, 2005.

CFD Analysis of a 24 Hour Operating Solar Refrigeration Absorption Technology Arunkumar. H, Benson P Sunny, Arun George, Jesbin Antony

Abstract: A computational fluid dynamics (CFD) model is used to investigate outlet temperatures in heat exchanger within generator by varying fluid velocities and also used to investigate outlet temperature in evaporator and heat flux rate at walls of evaporator. The solar refrigeration absorption system taken for analysis is a continuously operating refrigerant storage system. R- 717(Ammonia) is used as refrigerant. Aquaammonia vapor absorption refrigeration systems, which operate such that both, the generation of aqua ammonia vapors and the production of cold utilizing the generated aqua-ammonia vapors, take place at the same time are known as continuousbased operation systems. Model is completed using Solid works. Analysis is carried out in ANSYS 14. FLUENT is the software used to simulate fluid flow problems. It is generally used for computational Fluid Dynamics problems. It uses the finite-volume method to solve the governing equation for a fluid. It provides a wide field to solve problems. Numerical computations have been carried out to find coefficient of performance (COP). Variation of temperature at outlet of heat exchanger and evaporator are studied. Difference in maximum and minimum temperature at outlet of heat exchanger and evaporator at different fluid velocities are noted. The obtained profiles indicate variation in temperature of fluid. Graphs showing variation of COP with varying evaporator and generator temperatures are plotted. Air taken from outlet of evaporator via blower is used for refrigeration.

refrigeration system in two ways. First, solar energy can be converted into electricity using photovoltaic cells and is used to operate a conventional vapor compression refrigeration system. Second, solar energy can be used to heat the working fluid in the generator of vapor absorption system. The comparison showed that solar electric refrigeration systems using photovoltaic appear to be more expensive than solar thermal systems. Solar energy has a great potential renewable content that can be effectively utilized for refrigeration and air conditioning purposes using aqua ammonia vapor absorption system. However, the biggest challenge in utilizing solar energy, for uninterrupted cooling is its unavailability during the night time.

The available technology for the utilization of solar energy in refrigeration and air conditioning purposes are continuous operating systems and intermittent operating systems. Aqua-ammonia vapor absorption refrigeration systems, which operate such that both, the generation of aqua-ammonia vapors and the production of cold utilizing the generated aqua-ammonia vapors, take place at the same time are known as continuous-based operation systems. The advantage of the continuous operating systems are that such systems have comparatively high COP and present a compact design. But intermittent systems have comparatively very low COP, possess a huge system size [1]. So we use a continuous operating system for our study.

Keywords: Coefficient of Performance; Computational Fluid Dynamics

I. INTRODUCTION

The excessive demand for air conditioning is as a result of extreme temperatures during summer. Thus, it is imperative to use refrigeration and air conditioning in all fields of life. By this 24 hour operation solar refrigeration absorption system, the electrical energy which is a high grade source can be saved from its use in comfort sector and being utilized in production sector. Some liquids like water have great affinity for absorbing large quantities of certain vapors (NH3) and reduce the total volume greatly. The absorption refrigeration system differs fundamentally from vapor compression system only in the method of compressing the refrigerant. An absorber, generator and pump in the absorption refrigerating system replace the compressor of a vapor compression system.

In this paper, design and CFD analysis of heat exchanger within generator and evaporator within the continuous based refrigerant storage system is done. Design of heat exchanger within generator and evaporator is done using SOLID WORKS 2013. ANSYS FLUENT 14 is the software used to simulate fluid flow problems. For all flows, ANSYS FLUENT solves conservation equations for mass and momentum. For flows involving heat transfer and compressibility, an additional equation for energy conservation is solved.

II. RESEARCH METHODOLOGY

Out of the various renewable sources of energy, solar energy proves to be the best candidate for refrigeration and air conditioning because of the coincidence of the maximum cooling load with the period of greatest solar radiation input. Solar energy can be used to power a

The solar refrigeration absorption system taken for analysis is a continuously operating refrigerant storage system. R-717 (Ammonia) is used as refrigerant. Aquaammonia vapor absorption refrigeration systems, which

operate such that both, the generation of aqua ammonia vapors and the production of cold utilizing the generated aqua–ammonia vapors, take place at the same time are known as continuous-based operation systems. In this paper , we are considering design and analysis of heat exchanger with in the generator and evaporator within the solar refrigeration absorption system. Heat exchanger with in generator and evaporator are considered for design and analysis since these 2 parts play the most important role in deciding the performance of the solar refrigeration absorption system. Fig. 1: Continuously operated refrigerant storage solar–powered aqua– ammonia vapor absorption refrigeration system.

Model of heat exchanger within generator and evaporator is done in Solid Works (2013). Solid Works is a solid modeler, and utilizes a parametric feature–based approach to create models and assemblies. Solid Works files use the Microsoft structured storage file format. Analysis is carried out in ANSYS FLUENT 14. FLUENT is the software used to simulate fluid flow problems. It uses the finite – volume method to solve the governing equation for a fluid. For all flows, ANSYS FLUENT solves conservation equations for mass and momentum. For flows involving heat transfer and compressibility, an additional equation for energy conservation is solved. These are governing equations of ANSYS FLUENT and it is shown below.

A. Modelling: 1) Heat Exchanger With in Generator: In heat exchanger within generator, brine in the inner tube is used to heat the aqua-ammonia refrigerant passing through the outer tube. The modeling of heat exchanger with in generator is done in Solid Works. It is done with the following specifications:Table -1: Modeling specifications used in case of heat exchanger.

1) Navier Stokes Equation

2) Continuity equation

Fig. 2: Heat exchanger design using SOLID WORKS

3) Energy equation

Numerical computations have been carried out to find coefficient of performance (COP).

Sl. No.

Parameters

Specifications

Type of heat exchanger

Tube in tube

Type of flow

Counter flow

Inner tube diameter

25mm

Outer tube diameter

40mm

2) Evaporator:

Where, TE is the evaporator temperature in K. TG is the generator temperature in K. TC is the condenser temperature in K.

Aqua ammonia is used to cool the air in the evaporator and air taken from the outlet of evaporator via blower is used for refrigeration. The modeling of evaporator is done in Solid Works. It is done with the following specifications:-

between two subdomains, so that the approximate solutions inside various portions can be put together to give a complete picture of fluid flow in the entire domain. The subdomains are often called elements or cells, and the collection of all elements or cells is called a mesh or grid. The origin of the term mesh (or grid) goes back to early days of CFD when most analysis were 2D in nature. For 2D analyses, a domain split into elements resembles a wire mesh, hence the name.

Table -2: Modeling specifications used in case of evaporator Sl. No. 1 2 3 4

Parameters Inner pipe diameter Wall length Wall breadth Wall depth

Specifications 30mm 75cm 65cm 10cm

a) Heat Exchanger within Generator: Meshing of heat exchanger is done in CFD with the following specifications as given below:Table -3: Meshing Specifications of Heat exchanger Sl. No 1 2 3

Nodes Elements Type of mesher

Specifications 201683 171190. Triangular surface mesher.

Fig. 3: Model of evaporator designed using SOLID WORKS.

A. Analysis: The analysis is done in ANSYS FLUENT 14. The first step of analysis involves insertion of an external geometry file of model which is modeledin Solid Works in IGES format. Second step is to give naming for each part and also represent whether part is a solid or fluid. Third step is the meshing of model. Meshing is done with appropriate mesher and sizing. Fourth step is to select material and activate the energy equation in addition to the default continuity and navier stokes equations. Fifth step is to apply suitable cell zone and boundary conditions. Next step is to intialize hybrid initialisation and final run calculation is done with appropriate number of iteration until convergence tolerance is obtained.

Fig. 4: Meshing of heat exchanger within generator in CFD.

The meshing of heat exchanger within generator in CFD is as shown in the figure 4.4. Coarse meshing is done in model within 201683 nodes and 171190 elements using a triangular surface mesher i.e tetrahedron meshing.

b) Evaporator:

1) Meshing:

Meshing of Evaporator is done in CFD with the following specifications as given below:-

Table -3: Meshing Specifications of Evaporator Sl. No 1 2 3

Specifications Nodes Elements Type of mesher

46496. 38285. Triangular surface mesher.

III. RESULTS AND DISCUSSIONS

A. Heat Exchanger within Generator:

Fig. 5: Meshing of evaporator in CFD.

The meshing of evaporator in CFD is as shown in the figure 5. Coarse meshing is done in model within 46496 nodes and 38285 elements using a triangular surface mesher i.e tetrahedron meshing.

2) Cell Zone and Boundary Conditions:

Fig. 6: Temperature distribution of outlet aqua ammonia at fluid velocity of 0.4 m/s

For The figure 6 shows the temperature distribution at outlet of aqua ammonia of the heat exchanger within generator. From the figure, it is very clear that aqua ammonia gets heated up using the heat obtained from the brine which is passing through the inner tube of the counter flow heat exchanger. In this case brine has a velocity of 0.4 m/s.

The cell zone conditions involves the selection of the refrigerant or fluid needed from Fluent database. The boundary conditions includes the input parameters like velocity (in m/s) and temperature (in K) at inlet.

a) Heat exchanger with generator: Applying cell zone and boundary condition as follows:BRINE:  VELOCITY (IN M/S) = 0.4, 0.5, 0.6.

SL . no .

Inlet temperature = 360K. AQUA-AMMONIA: VELOCITY (IN M/S) = 0.4.

Fluid velo city (m/s)

Maximum Minimum temperature temperature (K) (K)

Differenc e in temperat ure

Inlet temperature = 300K.

Solution using CFD Type of initialization – Hybrid

0.4

330.27

317.59

12.679

0.5

326.187

315.61

10.576

0.6

327.344

315.47

11.87

b) Evaporator: Applying cell zone and boundary condition as follows:Air :-

Velocity (in m/s) = 1 INLET TEMPERATURE = 300K.

Aqua-ammonia:-

Velocity (in m/s) = 0.4. Inlet temperature = 268K Fig. 7: Temperature distribution of outlet aqua ammonia at fluid velocity of 0.5 m/s.

Solution using CFD Type of initialization – Hybrid

The figure 7 shows the temperature distribution at outlet of aqua ammonia of the heat exchanger within generator. From the figure, it is very clear that aqua ammonia gets heated up using the heat obtained from the brine which is passing through the inner tube of the counter flow heat exchanger. In this case brine has a velocity of 0.5 m/s. The minimum temperature of 315.611 K and maximum temperature of 326.187 K is observed at the outlet of aqua ammonia at brine velocity of 0.5 m/s.

Fig. 9: Temperature distribution at fluid velocity of 0.4 m/s.

The figure 9 shows the temperature distribution of the heat exchanger within generator. From the figure, it is very clear that aqua ammonia gets heated up using the heat obtained from the brine which is passing through the inner tube of the counter flow heat exchanger. The heat transfer between aqua ammonia is very clear from the above figure. In this case brine has a velocity of m/s. The minimum temperature of 299.84 K and maximum temperature of 370.007 K is observed at the outlet of aqua ammonia at brine velocity of 0.4 m/s.

Fig. 8: Temperature distribution of outlet aqua ammonia at fluid velocity of 0.6 m/s.

The figure 8 shows the temperature distribution at outlet of aqua ammonia of the heat exchanger within generator. From the figure, it is very clear that aqua ammonia gets heated up using the heat obtained from the brine which is passing through the inner tube of the counter flow heat exchanger. In this case brine has a velocity of 0.6 m/s. The minimum temperature of 315.474 K and maximum temperature of 327.344 K is observed at the outlet of aqua ammonia at brine velocity of 0.6 m/s. From figure 5, 6, 7, it was understood that as fluid velocity increases temperature difference that is difference in maximum and minimum temperature first increases and then decreases. Difference in temperature is found to be 12.679 K, 10.576 K and 11.87 K at fluid velocities 0.4, 0.5 and 0.6 m/s respectively. It was also observed that highest outlet temperature of ammonia is obtained in case of fluid velocity = 0.4m/s and value is330.27 K. From all the above information, it was observed that maximum heat transfer occurs in case of lowest velocity due to higher temperature difference between maximum and minimum.

Fig. 10: Temperature distribution at fluid velocity of 0.5 m/s.

The figure 10 shows the temperature distribution of the heat exchanger within generator. From the figure, it is very clear that aqua-ammonia gets heated up using the heat obtained from the brine which is passing through the inner tube of the counter flow heat exchanger. The heat transfer between aqua ammonia is very clear from the above figure. In this case brine has a velocity of m/s. The minimum temperature of 299.856 K and maximum temperature of 360.007 K is observed at the outlet of aqua ammonia at brine velocity of 0.5 m/s.

The Temperature distributions at the surfaces of the heat exchanger within generator at different brine velocities are shown below:-

Fig. 12: Temperature variation at air outlet

Fig. 11: Temperature distribution at fluid velocity of 0.6 m/s

The figure 12 shows temperature variation at air outlet in an evaporator. From the figure, it is very clear that air gets cooled using aqua ammonia within the evaporator and the maximum temperature is found to be 311.5 K and minimum temperature is found to be 268 K.

The figure 11 shows the temperature distribution of the heat exchanger within generator. From the figure, it is very clear that aqua ammonia gets heated up using the heat obtained from the brine which is passing through the inner tube of the counter flow heat exchanger. The heat transfer between aqua ammonia is very clear from the above figure. In this case brine has a velocity of m/s. The minimum temperature of 299.843 K and maximum temperature of 370.009 K is observed at the outlet of aqua ammonia at brine velocity of 0.6 m/s.

From analysis we found that the temperature of air leaving the wall of evaporator is increased by 43.5 K. From this we can infer that a part of the heat of the inlet ammonia is given to the air by forced convection. Thus ammonia is cooled at the outlet of evaporator tube and thus sufficient cooling is produced. The temperature difference is found to be 43.5 K and thus refrigeration effect is obtained from cold outlet using a fan due to forced convection.

Table -5: Temperature distribution in heat exchanger surface at different velocities. SL Fluid velocity Maximum . (m/s) temperature no (K) .1 0.4 370.007 2 0.5 360.007 3 0.6 370.009

Minimum temperature (K) 299.84 299.856 299.845

Difference in temperature 70.167 60.151 70.166

Maximum Temperature is found to be 370.007, 360.07 and 370.009K at different fluid velocities 0.4, 0.5, 0.6 m/s respectively. Minimum Temperature is found to be 299.84, 299.856 and 299.843 K at different velocities. The difference in temperature is found to be decreases with fluid velocity and then decreases. Fig. 13: Total heat transfer in evaporator in watts.

b) Evaporator:

Figure 13 shows heat flux at walls in evaporator. The total heat transfer rate at walls is found to be 306.72 W. Thus refrigeration effect is produced and is taken from the cold outlet.

Table -7: Values of COP Vs Generator Temperature

c) Performance Curves: Table -6: Values of COP Vs Evaporator Temperatures

Evaporator Temperatures (K)

COP

268

0.15

2 3 4

272.3 276.7 281

0.172 0.195 0.223

285.4

0.26

6 7

289.7 294.1

0.31 0.38

8 9 10 11

298.4 302.8 307.1 311.5

0.485 0.67 1.05 2.403

Sl. No. 1

Sl. No. 1 2 3 4 5 6 7 8 9 10

Generator Temperatures (K) 317.5 318.1 320 321.3 322.6 323.8 325.1 326.3 327.5 328.8

COP 0.073 0.089 0.144 0.181 0.217 0.251 0.287 0.319 0.352 0.387

330.02

0.419

Figure 15 shows performance curves for varying generator temperatures and evaporator temperature of 284.2 K. The figure implies as generator temperatures increases, COP linearly increases due to higher heat transfer rate in heat exchanger within generator. IV. CONCLUSIONS Following conclusions are obtained are as follows: 1) Total heat transfer rate at walls of evaporator is found out and is found to be 306.72 W. This is due to large temperature difference of 43.5 K in Evaporator. 2) Outlet temperatures of aqua ammonia in heat exchanger within generator are found out at different velocities 0.4, 0.5 and 0.6 m/s respectively. As fluid velocity increases temperature difference that is difference in maximum and minimum temperature first increases and then decreases. Difference in temperature is found to be 12.679 K, 10.576 K and 11.87 K at fluid velocities 0.4, 0.5 and 0.6 m/s respectively.

Fig. 14: Performance curves for varying evaporator temperatures.

Figure 14 shows performance curves for varying evaporator temperatures and generator temperature of 323.8 K. The figure implies as evaporator temperatures slightly increases and then increases to maximum, due to low heat transfer rate within evaporator.

It was also observed that highest outlet temperature of ammonia is obtained in case of fluid velocity=0.4m/s and value is 330.27 K. From all the above information, it was observed that maximum heat transfer occurs in case of lowest velocity due to higher temperature difference between maximum and minimum. 3) Performance curves against varying generator temperatures and varying evaporator temperatures are plotted. COP increases linearly with varying generator temperature because of higher heat transfer rate between brine and aqua ammonia within heat exchanger tubes. COP remains constant up to 300K and then increases with varying evaporator temperature because of lower heat

Fig. 15: Performance curve for varying Generator temperatures.

transfer rate in evaporator compared to heat exchanger within generator.

ACKNOWLEDGMENT The authors would like to acknowledge the support of Mechanical Engineering Department of Saintgits College of Engineering for conducting the present investigation.

REFERENCES [1] Said A. M., Maged AI EI-Shaarawi, Muhammad Siddique U., (2012)., “Alternative designs for a 24-h operating solar-powered absorption refrigeration technology”, International journal of refrigeration, Vol. 35. pp. 1967-1977. [2] Cerezo. J, Bourouis . M, Manel . V, Alberto . C, Roberto . B, (2009)., “Experimental study of an ammonia water bubble absorber using a plate heat exchanger for absorption refrigeration machines”, Appl. Therm. Eng, Vol. 29. pp. 1005-1011. [3] De Francisco, Illanes . A., Tones . R., Castillo .J.L.M., De Bias, Prieto . E., Garcia . A., (2002)., “Development and testing of a prototype of low power water-ammonia absorption equipment for solar energy applications”, Renewable Energy, Vol. 25, pp. 537-544. [4] Sumayths . K, Huang, Z.C. Li, (2002)., “Solar absorption cooling with low grade heat source – a strategy of development in south china”, Solar energy, Vol. 72(2), pp. 155-165.

Experimental Investigation of Performance and Emission Characteristics of Hybrid Fuel Engine Nirmal Chandran, Blessen Sam Edison, Christy Binu, Godwin Geo Sabu, Jobin K Abey

Abstract: Together with the growing economy in different parts of the world, there is an increasing demand for energy, thus relying on fossil fuels. As there are problems arising due to global warming and environmental degradation related with usage of fossil fuels, demand for alternative fuels is always high. Hydrogen being a green additive fuel is a potential renewable fuel for internal combustion engines, gas turbines, fuel cells etc. It has the advantage of ultra-low pollutions and high efficiency for these applications. The project consist of an on board hydrogen unit along with 4-stroke air cooled engine. The hydrogen produced in the unit was naturally aspirated to a petrol engine through intake of carburettor to substitute the total fuel energy at four engine loads at the engine speed of 750 rpm. The engine performance characteristics and emissions were experimentally investigated and various graphs were plotted to study the effects of these factors at four engine loads. The results obtained showed that the engine with addition of hydrogen had an efficiency of 21.3%. The combined effect of water injection decreased the former efficiency by 4.3%. The net efficiency of the entire setup including hydrogen and water injection was 17%.

As hydrogen can be used as a viable additive for green fuel, the next issue was to find a satisfactory method for the effective and safe administration of hydrogen into the engine. The handling of hydrogen poses a safety issue as it is highly inflammable. The introduction of hydrogen into the petrol engine can be done either by using a separate hydrogen cylinder or by setting an on- board water electrolysis unit. The use of hydrogen cylinder would ensure a continuous flow rate of hydrogen. But the replacement and the added weight of the hydrogen cylinders are the main troubles. Method of hydrogen on-board hydrolysis unit handles the safety issue of hydrogen storage by the production of hydrogen only when required. In either method, hydrogen is mixed with the fuel by the simplest method of external mixing process, where the hydrogen is mixed with air in the inlet manifold of the carburetor and the mixture is drawn into the inlet port. The mixing of hydroxygen or hydrogen in the carburetor poses a problem of back-firing due to the lower ignition energy of hydrogen. On considering the impact on the environment, hydrogen as alternative fuel eliminates the emission of Sulphur Oxides (SOx), Oxides of Carbon (CO and CO2), Unburned Hydrocarbons (UHC) and soot. But there would be an increase in Oxides of Nitrogen (NOx) due to the higher in-cylinder temperatures by hydrogen. Supplying hydrogen leads to higher local temperature resulting in higher NOx formation rate. The main techniques to control NOx emissions are water injection, addition of diluents, turbocharging with intercooling, etc. Also hydrogen causes another problem of hydrogen knocking which induces large magnitude of mechanical stress on the cylinder walls. Water injection technique used here is a solution for hydrogen knocking also. But pure water cannot be injected into the engine as it may lead to corrosion and mixing with the lubricating oil. In this study, the use of hydroxygen as a fuel additive was used along with water injection in a petrol engine. An onboard water electrolysis unit is incorporated to avoid the problem of hydrogen storage. A water injector was fitted near the inlet manifold to control the temperature rise due to hydrogen combustion and control NOx emissions. The load test was performed at a constant speed of 750rpm using a brake dynamometer. Similarly by keeping the speed constant the emissions were analyzed to check the effect of water injection. The graphs for the performance and emissions characteristics were plotted.

Keywords: Hydrogen, Performance, Emission, Efficiency

I. INTRODUCTION In the present scenario, renewable energy is a field where a lot of studies and researches are being conducted. The main objectives are to find a commercially viable alternative fuel which has reduced emissions. The emissions norms are becoming more stringent as the pollution levels are way above the acceptable limits. The proposed alternatives are ethane, methane, biodiesel and hydrogen. Of this hydrogen has been proved as to be a promising alternative to fossil fuel used in IC engines, mainly petrol engines. Hydrogen usage in diesel engines is not very common as the proper mixing is not available The properties of hydrogen in comparison to petrol, shown in Table 1, makes it a green additive fuel for IC engines. Table -1: Comparing Properties of Hydrogen and Petrol Properties Hydroge n Molecular Mass (g/mol) 2.016 3 Density (g/cm ) 83.764*1 0-6 Stoichiometric fuel to air 34.3 ratio(F/A) Minimum ignition energy 0.02 (mJ) Ignition temperature (K) 858 Lower heating value 120 (MJ/kg) Quenching gap (cm) 0.06

Petrol 107 0.70-0.75 14.6 0.24 530 44 0.2

II. EXPERIMENTAL ANALYSIS Table -2: Engine Specifications

A. Experimental Set Up:

Make and Hero Honda CD100 petrol engine General details Four stroke Air Cooled spark model No of cylinders Single ignitioncylinder engine Bore 50mm Stroke 49.5mm Maximum 7.5bhp @ 8000rpm power Maximum 0.73 @ 5000rpm torque Swept volume 99cc

In this research a single cylinder, four stroke, air cooled spark ignition engine is used which is connected to a brake drum for mechanical loading (figure 1). The detailed specifications of the engine used are given in table 2. A slight modification is made to the test engine by introducing a multi-point 4 nozzle water injector into the inlet manifold which is electromagnetic type. The energy released while burning hydrogen is more than that of petrol which results in increased cylinder temperature leading to increased NOx emission.

Load test were conducted for performance evaluation using a tachometer and burette. The CO, THC, NOx emission was measured by Horiba MEXA-7100DEGR. The test was conducted under constant speed of 750 rpm at different loads.

Fig. 1: Experimental Setup Fig. 2: Block Diagram of Experimental Setup

To limit this problem water injection is been provided which injects coolant at regular intervals (20seconds) using a controller. The injection fluid used in this experiment is lathe coolant rather than pure water. Other components include hydrogen unit, bubbler, diaphragm pump (12V, 20W) and a 555 timer (12V, 100W).

B. Experimental Method: The tests were conducted under a constant speed of 750 rpm at different loads. The engine was started for warm up using petrol for certain time. Load test and emission test were done for three test conditions.

Hydrogen unit consist of a tank with SS plates as electrode and a solution of NaOH in water. There is always a chance for back fire from engine if the unit is directly connected then this backfire could result in an explosion, to avoid such a problem bubbler is given and it also helps in identification of hydrogen formation through bubbles. Diaphragm pump is provided to pump the lathe coolant from coolant tank to the injector for water injection. Since the water injector used is an electronic device there is need for a controller to control the water injection timing and 555 timer serves this purpose.

Test condition 1 - When engine run with petrol. Test condition 2 - When engine run with petrol and hydroxygen mixture. Test condition 3 - When engine run with petrol and hydroxygen mixture along with water injector.

To For conducting load test, maximum load was first determined. The engine was started with no load condition. By keeping a constant speed of 750 rpm which is half speed at the top gear, the engine was loaded up to maximum load and time for 5ml fuel consumption (using a burette and stop watch) was noted in each load.

Hydroxygen was introduced through the carburetor where it adjusts the air fuel ratio, there by replacing some of the petrol by hydroxygen thereby reducing petrol consumption. Since there are chances of backfire from engine, bubbler is provided between the electrolysis unit and the hydrogen inlet at the carburetor, to avoid such a problem. For test 3 a water injector and 555 timer was used to provide water injection at an interval of 20 seconds. Hydroxygen flow rate was determined by measuring the time takes for 5ml drop of water in the electrolysis chamber by providing a level indicator.

pressure rise and drops which are observed in hydrogen enriched gasoline engines limits post combustion period resulting in reduced exhaust losses. Also, cooling loss of engine is reduced due to shortened combustion period. However; the cylinder temperature reduces with water injection as water vapour absorbs heat because heat capacity of water is high. For this reason, there is a slight decrease in thermal efficiency with water addition.

III. RESULT AND DISCUSSIONS

The Brake Specific Fuel Consumption for three different test conditions is plotted against the load and is given in the figure 4.

2) Brake Specific Fuel Consumption:

A. Performance Characteristics: 1) Brake Thermal Efficiency: The brake thermal efficiency for three cases, i.e. pure gasoline, gasoline & hydroxygen addition, and, gasoline & hydroxygen along with water injection are plotted against the load for comparison and is given in the figure 3. It was observed that brake thermal efficiency increases with load. From the graph it was observed that brake thermal efficiency values increases with load for hydroxygen addition but was decreased with water injection still it was higher than pure gasoline. The maximum brake thermal efficiency was observed at maximum load at 750 rpm.

Fig. 4: Brake Specific Fuel consumption

From the graph its was observed Brake Specific Fuel Consumption values decreases along with load for hydroxygen addition but was increased with water injection still it was lower than pure gasoline. The reason for rapid increase in brake specific fuel consumption with reduction in throttle opening is that frictional power remains essentially constant while the indicated power is being reduced, the brake power drops more rapidly than fuel consumption and thereby the brake specific fuel consumption rises.

3) Total Fuel Consumption: Fig. 3: Variation of Brake Thermal Efficiency with Load

The total fuel Consumption for three different test conditions are plotted against the load and is give in the figure 5.Total fuel consumption is simply defined as the amount of amount of fuel consumed in one hour. It is obvious that the Total fuel consumption will increases with load.

The flame temperature of hydrogen is about 5 times the flame temperature of gasoline and higher burning speed improves thermal efficiency. Also, hydrogen has a wider flammability limits than gasoline. Due to these reasons, hydrogen enriched gasoline mixture fuel will achieve shorter burning continuance and more complete combustion can be observed compared to pure gasoline.

From the graph its was observed total fuel Consumption values increases along with load for hydroxygen addition but was decreased with water injection. Still it was higher than pure gasoline. The total fuel consumption was found to decrease in the case of adding hydrogen as it is substituted in the total fuel energy and thus reducing the amount of petrol needed for combustion. With the water injection added to the above case causes the total fuel consumption to increase slightly because the net fuel energy needed for combustion was increased due to presence of water in the air fuel mixture.

Thus, combustion at constant volume can happen which means the SI engine resembles to a ideal cycle due faster burning speed of hydrogen-gasoline blends. On the other hand there is rise in cylinder temperature and pressure with hydrogen addition. However, these instantaneous

Incomplete combustion of fossil fuel creates hydrocarbon emission. The unburnt hydrocarbon in the tail pipe gas is called Total HydroCarbon (THC). Figure 7 shows the variation in total hydrocarbon emission with varying load under constant speed of 750 rpm under the different test conditions. The different test conditions were one with hydroxygen addition and other with hydroxygen and water injection compared with pure petrol condition.

Fig. 5: Variation of Total Fuel Consumption with Load B.

Emission Characteristics:

CO Emission:

Carbon monoxide is a colourless, odourless, toxic gas which is formed by incomplete combustion of carbon materials which otherwise would be converted into carbon dioxide on full oxidation. If the amount of oxygen is increased, carbon dioxide will be formed. Figure 6 shows the variation in carbon monoxide emission with varying load under constant speed of 750 rpm under the different test conditions. The different test conditions were one with hydroxygen addition and other with hydroxygen and water injection compared with pure petrol condition.

Fig. 7: Variation of Total Hydrocarbon Emission with Load

From the graph it can be inferred that the total hydrocarbon emissions were decreased at all engine loads. Decrease in Total hydrocarbon emissions were more when hydroxygen addition was employed than with hydroxygen and water injection. The amount of hydrocarbon portion in the total fuel is reduced with hydroxygen addition which causes it to reduce the total hydrocarbon emission and the higher flame speed of hydrogen and the involvement of OH radical reduces the amount of unburnt hydrocarbon. Quenching distance of hydrogen is less than petrol and thus the flame can travel close to cylinder wall and thus the amount of unburnt hydrocarbon is reduced. With water injection, the precombustion temperature decreases and thus reduces the cylinder temperature which in turn reduces the combustion efficiency and thus causes an small increase in total hydrocarbon emission from the case with only hydroxygen addition.

Fig. 6: Variation of Carbon Monoxide Emission with Load

From the graph it can be inferred that the CO emissions were decreased at all engine loads. Decrease in CO emissions was more when hydroxygen addition was employed than with hydroxygen and water injection. Hydrogen is a carbon free compound and thus when it is mixed with gasoline, the amount of carbon in fuel reduces and thus CO emissions were decreased. The high flame speed, higher diffusion rate and larger flammability of hydrogen than petrol results in increase in combustion efficiency and due to high cylinder temperature, the oxidation reaction improves and thus efficient conversion of CO to CO2 but on water injection causes reduction in cylinder temperature and thus oxidation reaction efficiency reduces. 2)

NOx Emission:

NO and NO2 together constitutes the NOx emissions and the NOx emission are formed due to the oxidation of atmospheric nitrogen. When nitrogen gas combined with oxygen at high temperature, NOX emissions are formed. ). Figure 8 shows the variation in NOx emission with varying load under constant speed of 750 rpm under the different test conditions. The different test conditions were one with hydroxygen addition and other with hydroxygen and water injection compared with pure petrol condition. From the graph it can be inferred that the NOx emission drastic increases with hydroxygen addition due to increase in cylinder temperature. The increase in cylinder temperature is due to high calorific value of hydrogen than petrol and also due to high flame speed of hydrogen .With the water

THC Emission:

injection the NOx emission is decreased from the former case. Due to high heat capacity value of water and high absorption of heat by water, the NOx emission reduces from the condition of combusting hydrogen only.

Fig. 8: Variation of NOx Emission with Load

emission was increased from the former case by 25.41% and thus the net reduction in THC emission was 32.02% on an average of four loads. With hydroxygen addition, CO emission were reduced by 43.32% and with the combined effect of hydroxygen addition and water injection, CO emission was increased from the former case by 11.45% and thus the net reduction in CO emission was 31.86% on an average of four loads. With hydroxygen addition, NOx emission were increased by 129.87% and with the combined effect of hydroxygen addition and water injection, NOx emission was decreased from the former case by 36.86% and thus the net reduction in NOx emission was 93.06% from that with hydroxygen addition only on an average of four loads.

IV. CONCLUSION The aim of doing this project is to develop an engine that works on a mixture of hydroxygen and petrol with less modification done to the engine. The engine was tested under different load conditions at a speed of 750 rpm. The hydroxygen for the process was developed on board and the mixture of fuel was given to the engine and performance and emission tests were conducted. It was found that with hydroxygen addition the efficiency of the engine was increased and the emissions and fuel consumptions were reduced .Water Injection was given to the engine to reduce the NOx emission. We can conclude as follows: -

ACKNOWLEDGMENT The authors would like to acknowledge the support of Mechanical Engineering Department of Saintgits College of Engineering for conducting the present investigation.

REFERENCES [1] Y. Karagoz , L. Yuksek , T. Sandalcı , A.S. Dalkılıc¸ “An experimental investigation on the performance characteristics of a hydroxygen enriched gasoline engine with water injection”, International journal of hydrogen energy Vol.40 , 2014, pp.692-702.[1]

Hydroxygen was produced by advanced electrolysis process using tri-ethylamine as the catalyst and the generation was done on-board and thus eliminating the need for storage. The advanced electrolysis method has increased the rate of hydroxygen by 38.368% than conventional electrolysis process. With the addition of hydroxygen, there was increase in brake thermal efficiency by 13.8% and decrease in fuel consumption by 11% , on an average of the four loads. The combined effect of hydroxygen addition and water injection, brake thermal efficiency was further decreased by 3.23% from the former case and the fuel consumption was increased by 3.89% on an average of the four loads. The net increase in brake thermal efficiency when the above two cases were increased by 10.62% and the net fuel consumption was decreased by 17.11% on an average of the four loads and thus with addition of hydroxygen and water injection causes an increase in brake thermal efficiency with reduction in fuel consumption. With hydroxygen addition, THC emission were reduced by 57.43% and with the combined effect of hydroxygen addition and water injection, THC

[2] T. D Andreaa, P.F. Henshawa, D.S.K. Tingb, “The addition of hydrogen to a gasoline-fuelled SI engine” , International Journal of Hydrogen Energy, Vol .29 , 2004, pp. 1541 – 1552.[2] [3] Romdhane Ben Slama , “ Production of Hydrogen by Electrolysis of Water: Effects of the Electrolyte Type on the Electrolysis Performances”, Computational Water, Energy, and Environmental Engineering, Vol.2, 2013, pp.54-58.[3] [4] M. L. Mathur, R. P. Sharma, “Internal Combustion Engine”, Dhanpat Rai Publications, Edition 2009

Six Stroke Engine Aarush Joseph Sony, Carol Abraham, Boney Mammen Ajith P Kurian, Prof. Sajan Thomas Abstract: The six-stroke engine is a type of internal combustion engine based on the four-stroke engine, but with additional two stroke intended to make it more efficient and reduce emissions. It uses fresh air for the second suction i.e. in the fifth stroke. It has a wide range of uses in Automobiles, heavy goods, construction-site and farm vehicles, Motor boats, motor-pumps, generator sets, stationary engines, etc. intended for agriculture and industry. Here we introducing a new and simplest method which is capable for mass producing these engines. This is done by altering an ordinary 4 valve 4 stroke petrol engine. The working of our engine is as follows: - 1st: suction stroke, 2nd: compression stroke, 3rd: power stroke, 4th: exhaust stroke, 5th: 2nd suction stroke where fresh air is sucked, 6th: exhaust stroke. The main changes are in design of camshaft, sprocket, and rocker arm. The engine used is a Bajaj pulsar 135 ls engine. Six stroke engines have a very high relevance now a days. It helps Reduction in fuel consumption, Reduction in pollution, better scavenging and more extraction of work per cycle, Lower engine temperature, and higher overall efficiency. This new engine is ecofriendly.

replaces the valve mechanism of a conventional engine and also it increases the compression ratio. The currently notable six stroke engine designs in this class include two designs developed independently: the Beare Head engine, invented by Australian farmer Malcolm Beare, and the German Charge pump, invented by Helmut Kottmann.

II.

WORKING

First stroke— during the first stroke the first inlet valve opens and air-fuel mixture from carburetor is sucked into the cylinder through the inlet manifold. Here the second inlet valve and both exhaust valves are in closed position. The piston moves from top dead centre (tdc) to bottom dead centre (bdc). Second stroke— during the second stroke, piston moves from bdc to tdc, both the inlet valves and exhaust valves are closed and the air-fuel mixture is compressed. The compression ratio of the modified engine is same as that of the original four stroke engine 9:1.

INTRODUCTION

One of the major problems faced by the current society is the energy crisis. Poor fuel efficiency, higher rate of pollution are the major problems faced by the existing IC engines. In order to overcome these major two problems we can use the concept of ‘Six Stroke Engine’. The term six stroke engine describes two different approaches in the internal combustion engine, developed since the 1990s, to improve its efficiency and reduce emissions. In the first approach, the engine captures the waste heat from the four stroke Otto cycle or Diesel cycle and uses it to get an additional power and exhaust stroke of the piston in the same cylinder. Designs either use steam or air as the working fluid for the additional power stroke. As well as extracting power, the additional stroke cools the engine and removes the need for a cooling system making the engine lighter and giving 25% increased efficiency over the normal Otto or Diesel Cycle. The pistons in this six stroke engine go up and down six times for each injection of fuel. These six stroke engines have 2 power strokes: one by fuel, one by steam or air. The currently notable six stroke engine designs in this class are the Crower's six stroke engine, invented by Bruce Crower of the U.S.A; the Bajulaz engine by the Bajulaz S A Company, of Switzerland; and the NIYKADO Six Stroke Engine designed, developed and patented by Chanayil Cletus Anil, of cochin India, in 2012.

Third stroke— during the third stroke, power is obtained from the engine by igniting the compressed airfuel mixture using a spark plug. Both the inlet valves and exhaust valves remain closed. Piston moves from tdc to bdc. Fourth stroke — during the fourth stroke, the first exhaust valve opens to remove the burned gases from the engine cylinder. Piston moves from bdc to tdc. Here the inlet valves and second exhaust valves are in closed position. Fifth stroke — during the fifth stroke, the second suction valve opens. Fresh air from the air filter enters the cylinder through the secondary air induction line. Here the first inlet valve and both exhaust valves are in closed position. Sixth stroke — during the sixth stroke, the secondary exhaust valve opens. The air sucked into the cylinder during the fifth stroke is removed to the atmosphere through the exhaust manifold. Here the both inlet valves and first exhaust valve are in closed position. Fig 4.6 shows the sixth stroke.

III.

ENGINE PARTS MODIFIED

In order to modify a 4 stroke engine to a 6 stroke engine we needed a 4 valve engine. Since this valve are independently activated at different times. So we took pulsar 135 model engine for our study and modification.

The second approach to the six stroke engine uses a second opposed piston in each cylinder which moves at half the cyclical rate of the main piston, thus giving six piston movements per cycle. Functionally, the second piston

First we have designed the complete engine model using solidworks 2013. Fig 1 shows the m o d e l .

Cam lobes/ camshaft

In the six stroke engine the 360 degrees of the cam has been divided into 60 degrees among the six strokes. New two lobes are to be further added to the existing camshaft. Thus a two lobed camshaft is changed to new four lobed camshaft. This four lobes open the valves at different timings. Out of the four lobes two lobes are for suction valves and rest is for exhaust valves. Material used for fabrication is EN8. Fig 3 shows Camshaft.

(a)

(b)

Fig 1(a) solid works model; (b) six stroke engine Table I Engine Specification Displacement Cylinders Max power Maximum torque Bore(mm) Strokes(mm) Valves per cylinder Fuel delivery system Fuel Type Ignition Spark Plugs (Per Cylinder) Cooling System

135 1 13 bhp @ 9000 rpm 11 Nm @ 7500 rpm 54 59 4 Fuel Injection Petrol Digital Twin Spark Ignition 2 Air Cooled

Fig 3 Camshaft C.

Rocker arms

New rocker arms has been designed using trial and error method. Their main aim is to activate the valve opening by the action of the camshaft. Four different types of same size were made. The basic sizes remains the same. Material used is Mild steel. Fig 4 shows the rocker arm.

A. Camshaft / crankshaft sprockets In the six stroke engine the crankshaft has 1080 degrees of rotation for 360 degree rotation of the camshaft per cycle. Hence their corresponding sprockets are having teeth in the ratio 3:1. In the original four stroke engine the teeth of the sprockets of the crankshaft and the camshaft were in 2:1 ratio. The 32 teeth sprocket of the four stroke engine camshaft was replaced by a 48 teeth sprocket in the six stroke engine. The crankshaft sprockets with 16 teeth remained as such. Material used for fabrication is MS. Fig 2 shows camshaft sprocket.

Fig 4 Rocker arm D. Secondary air induction system The secondary air induction system, supplies the air which is used during the fifth and sixth stroke. During the fifth stroke air from the air filter is sucked into the cylinder through the secondary air induction line. The second inlet valve opens to permit the air flow. During the sixth stroke, the air is removed through the exhaust manifold. The second exhaust valve opens and closes during this stroke

IV.

EXPERIMENTAL PROCEDURE

The same engine was altered as four stroke and six stroke to perform the experiments. Load test and pollution test

Fig 2 Camshaft Sprocket

were conducted. The load test was conducted using brake drum dynamometer. The final drive shaft from the engine to the wheel was used for loading during the experiment. The engines were tested for 400rpm under the same loading conditions. The time for consumption of 10cc of the fuel was noted during the experiment. The % vol. of CO in exhaust gas during idling was tested to check the pollution level of the engines. The results of load test and pollution test have been tabulated in table (1) and table (2) respectively.

Total fuel consumption increases with increase in brake power. It is seen that there is a TFC value when the brake power is zero. It is because of the frictional power. It is also inferred that the TFC6 is less than TFC4 for same brake power. It is also inferred that for six stroke engine it takes more time for same 10cc of fuel consumption. B. SFC vs. BP GRAPH 2 SFC vs. BP

Fig 5 engine test apparatus TABLE 2 Load Test Results N (RPM)

P (Kg)

BP (KW)

T4 (s)

T6 (s)

TFC4 (Kg/hr)

400 400 400 400 400

0 4 8 10 12

0 0.8952 1.7904 2.238 2.6858

84 79 74 71 68

98 94 90 86 80

0.3214 0.3418 0.3649 0.3803 0.3971

TFC6 (Kg/hr) 0.2755 0.2872 0.3000 0.3140 0.3375

SFC4 (Kg/KW hr) 0.3818 0.2038 0.1699 0.1478

SFC6 (Kg/KWh r) 0.3209 0.1676 0.1403 0.1257

REDN% (TFC) 14.29 15.96 17.78 17.44 15.00

Specific fuel consumption decreases with increase in brake power. It is inferred that the SFC6 is less than SFC4 for same brake power. C Pollution Test Results

RESULTS AND DISCUSSIONS

A. TFC Vs BP

4 Stroke Engine

6 Stroke Engine

% Pollution Redn.

0.92

0.32

65.2

GRAPH 1 TFC Vs BP It is inferred that the pollution is reduced by 65% compared to 4 stroke engine. There is a great reduction in CO, because

the CO produced during the exhaust stroke by the unburned fuel particles is converted to CO2 by fresh air entering in the 5th stroke. Thus complete oxidation of CO is possible, eliminating CO from the engine.

[9]file:///H:/abc/BEARESix%20Stroke%20Engine/Article%2 0The%20Beare%206%20Stroke%20Ducati%20%20Alan%20 Cathcart.htm [10]http://en.wikipedia.org/wiki/Crower_six_stroke

VI. CONCLUSIONS The six stroke engine modification promises dramatic reduction of pollution and fuel consumption of an internal combustion engine. The fuel efficiency of the engine can be increased and also the valve timing can be effectively arranged to extract more work per cycle. Better scavenging is possible as air intake occurs during the fifth stroke and the exhaust during the sixth stroke. Due to more air intake, the cooling system is improved. It enables lower engine temperature and therefore increases in the overall efficiency. One of the Advantage is that it doesn't require any basic modification to the existing engines. All technological experience and production methods remain unaltered. It can be used in Automobiles, heavy goods, construction-site and farm vehicles, Motorboats motor-pumps, generator sets, stationary engines, etc....intended for agriculture and industry. Our six stroke engine claims a powerful engine with reduction in specific fuel consumption and total fuel consumption. It engine is pollution free engine as literally saying no CO is produced. Better cooling than the 4 stroke engine. The future scope within this project is power can be increased by using a compressor in the second suction line. Improving this same technology for more mass production. REFERENCE 1]Analysing the implementation of six stroke engine in a hybrid car Published online January 10, 2014 http://www.sciencepublishinggroup.com/j/ijmea)doi:10.11648 /j.ijmea.20140201. [2]http://www.velozeta.com/ [3]http://www.newindpress.com/NewsItems.asp?ID=IEO200 60903112344&Topic=0&Title=Thiruvananthapuram&Page O [4]http://www.autocarindia.com/new/Information.asp?id=123 [5]http://en.wikipedia.org/wiki/Six_stroke_engine [6]Design Of Machine Elements V.B Bhandari [7]Fundamentals of machine component design Juvinall R C & Marshek K M [8]http://www.autoweek.com/apps/pbcs.dll/article?AID=/200 60227/FREE/302270007/1023/THISWEEKSISSUE

A STUDY ON THE MECHANICAL PROPERTIES OF NATURAL FIBRE HYBRID COMPOSITE MATERIALS P.Sivasubramanian, Dr.M.Thiruchitrambalam,

Abstract: Natural fiber composites are emerging as realistic alternatives to glass-reinforced composites in many applications. Natural fiber composites such as banana fiber, hemp fiber-epoxy, flax fiber-polypropylene (PP), and china reed fiber-PP are particularly attractive in automotive applications because of lower cost and lower density. Natural fiber composites are also claimed to offer environmental advantages such as reduced dependence on non-renewable energy/material sources, lower pollutant emissions, lower greenhouse gas emissions, enhanced energy recovery, and end of life biodegradability of components. Since, such superior environmental performance is an important driver of increased future use of natural fiber composites. This paper deals with Banana and glass fiber composites. It is one of the fiber reinforced composites. Banana and glass fiber is used as reinforcement and the polymer based resin is used as a matrix. The mechanical properties like Tensile, Flexural and Impact strength are analyzed in detail. KEY WORDS : Natural Fiber, Hand lay, Tensile strength, Flexural strength, Impact strength.

From the literature reviewed it was identified the analyzes on banana and the glass fiber combination need to have attention. So the objective of this work are, 1. To fabricate natural fiber reinforced composites with varying layers. 2. To analyze the properties like Tensile strength, flexural strength and impact strength.

EXPERIMENTAL DETAILS

The methodology of the work is given in fig. 2.1. The fabrication process consists of fabricating different layers of composites by using hand-layup method.

INTRODUCTION

In an advanced society like ours we all depend on composite materials in some aspects of our lives. Composite materials have a long history of usage. Their beginnings are unknown, but all recorded history contains references to some form of composite material. Fiber glass, developed in the late 1940s, was the first modern composite and is still the most common. Roger M. Rowell, et.al presented a paper on Utilization of natural fibers in plastic composites [1]. Results suggest that agro-based fibers are a viable alternative to inorganic/material based reinforcing fibers in commodity fiber-thermoplastic. These renewable fibers have low densities and high specific properties. Kenaf fivers, for example, have excellent specific properties and have potential to be outstanding reinforcing fillers in plastics. H.Y.Sastra, et.al analyzed the flexural properties of Agenta Pinnata fiber reinforced Epoxy composites [2]. Results from the flexural tests of Arenga pinnata fiber reinforced epoxy composite by Hand lay up method are that the 10% wt of woven roving Arenga pinnata fiber showed the highest value for maximum flexural properties.

Using Universal Testing Machine (UTM), the Mechanical properties like Tensile and Flexural strength of the fabricated composites were tested and to be presented in this work. In addition to the stress-strain diagram, the important parameters like maximum deflection, ultimate stress, peak load, etc. are also analyzed separately. Flexural strength of fabricated composites are also tested using UTM with required attachment. In order to find out the toughness of the fabricated composites, Izod impact was conducted. In order to assess the elastic re-bounce on stresses, many holes were drilled in the material and the nature and profile of the holes is analyzed using profile projector.

Fig. 3.1 One Banana and a Glass Fiber Composite

III FABRICATION OF COMPOSITES 3.3 Triple Layer Triple Layer consists of two layers of banana and a layer of glass fiber in between the two layers or two layers of glass fiber and a layer of banana fiber act as reinforcement and polymer based resin act as matrix.

The materials used in our fabrication process are General Purpose Resin (G.P.Resin chemically Polyester) Accelerator (Methyl Ethyl Ketone) Catalyst (Cobalt) Poly Vinyl Polythene Sheets & Glass Plates Banana Fibers & Glass Fibers

a) Two banana fibers and a glass fiber composite This composite consists of two sisal fiber layer and a glass fiber layer. In the fabrication of two banana fiber and a glass fiber composite, first the resin mixture is applied over the polythene sheet. Then banana fiber is placed and again resin is applied over it. Then a layer of glass fiber is placed over it, and again the resin mixture is applied. Then another banana fiber is placed, then the resin mixture is applied, and it is finally covered by a polyvinyl applied polythene sheet.

3.1 Fabrication Procedure The steps followed during fabrication are • Prepare the banana and glass fiber to the required size say 15cm X 15cm. • Preparation of binding mixture resin in a proper proportion. For 60ml of GP Resin, 20 drops of Accelerator and 12 drops of Catalyst are mixed together. • Apply Polyvinyl on the plain polythene sheet and allow it to dry. • Apply the binding mixture over the dried sheet which acts as polymer resin matrix. • Reinforce the required fibers over the polymer resin matrix. • Again apply the binding mixture resin over the fiber reinforcement. • Cover the reinforcement with polythene sheet coated with polyvinyl. • Place the reinforcement in between two glass plates and allow it to dry for 3 to 5 hours. • After drying we can obtain the required composite. The various types of layers in the fabrication process are • Double Layer • Triple Layer • Layer with Hard Particle dispersion. 3.2 Double Layer Double Layer consists of both banana as well as glass fiber acts as reinforcement and polymer based resin acts as matrix. In the fabrication of double layer, polythene sheet is placed in which resin mixture is poured. And above which banana fiber is placed and again resin mixture is applied, and over which the glass fiber is placed, then the mixture is poured and finally it is covered by a polythene sheet.

b) Two Glass Fiber and a banana Fiber Composite This composite consists of two glass fiber layer and a banana fiber layer. In the fabrication of two glass fiber and a banana fiber composite, first the resin mixture is applied over the polythene sheet. Then glass fiber is placed and again resin is applied over it. Then banana fiber is placed over it, and again the resin mixture is applied. Then another glass fiber is placed, then the resin mixture is applied, and it is finally covered by a polythene sheet.

Fig. 3.2 Two Glass Fiber and a Banana Fiber Composite

IV RESULTS AND DISCUSSIONS ON MECHANICAL PROPERTIES

14.7 14.65

4.1Tensile Test without Moisture Tensile test is done on a dried specimen with a size of 15cm X 1.5 cm X .4cm. The following figure illustrates a sample stress strain curves fabricated composites. The figure 4.1 depicts that when the load is applied above 13 KN, the composites begin to deform. As the load increases, the deformation begins to increase. The fluctuations in the figure are due to the breaking of fiber particles and the composite material breaks at the point of breaking load.

Breaking Load(KN)

14.6 14.55 14.5 14.45 14.4 14.35 14.3 14.25 14.2 1

Layer

Fig 4.2 Effect of layer on Breaking Load (Without Moisture) 15

Max. Disp(mm)

14.5 14 13.5 13 12.5 12 11.5 11 1

Fig. 4.1 Two Banana & A Glass Fiber Composites

The following figure shows the variations of various parameters with respect to layers. The figure shows the effect of layer on peak load & displacement. The peak load is maximum for glass fibers as it is brittle in nature. Though the displacement remains almost same for all layers, the two glass fiber and a banana fiber layer exhibits better mechanical property.

Layer

Fig 4.3 Effect of layer on Max Displacement (Without Moisture)

0.45

Ult.Stress(KN/sq.mm)

0.4

1- One Banana and A Glass Fiber Composite 2- Two Banana and a Glass Fiber Composite 3- Two Glass and a Banana Fiber Composite

0.35 0.3 0.25 0.2 0.15 0.1 0.05 0

The resin matrix distributes the load evenly to the glass and banana fiber composites and so it could withstand heavy loads and it could show better mechanical property. The displacement is maximum in glass fibers as it elongates while applying load.

Layer

Fig 4.4 Effect of layer on Ultimate Stress (WithoutMoisture)

4.2 Flexure Test Flexure test is done on a specimen of size 15cm X 2.5cm X .4 cm thick. It is done in UTE (100) Universal Testing

Machine. The following figure shows the failure of the specimen when a load is applied.

36 34

Max.Disp(mm)

32 30 28 26 24 22 20 1

Layer

Fig. 4.5 Flexure Failure of the Specimen

Fig. 4.7 Effect of layer on Maximum Displacement (Without Moisture)

The following figures explain the stress-strain curves of the various layers of composites. The fig. 4.5 shows that the load almost remains constant. The deformation increases at constant load due to the presence of resin matrix and the presence of glass fiber composites. Flexure test is done on specimen without moisture in a dried condition. The following figure explains the effect of layer on various parameters. The banana fiber and glass fiber composites can withstand high loads since it exhibits brittleness. The fracture mechanism of composite is brittle fracture. Under this condition, the double layer composite shows mechanical properties.

0.16

Ult.Stress(KN/sq.mm)

0.15 0.14 0.13 0.12 0.11

1- One Banana and A Glass Fiber Composite 2- Two Banana and a Glass Fiber Composite 3- Two Glass and a Banana Fiber Composite

0.1 1

Fig 4.8 Effect of layer on Ultimate Stress (Without Moisture)

4.3 Impact Test Impact test is done in Chorpy Impact test bed. The specimen for impact test is 9cm X 1.5cm. The specimen is placed horizontally in the test bed. The pendulum is lifted and is made to hit the specimen from height. Each particle absorbs energy when it is hit under some height. The fig. 4.9 depict the failure of the specimen under impact load.

14.75 14.7 14.65 Breaking load(KN)

2 Layer

14.6 14.55 14.5 14.45 14.4 14.35 14.3 1

Fig.4.9 Impact Failure of the Specimen

Layer

The impact test results show that the impact strength is increased with increase in layer. The glass fibers resist more to the impact loading and so the impact strength is high for glass fibers. Therefore glass and banana fiber composites have high

Fig. 4.6 Effect of layer on Breaking Load (Without Moisture)

Impact strength (J/sq.m)

impact strength. The impact strength increases with moisture. Also the resin matrix distributes the impact load evenly and it increases the impact strength of the composites.

4. Kazuya Okubo, Toru Fujii and Yuzo Yamamoto (2004), “Development of bamboo-based polymer composites and their mechanical properties”, Composites Part A: Applied Science and Manufacturing, 35 (3), 377-383.

100 90 80 70 60 50 40 30 20 10 0

5. Guinez D, Jasso C, Fuentes F, Navarro F, Dávalos F and Ramos J (2005), “Chemical Treatments on Sisal Fibers to Produce Composite Materials with Polyethylene and Polystyrene”, Proceeding of the 8th Polymers for Advanced Technologies International Symposium, Budapest, Hungary, 13-16 1

6. Dipa ray, Sarkar B K, Rana A K and Bose N R (2001),

“Effect of alkali treated jute fibres on composite properties”, Bull. Mater. Sci., 24 (2), 129–135.

Layer

Fig 4.10 Effect of layer on Impact Strength

7. Thi-Thu-Loan Doan, Shang-Lin Gao and Edith Mäder (2006), “Jute/polypropylene composites I. Effect of matrix modification”, Composites Science and Technology, 66, (7-8),952-963

The impact strength of the two glass and a banana fiber composite is found to be high due to the presence of glass fibers. The glass fiber is brittle in nature and hence it exhibits better impact strength.

8. Antich P, Vázquez A, Mondragon I and Bernal C (2006), “Mechanical behavior of high impact polystyrene reinforced with short sisal fibers”, Composites Part A: Applied Science and Manufacturing, 37 (1), 39-150

V CONCLUSION   

The tensile testing of fiber composites without moisture proves that the two glass and a banana fiber composites shows better tensile strength. The flexure testing of fiber composites without moisture proves that the one glass and two banana fiber composite show better flexural strength. The Impact testing results of fiber composites with and without moisture show that the two glass and a banana fiber composites produces high impact strength. VI REFERENCES

1. Rowell R.M, Sanadi, A.R, Caulfield D.F, and Jacobson R.E (1995), “Renewable agricultural fibers as reinforcing fillers in plastics: Mechanical properties of Kenaf fiber -polypropylene composites, Ind. Eng. Chem. Research, 34, 1889-1896.

2. Manikandan V and Velmurugan

R (2005), “Mechanical properties of Sisal/palmyra fiber waste sandwich composites”, Indian Journal of Engineering & Materials Sciences 12 (9), 563-570

3. Sastra H. Y, Siregar J. P, Sapuan S. M and Hamdan M. M (2006), “Tensile Properties of Arenga pinnata Fiber-Reinforced Epoxy Composites”, PolymerPlastics Technology and Engineering, 45 (11), 149 – 155

Flue Gas Low Temperature Heat Recovery System for Air-Conditioning Nirmal Sajan , Ruben Philip , Vinayak Suresh , Vishnu M , Vinay Mathew John

be preheating of combustion air, space heating, or pre-heating boiler feed water or process water. With high temperature heat recovery, a cascade system of waste heat recovery may be practiced to ensure that the maximum amount of heat is recovered at the highest potential. Main objective of this work is to utilize the waste heat available in exhaust gases coming out of the Boiler of a thermal power plant. It also intends to use the waste heat available to run a Vapour Absorption Refrigeration System which replaces existing Vapour Compression Refrigeration System which is present in the administrative block of the plant. This work also aims in replacing Freon-12 refrigerant which causes ozone depletion and to reduce the temperature of exhaust gas emitted to the atmosphere which causes global warming.

Abstract— Huge amount of energy wasted through the flue gas in thermal power station causes great concern in recent years. Discharging hot flue gas in the environment is not only a wastage of energy but also increases the rate of global warming. Efforts are given world -wide to harness the energy for useful purposes. In this work, the waste heat of flue gas in a 350 MW thermal power plant is utilized in vapor absorption air conditioning plant. Gas to liquid multi-pass cross flow heat exchanger that have been placed in the existing space between boiler and chimney. The dimensions of the finally selected heat exchanger are 0.106m × 2.4m × 3.4m. The number of pipes required for the heat exchanger is found to be 12 using iteration method and temperature of water at the outlet of last pipe is 101.1℃. The extracted energy from the flue gas is used to heat water to be utilized in the generator of a vapor absorption refrigeration system that has produced a refrigerating capacity of 70 TR. approximately. Due to the corrosive nature of flue gas, heat recovery is confined up to the acid dew point temperature of the flue gas. Suitable software is used to find out the detailed design parameters of Gas to liquid multi-pass cross flow heat exchangers. Out of many feasible designs of heat exchangers, the most economic design is selected as the final design.

II. METHODOLOGY This work mainly focus only on the heat recovery from the flue gas in order to run the Li-Br VAM which is having a cooling capacity of 70 TR. Temperature of the flue gas available is very low and is about 125°C. Since the temperature of the flue gas available is very low compared to other power plants, only single effect VAM can be used for this air conditioning purpose. Commercially available single effect VAM does not require very high temperature and works on the temperature in the range 80-120℃ and its COP varies from 0.6 to 0.8. COP of VAM chosen is 0.7.

Keywords—Air Conditioning; Flue Gas; Heat Exchanger; Heat Recovery; Vapour Absorption Machine

I. INTRODUCTION Waste heat is heat, which is generated in a process by way of fuel combustion or chemical reaction, and then dumped into the environment even though it could still be reused for some useful and economic purpose. The essential quality of heat is not the amount but rather its value. The strategy of how to recover this heat depends in part on the temperature of the waste heat gases and the economics involved. Large quantity of hot flue gases is generated from Boilers, Kilns, Ovens and Furnaces. If some of this waste heat could be recovered, a considerable amount of primary fuel could be saved. The energy lost in waste gases cannot be fully recovered. However, much of the heat could be recovered and loss minimized by adopting suitable measures. Depending upon the type of process, waste heat can be rejected at virtually any temperature from that of chilled cooling water to high temperature waste gases from an industrial furnace or kiln. Usually higher the temperature, higher the quality and more cost effective is the heat recovery. In any study of waste heat recovery, it is absolutely necessary that there should be some use for the recovered heat. Typical examples of use would

Fig. 1. Isometric view of the flue gas low temperature heat recovery system

In order to produce 70 TR, 350 KW of heat is supplied to the generator of the VAM. So we designed a Multi-pass Gas to Water heat exchanger to recover waste heat from flue gas to produce Air conditioning effect. Shape of the heat exchanger is

used in high temperature application and are very costly. Table 1. shows the comparison of properties of Aluminum and Copper which are the possible options for material for the heat exchanger. Since this heat recovery is in the very low temperature and also aluminum is less denser it is the most suitable choice.

selected as serpentine and contains 12 pipes each of 10 cm diameter. The diameter of the pipe is selected based on the predetermined calculations. Fig. 1. shows the model of the heat exchanger used for this purpose. The 1:1 model of the heat exchanger as well as the water flow simulation was done using Solidworks software. The flow analysis through the tubes as well as the optimization of the number of the tubes was done using ANSYS FLUENT software on a 1: 10 model of the heat exchanger using iteration method. Only a single pipe is considered for analysis because the dimensions of each of the pipe as well as the properties of flow through each of the pipes are the same.

Table 1. Comparison of Physical Properties of Materials Material

Before finding the outlet water temperature of the heat exchanger using ANSYS Fluent Software following assumptions are considered regarding the flow of water through the heat exchanger and they are, •

Fully developed flow

•

Steady flow

•

Incompressible flow

•

Laminar flow

•

There will be perfect mixing of different layers of water occurring at the bend of pipes in heat exchanger.

Density

Melting Point

Boiling Point

Aluminium

2.70 g·cm−3

660.32 °C

2470 °C

Copper

8.96 g·cm−3

1084.62 °C

2562 °C

The heat exchanger is to be installed in the space between the boiler and chimney. The region is rectangular in cross section with a dimension of 1.25m × 7.48m × 17.4m. The dimensions of the final design of the heat exchanger is 0.106m× 2.4m× 3.4m. The heat exchanger is to be installed in a similar way as that of the radiator in an automobile i.e. each tube pass of the heat exchanger intercepts the flow of the flue gas as it flows from the boiler to the chimney.

In this iteration method, the input temperature of water passes to the first pipe of heat exchanger is taken as ambient temperature of 300 K and its corresponding output temperature is found out by taking the arithmetic average of temperatures of different layers at the outlet of the pipe available using the ANSYS software. At the bend of the first pipe we assumed that perfect mixing of different layers of water is occurred so as to get a uniform water temperature. Then the outlet water temperature of first pipe of heat exchanger is taken as the input of the second pipe and again the output temperature of water is found out. This process is continued until the desired water output temperature is available at the outlet of the twelfth pipe which is about 374.1 K.

III. ANALYTICAL SETUP The system consists of a water reservoir with makeup feed arrangement, pump, heat exchanger, vapour absorption refrigeration system and cooling tower, all of which are connected by pipes of suitable dimensions. Fig. 2. shows the detailed sketch of the proposed system. This paper encompasses the design and analysis of the heat exchanger only. The specification of the VAM will be adopted according to the cooling load requirement of the building under consideration and the potential of the flue gas available at the plant. The heat exchanger will be designed to provide the necessary input to the VAM so as to deliver the desired air conditioning effect. The specifications of the remaining part of the system i.e. the reservoir, the pump and the connecting pipes is to be chosen according to the flow requirement of the system.

In order to compensate heat losses due to friction due to bend of pipes and pipe wall, required temperature to be supplied to generator in the VAM is taken as 400 KW instead of 350 KW which was the calculated value. This Gas to Water Cross flow Heat Exchanger is to be placed in the space between boiler and chimney. The hot flue gas coming out from boiler passes across the cross flow multi pass heat exchanger and thus heats the water inside the heat exchanger. This flue gas after passing across the heat exchanger will goes out of the chimney. The hot water serves as an input to the Vapour Absorption Machine (VAM) driving Li-Br cycle to produce the desired air conditioning. Thermal and structural stress effects need not be considered at pressures below 15 atm or temperatures below 150°C.Thus the thermal and structural analysis of the heat exchanger is not carried out in this work. But these effects are major considerations above 70 atm or 550°C and seriously limit the acceptable materials of the heat exchanger. The common materials used for fabrication of industrial heat exchangers are aluminum, copper, stainless steel and high carbon steel. Since this work involves low temperature heat recovery, stainless steel and high carbon steel are not considered as they are commonly

Fig. 2. Detailed sketch of analytical setup

A. Working Process The system is proposed for waste heat recovery in a cascade process so that the heat recovery process will be efficient. The working process is intended for maximum heat recovery from the flue gas which is at a temperature of 125â&#x201E;&#x192;, which is a very low temperature compared to that of most of the thermal power plants. At this very low temperature the thermal and structural effects on the heat exchanger to be designed can be neglected. The working fluid selected is water because of its relative abundance and its non-toxic nature along with its high heat capacity.

B. Outlet Temperature of Flue Gas The outlet temperature of the flue gas is found out using the equation, Q = mĚ&#x2021;Cpâ&#x2C6;&#x2020;T = mĚ&#x2021;Cp (Tin â&#x20AC;&#x201C; Tout)

(2)

where Q is the heat transferred from flue gas to water, mĚ&#x2021; is the mass flow rate of flue gas, Cp is the specific heat capacity of flue gas, Tin is the inlet temperature of flue gas and Tout is the outlet temperature of flue gas.

The process begins when the heat exchanger installed in the space between the boiler and the chimney taps the heat from the flue gas. The flue gas comes out of two of the combustion chambers coupled to each of the two gas turbines installed in the plant. The temperature of the flue coming out of the turbines are of the order of 550Âą50â&#x201E;&#x192;. This being a very high temperature is effectively used to generate steam in a HRSG (Boiler).The generated steam is then used to run a steam turbine, thus making the power plant a combined cycle power plant. The temperature of the flue reduces to almost 125â&#x201E;&#x192; after rejecting heat to the boiler. This flue is made to flow across a multi - pass cross flow heat exchanger. The flue gas after rejecting heat to the heat exchanger passes through the chimney. A pump of predetermined mass flow rate is used to transfer water from a reservoir to the heat exchanger which heats up to the desired temperature through a cascade process involving multi-pass tubes of the heat exchanger.

C. Logarithmic Mean Temperature Difference (LMTD) The next important step is finding out the LMTD of the heat exchanger, which is given by LMTD

= â&#x2C6;&#x2020;Tm =

â&#x2C6;&#x2020;đ?&#x2018;&#x2021;đ?&#x2018;&#x2013;â&#x2C6;&#x2019; â&#x2C6;&#x2020;đ?&#x2018;&#x2021;đ?&#x2018;&#x2019; â&#x2C6;&#x2020;đ?&#x2018;&#x2021;đ?&#x2018;&#x2013; â&#x2C6;&#x2020;đ?&#x2018;&#x2021;đ?&#x2018;&#x2019;

(3)

where, â&#x2C6;&#x2020;đ?&#x2018;&#x2021;đ?&#x2018;&#x2013; = Th1 â&#x20AC;&#x201C; Tc2

(4)

â&#x2C6;&#x2020;đ?&#x2018;&#x2021;đ?&#x2018;&#x2019; = Th2 â&#x20AC;&#x201C; Tc1

(5)

where Th1 and Th2 are the inlet and outlet temperatures of the flue gas and Tc1 and Tc2 are the corresponding values of water.

The heated water is then pushed forward by the pressure existing in the system to the generator part of the VAM which have a capacity of 70 TR and a COP of 0.7. The water coming out of VAM which is still at a considerable temperature is brought to ambient temperature by passing it through the cooling tower which is already present at the plant. The cooled water is then returned to the reservoir from where it is again pumped by the water pump. A makeup feed water arrangement is also provided with the reservoir to compensate for any losses.

D. Surface Area of the Heat Exchanger Area of the heat exchanger is found out using the equation, Heat transfer, Q = UFAâ&#x2C6;&#x2020;Tm

(6)

where, U is the overall heat transfer coefficient, in W/m2 Â°C, A is the surface area of the heat exchanger in m2 and â&#x2C6;&#x2020;Tm is the LMTD in â&#x201E;&#x192; and F is the correction factor.

IV. DESIGN DATA

E. Mass Flow Rate of Water through Heat Exchanger We know that heat transfer,

The heat exchanger is designed according to the VAM requirements. So firstly, the amount of heat that is to be supplied to the generator of the VAM is to be found out. The available inputs are the capacity of the required system and its coefficient of performance.

Q = mĚ&#x2021;Cpw â&#x2C6;&#x2020;T = mĚ&#x2021;Cpw (Tout â&#x2C6;&#x2019; Tin )

(7)

where, mĚ&#x2021; is the mass flow rate of water in Kg/sec, Q is the heat transfer in KW, Cpw is the specific heat capacity of water, Tin is the inlet temperature of water in â&#x201E;&#x192; and Tout is the outlet temperature of water in â&#x201E;&#x192;.

A. Heat to be supplied to the Generator of VAM The heat to be supplied to the generator of VAM can be found out by the equation, Q COP = E (1)

F. Number of Tubes, Diameter and Length of the Pipe For a heat exchanger consisting of n tubes, the total surface area is given by,

where QG is the heat to be supplied to the generator of VAM,QE is the heat absorbed in the evaporator and COP is the coefficient of performance.

A = Ď&#x20AC;dLn

rates. These can be essentially used as inputs for software analysis. The solution obtained from the software is obtained as a streamline simulation.

(8)

where, d is the diameter of the tubes, L is the length of a single tube. From the above equation the values of d, L, n are optimised using iteration by taking different values for d, n and L for a constant surface area and the optimised values are; d = 10cm L = 2m n = 11 G. Velocity of Water through the Pipes It is clear that mass flow rate, đ?&#x2018;&#x161;Ě&#x2021; = đ?&#x153;&#x152;đ??´đ?&#x2018;? đ?&#x2018;&#x2030;

(9) Fig. 3. Velocity streamlines of both flue gas and water

where, Ď is the density of water in Kg/m3, Ac is the cross sectional area of heat exchanger, in m2 and V is the velocity of water through heat exchanger in m/s.

Fig. 3. shows the velocity streamlines of both flue gas and water. From the figure, it can be understood that the velocity of flue gas increases when it approaches the pipe and decreases when it passes the pipe. It may be due to, the reduction in area that occurs when the flue gas approaches the pipe and the subsequent reduction in pressure. As the flow area increases the velocity of the flue gas decreases correspondingly.

H. Energy Savings Power required for operating VCM =78.2985 KW Power required for operating VAM = 2% of VCM =1.566 KW Total Power Saved = 78.2985 â&#x20AC;&#x201C; 1.566 = 76.732 KW

Fig. 4. shows the velocity streamline of flue gas only. From the figure it can be inferred that the velocity of the flue gas directly below the pipe is almost zero. This may be due to the near stagnation condition that arises at that region. This is mainly because of the fact that the particular layer of flue gas has less chance to escape due to the obstruction created by the pipe and the continuous collision with fresh flue gas which nearly impedes its motion. Thus there is less chance of fresh flue gas interaction with the pipe wall at this region.

Energy saved if air-conditioner works 12 hours per day = 76.732 Ă&#x2014; 12 = 920.784 KWhr = 920.784 Units/day. V. ANALYSIS The heat exchanger analysis is being carried out using ANSYS FLUENT software. Although the design involves a multi-pass heat exchanger consisting of twelve pipes, the analysis is carried out only on the first and the last pipe of the heat exchanger. This is because the properties of flue gas flowing through the space between boiler and chimney and the water flowing through the pipe respectively are same for each pipe. The dimensions of the heat exchanger is being scaled down to one â&#x20AC;&#x201C; tenth of its original dimensions due to considerable difficulty faced during the analysis of 1:1 model of the heat exchanger. But the resulting error will be only one percent. A rectangular control volume of cross sectional area of 30 đ?&#x2018;?đ?&#x2018;&#x161;2 is also considered which encloses the pipe. The flow analysis of both the cold fluid and the hot fluid is being carried out in the control volume considered.

Fig. 4. Velocity Streamline of Flue Gas

A. Velocity Analysis Since the velocity of flow of flue gas across the heat exchanger and the velocity of water flowing through each pipes are the same, only a single pipe including the control volume is being analysed. The velocity of flow of the flue gas and water can be theoretically found out using their known mass flow

Fig. 5. shows the velocity contour plot of water flow at the outlet of the first pipe. The plot gives the velocity variation in the radial direction. It can also be inferred from the figure that the velocity of water layers close to the pipe boundary is low as compared to the velocity of water layer passing through the

center of the pipe. This is due to the viscous effects that becomes prominent as the proximity to the pipe wall increases.

Fig. 6. shows the temperature contour across inner wall of pipe 1. From the figure we can see that top surface of pipe 1 shows higher temperature than the bottom surface or any other surface. It may be due to the vortex flow created by the flue gas due to the curved shape of the pipes, so that flue gas molecules from both sides hits the top surface of pipe. This causes higher temperature of top surface than any other surface. Temperature of the top surface is almost same as the flue gas which is at 125â&#x201E;&#x192;. It is through the wall of the pipe heat passes to water inside the pipe. Fig. 7. shows the temperature contour of inner wall of pipe 12. From this pipe we can see that temperature is same at all regions of the wall. Water enters the last pipe after passing through all the 11 pipes and the temperature of water goes on increasing as it pass through each pipe since it is a multi-pass heat exchanger. High temperature water at about 95â&#x201E;&#x192; enters into the last pipe. Since temperature of the water is very high, heat from the walls is distributed to the walls of the pipe. Also wall is heated due to temperature of flue gas. This may be the reason that inner wall of pipe has higher temperature at all its regions.

Fig. 5. Velocity contour at the outlet of pipe

The velocity analysis is the basis for all other subsequent analysis in this work. The variations in velocity is the prime determinant for the variation of properties like Temperature and Pressure all across the control volume. It is clear from the figure that although the velocities of the flue gas and water involved are small, but they are sufficient enough to bring a considerable amount of heat transfer in this work. Many works states that minimizing the pressure drop and the mass flow rate of the fluids will minimize the operating cost of the heat exchanger, but it will maximize the size of the heat exchanger and thus the initial cost. As a rule of thumb, doubling the mass flow rate will reduce the initial cost by half but will increase the pumping power requirements by a factor of roughly eight. Low velocities are helpful in avoiding erosion, tube vibrations, and noise as well as pressure drop.

Fig. 7. Temperature contour of the inner wall of pipe 12

B. Temperature Analysis Temperature analysis is carried out by considering only the inner wall of the pipes 1 and 12. Other pipes are not considered. This is because all the pipes exhibit same behavior.

VI. RESULTS AND DISCUSSIONS A. Temperature at Outlet of Each Pipe The temperature at the outlet of each pipe is taken as an average value of temperatures at each section considered along the radial direction. This is because the temperature at any particular section cannot represent the outlet temperature correctly. These temperatures are obtained by plotting charts at each considered section. The average temperatures at the outlet of each pipes of the heat exchanger are shown in the Table 2. The temperature of water entering the first pipe is taken as ambient temperature, which is 300K. Finally at the end of the last pipe, the average outlet temperature is almost 374.1K. The iteration procedure is stopped at the twelfth pipe mainly due to two reasons. The first reason is that unlike all the other eleven preceding pipes the temperature rise in the twelfth pipe is a mere 2â&#x201E;&#x192; compared to five in all the other tubes, thus it is useless continuing the iteration procedure any further. The second

Fig. 6. Temperature contour of the inner wall of pipe 1

reason is that the outlet temperature of the twelfth pipe is almost 374.1 K which vaporises a small quantity of water to steam which is undesirable. This value is different from the theoretical outlet temperature of water (363K). Thus along with maximum possible heat transfer, this design also provides a factor of safety for the design.

centre and gets heated up. The velocity of the fluid layer at the center will be more thus there is less chance for heat transfer between the different layers of fluid in that region. Temperature of water layer close to the top boundary is more as compared to that of bottom layer. This may be due to the reason cited earlier i.e. the stagnation condition existing below the heat exchanger pipe. Thus the stagnant layer of flue gas prevents the transfer of heat by fresh flue gas. But the top surface will always face a fresh flue gas flow (Vortex flow) thus increasing the boundary temperature there.

Table 2. Average outlet temperatures of different pipes. Pipe No.

Inlet Temperature (K)

Outlet Temperature (K)

300

309.6

320.3

325.1

333.6

341.4

347.7

353.6

359.1

363.6

368

371.5

374.1

C. Temperature vs. Longitudinal Distance

B. Temperature vs. Radial Distance (pipe 1)

Fig. 9. Temperature variation along the length of pipe 1 close to the pipe wall

The temperature vs. longitudinal distance curve for the first pipe at a section close to the pipe wall region is shown in the Fig. 9. It shows the variation of temperature along the length of the tube. Only a single section is considered for analysis because the charts considered along different sections along the length have same trends. From the graph it is clear that, the temperature is not uniform throughout the length of the pipe. Both increase and decrease in the temperature can be seen from the chart. This may be due to the temperature gradient existing between different layers of the fluid. As a result there will be density gradient at different layers of the fluid. This causes random movement of fluid molecules thus distributing temperatures unevenly. Fig. 8. Temperature variation along the radial direction at the outlet of pipe 1

D. Temperature vs. Radial Distance (pipe 12) The graph of Temperature vs. Radial distance at the outlet of the first pipe is shown in the Fig. 8. This chart gives an idea about the variation of temperature with radial distance above and below the axis of the pipe. From the graph it is clear that temperature is maximum at the top and bottom of the pipe and there will be almost no change in the temperature along the centre portion of the pipe (+3.5 to -3.5 cm). This may be due to the fact that the flue gas transfers its heat to the walls of the pipes and the water layer that is nearer to the boundary stays there long due to viscous effects as compared to the fluid layers at the

The graph showing Temperature vs. Radial distance for the last pipe is shown in the Fig. 10. It can be easily noticed that the pattern of the curve is very much similar to the curve shown in figure 8. Only difference is that the temperature at the top and bottom layer are comparable in this case .This may be due to the high temperature of water entering the twelfth pipe unlike the first pipe. All the other pipes will be showing similar trends like that of Fig. 8 and Fig. 9, except that there operating temperature will be different.

from flue gas and using the same for day-to-day applications, in this case for air conditioning application. The main conclusion that can be drawn from this work is the relative advantage that a VAM has over the VCM. The dimensions of the final design of the heat exchanger was obtained as 0.106 m × 2.4 m × 3.4 m. The finally optimized total number of pipes was 12 and it was found that further increase in the number of pipes is not justifiable because the rise in water temperature per pipe is not above 1℃.The optimized total length and pipe diameter of the heat exchanger was obtained as 30 m and 0.1 m respectively. The required mass flow rate of water through the heat exchanger is 1.516 kg/sec and the average outlet temperature of last pipe is 101.1 ℃. The temperature of water exiting the heat exchanger is potential enough to run a single effect Vapour Absorption Machine. The final proposed Vapour Absorption Machine effectively replaces the exiting Vapour Compression Machine. Fig. 10. Temperature variation along the radial direction at the outlet of pipe 12

REFERENCES VII. CONCLUSIONS

[1]

As the energy demand in our day to day life escalates significantly, there are plenty of energies are shuffled in the universe. Energies are put in an order of low grade and high grade energies. The regeneration of low grade energy into some beneficial work is a fantastic job. One such low grade energy is heat energy. So it is imperative that a significant and concrete effort should be taken for using heat energy through waste heat recovery. This work focuses on tapping the unused heat energy

[2] [3] [4] [5]

K. Balaji and R. Senthil Kumar, “Study of Vapour Absorption System Using Waste Heat in Sugar Industry,” IOSR Journal of Engineering (IOSRJEN), Volume 2, Issue 8, pp. 34-39, 2012. Ramesh K. Shah and Dusan P. Sekulic, Fundamentals of Heat Exchanger Design, John Wiley & Sons, Inc., 1st Edn., Hoboken, New Jersey,2003. Kuppan Thulukkanam, Heat Exchanger Design Handbook, CRC Press, 2nd Edn., Boca Raton, 2013. R. K. Rajput, Heat and Mass Transfer, S. Chand, 5th Edn., New Delhi, 2014. R. S. Khurmi and J.K. Gupta, A Textbook of Refrigeration and Air Conditioning, S. Chand, 5th Edn., New Delhi, 2014.

SEMI AUTOMATED COCONUT TREE CLIMBER Rahul V, Sameer Moideen CP, Sebin Babu, Vineeth VP, Nikhil Ninan

rarity these days. The scarcity of labour disrupts harvesting cycles causing loss of income to the growers. As against the general norm of harvesting cycles of 45-60 days, farmers are currently able to harvest only once in three to four months. Considering this scenario, device which helps the user to climb coconut tree easily will be useful for those having coconut cultivation as well as residents who is having less coconut trees. This kind of devices will encourage more people to come forward to agricultural sector .

Abstract Primary goal of the project is to design a coconut tree climbing device for farmers and residents. It is very difficult to climb on coconut tree manually due to the constant cylindrical structure and single stem. In other type of trees there will be branches for holding and to support the climber. A professional climber with proper training could only be able to climb coconut tree. Due to the risk involved, nowadays a very few are coming forward to climb on coconut trees. Agricultural workers employed for coconut tree climbing suffer musculoskeletal disorders than any other type of injury or illness. As the educational background of Indian youth is increasing, most of them may hesitate to come in climbing profession. Considering this scenario, a device which helps the user to climb coconut tree easily will be useful for those having coconut cultivation as well as residents who is having less coconut trees. In this project, we aim to design a mechanism which is simple and easy to operate. For this we first made a rough sketch considering average diameter of a coconut tree as 30 cm and designed it in Solid Works. Later a static analysis was done using ANSYS to ensure its stability. After that we moved on to the fabrication part. The material used is GI steel. Three linear electrical actuators are used in this mechanism – two for gripping and one for the vertical up and down motions. Each actuator can carry up to 400kg. The analysis done using ANSYS proved the design to be safe and the fabrication was completed successfully.

II.OBJECTIVES After conducting literature review and field reviews, we found out several technological gaps in the existing prototypes. And moreover, the life of the existing unmanned coconut harvester is less and cost is on higher side. Moreover a good demand of unmanned coconut tree climber exists in the market for an alternate solution which will be ergonomic and economical. The main objectives of our project are  To make an unmanned coconut tree climber.  To make a low cost coconut tree climber.  Both men and women irrespective of age should be able to operate the device.  To control the climber from the ground.  Ease of operation  Simple mechanism and design  Flexibility

I. INTRODUCTION

III. METHODOLOGY

In olden days most of the activities were done manually. Gradually so many big and small equipments were developed to ease human activities, thus to lessen the human efforts to do the things. Nowadays, most of the activities which included human efforts were either replaced or automated by the use of machines or other kind of equipments. India is the third largest producer of coconut in the world. Coconut is grown in an area of about 18.7 million hectares with a productivity of 5718 nuts per hectare in India (National Horticulture Board, 2011). Usually all over the country, farmers practice conventional harvesting method in which coconuts are picked by specially trained, skilful and experienced climbers. Due to the height and lack of branches, it is very difficult to climb on coconut trees. A professional climber with proper training only could climb coconut tree. Due to the risk involved, nowadays a very few are coming forward to climb on coconut trees. Due to the lack of professional climbers, the existing professionals may charge more from the owners. Many young men now avoid coconutpicking in favour of white collar jobs, meaning there is no longer a guaranteed labour force. Coconut tree climbers are a

The first step was the collection and study of various data regarding the design and mechanism of the new product. Next step was to design the model using Solid Works 14. Then static load analysis of the model was done using ANSYS 14.5. In the static load analysis total deformation and maximum stress induced were determined and then we moved on to the fabrication part. For fabrication, GI steel was used as the material because of its high strength, weldability, availability and low cost. The next step was the selection of suitable lowering device for the gripping and vertical motion of the mechanism. For this we chose linear electrical actuators. For the smooth operation we used three actuators, two for gripping, having a stroke length of 15 cm and providing 4000 N. For vertical motion, actuator having stroke length of 40 cm and capable of providing 6000 N was used. A 12 V DC battery was used to provide power for the actuators. The prototype was made as per the design and tested in the real conditions and suitable modifications were made to the final model.

IV. PRODUCT DESIGN 4.1 PRODUCT LIST For designing the parts of the product, first we developed a rough sketch of the product considering average diameter of a coconut tree as 30 cm. After making suitable alterations and corrections we arrived at the final design. Based on the final design developed, the

system was modelled using the software Solid Works 14. The design parts are listed below;

No of

Part Name

Material

Main bar

GI Steel

Angular link

GI Steel

Straight link

GI Steel

Bush

GI Steel

Central linear

No.

It is a rectangular bar of 50 x 20 mm cross section and having a length of 500 mm. There are two holes of 10 mm diameter from the centre to either side of the bar. The two angular links are pivoted on the main bar at these points. Holes are also provided at the centre of the main bar for clamping the linear actuator on to it. The main bar is made of GI steel. Two main bars are used, which are fixed on the top and bottom of the central body. It acts the base for the climbing mechanism.

units

actuator cylinder 6

Central linear

2. Angular Link Angular link is one of the important part of the gripping mechanism. It is an arm like link which is used to hold onto and release from the tree like a human arm. It is also made up of 30 x 20 rectangular cross sectional GI steel bar. Two angular links are pivoted on each of the two main bars at its centre. At the two ends of the angular links, holes of 10 mm diameter are provided. One for pivoting gripper and the other for pivoting one end of straight link. There are total of four angular links are in one climber.

actuator piston 7

Gripper linear

actuator cylinder 8

Gripper linear

actuator piston

4.2 MATERIAL DESCRIPTION GI Steel is used as the material for all the components manufactured because it is easily available, good weldability, high strength and low cost. It has a density of 8000 kg/mÂł making it suitable for selection based on weight reduction of the prototype within the available material. Its Poissonâ&#x20AC;&#x2122;s ratio is 0.3 and possesses hardness number of 95 HR B, its maximum strength is 193 GPa. So it can be made sure that the material can withstand considerable stress without failure. Thus GI steel is used as the material for main bars, angular links and straight links. Linear electrical actuators were chosen for providing power source. Electrical linear actuators were chosen because it is noise less, pollution free and easy to supply power as it operates on a 12 V DC battery. Here, three actuators were used. The specifications of the actuators were primarily based on their stroke length. Two of them having a stroke length of 150 mm were used for gripping mechanism as it would require only 150 mm stroke length maximum to hold on to the tree firmly. These actuators are capable of providing a maximum force of 4000 N. The third actuator used as the central body has a maximum stroke length of 400 mm as it is required to climb maximum safe distance vertically up or down along with the gripper mechanisms. It has the capability of providing a maximum force of 6000 N. 4.3 PRODUCT PARTS 1. Main Bar

3. Straight Link Straight link is a rectangular cross sectional GI steel bar of 300 mm length. One end of the straight link is pivoted at one end of the angular link and the other end is pivoted to the linear actuator piston end. There are two straight links in one gripping mechanism. The force applied by the linear actuator is distributed to the angular links through these straight links. There are a total of four straight links; two for each gripping mechanism.

4. Bush It is an arc like structure made up of metallic rectangular bar. It acts like a palm of a human being for gripping on the tree surface as the angular links contract together. The bush is pivoted at the free end of the angular link. There are two bushes in a gripping mechanism.

7. Gripper linear actuator Cylinder It is the cylinder of the linear actuator used in gripper mechanism for the movement of links. The actuator is firmly fixed at the centre of the main bars by means of clamping and bolting.

5. Central linear actuator cylinder It is the cylinder of electrical linear actuator in which the piston of actuator moves up and down. The closed end of the cylinder is fixed on the bottom gripping mechanism at the centre of the main bar through bolting.

8. Gripper linear actuator piston It is the piston of the linear actuator used in gripping mechanism. One end of each straight links in the gripping mechanism is pivoted at the free end of this piston.

FINAL ASSEMBLY The final assembly of the semi automated coconut tree climber is obtained by assembling each part of the product as per the design. The assembly mainly consist of three parts. They are two gripping mechanisms and one central body. The gripping mechanism consists of two angular links, two arms, two straight links and a linear actuator as shown in the figure. One of the two gripping mechanisms is fixed on the top of central linear actuator piston and other one is fixed at the bottom end of central linear actuator cylinder. 6. Central linear actuator piston It is the piston of linear actuator of the central body. The free end of the piston is fixed on the upper gripping mechanism at the centre of the main bar.

outward movement. The actuator consists of a piston, cylinder and a 12V DC motor. The 12V DC motor is powering a long threaded screw on which the piston moves to and fro. As the motor rotates in one direction, the piston screwed out and on opposite rotation of the motor, the piston moves linearly inward. Thus the outward and inward movement of the piston can be achieved by simply changing the polarity of the motor. For smooth movement of the piston and for reduction of effort, running metallic balls are used between the piston and screw. The linear electrical actuator is designed in such a way that the piston movement can be controlled by electrical signals. The motor gets stopped automatically when the maximum stoke length of the piston is reached. The linear electrical actuator used in the central body is having a stroke length of 400 mm and a velocity of 15 mm/sec. It has a maximum capacity of 6000 N.

2. Gripping Mechanism It is the mechanism used for griping and holding on the cylindrical tree surface. The mechanism is a simple link mechanism consisting of four links and a base bar. Rectangular hollow GI steel bar is used for links. There are two angular arm links provided on the base bar, with a 30 mm distance between them as shown in the figure, to hold on to the tree. These links can rotate about the pivoted points on the base bar. At one end of each angular link arc shaped grippers are provided which comes in contact with the tree surface. Other end of the angular link is connected to a straight rod by pivoted joint. Other end of the straight rod is fixed on the piston end of the linear electrical actuator. The linear actuator used for gripping has a stroke length of 150 mm and can provide a force of 4000 N. The actuator is fixed firmly at the centre of the base bar by clamping and bolting. As the piston moves outward, it pushes both angular links through the straight rod at the point of contact of straight link with the angular link. Since the angular link is pivoted on the base rod, it can rotate about it, resulting in contraction of two arms. Thus the mechanism gets gripped on the tree surface. Similarly, as the piston moves inwards, the arms expand and the gripping is loosened.

V. MECHANISM AND WORKING Mechanism and working of semi automated coconut tree climber is very simple and easy. There are mainly three parts in this semi automated coconut tree climber. They are - two climbing mechanisms and a central body.

The gripping mechanism is used for gripping and holding on the coconut tree and central body consist of an electrical linear actuator which is used for vertical up and down motion through the tree. Each gripping mechanism is provided on the top and bottom of the central body which is the electrical linear actuator i.e. one gripping mechanism is fixed on the top of the piston of linear actuator other one is fixed on the bottom of the cylinder of linear actuator as shown in the figure. 5.1 MAIN PARTS 1. Central body The central body consists of an electrical linear actuator. An electrical linear actuator is a device used for linear inward and

6.1 STATIC LOAD ANALYSIS The static load analyses were carried out by applying the following conditions. 1. The contact surface of the bush is fixed.

3. Control Unit The workings of the linear actuators are controlled using a control unit. It consists of three centre-off-switches. Switches A and B are used for the expansion and contraction of the grippers at the top and bottom respectively. Switch C is used for the vertical up and down motion of the body.

2. Static force applied to the plunger is 20N

5.2 WORKING OF CLIMBER The climbing mechanism of the semi automated coconut tree climber is very much similar to a man climbing up and down a tree. There are five sequential actions for climbing the tree. They are tightening the lower grip, raising the central body along with the upper gripper, tightening the upper gripper, releasing the lower gripper and finally raising the central body along with the lower gripper. At first, the lower gripper is fixed on to the tree by operating the switch A on the control unit. Once the lower gripper is fixed, then the switch C is operated. By operating switch C, the piston of the central body moves upward to its maximum stroke length of 40mm. Once it reaches its maximum stroke length then switch B is operated to fix the top gripper on the tree. After the top gripper is fixed, the lower gripper is loosened by operating switch A. Finally, switch C is operated to carry the lower gripper upwards by the backward motion of the central actuator. This cycle of operation is continued till it reaches the top. For climbing downward, first switch A is operated for losing the lower gripper followed by switch C for downward motion of the central body. Then again switch A is operated to hold on to the tree. Next switch B is operated to loose the upper gripping followed by switch C to carry the upper gripper downward. This cycle of operations are then carried out to climb down.

3. Self weight is acting by gravity.

7.2 SOLUTION 1. Total deformation

VI. RESULTS & DISCUSSION

Figure shows the total deformation of the structure when a piston force of 20 N were applied. The maximum value of deformation was 0.736 mm and it occurs at the piston. The minimum deformation occurs at the bush and its value was found to be zero. Since the deformation value was very low, it was neglected. So the structure was found out to be safe after applying the force.

REFERENCES [1] Jothilingam A, Mani A, “Design and Fabrication of Coconut Harvesting Robot: COCOBOT”, International Journal of Innovative Research in Science, Engineering and Technology, Volume 3, Special Issue 3, March 2014. [2] Rajesh Kannan Megalingam, R Venumadhav, Ashis Pavan K, Anandkumar Mahadevan, Tom Charly Kattakayam, and Harikrishna Menon T, “Kinect Based Wireless Robotic Coconut Tree Climber”, 3rd International Conference on Advancements in Electronics and Power Engineering ,January 2013. [3] A. P. Mohankumar, D. Anantha Krishnan and K. Kathirvel, “Development of ergo refined coconut tree climbing device”, African Journal of Agricultural Research, Volume 8, November 2013.

2. Stress distribution Figure shows the stress distribution on the structure as a result of the force applied. The maximum value of normal stress was 14.8 MPa and it occurs at the region where the straight links are attached to the piston end. The maximum stress was observed at that region were it comes in direct contact with the applied force by the piston. The minimum normal stress occurs at the angular links and its value was found out to be -14.78 MPa. Since the maximum value of normal stress was found out to be very much lower than the permissible limit of 193 GPa, the design was found to be safe under the given conditions and load.

VII. CONCLUSION & FUTURE SCOPE The design of the prototype was done using Solid Works 14 and the static load analysis by ANSYS 14.5. Using trial and error method and static load analysis, suitable material was chosen and fabrication of the prototype was successfully done. From the analysis, the maximum stress was obtained as 1.4815 ×107 Pa which is safe and it occurred at the region were the links are attached to the actuator. The prototype was then tested under real life conditions and suitable changes were made to the prototype. The final prototype thus obtained was found to be successful and fully operational. In the future, the climber can be fully automated. Instead of manual controlling, the whole operation can be programmed into a micro controller. Pressure sensors can be used to determine how much pressure to be applied after the bush comes in contact with the wood. A robotic arm can be used to harvest coconuts. Ph sensors can be used to differentiate between tender coconut and coconut. At present GI steel is used as the material. It can be replaced with aluminium composites or nano fibres which are 10 times stronger and lighter than GI steel.

HIGH ALTITUDE AIR FLOW REGULATION FOR AUTOMOBILES Arun K Varghese, Saran S, Shaiju Joseph, Sherin George, Sreelal M

Abstract: High altitude performance is a major concern for automobiles. Due to lack of air density and pressure at high altitude the mass flow rate to engine drops considerably with altitude. This in turn will affect the volumetric efficiency of the engine. This is an area of great concern for Indian road conditions. The Indian road condition varies from sea level to around 6000m. Thus the engine performance varies drastically will altitude. We had considered flow through the inlet manifold for a four cylinder turbocharger diesel engine at low and high rpm. At lower rpm at around 1500 the turbocharger boost pressure will negligible, thus the engine will be in natural aspiration. Now at this normal running condition the mass flow to engine drops considerably with altitude. Now for a speed of around 2500 rpm there is sufficient flow to around 3000m and then drops. The flow pattern for a single cylinder in open condition has analyzed to find the average mass flow for different altitude.

of HC, CO, NOx and smoke of diesel engine increase, as well as diesel exhaust particles number, especially at the engine speed of 2000 r/min [1]. At some special engine conditions, that is heave-load and low-speed, the reduced emissions of HC and NOx can be observed at high altitudes. Kevin Norman et al.(2009), suggested clogging the air filter has no significant effect on the fuel economy of the newer vehicles (all fuel injected with closed-loop control and one equipped with MDS) [2]. The engine control systems were able to maintain the desired AFR regardless of intake restrictions, and therefore fuel consumption was not increased. The engine did show a decrease in fuel economy with increasing restriction. However, the level of restriction required to cause a substantial (10â&#x20AC;&#x201C;15%) decrease in fuel economy was so severe that the vehicle was almost un drivable. Acceleration performance on all vehicles was improved with a clean air filter. Nik Rosli Abdullah et al.(2013),analyzed the impact of air intake pressure on engine performance and emission characteristics of an SI engine [3]. This study will encourage the vehicle users to ensure their vehicleâ&#x20AC;&#x2122;s air filter is always in clean and good condition. Ensuring clean and good condition of air filter will maintain higher air intake pressure and absorption of polluted particles through air filter. Clogged and dirty air filter reduces the air intake pressure and thus the engine performance and fuel economy.

I. INTRODUCTION Altitude has a big effect on engine performance. The reason as altitude increases, air thins and as air is required for combustion, power produced by the engine decreases .But engine horse power falls off about 3 percent for each 1000 feet above sea level. In India the road conditions ranges from sea level to 6000m. That is power produced by engine falls to 18%. We know that volumetric efficiency is one of major factor that determines the performance of an ICE. One of the major factors that influence on volumetric efficiency is air mass flow rate towards engine. As altitude increases atmospheric pressure decreases so mean effective pressure decreases. Altitude increases air density also decreases. We can note considerable deduction in engine performance. One of the methods of increasing power output is by means of increasing mean effective pressure. Our aim is to provide sufficient air flow to the engine so as to improve the efficiency of the engine at normal speeds even at high altitudes. In order to obtain that we are modifying intake system of an engine, by providing an additional passage with an electric supercharger at one end and connected to existing intake manifold. The mass flow rate and volumetric efficiency of existing system and proposed system has been studied and compared. Engine performs well at atmospheric condition so our aim is to provide sea level conditions at higher altitude. Supercharger is controlled with help of microcontroller governed by pressure and altitude sensors. When we reach an altitude of 1000m the supercharger is switched on. This system operates with in the turbo lag period Chao He et al.(2011),conducted a study on emission characteristic of a heavy duty diesel engine at higher altitudes and they inferred that as the altitude increases, the emissions

II. PROBLEM DEFENITION AND BACKGROUND In India the road conditions ranges from sea level conditions to around 6000m. As altitude increases the atmospheric pressure and air density decreases. This decrease in properties will reduce the performance of the engine at higher altitudes greatly affects volumetric efficiency. Even though there is a system to provide air at higher pressure to engine in order to improve the performance of the engine this is possible only when the engine rpm is above 1750. Up to this much of time engine gets only thin air so there by the engine performance obtained is undesirable. The lag noticed in boosting of air pressure accordance with engine rpm is called turbo lag. So our prime aim is to avoid turbo lag that is to create a situation at higher altitudes where engine gets required pressurized air at normal speed to obtain this condition. In order to obtain that we are modifying intake system of an engine, by providing an additional passage with an electric supercharger at one end and connected to existing intake manifold. The mass flow rate and volumetric efficiency of existing system and proposed system has been studied and compared. Engine performs well at atmospheric condition so our aim is to provide sea level conditions at higher altitude.

increase driving difficulties. Technically speaking as we go to higher altitudes the volumetric efficiency of the engine is found to be decreasing. So our first step towards this project is to verify the problem. We discussed in team, guide and heavy vehicle drivers. After that we verified the problem, then our next step was to find key factor that cause these problems. Then we notice that as altitude increases the atmospheric pressure and air density is found to be decreasing. Then we studied the effect of decrease in atmospheric pressure and air density in the performance of the engine. To make analysis simpler we chosen different altitudes, 0m, 1500m, 3000m, 4500m, 6000m. Our next step to find out atmospheric pressures and air densities at above mentioned altitudes. Various atmospheric pressure and densities as shown in Table I and Table II. Pressure at various altitudes obtained by using the relation, P=100{ [44331.514-Z ] / 11880.516 }5.255

Supercharger is controlled with help of microcontroller governed by pressure and altitude sensors. When we reach an altitude of 1000m the supercharger is switched on. This system operates with in the turbo lag period.

X axis- altitude (m)

Y axis-pressure (kPa)

Fig. 1 Pressure variation with altitude

TABLE I VARIATION OF ATMOSPHERIC PRESSURE WITH ALTITUDES

1.4

ALTITUDE, Z (m) 0 1500 3000 4500 6000

1.2 1 0.8 0.6 0.4

Variation of density with altitude using the relation, P = Ď RT Temperatures at different altitudes find out Gay Lusaccâ&#x20AC;&#x2122;s law, then substituting in above equation, we get densities,

0.2 0 0

2000

4000

6000

PRESSURE(kPa) 101.325 85 72 61 51

8000

TABLE II VARIATION OF DENSITY WITH ALTITUDES

X axis-altitude (m) Y axis-density (kg/m^3)

ALTITUDES (m) 0 1500 3000 4500 6000

Fig. 2 Variation of air density with altitude

From the above two Figures, we can see that as we going to higher altitude there is a considerable decrease in atmospheric pressure and air density. The density of air decreases about 7% for every 1000m altitude. The Indian road conditions ranges between 0 to 6000m. We can see that for top road conditions performance decreases about 50%. At present automobiles employ supercharging and turbocharging systems that rely only on engine speed. They are capable of providing sufficient boost at high rpm. But at normal speeds the boost is so low. Thus for normal speeds the need for pressure boost is needed, the system must be independent of engine speeds but depend on the altitude of operation and manifold pressure. This will allow us to provide the sufficient boost at normal speeds based on altitude only.

DENSITY (kg/m3) 1.225 1 0.83 0.71 0.635

We calculated volumetric efficiencies of the engine at different conditions for speed of 1500 rpm. We compared the volumetric efficiency of the proposed system with that of existing one at a speed of 1500 rpm. The flow pattern, static pressure and velocity profile has been analyzed using ANSYS 15. The Figures 3 and 4 shows the turbulence produced at different inserting positions. To identify the optimum position to insert secondary passage, we considered two cases in which the secondary passage given perpendicular to main inlet and in other case the secondary passage given at an inclined angle (450). It is observed that in first position the mass flow rate found to be lesser than that of second case. And observed that the turbulence kinetic energy also found to be lower than that

III. METHODLOGY ADOPTED For starting every work we should find out a problem, the topic was selected by us by counting difficulties faced in driving at higher altitudes. When we go to higher altitudes vehicle pulling power is found to be decreasing this will

of second case. So the undesirable effect cavitation can be reduced in second case. So second position considered.

Fig. 5 Existing model

Fig.3 Turbulence effect for the given position

Fig. 6 Proposed model TABLE III MESH DETAILS

Nodes Elements Mesh size Equation used Analysis type Fig.4 Turbulence effect for the given position

2279 2120 0.05mm K and epsilon Steady state

Table III shows mesh details of ANSYS analysis. First we had obtained the various inlet and exit values of the manifold. We are considering a steady state analysis of the manifold with a single cylinder in open condition. Thus a suction pressure is provided at the cylinder and different air pressures are provided at inlet. The main two pressure losses are due to friction losses and filter losses. The friction losses occurring in the intake system is assumed to be a constant whose value is around 8.5 kPa. The other main loss is filter losses, it is around 1.5kPa. So the total loss is around 10 kPa, which is a constant. Figure 7 shows air pressure filter losses in intake manifold.

IV. HIGH ALTITUDE AIR FLOW REGULATOR In order to create model first of all we need to select an engine to get dimensions for modelling of intake manifold. The most popular Hyundai i20 CRDI 1.4 l diesel engine selected. The engine specification given below, • 4 cylinder 4 stroke diesel • Swept volume 1336 cc • Maximum torque 220 Nm • Bore 2.95” • Stroke 3.11” • Maximum power 89 bhp In order to provide air at a higher pressure we use a turbocharger which will come in to operation when engine rpm gets beyond 1750 rpm. The turbocharger placed in main passage which will compress the air to required pressure. But this is not sufficient at higher altitudes at normal speeds due to lack of boost pressure at lower rpm. The Figures 5 shows catia model of existing manifold and Figure 6 shows catia model of proposed system. In order to avoid the problem faced in higher altitudes we introduce a secondary passage which runs parallel to main passage. The secondary passage gives sufficient air flow to the manifold with the help of supercharger fitted at one end.

Fig. 7 Air filter losses

TABLE IV BOUNDARY CONDITIONS FOR EXISTING SYSTEM

INLET PRESSURE (kPa) 91 75 62 51 41

ALTITUDE (m) 0 1500 3000 4500 6000

OUTLET PRESSURE (kPa) -10 -10 -10 -10 -10

condition. To get transient values we took rms values of steady state analysis. Using above given values steady state analysis of the manifold using ANSYS workbench 15.0.The values obtained were compared and plotted. The micro controlled based governing system has been proposed along with analysis. The governing system consist of manifold absolute pressure sensor and an altitude sensor for real time data acquisition. The values obtained are passed through micro controller which governs the running of supercharger.

DENSITY (kg/m3) 1.225 1 .82 .71 .635

To improve the performance we runs a secondary passage parallel to main intake ,the secondary passage connected to main to a point before the region of turbulence to avoid cavitations. The secondary passage consist of an electric super charger ,an MAP is placed in main passage. When going to higher altitude then air density decreases at this time the electric super charger placed in secondary passage starts working and compress the air to a higher pressure corresponding to altitude, that is this system always trying to maintain sea level conditions. When the pressure reaches sea level conditions the electric super charger get switch off. Tables IV and V shows the boundary conditions of existing and proposed systems.

Fig.9 Diagram of proposed intake

The flow diagram of proposed system is shown in Figure 9, that there is an electrical control module with in which a barometric pressure sensor is placed. This will sense the pressure variation with altitude. The air pressure in main duct can be measured by MAP. We can set a suitable pressure value in control module which is close to sea level conditions. As the vehicle going to higher altitude the difference between MAP and barometric reading increases. When the difference goes beyond the limit the supercharger placed in secondary passage will activated. So mass flow of air can be improved. When MAP reads sea level condition the secondary duct will cut off automatically. Our prime aim is to improve the volumetric efficiency,

TABLE V BOUNDARY CONDITIONS OF PROPOSED SYSTEM

Primary inlet pressure (kpa) 91 75 62 51 41

Secondary inlet pressure (kpa) 91 109.47 96.47 85.47 75.47

Altitude (m)

Outlet pressure (kpa)

Density (kg/m3)

0 1500 3000 4500 6000

-10 -10 -10 -10 -10

1.225 1 0.83 0.71 0.635

 vol 

3456  CFM CID  RPM

CID = NOC x 0.7854 x bore2 x stroke CID = 4 x 0.7854 x 2.95 x 3.11 x 2.95 =85.08 in3 The mass flow of air of existing and proposed system studied and compared. After that the improvement in volumetric efficiency checked. TABLE VI COMPARISON OF MASS FLOW RATE Fig. 8 Valve timing diagram of 4 stroke engine

Altitude (m)

Even though the flow condition is transient we did our analysis on steady state condition. By noticing the above Figure 8 we can see that in every point on every stroke of engine there is suction taking place in one of four cylinders. So we can infer that the effect produced when one cylinder is opened for a period of time is equal to actual working

0 1500 3000 4500 6000

Mass flow of existing system (kg/s) 2.40 1.94 1.64 1.39 1.20

Mass flow of proposed system (kg/s) 2.4 2.2 1.89 1.65 1.44

From the Table VI we can see that the mass flow rate of air is increased as compared to existing system. By in cooperating additional passage to existing passage it will definitely improve the mass flow rate. It is seen that the mass flow rate increase about to 20% to 30%.

an additional secondary passage which will come in to action when the air pressure in main duct falls below. 90

TABLE VII COMPARISON OF VOLUMETRIC EFFICIENCY

Altitude(m) 0 1500 3000 4500 6000

ɳvol existing system (%) 78.56 64.8 53.7 45.73 39.02

ɳvol proposed system (%) 78.56 72.04 65.85 57.47 49.977

0 0

By in cooperating additional passage to existing passage it will definitely improve the mass flow rate. It is seen that the mass flow rate increase about to 20% to 30%. These variations are shown in Figures 10 and 11. VI. CONCLUSIONS It is seen that in existing automobiles when going to higher altitude mass flow rate found to be decreasing so that performance found to be inadequate. In order to improve the mass flow rate a secondary duct run parallel to main duct. Which is provided with an electric super charger. Which will come in to action when main inlet pressure falls under atmospheric pressure. The secondary duct helps to maintain pressure almost equal to sea level conditions. Improve the efficiency of the engine at normal speeds even at high altitudes. Proposed system the volumetric efficiency is found to be higher than that of existing system. The mass flow rate and volumetric efficiency of existing system and proposed system has been studied and compared. To provide sea level conditions at higher altitude. By doing so performance of the engine can be improved. The proposed system will improve the volumetric efficiency of the engine by about 10% in all altitudes. This system is cost effective and can be successfully implemented in any given vehicle with minimal modifications. The best suitable position for fixing the secondary passage is in between the inlet manifold and inlet duct. The flow pattern will not get changed inside the manifold in addition of the secondary duct. Thus this flow will not affect the resonator design. The flow pattern and the pressure developed in the manifold shows a improvement in flow rate at various altitudes. Air flow to engine is the only external factor that affects the engine performance at altitudes. The improvement

proposed system's mass flow(kg/s) 0

1500 3000 4500 6000

X -altitude(m)

Y-Volumetric efficiency(%)

Fig.11 Volumetric efficiency comparison

existing system's mass flow (kg/s)

1500 3000 4500 6000

X-Altitude(m)

2.5

0.5

Column1

V. RESULTS AND DISCUSSION It is seen that by adopting proposed system the volumetric efficiency can be improved to 8-15% from sea level to extreme high road conditions. Which is obtained by improving the mass flow rate to engine. So by referring to analysis report we can infer that our proposed system is a solution to get high volumetric efficiency in higher altitudes. Declined volumetric efficiency of current system is due to less air density in higher altitudes, this problem is rectified by providing a secondary passage with electric super charger. The supercharger is governed by micro controller.

1.5

proposed system's volumetric efficiency

From the above Table VII we can see that the volumetric efficiency of proposed system is higher than existing system. When the mass flow rate increases it will definitely increase the volumetric efficiency. With proposed system the volumetric efficiency can be increased to 8 % to 12 %.

existing system's volumetric efficiency

Y-mass flow rate(kg/s)

Fig. 10 Mass flow rate comparison

We can see that the mass flow rate of air is increased as compared to existing system. In our proposed system there is

in airflow will thus enhance the volumetric efficiency and in turn the overall efficiency of the engine. With the improvement in air flow the combustion will be better and the emission characteristics of the engine. Thus the CO emission and particulate emission will also drops. REFERENCE [1] Chao He, Yunshan Ge, Chaochen Ma, Jianwei Tan, Zhihua Liu, Chu Wang, Linxiao Yu, Yan Ding, "Emission characteristics of a heavy-duty diesel engine at simulated high altitudes", AJME, Vol. 409, 2011, pp 3138-3143. [2] Kevin Norman, Shean Huff, Brian West, "Effect of intake air filter condition on vehicle fuel economy", AJME, Vol. 68, 2009, pp 278-284. [3] Nik Rosli Abdullaha, Nafis Syabil Shahruddina, Aman Mohd, Ihsan Mamata, Salmiah Kasolanga, "Effects of Air intake pressure to the fuel economy and exhaust emissions on a small SI engine", MITC, Vol. 68, 2013, pp 264-273. [4] Shaohua Liu, Lizhong Shen, Yuhua Bi, Jilin Lei, "Effects of altitude and fuel oxygen content on the performance of a high pressure common rail diesel engine", AJME, Vol. 118, 2014, pp 243-249. [5] Xin Wang, Yunshan Ge, Linxiao Yu, Xiangyu Feng, "Effects of altitude on the thermal efficiency of a heavy-duty diesel engine", AJME, Vol. 59, 2013, pp 543-548. [6] John Heywood,"Internal combustion engines fundamentals",Tata Mcgraw Hill Education,UK, Vol 1,2011

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MULTISTAGE EPICYCLIC LUG WRENCH Nevin G Ninan, Nithin George, Salu Zachariah, Shinu Baby, Aju Zachariah Mani

Abstract— Each and everyone have some kind of vehicle for their daily usage and those who don’t have one, use any of the public transport. A common problem associated with all these vehicles is the removal and replacement of their wheels once they get damaged or flat. The lug nuts of heavy vehicles are removed by connecting a socket spanner to a long handle and then blowing this handle manually or with hammers. This takes a lot of human effort and may distort the fasteners and nuts. Although there are various mechanisms for removing lug nuts like lug wrenches, ratcheting socket wrench, impact wrenches, etc. but they are either time consuming, difficult to handle, non portable, power consuming or requires a lot of manual effort. Our aim through this project is to reduce the human effort in unscrewing the lug nut. The huddle lies in the fact that the equipment to be designed must be light weight, portable and lower in power and time consumption. For this, in the present project a multistage epicyclic gear train device is designed to unscrew the lug nuts of vehicles. The device is very compact, simple in construction, easy to handle, reduces the unscrewing time to a considerable extend, portable and is user friendly.

Keywords— Gears, gear design, multistage gears, case hardened alloy steel, torque

I. INTRODUCTION Nowadays automobiles are an essential part of human life. We cannot imagine a world without them. Each and everyone have some kind of vehicle for their daily usage (whether it is a car or a bike) and those who don’t have one use any of the public transport. Heavy vehicles like trucks are used to transport goods and other items. A common problem associated with all these vehicles is the removal and replacement of their wheels once they get damaged or flat. The tool set-up for each vehicle is a T-nut wrench and screw jack which is hard to use for a woman or teen to open their vehicle’s lug nuts. Although there are various other mechanisms to unscrew lug nuts, they are either time consuming, non-portable or need a lot of human effort. A lug nut or wheel nut is a fastener, specifically a nut, used to secure a wheel on a vehicle. Commonly used tool for lug nut removal is lug wrench. Lug wrenches may be Lshaped, or X-shaped. The form commonly found in car trunks is an L-shaped metal rod with a socket wrench on the bent end and a prying tip on the other end. Lug wrenches are much less

expensive because they lack the ability to measure or limit the force used. Installing a wheel with a lug wrench thus requires a bit of rough guessing about proper tightness. Excessive force can strip threads or make the nuts very difficult to remove. Also, uneven torque between the various lug nuts, or excessive torque, can lead to warping of the brake rotor if the car is equipped with disc brakes. An improved form of the lug wrench is the ratcheting socket wrench, often called a ratchet. There are also power tool versions of "air" ratchets which use compressed air power to drive air powered socket wrenches which tighten or loosen nuts or bolts. A second major variety of compressed air powered tools are impact wrenches which are used for common tasks such as lug nuts on wheels. Electric powered impact wrenches for the same tasks are not uncommon. Small cordless 12 Volt and 18 Volt impact drivers are often used today as powered ratchets to remove and install nuts and bolts. Hydraulic motor ratchets with their characteristic higher torque characteristics are rare outside of heavy industry. An impact wrench is a socket wrench power tool designed to deliver high torque output with minimal exertion by the user, by storing energy in a rotating mass, then delivering it suddenly to the output shaft. Compressed air is the most common power source for impact wrenches, providing a lowcost design with the best power-to-weight ratio. A simple vane motor is almost always used, usually with four to seven vanes, and various lubrication systems, the most common of which uses oiled air, while others may include special oil passages routed to the parts that need it and a separate, sealed oil system for the hammer assembly. Most impact wrenches drive the hammer directly from the motor, giving it fast action when the fastener requires only low torque. Electric impact wrenches are available, either mains powered, or for automotive use, 12-volt, 18-volt or 24-volt DC-powered. Recently, cordless electric impact wrenches have become common, although typically their power outputs are significantly lower than corded electric or air-powered equivalents. Some industrial tools are hydraulically powered, using high-speed hydraulic motors, and are used in some heavy equipment repair shops, large construction sites, and other areas where a suitable hydraulic supply is available. Hydraulic impact wrenches have the advantage of high powerto-weight ratio. But these are not portable. Some of the drawbacks of pneumatic power systems include high cost,

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require large size compressors to generate high torque and large power consumption. Disadvantages of electrical power systems include inability to operate at low speeds, physically large, expensive to produce and high maintenance cost. Hence an attempt was made to design a simple device to unscrew the lug nuts of heavy vehicles using epicyclic gear trains which can be hand operated, portable, less expensive and low weight. Objective of the current work also included the development of a solid model of the device in Solid Works as per the design and to conduct structural analysis of the developed model in ANSYS. In the current work we use gears to design a system that reduces the manual effort. Gears were invented by the Greek mechanics of Alexandria in the third century B.C., were considerably developed by the great Archimedes, and saw wide use in the Roman world. They found two main applications: in heavy-duty machines such as mills and irrigation wheels, where they transmitted considerable power, and in small-scale water-clocks, calendrical instruments and automata which could be of extraordinary sophistication, incorporating the differential and perhaps the hypoid gear [1]. In the current work our objective was to design a multistage speed reducer so that initial input torque given is minimum. A detailed overview of the design of a new two-stage cycloidal speed reducer with tooth modifications can be found in [2]. The effects of the design parameters of involute gears generated by rack-cutters and also a general algorithm for the kinematic synthesis of spur and helical gears can be found in [3]. Planetary gear sets possess numerous advantages over their parallel-axis counterparts in terms of their power density, tolerance insensitivity and noise attributes in addition to their kinematic flexibility. One potential disadvantage of planetary gear sets is power losses due to multiple planet branches, resulting from an increased number of gear meshes and bearings. The power losses of a planetary gear set can be grouped in two categories based on their dependence on load. Load-dependent (mechanical) power losses are induced by friction in external and internal gear mesh contact interfaces as well as at planet bearings while load-independent (spin) losses are associated with drag of the carrier assembly and gears, bearing viscous losses and oil-air pocketing at gear mesh interfaces. With the assumption that power losses of these components are independent of each other, a methodology that implements a family of models to predict total power loss of planetary gear sets including primary mechanical and spin loss components is proposed in [4]. II. EXPERIMENTAL METHODOLOGY We had to design an epicyclic gear train device which reduces the mechanical leverage in unscrewing lug nuts. It should be compact, easy to handle, have low weight and should be able to produce the desired output torque with least human effort. For heavy vehicles like buses and trucks maximum torque required to unscrew lug nuts is 1000Nm. So if we use a single stage epicyclic gear train, the system will be

of large size, heavy and difficult to handle. So we have to use a multistage epicyclic gear system for torque multiplication. In order to construct a multistage epicyclic gear train, initially we need to find the output of a single stage. So to find the number of rotations of the output shaft for a given input rpm, output torque and the number of stages required to produce the required torque, motion analysis and torque analysis was done [5]. After finding the number of stages required and the output of each stage, we had to find the spur gear data required for the design calculations. So formulas for the dimensional calculation of spur gear in terms of diametral pitch (P) and number of teeth (N) were used. These spur gear data were then used for the design of the system. For design three different materials were considered. These include case hardened alloy steel, cast iron and bronze. These materials were then checked for dynamic, static and wear tooth loads. For safe design static and wear tooth loads should be more than dynamic tooth load [6]. Next, we had to create a model of the device. So, using Solid Works a model of the required device was created. First, different components including sun gear, planet gears, ring gear, shaft, connecting bar, handle, etc. were generated as different parts and then assembled to have the required device.

Fig. 1 Meshed view of section of the device being analysed

Finally, static structural analysis of the created model was done in ANSYS for case hardened alloy steel, cast iron and bronze to find the equivalent stress, equivalent strain and total deformation of the device for various input conditions. This was done to find whether the material used for design was safe. III. RESULTS AND DISCUSSIONS A. Velocity of Arm & Number of Stages Data obtained from the motion analysis and torque analysis of the system is show in the Table.1. From the table it is clear

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that for an input velocity of 20rpm the velocity of the arm reduces to 3.75rpm in a single stage. So the velocity ratio of the system is found to be 0.1875. Results of torque analysis shows that three stages of epicyclic gear train are required to produce the desired torque output. Gear ratio of the system is 5.33. Table.2 shows the input and output velocities and torques for each of the three stages. For an input torque of 10Nm and 20Nm, the output at the end of third stage is 1517.22Nm and 3034.44Nm respectively. TABLE I RESULTS OF VELOCITY AND TORQUE ANALYSIS

Input velocity = 20rpm

TABLE III

DYNAMIC, STATIC AND WEAR TOOTH LOADS FOR DIFFERENT MATERIALS Dynamic

Static tooth

Wear

tooth load

load

tooth load

(N)

Bronze

2118.749

437.310

142.439

Cast iron-Grade 35

2118.750

359.015

449.092

Case hardened alloy steel

2118.774

2197.370

2428.725

Material

Input torque = 10Nm

Parameters

Magnitude

No. of stages

Velocity at the end of stage one

3.75rpm

Velocity at the end of stage three

0.13182rpm

Maximum output torque

1517.22Nm

Velocity ratio

0.1875

Gear ratio

5.33

C. Solid Model Figure.2 shows the model of the multistage epicyclic gear train device design to unscrew the lug nut of vehicles. The device works on hand power. Whenever a lug nut is to be removed, a socket is attached to the lug nut and the output shaft of the device is connected to the socket. Then the input shaft is rotated by means of a handle. The input torque now gets multiplied in each of the three stages, thus providing the necessary torque at the output shaft required to unscrew the lug nut with least human effort. The outer ring serves as the casing for the device, so no additional casing is required. Since the device is compact and is of less weight it can be easily handled and is portable.

TABLE II

INPUT AND OUTPUT VELOCITIES AND TORQUES FOR EACH STAGE Stage 1

Velocity

Input

3.75

0.703

(rpm)

Output

3.75

0.703

0.13182

Input

53.33

284.495

Torque

Output

53.33

284.495

1517.22

(Nm)

Input

106.667

568.99

Output

106.667

568.99

3034.44

B. Spur Gear Design Data In the present project, design of spur gear using three different materials was analysed for satisfying different design requirements. The materials used include case hardened alloy steel of BHN 650, cast iron of BHN 225 and bronze of BHN 80. Gears were tested for dynamic, static and wear tooth loads. Table.3 shows results of spur gear design using different materials. From the Table.3 it is clear that the static and wear tooth loads for bronze and cast iron are less than the dynamic tooth load. But for the design to be safe, static and wear tooth loads should be more than the dynamic tooth load. So it is not safe to use bronze and cast iron as gear material in the design. But in the case of case hardened alloy steel the static and wear tooth loads are more than the dynamic tooth load. So case hardened alloy steel is safe for design.

Fig. 2 Multistage epicyclic lug wrench

D. Structural Analysis Data The model of the device created was structurally analysed in ANSYS for equivalent stress, equivalent strain and deformation for three different materials (i.e. case hardened alloy steel cast iron and bronze). Table.4 shows the maximum and minimum values of stress, strain and deformation for each of the different materials. From Table.4 it is clear that the equivalent strain, equivalent stress and total deformation for

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case hardened alloy steel is much lower than cast iron and bronze. This may be due to the better material properties and strength of case hardened alloy steel compare to the other two. Alloy steel is case hardened by carburizing, quenching and tempering, which increases their fatigue resistance, toughness, hardness and wear resistance. The maximum equivalent stress of alloy steel is less than its ultimate stress, but it is not so in the case of bronze and cast iron. So alloy steel is structurally safe for design, which is in agreement with numerical calculation.

Fig. 5 Equivalent stress distribution for cast iron

IV. CONCLUSIONS

TABLE IV

MAXIMUM AND MINIMUM VALUES OF STRESS, STRAIN AND DEFORMATION

A mechanical device for unscrewing the lug nuts of vehicles was design using multistage epicyclic gear trains. The device offers better advantage over pneumatic, electric and hydraulic impact wrenches as it is hand operated and does not require any external power other than a little human effort. The device is compact, portable and is of less weight, so it can be easily handled. The use of the device can be extended to unscrewing nuts and bolts which are difficult to remove other than the lug nuts. A model of the device was created in the Solid Works and it was analyzed in ANSYS to find its equivalent stress, equivalent strain and total deformation.

Material Parameter Bronze

Cast iron

Alloy steel

Minimum

1.23×10-15

7.28×10-16

1.33×10-16

Strain

Maximum

2.34×10-2

2.22×10-2

4.08×10-3

Equivalent

Minimum

7.03×10-11

3.27×10-11

1.15×10-11

(MPa)

Maximum

2.37×103

2.38×103

8.38×102

Total

Minimum

Maximum

2.25×10-1

2.12×10-1

3.90×10-2

Equivalent Elastic

Stress

REFERENCES [1]

Deformation (mm)

[2]

Equivalent stress distribution obtained from static structural analysis of the section of the device for case hardened alloy steel, bronze and cast iron are show in Figures 3, 4 and 5. From Figures 3, 4 and 5 it is clear that the maximum stress is minimum in the case of case hardened alloy steel. Also, for alloy steel the maximum stress is below its ultimate stress, but it is not so in the case of bronze and cast iron. So alloy steel is safe for design.

Fig. 3 Equivalent stress distribution for case hardened alloy steel

Fig. 4 Equivalent stress distribution for bronze

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[3]

[4]

[5] [6]

M.J.T Lewis., “Gearing in the ancient world,” Endeavour, Vol. 17, 1993, Issue 3, pp. 110-115. Wan-Sung Lin., Yi-Pei Shih, Jyh-Jone Lee, “Design of a two-stage cycloidal gear reducer with tooth modifications,” Mechanism And Machine Theory, Vol. 79, 2014, pp. 184-197. G.Figliolini, P.Rea., “Effects of design parameters of involute gears generated by rack-cutters,” International Gear Conference, Lyon, 2014, pp. 294-302. D.Talbot, A.Kahraman., “A methodology to predict power losses of planetary gear sets,” International Gear Conference, Lyon, 2014, pp. 625-635. S.S. Rattan., Theory of machines, 3rd ed., Mc Graw Hill Publications, 2009. R.S. Khurmi, J.K. Gupta., Textbook of machine design, 14th ed., S Chand Publications, 2005.

REGENERATIVE SHOCK ABSORBER Tobin Thomas, Nidhin Abraham Mammen, Sethu Prakash S, Steve John, Varughese Punnoose Kochuparackal

Abstract: In the past decade, regenerative braking systems have become increasingly popular, recovering energy that would otherwise be lost through braking. However, another energy recovery mechanism that is still in the research stages is regenerative suspension systems. This technology has the ability to continuously recover a vehicle's vibration energy dissipation that occurs due to road irregularities, vehicle acceleration, and braking, and use the energy to reduce fuel consumption. A regenerative shock absorber is a type of shock absorber that converts intermittent linear motion and vibration into useful energy, such as electricity. Conventional shock absorbers simply dissipate this energy as heat. Regenerative shock absorbers utilize piston cylinder arrangement or generation of electricity. Piston undergoes compression and expansion with movement of vehicle. The system is designed in SOLIDWORKS. When used in an electric vehicle or hybrid electric vehicle the electricity generated by the shock absorber can be diverted to its power train to increase battery life. In non-electric vehicles the electricity can be used to power accessories such as air conditioning. Several different systems have been developed recently, though they are still in stages of development and not installed on production vehicles. This could be used on electric or hybrid vehicles (or normal vehicles) to capture energy which would otherwise be absorbed and wasted, and then convert it into electricity. The regenerative shock absorbers can harvest the power in a continuous way. We analytically determine the pressure and velocity at 0.5Hz and 1Hz. A graph is plotted between pressure and velocity. Analysis is performed in CFD and values are determined.

I. INTRODUCTION It is known that automobiles are inefficient, wasting over 80% of the energy stored in the fuel as heat. Thus eight of every ten gallons in the vehicleâ&#x20AC;&#x2122;s tank donâ&#x20AC;&#x2122;t help propel the vehicle; they are burned to overcome losses in the system. Automobile manufacturers have made costly strides to improve fuel economy. For example, regenerative braking is standard on many hybrid automobiles. Car manufacturers also spend a great deal of effort to reduce wing drag so as to improve fuel economy through streamlined, low drag automobile body designs. Manufacturers also use lighter, yet more expensive, materials to reduce vehicle weight to reduce fuel consumption. This investigation looks into the most efficacious rotary hydraulic mechanism of harvesting energy from a vehicle suspension system. More specifically, it investigates the viscous nature of the working fluid in a rotary design regenerative shock for more effective power transduction. Custom apparatuses were fabricated for the purpose of this investigation. Both dynamometer and vehicle retrofit testing were performed to evaluate the results of electrical generation.

Ebrahimi has proposed energy electromagnetic dampers that are capable of harvesting energy [1]. He employed existing suspension system and damper design knowledge to develop concept of electromagnetic dampers. The ultimate objective of this thesis is to employ existing suspension system and damper design knowledge together with new ideas from electromagnetic theories to develop new electromagnetic dampers. At the same time, the development of eddy current dampers, as a potential source for passive damping element in the final hybrid design, is considered and thoroughly studied. For the very first time, the eddy current damping effect is introduced for the automotive suspension applications. Li et al. proposed the vibration to be damped by both oil viscosity and operation of an electrical mechanism [2]. A three stage identification approach is introduced to facilitate the model parameter identification using cycle loading experiment. This paper has reported a novel energyharvesting hydraulic damper for simultaneously damping vibrations and harvesting energy. The vibration acting on the two terminals of a hydraulic damper was converted into amplified rotation of a hydraulic motor. The output of the motor was then connected to the rotor of an electromagnetic generator, thereby yielding considerable power. In the process, some of the energy of the vibration was dissipated by the oil flow and some by the electromagnetic generation. An analytical model was proposed to depict both the mechanical and electrical responses. Wang et al. studied the mathematical modeling of the shock absorber system [3]. A dynamic model of a shock absorber was evaluated. The results indicate that hydraulic circuit configuration regularizes the hydraulic flow to improve the efficiency of hydraulic motor in low-speed or high-pressure. For effective energy regeneration and vibration dampening, energy regenerative suspension systems have received more studies recently. This paper presents the dynamic modeling and a test system of a regenerative shock absorber system which converts vibration motion into rotary motion through the adjustment of hydraulic flow. We the group of young engineers found that, there is an impending need to make Non Conventional energy attain popular acclaim. This is also very essential to preserve the conventional sources of energy and explore viable alternatives like sustainable energy (the energy which we are already utilizing but for some safety of other uses we are suddenly wasting it, that can be reutilized), solar, wind and biomass that can enhance sustainable growth. What is more, such alternatives are environment friendly and easily replenishable. Therefore, they need to be thoroughly exploited with a functionally expedient, energy matrix mix. Adaptation of technology and employing them should be pursued right from

105

this moment to have a head start, be informed of the barriers in technology applications of the renewable variety and synergizing them with the existing, traditional power production technology and T&D networks. It is known that in coming times, wind energy will be the most cost-effective renewable resource. Yet, it is doubtful if any individual technology would hold centre-stage. Thus we selected kinetic generator means the “Energy in motion when it is suddenly applied with a sort of obstacle, then according to Newton’s law for every action there is an equal and opposite reaction. Utilization of this reaction is the basic reason behind the selection of this project work.” II. METHODOLOGY A. Working Of Regenerative Shock Absorber This is a hydraulic rotary shock absorber, a device that converts vertical motion into rotary motion via a hydraulic motor. It includes a piston disposed for reciprocating motion within a cylinder as a vehicle’s suspension system deflects. Hydraulic fluid is contained within the cylinder. A first circuit is in fluid communication with a first chamber in the cylinder on a first side of the piston, in fluid communication with a hydraulic motor and in fluid communication with a capacitive reservoir. Upon compression of the piston, hydraulic fluid passes through the hydraulic motor thereby turning a shaft thereby. A second fluid circuit is in fluid communication with a second chamber in the cylinder on the second side of the piston and also in fluid communication with the first chamber. Upon extension of the piston, hydraulic fluid passes from the second chamber to the first chamber. An electric generator is connected to the hydraulic motor shaft for generating electricity upon rotation of the shaft.

vehicle’s battery. It is preferred that the harvested electricity be used to power components on a vehicle that would otherwise strain the internal combustion engine, thereby increasing fuel efficiency. Beyond the basic fluid losses in the hydraulic circuits, damping is provided mostly by the electric generator as the counter-emf resists rotational motion of the armature relative to the stator. This resistance is transferred directly to the shock fluid by the hydraulic motor. The damping force provided by the motor is selected to be directly proportional to the velocity of the hydraulic fluid so that increased fluid velocity results in an increased damping force. The capacitive reservoir accommodates the piston shaft volume that is introduced upon the compression stroke of the shock absorber. The model chosen to use is a simple spring-based model in which the energy that is present in the vertical motion of a car can be observed in the compression and extension of its springs. The energy in a compressed spring is given by the equation 1 E   Fdx  kx 2 2 Using an experimentally determined value for k of 1.2 x 105 N/m, we find that for a 3500 pound automobile, vertical displacements store the amounts of energy in a single spring as shown below. We note that heavy truck springs are much stiffer. TABLE I POTENTIAL ENERGY THAT CAN BE HARVESTED

1 cm displacement: 6 J 3 cm displacement: 54 J 6 cm displacement: 216 J 9 cm displacement: 486 J

24 J Summing over four wheels

216 J 864 J 1994 J

We have approximated a normal city drive. Thus by assuming that the springs undergo vibrations of magnitudes 2 cm at a frequency 0.5 Hz and 1 Hz, keeping in mind that work is done both compressing and extending the spring so that energy can be harvested from both of these motions. Based on these assumptions, a one hour drive generates 1.34 kilowatthour of energy available to harvest. Fig. 1 Schematic Representation of Regenerative Shock Absorber

The device also includes a hydraulic circuit arrangement so that energy may be harvested during both compression and relaxation of the shock absorber. In this embodiment, upon compression or relaxation of the shock absorber, the resulting pressure differential across the hydraulic motor will induce rotational motion of its output shaft. This output shaft is directly connected to a permanent magnet generator or a DC electric motor. The wattage rating of the motor is selected entirely based on the vehicle’s mass and spring stiffness. The electrical energy generated may be used by the vehicle as it is generated or stored in, for example, the

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Fig. 2 Equilibrium Position of Regenerative Shock Absorber

With reference now to the drawing, Figure 2 illustrates the overall system in a first embodiment. Shock body 2 is a cylinder in which a piston 1 resides for reciprocating motion. Check valves 5, 6 and 7 control the flow of hydraulic fluid. The system also includes a hydraulic motor 3 and a capacitive reservoir 4. As the piston 1 is compressed, pressurized hydraulic fluid builds in the top part of a chamber 8 and is passed through the check valve 6. Check valve 5 prevents the hydraulic fluid from flowing into a bottom chamber 9. After passing through the check valve 6, the fluid is directed into a hydraulic motor 3 and into a capacitive reservoir 4. The capacitive reservoir 4 acts to store any impulsive pressure surges and smoothes out the pressure of the hydraulic fluid as it is fed into the hydraulic motor 3.

Fig. 3 Compressed Position of Regenerative Shock Absorber With reference now to Figure 3, as hydraulic fluid passes through the hydraulic motor 3, it rotates the motor’s shaft. The shaft of the motor 3 is coupled to a generator such as a permanent magnet generator. The output of the generator may charge a battery or power an automobile’s electric systems when the hydraulic motor turns.

Fig 5 Relaxation Position Flow characteristics of at least one of the fluid flow circuits may be selected to provide an effective damping in addition to recovery of energy. In this way, the system of the invention not only provides for energy recovery, but also effective damping for wheel control, thereby eliminating the need for a conventional shock absorber. The regenerative shock absorber of the present invention is applicable to any wheeled vehicle; heavy trucks remain a compelling target because of their substantial weight and high suspension spring stiffness. B. Working Fluid The conversion of linear to rotary motion is the basic mechanism that enables this to harvest the wasted energy of a vehicle’s suspension system. It is accomplished via hydraulics and the working fluid remains an essential component to investigate for optimal recovery. The viscosity of this fluid is of particular interest as it directly correlates to how pressure in the fluid flow is transduced to rotational motion of the hydraulic motor. The working fluid must have a medium range of kinematic viscosity. Too low a viscosity, there are losses in the pressure drop across the hydraulic motor. At the same time, however, there is less shear force experienced in bends around the fluid circuit. With a high viscosity fluid, there is highly effective power transfer at the hydraulic motor end, but losses sustained in the fluid circuit due to shear forces against the tubing walls. So we take Fork Oil 5W light as our working fluid. Fork Oil 5W light has been developed for universal use. III RESULTS AND DISCUSSIONS The following are the details of meshing done in ANSYS 15.0. Quad meshes are used for meshing. The meshing is done in ICEM software in ANSYS.

Fig. 4 Top Chamber Position of Regenerative Shock Absorber

Figure 4 illustrates fluid flow as the piston 1 extends. When the piston 1 moves downwardly, pressurized hydraulic fluid is compressed in the bottom portion of the chamber 9 and passes through check valve 5. Check valve 7 prevents the fluid from flowing back into the hydraulic motor 3. The fluid passing through the check valve 5 flows into the top chamber 8.

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Fig. 6 Gear Meshing

A. Specifications Cylinder height, h = 200mm Cylinder bore diameter, đ??ˇđ?&#x2018;?đ?&#x2018;&#x153;đ?&#x2018;&#x;đ?&#x2018;&#x2019; = 50mm Piston rod diameter, đ??ˇđ?&#x2018;&#x;đ?&#x2018;&#x153;đ?&#x2018;&#x2018; = 30mm Diameter of pipe, đ??ˇđ?&#x2018;?đ?&#x2018;&#x2013;đ?&#x2018;?đ?&#x2018;&#x2019; = 9.5mm The material used for cylinder is mild steel and for that of piston is steel. The youngâ&#x20AC;&#x2122;s modulus of steel is 210GPa.

The above contour represents the gear velocity when the pressurised fluid from the cylinder is passed through the gear. It is this velocity that determines how much the gear rotates so that the shaft attached along the centre of gear also rotates. Neglecting the losses, it is the shafts rotation that produces the voltage when coupled with the generator. From the above contour we can infer that at inlet of gear we obtain a velocity of 0.81m/s.

B. Contour Plots

Fig. 9 Velocity of gear at 0.5Hz

Fig.7 Compression stroke

Figure 7 represents the pressure at the inlet and outlet of cylinders. As mentioned above in the methodology the piston is compressed hence the fluid inside the cylinder is also compressed. Maximum compression occurs at a time of 0.53sec. From the contours so obtained we can infer that the pressure at inlet 3.9 x 103 Pa which is represented by the blue colour. At the other end the pressure is 21.8 Pa represented by the red colour. We can also infer that the pressure at inlet is the highest. This pressure is the potential driving force for the motor. During the return stroke the piston moves back to its original position thereby compressing the fluid below the piston. This forces the fluid back into the top chamber and ready for the next cycle of operation. From the contours obtained we can infer that during compression stroke the maximum pressure obtained is 2.9x103 Pa represented by the blue colour. At the top chamber the pressure is 6.29 Pa represented by the red colour. During return stroke a partial vacuum is created in the top chamber which forces the liquid to flow into the chamber.

Within this velocity range the type of motor to be coupled with along with the shaft is low rpm motors of range 300-900 rpm. The velocity decreases along the gear part because the fluid hits the teeth of the gear pump inorder to rotate it. The kinetic energy of fluid flow is used for the rotation of the gear.

Fig. 10 Velocity of fluid at 1Hz

The above figure shows the velocity of fluid in the cylinder when the analysis was carried for 1Hz. During compression stroke the fluid attains velocity as it passes through the gear pump and enters the bottom of cylinder.

Fig. 11 Pressure at 1HZ

Fig. 8 Return Stroke

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The above figure represents the velocity vectors along with the total pressure. We use vectorial representation for velocity. This contour is obtained by analysing the operation of damper at 1Hz.

[2] Chuan Li and Peter W Tse, “Fabrication of an energy harvesting hydraulic damper”, Department of systems engineering and engineering management, City University of Hong Kong, China, 2013. [3] Ruichen Wang, Zhi Chen, HaijunXu, Karsten Schmidt, FengshouGu and Andrew.D. Ball, “Modelling and Validation of a Regenerative Shock Absorber System”, Department of Computing and Engineering, Frankfurt University of Applied Sciences, Frankfurt, Germany. Proceedings of the 20th International Conference on Automation & Computing, Cranfield University, Bedfordshire, UK, 2014.

Fig. 12 Pressure velocity curve of 0.5 Hz

The Figure 12 shows the pressure Vs velocity curve obtained at 0.5 Hz. Here pressure is plotted along x-axis and velocity plotted along the y-axis. From the graph we can observe that with increase in pressure velocity increases. The values that are plotted is obtained from the analysis carried out for 0.5Hz at a time interval of 0.01sec. IV CONCLUSIONS A regenerative shock absorber system is designed and analysed, which utilizes hydraulic and mechanical transmissions so that it can convert the linear motion into rotary motion to generate electricity by excitation input. A sinusoidal input has been provided so that pressure and velocity at any frequency and amplitude can be tabulated. For this purpose a user defined function (UDF) is created. From the analysis performed sufficient pressure and velocity can be achieved inorder to couple a low rpm motor so as to generate electricity. Sinusoidal inputs of 0.5Hz and 1Hz is provided. A pressure Vs velocity curve is plotted and it can be seen that as pressure increases velocity also increases. With 0.5Hz and 1Hz we find that dampers designed for 1Hz has a higher pressure on the fluid. It can be concluded that different dampers can be designed for different frequency of operations. In future, there is possibility of developing the following:  To build a prototype of the regenerative shock absorber and determine the electricity produced quantitatively.  To utilize the power so generated to run auxiliary systems experimentally.  To develop shock absorber that is capable of generating electricity during both its stroke. REFERENCES [1] Babak Ebrahimi “Hybrid Electromagnetic Dampers for Vehicle Suspension Systems”, University of Waterloo, 2011.

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An Assessment on Design parameters and Vibration characteristics of Boiler Feed Pump for Auxiliary power consumption Nikhil Abraham , Sachin Chacko , Sethu Sathyan , Sreenath K G , Parvathy Venugopal

Abstract

Keywordsâ&#x20AC;&#x201D;High Pressure boiler Feed Pump; Deaertor; Boiler Drum;

High pressure boiler feed pump is a six stage horizontal centrifugal pump of barrel design casing. At RGCCPP, Boiler feed pump (BFP) takes water from the feed water system i.e. from the deaerator and provide this water to the boiler system, to generate steam which is responsible for rolling the Turbine to generate electricity. Normally Feed water pumped to the boiler is pumped to the Boiler's Drum where at the top point of the boiler, so we have to provide a pump that can handle huge pressure with high discharge to the boiler. BFP is usually rotate with 5000 rpm, 150 bar and can provide about 265 T/H. The HPBFP discharge pressure was around 160 kg/cm2, whereas HP Drum pressure (i.e. working pressure) is around 80 kg/cm2. So there was a large difference in pressure in HP Drum and HPBFP discharge, which should be the same.

I. INTRODUCTION Eighty Percentage 80% of thermal power plants has boiler feed pump, that takes the water from the feed water system i.e. from the deaerator and provide this water to the boiler system, to generate steam which is responsible for rolling the Turbine to generate electricity. Normally Feed water pumped to the boiler is pumped to the Boiler's Drum where at the top point of the boiler, so we have to provide big pump that can handle big pressure with great flow to the boiler.

Various methods suggested for controlling HPBFP discharge pressure are,

Boiler Feed Pump is one of the most sophisticated equipment in a thermal power station. This equipment is responsible for uninterrupted supply of feed water to the boiler under all operating conditions and therefore its reliability is of paramount importance. Furthermore, this being the highest speed rotating element in the whole combined Cycle, its efficient and reliable operation plays a major part in the reliability of the set which in turn depends upon the sizing criterion adopted along with design and manufacturing aspects.. It has got significant role in the operation of boilers. Boiler feed pump is used to feed water to steam generator boiler drum at desired pressure and temperature. As the water is fed to the steam generator it has to be at the temperature & pressure that of the steam generator. Boiler feed pump extract water from de-aerator and feed it to the boiler drum via economizer. Layout of boiler feed pump

a) Throttling b) Fluid coupling c) Impeller trimming d) Variable frequency drive e) Replacement of HPBFP gear box with modified gear box f) Magnadrive Among these Replacement of HPBFP gear box with modified gear box is the accepted solution by the industry. Modifying the gear ratio reduces output speed of BFP. As speed reduces, discharge pressure also reduces. Our aim was to reduce discharge pressure of BFP, thereby finding the most efficient method of reduced power consumption, which increases the efficiency of the plant. As the gearbox is getting replaced, it is essential to study vibration behavior of the pump. Hence experimental and numerical analysis of vibration characteristics is analyzed.

110

Table 1 showing specification of BFP in NTPC,kayamkulam Pump type

FK6D30 centrifugal pump)

No. of stages

Direction of rotation

Anticlockwise

Suction temperature in ( â&#x201E;&#x192;)

150

Specific weight (kg/cum)

916.9

Design flow in ( đ?&#x2018;&#x161;3 â &#x201E;â&#x201E;&#x17D;đ?&#x2018;&#x;)

265

Dynamic head ( m)

1409

Nomenclature

(Horizontal multi stage

Efficiency %

Speed rpm

4285

Input power kW

1166

Medium

Water at 150 deg c

Rating kW (Drive motor)

1500

Speed (motor)

1493 rpm

Electrical supply

6.6kV, 3 phase, 50Hz

A a c D f F l T t v đ?&#x153;&#x152; hf P N W p G đ?&#x153;&#x2018;

Cross sectional area (m2) Acceleration (m/s2) Centre distance (mm) Equivalent diameter of pipe (m) Coefficient of friction (dimensionless) Frequency (Hz) Equivalent length of pipe (m) Temperature (â&#x201E;&#x192;) Time (s) Velocity (m/s) Density (kg/m3) Head loss due to friction (kg/cm2) Pressure (N/m2) Speed (rpm) Angular speed (rad/s) Power (kW) Gear ratio (Dimensionless) Helix angle (Degree)

Subscripts b bfp e f g s m 1 2

Booster pump Boiler feed pump Exit Coefficient of friction Gear box Suction Motor Refers to pinion gear Refers to main gear

II. METHODOLOGY Reduction in discharge pressure can implementing any of the following 5 methods,

attained

[1] Variable frequency drive [2] Magna drive

The HPBFP is designed to give a discharge pressure of 160 kg/sq.cm. ie; when turbine runs at peak load. But it is not necessary for the turbine to run at peak load and it results in various damages. So the HPBFP is over designed. The discharge pressure of BFP can be reduced to required pressure I.E, 80 kg/sq.cm. when the steam turbine runs at base load. The project is concentrated on design parameters of a boiler feed pump, which is the most important feed pump in steam turbine plant of NTPC. The project includes vibration characteristics of the system also. The final effort is to reduce the power consumption and increase overall efficiency of the system.

[3] Impeller trimming [4] Throttling [5] Fluid coupling [6] Replacement of HPBFP gear box with modified gear box

Among the six methods, Replacement of HPBFP gear box with modified gear box is the accepted solution by the industry. Modifying the gear ratio reduces output speed of BFP. As speed reduces, discharge pressure also reduces. Our aim was to

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reduce discharge pressure of BFP, thereby finding the most efficient method of reduced power consumption, which increases the efficiency of the plant.

hf = Minor losses

7.237 kg/cm2 0.5 kg/cm2

Static head loss =

2.91 kg/cm2

Total head loss =

13.426+7.237+0.5+2.91

III. MAIN WORK A .Calculation for Finding Optimum Value of Discharge

24.073 kg/cm2

Pressure Pressure inside the Boiler drum

Equivalent length of pipe (HPBFP to deaerator), l = 40m Equivalent diameter of pipe, D = 0.130m

ď&#x201A;ˇ

Flow margin - 10% when operating at maximum capability corresponding to peaking capacity of the module.

ď&#x201A;ˇ

Pump head - be computed at frequency 47.5 Hz when the last SV of the drum is blowing at the max capability point

Velocity of flow through pipe = Ď Av m = Ď A

Mass flow rate,m velocity, v Discharge Ď

= 187 T/hr

Velocity of flow, v =

= 82 kg/cm2

Margin on friction pressure loss shall be = 20%

187â&#x2C6;&#x2014;103 â&#x2C6;&#x2014;4 1000â&#x2C6;&#x2014;đ?&#x153;&#x2039;â&#x2C6;&#x2014;0.1302 â&#x2C6;&#x2014;3600

Required pressure to be developed by HPBFP

= 3.91m/s Coefficient of friction,

= 0.14

Head loss due to friction, hf = =

= 82+24.037+margin

4flv2

=127.244 kg/cm2

2gd

4â&#x2C6;&#x2014;.14â&#x2C6;&#x2014;40â&#x2C6;&#x2014;3.912

B. New Speed Calculation For Required Pressure Using Affinity Law

2â&#x2C6;&#x2014;9.81â&#x2C6;&#x2014;0.130

= 134.26 m

2 Ps Nm = 2 Pe Ng

= 13.426 kg/cm2 Head loss in economizer mass, m

Where, Ps= pressure at suction

187 â&#x2C6;&#x2014; 103 = 3600 â&#x2C6;&#x2014; 920

Pe= pressure at exit

= 0.056 kg/s velocity, v

. 056 đ?&#x153;&#x2039; 1000 â&#x2C6;&#x2014; â&#x2C6;&#x2014; 0.1322 4

velocity, v hf

Nm=speed of the moter Ng=speed of the gear 20 14932 = 127 Ng2

= 0.07 m/s = =

Ng = 3762.24 rpm

4flv 2 2gd 4â&#x2C6;&#x2014;0.14â&#x2C6;&#x2014;18â&#x2C6;&#x2014;0.072

Power calculation

2â&#x2C6;&#x2014;9.81â&#x2C6;&#x2014;0.032

3 pb Nm = 3 pbfp Ng

= 0.078 m/tube For 920 tubes hf =

0.072*920 =

Where, Pb= Power at booster pump

72.37 m

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Pbfp = Power at HPBFP

Therefore T2 = 2.71 T1

70 14933 = Pbfp 37623

Since centre distance, c = 300=

Pbfp =1119.8 kW

[

đ?&#x2018;&#x2021;1

2đ?&#x153;&#x2039; 0.81

Power at HPBFP before replacing the gear = 1305 kW

T1 =30

Difference in power

= 1305- 1119.8

T2 =79

Power saved

= 185.2 kW

2.71 đ?&#x2018;&#x2021;1 0.86

[

đ?&#x2018;&#x2021;1

2đ?&#x153;&#x2039; cos 35Â°

đ?&#x2018;&#x2021;2 cos 30Â°

]

C. Gear Design Calculation

As the gearbox is getting replaced, it is essential to study vibration behavior of the pump. Due to faulty replacement there is unbalance in the system which causes excessive and unpleasant stresses in rotating system because of vibration. The vibration causes rapid wear of machine part such as bearings and gears.

In Helical gear, teeth are inclined to the axis of a gear. They can be right handed or left handed, depending upon the direction in which the helix slopes away from the viewer when a gear is viewed parallel to the axis of the gear. The two mating gears have parallel axes and equal helix angle. The contact between two teeth on the two gears is first made at one end which extends through the width of the wheel with the rotation of gears.

When the natural frequency of the system coincides with the external forcing frequency, it is called resonance. The speed at which resonance occurs are called critical speed or whipping speed. So it is important to find frequency of system to avoid the occurrence of critical speed, which may result in excessive noise and its breakage into pieces. Present case system has frequency around 50Hz, so after the replacement of HPBFP gear box the frequency of system should within the limit.

Therefore, Auxiliary power consumption of the boiler feed pump is reduced by 10%

D. Theoretical Calculation For Finding Frequency Of Hpbfp

Terminology of helical gears is ď&#x201A;ˇ ď&#x201A;ˇ

ď&#x201A;ˇ

The following data is obtained using lab view software

Helix angle: it is the angle at which the teeth are inclined to the axis of a gear. Circular pitch: it is the distance between corresponding points on adjacent teeth measured on the pitch circle Normal circular pitch: it is the shortest distance measured along the normal to helix between corresponding points on the adjacent teeth.

New speed Ng = 3962 rpm Therefore the gear ratio is, G =

Ng Nm

3962 1493

= 2.71

Velocity,

= 0.005m/s

Displacement,

= 1.5 * 10â&#x2C6;&#x2019;5 m

Therefore time,

= = 0.003s

Acceleration,

= = 1.66

d v

v t

Since, acceleration, a

= w2 d

i.e. angular speed, w

= 332.66 rad/s

Thus, frequency,

= 51Hz

Helix angle ,đ?&#x153;&#x2018;1 =35Â° and đ?&#x153;&#x2018;2 = 30Â° E. Analysis Of Frequency Of System Using Ansys 12.1 Centre distance = 300 mm Components of layout are booster pump,motor,gear box and boiler feed pump. Mass of each components are different so the frequency of vibration of entire system should be with in the limit. So it is important to study the vibrational characteristics of the layout after the replacement of gear box. Procedure used in ANSYS,

normal pitch = Pn =14 mm Let T1 = Number of teeth on pinion gear T2 = Number of teeth on main gear Gear ratio=

đ?&#x2018;&#x2021;2 đ?&#x2018;&#x2021;1

Input geometry

= 2.71

ď&#x201A;ˇ

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Read in geometry input file

Define materials  Set preferences as Structural  Define constant material properties Generate mesh  Define element type  Mesh the area  Extrude the meshed area into a meshed volume Apply loads  Unselect 2-D elements  Apply constraints to the model Obtain Solution  Specify analysis types and options  Solve Review results  List the natural frequencies  Animate the five mode shapes  Exit the ansys program

Fig 2 Contour plot of the deformation obtained

Table 2 Arrangement of components NUMBER COMPONENT 1 SUPPORT 2 BOOSTER PUMP 3 MOTOR 4 GEAR BOX 5 BOILER FEED PUMP 6 SUPPORT

Fig 3 Nodal solution

Fig 1 Analytical setup for vibration study

Fig 4 Result Summary

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From the theoretical calculation, the value of frequency is found to be 51Hz.Before replacement of gear box the frequency of system is around 50Hz.After the replacement, the frequency of system (52Hz) is within the limit. The theoretically found values are also compared using ANSYS software .since the values are within the limit, whipping speed will never occur. Thus the system is free from the problem related to vibration.

Number

pinion

gear

= 30 Number of teeth on main gear

= 79

Benefits of replacing gearbox ď&#x201A;ˇ

IV. RESULTS AND DISCUSSIONS ď&#x201A;ˇ

REPLACEMENT OF HPBFP GEAR BOX WITH MODIFIED GEAR BOX

Present case of speed gear box

ď&#x201A;ˇ

Let Pb be the discharge pressure of booster pump = 20 kg/cm2 Pbfp be the discharge pressure of Boiler feed pump = 160 kg/cm2 Nb be the speed of booster pump = 1493 rpm Nbfp be the speed of boiler feed pump = 4250 rpm

ď&#x201A;ˇ ď&#x201A;ˇ ď&#x201A;ˇ ď&#x201A;ˇ ď&#x201A;ˇ

Gear ratio of the system is 2.88 Whereas HP drum pressure is around 80 kg/cm2. So there is huge loss of pressure in HPDrum, hence instead of 160 kg/cm 2 (present case), we need only 120 kg/cm2 (Maximum).

Reduction in Power consumed by the pump is 225 kW / pump & ultimately APC by.0.25%. Annual saving is Rs 40 lakhs (considering 80% PLF & Rs. 1.3 as variable charge on gas). Total cost of replacement is around 41 lakhs (For gear box). It also resulted in reduction in HPBFP motor winding temp which normally goes up to alarm limit in peak summer. Reduced maintenance. No misalignment and vibration issues Less time and money spent aligning and maintaining equipment Longer equipment life

Table 3 Specifications of BFP before and after replacing the gear box

Modification Pb be the discharge pressure of booster pump = 20 kg/cm2 Pbfp be the modified discharge pressure of Boiler feed pump = 127 kg/cm2 Nb be the speed of booster pump = 1493 rpm Nbfp be the speed of boiler feed pump = x rpm Gear ratio of the system is 2.71 To find x, According to the affinity laws, Pb đ?&#x2018; đ?&#x2018;?2 = 2 Pđ?&#x2018;?đ?&#x2018;&#x201C;đ?&#x2018;? đ?&#x2018; đ?&#x2018;?đ?&#x2018;&#x201C;đ?&#x2018;? Therefore Nbfp =3762.24 rpm Power at HPBFP before replacing the gear

PARAMETER

BEFORE

AFTER

Speed

4250rpm

3762rpm

Power

1305Kw

1120kW

Discharge

187T/hr

Frequency

50Hz

51Hz

Number teeth on

Pressure

160kg/sq.cm

128kg/sq.cm

Gear ratio

2.88

2.71

pinion

= 1305 kW

Number teeth on Difference in the value of power after the replacement of gear box

teeth

main gear

= 1305- 1119.8 = 185.2 Kw

Modified Gear ratio of the system = 2.71

115

V.CONCLUSIONS

Annual saving is Rs 40 lakhs. Reduction in Power consumed by the pump is 185 kW / pump. Reduced maintenance in RC valve, HRSG valves etc Due to dynamic nature of environment in which power plant operate, optimization of plant auxiliaries should be a continues process. This will help in better plant performance and also to increase the profit margin.

The project is concentrated on design parameters of a boiler feed pump, which is the most important machinery in NTPC. The study includes vibration characteristics of the system also. The project has been made for the “Reduction in Auxiliary power consumption by the optimization of design parameters for Boiler Feed Pump”.

. Our endeavor has been to ensure that the selection results in the most economical and optimum design for continuous operation throughout the life of the plant. Main aim was to reduce discharge pressure of BFP, thereby finding the most efficient method of reduced power consumption, which increases the efficiency of the plant. Detailed study about reducing discharge pressure of boiler feed pump and most efficient method of reduced power consumption shows that the Replacement of HPBFP gear box of gear ratio 2.88 with modified gear box of gear ratio 2.71 is the best solution for the present case. Selection is due to low cost of replacing gearbox and with minimum change in existing system. Present case system has frequency around 50Hz, after the replacement of HPBFP gear box the frequency of system is within the limit. Thus the replacement of gear box in the system is safe.

REFERENCES [1] Sambhrant Srivastava et al ,Design analysis of Mixed Flow Pump Impeller Blades Using ANSYS and Prediction of its Parameters using Artificial Neural Network, International Journal of Engineering Research & Technology ,Vol. 2, Issue 7, pp.229-237, 2011 [2] Hu Si-ke et al ,Regulating Characteristics Analysis of Boiler Feed-water Pump, International Journal of Engineering Research & Technology,vol.1,issue 4, 2011 [3] Dr. R K Bansal “Fluid mechanics and hydraulic machines”, Lexmi Publication, 9th edition 2011. [4] V P Singh “Mechanical vibrations”, Dhnapat Rai Publication, 2nd edition 2011. [5] S.S Rattan “Theory of Machines” , Tata Mcgraw hill education Publication 3rd edition 2009. [6] Maintenance manual of Boiler feed pump from NTPC Kayakulam.

By replacing gearbox, auxiliary power consumption is reduced by 14 % and efficiency of the system is increased by 81.2%.Total cost of replacement is around 41 lakhs.

116

LEVER DRIVEN BICYCLE Mebin Mathew, Natheem Nasar, Rahul Mohan M, Vijaya Krishnan R, Er. K C Joseph

Abstract- The bicycle is only one of the many man-developed lever systems for land transport, but it is the sole remaining type that has a limited propulsive power. Millions of people around the world still rely on their trusty clunkers for cheap and efficient transportation. In fact, the global fleet approaches a billion, with the vast majority circulating in developing countries like Cuba and China where automobiles remain a luxury. Recreational riders continue to take to their wheels for exercise, adventure, and companionship. The Lever Driven Bicycle consists of the following parts: mounting plate, torsion spring and oscillating lever. The lever is pivoted at a point on the mounting plate which is fixed to the bicycle frame and a torsion spring is present in between the mounting plate and the lever. The end of the lever contains a gear sector which is in mesh with the free wheel. This changes the existing conventional driving mechanism by the oscillating motion of a lever into rotatory motion of the wheel. The downward motion of the lever is powered by the human leg and the return or the upward movement of the lever is achieved by the use of torsion spring. The main objectives of this project work is to reduce the effort which is required for cycling and provides a means of transportation to peoples with small disability to his or her legs (i.e. a person with a leg shorter than the other), reduced maintenance which is regularly required for a conventional bicycle (lubrication and tightening of the chain, freewheel and crank set), provides a way of transportation by applying effort only on a single lever and a new way for cycling to the cycling enthusiasts. Keywords— Bicycle Drives, Freewheel Mechanism, Mechanical Advantage, Torsion Spring.

INTRODUCTION

A. History The dandy horse, also called Draisienne or laufmaschine, was the first human means of transport to use only two wheels in tandem and was invented by the German Baron Karl von Drais. It is regarded as the modern bicycle's forerunner; Drais introduced it to the public in Mannheim in summer 1817 and in Paris in 1818. Its rider sat astride a wooden frame supported by two in-line wheels and pushed the vehicle along with his/her feet while steering the front wheel.

The first mechanically-propelled, two-wheeled vehicle may have been built by Kirkpatrick MacMillan, a Scottish blacksmith, in 1839, although the claim is often disputed. In the early 1860s, Frenchmen Pierre Michaux and Pierre Lallement took bicycle design in a new direction by adding a mechanical crank drive with pedals on an enlarged front wheel (the velocipede). Another French inventor named Douglas Grasso had a failed prototype of Pierre Lallement's bicycle several years earlier. Several inventions followed using rear-wheel drive, the best known being the rod-driven velocipede by Scotsman Thomas McCall in 1869. In that same year, bicycle wheels with wire spokes were patented by Eugène Meyer of Paris. The French vélocipède, made of iron and wood, developed into the "penny-farthing" (historically known as an "ordinary bicycle". In 1868 Rowley Turner, a sales agent of the Coventry Sewing Machine Company (which soon became the Coventry Machinist Company), brought a Michaux cycle to Coventry, England. Further innovations increased comfort and ushered in a second bicycle craze, the 1890s Golden Age of Bicycles. In 1888, Scotsman John Boyd Dunlop introduced the first practical pneumatic tire, which soon became universal. Soon after, the rear freewheel was developed, enabling the rider to coast. This refinement led to the 1890s invention of coaster brakes. Dérailleur gears and hand-operated Bowden cable-pull brakes were also developed during these years, but were only slowly adopted by casual riders. Bicycles and horse buggies were the two mainstays of private transportation just prior to the automobile, and the grading of smooth roads in the late 19th century was stimulated by the widespread advertising, production, and use of these devices. B. Problem To date there have been three principal drive types used to drive the motorcycle rear wheel. Shaft drive, belt drive and chain drive. All of them date back around 100 years, all have advantages and disadvantages. Shaft drive is very clean, very reliable and very durable but it is also complex, heavy and much more expensive to produce. On top of that, it has little or no ability to vary the final drive ratios making it almost useless for any

117

type of sports bike. Its use is generally restricted to big and fairly expensive touring bikes.

the complete rotation of the crank set for motion. He just only requires oscillating the lever with his legs up to his ability.

Belt drive is also very clean, quiet and relatively inexpensive to produce. However, the belts are not nearly as strong as chains. To make them as strong, they would need to make them wider and a belt running on a modern day superbike would need to be many inches wide, making it completely impractical. Changing gearing is also much more difficult and they are completely impractical off road.

The other objective of this project is the reduction of the maintenance which is regularly required for a conventional bicycle (lubrication and tightening of the chain, eliminates lubrication and replacement of the ball bearing in the crank set due to wearing while pedaling). Also it provides a way of transportation by applying effort on only a single lever.

Chain drive, on the other hand, is cheap to produce, is fairly durable, is narrow enough to pass the rear wheel easily, is strong enough for all modern day applications, can be used on or off road and can easily vary the gearing ratios. Its only real negatives are that it gradually wears out, is fairly noisy and is relatively messy with chain lubrication. Also regular tightening of the chain is always required for proper traction.

It also provides a new way for cycling to the cycling enthusiasts.

With this project the reduction in the regular maintenance and lubrication of the drive mechanism can be achieved. The main advantage of this project is that it reduces the effort while pedaling in an ordinary/conventional bicycle. A person with small disability can use this bicycle without any problem.

III. DESIGN A. Mechanical Advantage The mechanical advantage of a lever is the ratio of the length of the lever on the applied force side of the fulcrum to the length of the lever on the resistance force side of the fulcrum. It is also defined as the ratio of the resistance force to the applied force. MA =

C. Methodology To overcome the disadvantages of the existing drive mechanisms used in conventional bicycle, a new drive mechanism was designed. The designed mechanism is known as Lever Drive. Using SOLIDWORKS software, the new mechanism was designed and the analysis was done using ANSYS software. Finally the new drive mechanism was fabricated, implemented and tested on the conventional bicycle.

B. Arc Angle Angles are formed when two lines meet at a point. It is defined as the measure of turn between the two lines. The unit of angle is radians or degrees. It can be measured in degrees using the radius and the arc length of the circle. There are also other angles like complementary angles, supplementary angles, interior angles etc.

II. OBJECTIVES The main objective of this project is to modify the existing drive mechanism of a bicycle so as to reduce the effort which is required for the driving of a conventional bicycle. This can be achieved by modifying the existing drive mechanism of our conventional bicycle by removing the chain drive and attaching an oscillating lever pivoted at a point on the bicycle frame as discussed below and providing a gear sector at the end of the lever. The lever oscillates by an effort on the other end of the lever by human legs. Similarly there is another lever at the other side of the bicycle frame. The next objective of this project is to provide a means of transportation on the bicycle to a person with a small disability to his or her legs (i.e. a person with a leg shorter than the other). Thus by using the Lever Driven Bicycle the person with the disability will not have to extent his legs for

C. Helical Torsion Spring These are wound in a similar manner as helical compression or tension springs but the ends are shaped to transmit torque. The primary stress in helical torsion springs is bending stress whereas in compression or tension springs, the stresses are torsional shear stresses. Bending stress, ﾏッ = where T is the Torque acting on the spring and d is the diameter of the spring wire. Number of coils, n =

118

where Ć&#x; is the angle of twist, E is the modulus of elasticity and D is the mean diameter of the spring.

IV.

RESULTS AND DISCUSSIONS

The Lever Driven Bicycle consists of the following parts such as a mounting plate, a torsion spring, an oscillating lever. The parts of the Lever Driven Bicycle are shown in the fig. 1(b) and (c). The lever consists of a gear sector (in mesh with freewheel) at one end and a pedal at the other end. The mounting plate is mounted on the bicycle frame; the lever is mounted and pivoted at a point on the mounting plate and a torsion spring is present in between the mounting plate and the lever. This changes the existing conventional driving mechanism into Lever Drive mechanism, in which the lever oscillates by the effort of the human leg on the pedal. This oscillating motion of the lever is converted into rotatory motion of the free wheel and thus the rear wheel. The return of the lever is achieved by the use torsion spring at the pivoted point.

The equivalent stress distribution on the bicycle frame due to the loading is as shown in the fig. 2(c). It shows that a maximum of 2.1879e6 Pa is the maximum stress which is acting on the bicycle frame due to the loading. But the ultimate strength and yield strength of the bicycle frame material are 4.6e8 Pa and 2.5e8 Pa respectively. Therefore we can conclude from the analysis that the design of the bicycle frame is safe.

Fig.2 (a) Bicycle Frame. (b) Total Deformation. (c) Stress Distribution. (d) Strain Distribution.

Fig.1 (a) Lever Driven Bicycle. (b), (c) Parts of Lever Driven Bicycle.

Static structural analysis was carried out on the bicycle frame and is as shown in the figure 1. The total deformation of the frame was analyzed which is shown in the fig. 2(b). A load of 981 N was applied on the frame and the total deformation distribution was studied. A maximum of 8.7476e-8 m and a minimum of zero deformation were obtained. The equivalent elastic strain distribution on the bicycle frame due to the loading is as shown in the fig. 2(d). It shows that a maximum of 1.094e-5 m/m is the maximum elastic strain acting on the bicycle frame due to the loading.

The static structural analysis of the Lever Driven Bicycle was studied and various distributions were formulated. The fig.3 (a) shows the whole assembled Lever Driven Bicycle with the main parts: oscillating lever, torsion spring, mounting plate and gear sector. The total deformation of the assembly was analyzed which is shown in the fig.3 (b). A load of 441.45 N was applied on the assembly and the total deformation distribution was studied. A maximum of 0.0011187 m and a minimum of zero were obtained. The equivalent elastic strain distribution on the assembly due to the loading is as shown in the fig.3 (d). It shows that a maximum of 0.00070512 m/m is the maximum elastic strain acting on the assembly due to the loading. The equivalent stress distribution on the assembly due to the loading is as shown in the fig.3 (c). It shows that a maximum of 1.3961e8 Pa is the maximum stress which is acting on the assembly due to the loading. But the ultimate strength and yield strength of the material which used are 4.6e8 Pa and 2.5e8 Pa respectively. Therefore we can conclude from the analysis that the design of the Lever Driven Bicycle is safe. The mechanical advantage of the Lever Driven Bicycle was found to be greater than one. But for conventional bicycle the mechanical advantage was found to be less than one. All that it means is that the conventional bicycle is not designed to amplify force, but the Lever Driven Bicycle is designed for the same. Therefore we can say that the effort for riding a bicycle was reduced and the Lever

119

Driven Bicycle makes riding effortless. It provides a means of transportation on the bicycle to a person with a small disability to his or her legs (i.e. a person with a leg shorter than the other). Thus by using the Lever Driven Bicycle the person with the disability will not have to extent his legs for the complete rotation of the crank set for motion. He just only requires oscillating the lever with his legs up to his ability. The reduction of the maintenance which is regularly required for a conventional bicycle such as lubrication and tightening of the chain, eliminates lubrication of the ball bearing in the crank set and the replacement of the ball bearings in the crank set. It also provides a way of transportation by applying effort only on a single lever. It also provides a new way for cycling to the cycling enthusiasts.

The next conclusion of this project is to provide a means of transportation on the bicycle to a person with a small disability to his or her legs (i.e. a person with a leg shorter than the other). Thus by using the Lever Driven Bicycle the person with the disability will not have to extent his legs for the complete rotation of the crank set for motion. He just only requires oscillating the lever with his legs up to his ability. The other conclusion of this project is the reduction of the maintenance which is regularly required for a conventional bicycle such as lubrication and tightening of the chain, eliminates lubrication of the ball bearing in the crank set and completely removes the regular replacement of the ball bearing in the crank set. It also provides a way of transportation by applying effort only on a single lever. It also provides a new way for cycling to the cycling enthusiasts.

REFERENCES [1] S.S Rattan, “Theory of Machines”, 3rd Edition, McGraw Hill education Pvt. Ltd, 2013, pp. 23. [2] R.S Khurmi, “A Textbook of Machine Design”, 25th Revised Edition, S Chand Publication, 2005, pp. 820-884. [3] K. Lingaiah, “Machine Design Data book”, 2nd Edition, McGraw-Hill handbooks, 2007, pp. 20.1-20.33. [4] PSG, “Design Data”, 3rd Edition, Kalaikathir Achchagam Publication, 2012, pp. 7.131 [5] K.M. Boon, P. Klap, J.A. van Lanen, G.J. Letsoin, A.J. Jansen, “Does pedalling on a recumbent bicycle influence the cyclist’s steering behaviour?”, Procedia Engineering, Vol.72, 2003, pp.660-665. [6] ASTM A227 / A227M, “Standard Specification for Steel Wire, Cold-Drawn for Mechanical Springs”, Vol. 01.03, 2006, pp. 16-19.

Fig. 3 (a) Lever Driven Bicycle. (b) Total Deformation. (c) Stress Distribution. (d) Strain Distribution.

CONCLUSIONS

With the attachment of the mounting plate, the torsion spring, the lever and the gear sector on the bicycle frame we can reduce the effort for powering the bicycle. With successful fabrication we can say that the bicycle has been transformed into Lever Driven Bicycle. With the use of the Lever Driven Bicycle we can conclude the following 1.

The mechanical advantage of the Lever Driven Bicycle was found to be greater than one. But for conventional bicycle the mechanical advantage was found to be less than one. All that means is that the conventional bicycle is not designed to amplify force, but the Lever Driven Bicycle is designed for the same. Therefore the effort for riding a conventional bicycle was reduced by modifying it into a Lever Driven Bicycle.

120

Semi-Active Suspension for Two Wheelers Sanoop Soman, Sherry Shaji, Vipin T Thomas, Vishnu E.M, Arun K Varghese

Abstract—The Suspension of vehicle serves multi-purpose. It contributes to handling and provides comfort and safety. The most common form of front suspension for a modern motorcycle is the telescopic fork. The present telescopic suspension behaves in a similar manner at all road conditions. For example, a two wheeler with rigid suspension provides good handling and riding comfort on highways at high speeds. But it may not be suitable to rough road conditions. For such roads much softer suspension is preferred. It is clear that if the nature of the suspension can be varied according to the road conditions it will contribute to handling and riding comfort. The existing telescopic suspension in motorcycle is ‘passive’ in nature. In such a suspension the suspension characteristics are fixed by mass, spring and damper elements which are non-adjustable. They are effective only over a narrow range of disturbance inputs. A typical semi-active suspension is composed of a spring type element and a damper that is continuously adjustable. Thus the damper characteristics are continuously variable which makes it more preferable over passive suspension. In our work, we are developing an economic semiactive suspension system for two wheelers by modifying the existing telescopic suspension. Here we are varying the pressure of air column above the damping oil which changes the stiffness of the suspension. Thus the suspension characteristics can be varied by the rider according to the road condition and thus good handling and riding comfort can be achieved. The major advantage of this semi-active suspension is that it uses pressurized air for its functioning which is easily available and is of low cost. Also the rider has the provision to adjust the suspension according to his will which make it more flexible and user friendly. Keywords—Suspension System, Telescopic Fork, Damper Characteristics , Semi-active Suspension

INTRODUCTION

Suspension is the system of springs, shock absorbers and linkages that which connects a vehicle to its wheels and allows relative motion between the two. Suspension systems serve a dual purpose- contributing to the vehicle's road holding/handling and braking for good active safety and driving pleasure, and keeping vehicle occupants comfortable and reasonably well isolated from road noise, bumps, and vibrations. Isolation from the forces transmitted by external excitation is the fundamental task of any

suspension system. The suspension has several important functions. They are: 1)Support the weight of the frame, body, engine, transmission, drive train, and passengers, also called sprung weight. 2) Provide a smooth ride with minimal body movement. 3) Keep the tires firmly planted on the road surface for maximum control at all times. 4) Prevent excessive body squat during acceleration. 5) Prevent excessive body dive during deceleration. 6) Allow the wheels to turn from side to side for steering. 7) Work with the steering system to help keep the wheels in correct alignment. The typical motorcycle has a pair of fork tubes for the front suspension, and a swing arm with one or two shock absorbers for the rear suspension. The most common form of front suspension for a modern motorcycle is the telescopic fork. Other fork designs are girder forks, suspended on sprung parallel links (not common since the 1940s) and bottom leading link designs, not common since the 1960s.The forks can be most easily understood as simply large hydraulic shock absorbers with internal coil springs. They allow the front wheel to react to imperfections in the road while isolating the rest of the motorcycle from that motion. The top of the forks are connected to the motorcycle's frame in a triple tree clamp which allows the forks to be turned in order to steer the motorcycle. The bottom of the forks is connected to the front axle around which the front wheel spins. Motorcycles commonly have passive suspension. In passive type suspensions the suspension characteristics are fixed by the mass, spring, and damper elements and are nonadjustable. The fixed setting of a passive suspension system is always a compromise between comfort and safety for any input set of road conditions. Therefore, they are most effective over a narrow range of disturbance inputs. This is the main drawback of passive suspension which is widely used today. In this work, we are developing a semi-active suspension system for two wheelers by modifying the existing passive telescopic suspension. In a semi- active suspension the damping characteristics are continuously adjustable. Here we are varying the pressure of air column above the damping oil which changes the stiffness of the suspension. Thus the property of the suspension can be varied by the rider according to the road condition and thus handling and riding

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comfort can be improved. By adding variable damper and/or spring, driving comfort and safety can be considerably improved compared to suspension setups with fixed properties.

proposed system is economical and provides good handling and ride quality at all road conditions. The system requires much less power, and is less complex and more consistent and can provide great improvement in ride quality. III. DATA ACQUISITION

A. Problem Motorcycles commonly have passive suspension. In passive type suspensions the suspension characteristics are fixed by the mass, spring, and damper elements and are nonadjustable. The fixed setting of a passive suspension system is always a compromise between comfort and safety for any input set of road conditions. Therefore, they are most effective over a narrow range of disturbance inputs. This is the main drawback of passive suspension which is widely used today. Semi active / active suspension systems try to solve or at least reduce this conflict. The mechanism of semi active suspension system is the adaptation of the damping and / or stiffness of the spring to the actual demands. Active suspension in contrast provide an extra force input in addition to possible existing passive systems and therefore need much more energy. It is quite obvious that with increase in suspension stiffness there is improvement in quality of handling. But the ride quality is adversely affected. Existing suspensions in motorbikes uses much softer spring which provides better comfort but the handling is adversely affected. So a suspension which changes its stiffness will provide better handling and riding comfort at various road conditions. Semiactive suspensions such as Electro Rheological (ER) and Magneto Rheological(MR) are presently employed in four wheelers. But they are not feasible in two wheelers due to complex structure and high cost. So a low cost semi-active suspension which is simple and flexible has to be developed particularly for two wheelers.

A. Experimental Set-up The idea is to develop a test set-up of semi-active suspension by modifying the existing telescopic suspension. For that a motorbike with telescopic front fork (TVS Star) is selected. It is made sure that the suspension is in good working condition and the fork oil is changed for better result. Initially the bolts on top of the inner fork tubes are removed and the nuts inside the fork tubes which mates with the bolt is drilled vertically. Thus a direct contact is made between the atmosphere and suspension oil. Then air valves that are commonly used in tires are gas welded to the top of the nuts without any air gap. This set-up provides the provision to supply air at any pressure above the suspension oil. After that frames were made to fix the accelerometer to measure the vibrations of suspension. Two frames were made, one is fixed near the wheel hub and the other is fixed near the bracket as illustrated in Fig.1. The frames are placed in such a way that the accelerometer can be placed horizontally which in turn gives accurate results during testing. Data acquisition is done using an accelerometer and a data acquisition system coupled with LABVIEW software. Air is provided at different pressures to the suspension in order to find out the maximum pressure the oil seal can bear and it was found that the oil seal fails at a pressure of 85 kg/sq.cm. So the maximum pressure that can be supplied to the fork is 80 kg/sq.cm.

B. Methodology The passive telescopic suspension is studied in detail & the various factors affecting suspension behavior are analyzed. Then the suspension model is created using MATLAB and analyzed for various air pressures. To test the performance of suspension by varying air pressure, an experimental setup is made on a motor bike (TVS star). Modified suspension is tested at different road condition and data acquisition is done using an accelerometer coupled with LABVIEW software. To assess the suspension behavior, subjective rating done by riders with varying air pressures through various road conditions. II. OBJECTIVES The objective of this work is to study and develop a semi-active suspension system for two wheelers by modifying the existing telescopic suspension. The major disadvantages of the existing semi-active suspension technologies are the complexity and high cost associated which makes almost impossible to implement them in a common motor bike. The

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Fig. 1 Fixtures for Accelerometer

B. Governing equations Stiffness of coil spring C=

Gd4/8Nd3

where G = Modulus of rigidity d = Wire diameter n = No: of active turns D = Mean coil diameter Stiffness of air column KA = PA2/V where P = Pressure of air column A = Cross sectional Area V = Volume Fig. 3 Time vs Displacement & Time vs Velocity Graphs for Unsprung Mass at Normal Pressure

IV. RESULTS AND DISCUSSSIONS A.

Analytical Results

The work presented here tries to analyze the effect of suspension on vehicle performance for a given road input using different approaches namely analysis by using state space equations in MATLAB and through physical modeling using Simscape blockset library. Here we simulate the output response for sudden change in road profile of 0.1 m height.

Consider the time vs velocity graphs. At atmospheric pressure, the relative velocity of sprung and unsprung mass is found to be 2.55m/s. At high pressure, the relative velocity of sprung and unsprung mass is found to be 2.1m/s. There is about 0.45 m/s reduction in velocity. The decrease in relative velocity indicates the reduction in suspension movement and confirms that the suspension has become stiff when air pressure is increased.

The results obtained by analysis done using MATLAB software are illustrated. Fig. 2 and Fig. 3 shows the Time vs displacement and time vs velocity graphs for sprung and unsprung mass respectively at normal pressure.

Fig .4 and Fig.5 illustrates the Time vs Displacement and Time vs Velocity graphs for sprung and unsprung masses respectively at a pressure of 80 kg/sq.cm for a road profile of 0.1 m height.

Fig. 2 Time vs Displacement & Time vs Velocity Graphs for Sprung Mass at Normal Pressure

Fig .4 Time vs Displacement & Time vs Velocity Graphs for Sprung Mass at 80 kg/sq.cm

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Fig. 5 Time vs Displacement & Time vs Velocity Graphs for Unsprung Mass at 80 kg/sq.cm

It is known that even ven a small decrease or increase in sprung mass velocity can affect handling. Consider the graphs 4 and 3. Here,, in the time vs velocity plots the variation is about 0.45 m/s and it shows that variation of pressure has great effect on suspension behavior. The same can be inferred from the time vs displacement graphs. B. Experimental Results The results of objective assessment is plotted as PSD(Power Spectral Density) vs Frequency. ncy. The graphs show the behavior of the proposed suspension at various vari road conditions. Fig. 6 and Fig. 7 illustrates the graphs which shows PSD vs Frequency at smooth and rough road conditions respectively.

Fig. 6 PSD vs Frequency for Smooth Road at 80kg/sq.cm and Normal Pressure (At Sprung Mass)

Fig. 7 PSD vs Frequency for Rough Road at 80kg/sq.cm and Normal Pressure (At Sprung Mass)

The area under the PSD vs Frequency graphs indicates the energy content. The energy content available at the sprung mass is increased in both cases which show that the suspension is becoming stiff. For smooth road the energy content almost remains same. Butt for rough road the energy content at the sprung mass is very high at 80 kg/sq.cm when compared with that at atmospheric pressure. This very high energy content at sprung mass indicates that the rider will feel uncomfortable when he rides the bike at high pressure through rough road. V. CONCLUSIONS The ride comfort and handling quality are two important aspects of the customer while choosing a motor bike. The nature of suspension system and motorcycle geometry is the major factors which affect the above mentioned qualities. In our work we are to optimizing these qualities at various road conditions. For an existing motorbike, it is almost impossible to vary the geometric parameters to have effect in the riding. So, So the only way of controlling the ride comfort and handling is by varying the nature of the suspension system. The existing telescopic suspension in motorcycle is â&#x20AC;&#x2DC;passiveâ&#x20AC;&#x2122; in nature. In such a suspension the suspension characteristics are fixed by mass, spring and damper elements which are non-adjustable. adjustable. They are effective only over a narrow range of disturbance inputs. Also the common motorcycle suspensions are designed with much softer springs which will provide good riding comfort but handling becomes very difficult at certain conditions. This problem can be tackled by employing a semi-active active suspension system. In semi-active active suspension systems the damper characteristics is continuously variable which makes it more preferable over passive suspension. Even ven though there are many semi semi-active

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suspensions already present, they are meant for four wheelers and cannot be employed in a two wheeler-vehicle. Cost is another major factor which retards the implementation of semi-active suspensions in two-wheelers. In our work, we are developing an economic semi-active suspension system for two wheelers by modifying the existing telescopic suspension. Here we are varying the pressure of air column above the damping oil which changes the stiffness of the suspension. The stiffness of suspension can be varied by changing the pressure of air column above the suspension oil.

The system is very economic as the primary requirement is air which is easily available. The rider has the provision to vary the suspension characteristics which makes the system more flexible. The robust nature of the system makes it easily adaptable for most two wheeler vehicles with telescopic forks.

For smooth roads the air pressure inside the suspension should be increased so that handling can be improved without affecting comfort. But for rough road condition the pressurized air should be released from the forks so that the suspension becomes soft and thus improves the comfort which is the primary concern in such road conditions. While negotiating a curve the stiffer suspension provides good control. Another advantage is that it prevents excessive dive during sudden braking or deceleration and prevents excessive squat during acceleration.

[2]

REFERENCES [1]

[3]

[4]

[5]

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A.H.Gupta, “A Review Study- Design And Analysis Of Suspension System”, IJSRD - International Journal for Scientific Research & Development, Vol. 2, Issue 03, pp.1286-1289, 2014 Hashmi Ayas Jameel Ahmed, M.G Rathi, “Effects Of Damping Parameters On Damping Force Of Two Wheeler Front Suspension”, International Journal of Engineering Research & Technology, Vol. 2, Issue 7, pp.229-237, 2013 Rijumon, Ajith Krishnan, “A comparison between passive & semi active suspension systems”, International Journal of Innovative Research in Science, Engineering and Technology, Vol. 2, Issue 6 ,pp. 2412 - 2416, 2013 Pankaj Sharma, “Analysis of Automotive Passive Suspension System with Matlab Program Generation”, International Journal of Advancements in Technology, Vol. 4, pp. 115-119, 2013 Williamson M, “Design and Analysis of Two Wheeler Shock Absorber Coil Spring”, International OPEN ACCESS Journal Of Modern Engineering Research (IJMER) , Vol. 3, pp.136-142 , 2012

DESIGN AND FABRICATION OF HAND PUMP OPERATED WATER PURIFICATION SYSTEM USING REVERSE OSMOSIS Nikhil Jacob Zachariah, Vimal P Sunil, SachinTomy, Vijith K

Abstract: Drinking water is a necessity to which millions of people throughout the world have limited access. Water is often seen as the most basic and accessible element of life, and seemingly the most plentiful. More than a billion people lack access to drinking Water. Simply providing access to clean Water could save two million lives each year. As the population grows, the freshwater available to each resident dwindles. Water purification is the removal of contaminants from untreated water to produce drinking water that is pure enough for human consumption. Substances that are removed during the process include parasites, bacteria, algae, viruses, fungi, minerals (including toxic metals such as lead, copper and arsenic), and man-made chemical pollutants. In this paper, an apparatus and methods for producing purified drinking water are disclosed. A hand pump is used in a closed system to generate pressure to pass the water through a series of filters and a reverse osmosis membrane to obtain potable water at the outlet. The flow obtained was analysed using ANSYS and the system delivering highest output was chosen. The project facilitates the availability of pure drinking water without using any electrical components or devices. It is a cheap and efficient means to produce drinking water.

I. INTRODUCTION Safe drinking water is essential to humans and other life forms even though it provides no calories or organic nutrients. Access to safe drinking water has improved over the last decades in almost every part of the world, but approximately one billion people still lack access to safe water and over 2.5 billion lack access to adequate sanitation. However, some observers have estimated that by 2025 more than half of the world population will be facing water-based vulnerability. Water that is not potable may be made potable by filtration or distillation, or by a range of other methods. Currently, about a billion people around the world routinely drink unhealthy water. Globally, improving water, sanitation and hygiene has the potential to prevent at least 9.1 per cent of the disease burden, or 6.3 per cent of all deaths. Deaths due to water related diseases in India are in the range of nearly 80%. The availability of fresh and good quality drinking water to all Indians remains a concern. As such we decided to design an apparatus that could produce clean and safe drinking water at low cost and effectively and also without using electricity since majority of the remote areas of our country still don't have access to electricity. Hence an attempt was made with following objectives:

To design a simple device that could produce clean and safe drinking water. To develop a solid model of the device in Solid Works and meshing was done using ICEM CFD. To conduct analysis using ANSYS FLUENT. To analyse different configurations and based on the results the working model is fabricated. To test the purity of water hence obtained. II. THEORY A. WATER PURIFICATION Water purification is the process of removing undesirable chemicals, biological contaminants, suspended solids and gases from contaminated water. The goal of this process is to produce water fit for a specific purpose. Most water is disinfected for human consumption (drinking water) but water purification may also be designed for a variety of other purposes, including meeting the requirements of medical, pharmacological, chemical and industrial applications. In general the methods used include physical processes such as filtration, sedimentation, and distillation, biological processes such as slow sand filters or biologically active carbon, chemical processes such as flocculation and chlorination and the use of electromagnetic radiation such as ultraviolet light. The purification process of water may reduce the concentration of particulate matter including suspended particles, parasites, bacteria, algae, viruses, fungi; and a range of dissolved and particulate material derived from the surfaces that water may have made contact with after falling as rain. The standards for drinking water quality are typically set by governments or by international standards. These standards will typically set minimum and maximum concentrations of contaminants for the use that is to be made of the water. B. HAND PUMP Hand pumps are manually operated pumps they use human power and mechanical advantage to move fluids or air from one place to another. They are widely used in every country in the world for a variety of industrial, marine, irrigation and leisure activities. There are many different types of hand pump available, mainly operating on a piston, diaphragm or rotary vane principle with a check valve on the entry and exit ports to the chamber operating in opposing directions. Most hand pumps have plungers or reciprocating pistons, and are positive displacement.

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B. PRE CARBON FILTER Carbon filtering is a method of filtering that uses a bed of activated carbon to remove contaminants and impurities, using chemical absorption. Each particle/granule of carbon provides a large surface area/pore structure, allowing contaminants the maximum possible exposure to the active sites within the filter media. One pound (450 g) of activated carbon contains a surface area of approximately 100 acres (40 Hectares). Active charcoal carbon filters are most effective removing chlorine, sediment, volatile organic compounds (VOCs), taste and odor from water. They are not effective at removing minerals, salts, and dissolved inorganic compounds. Typical particle sizes that can be removed by carbon filters range from 0.5 to 50 micrometers. The particle size will be used as part of the filter description. The efficacy of a carbon filter is also based upon the flow rate regulation. When the water is allowed to flow through the filter at a slower rate, the contaminants are exposed to the filter media for a longer amount of time. .

apore size of 0.5 microns. The sediment filter and the precarbon filter are placed before the RO membrane in order to prevent any damage to it. The maximum pressure the sediment filter can withstand is 125 psi. A 2-D model is created using SOLIDWORKS Software and Meshing was done using ICEM CFD. Analysis is done using ANSYS FLUENT. For analysing, four different configurations were used and based upon the results, the working model was fabricated. The water from the outlet is then tested for purity. IV. RESULTS AND DISCUSSIONS A. CONFIGURATIONS AND OUTPUT PRESSURES In order for more economical and high output efficiency different configurations were analysed. The different configurations that were analysed are Carbon filter at the end configuration, Pre-filtration and RO membrane only configuration; Carbon filter not included configuration and RO membrane at the end configuration. The output pressure from these configurations were analysed and the configuration with the maximum output pressure was finally chosen.

C. REVERSE OSMOSIS FILTER Reverse osmosis (RO) is a water purification technology that uses a semi permeable membrane to remove larger particles from drinking water. This membrane technology is not considered a proper filtration method. In reverse osmosis, an applied pressure is used to overcome osmotic pressure, a colligative property,that is driven by chemical potential, a thermodynamic parameter. Reverse osmosis can remove many types of molecules and ions from solutions, including bacteria, and is used in both industrial processes and the production of potable water. The result is that the solute is retained on the pressurized side of the membrane and the pure solvent is allowed to pass to the other side. To be "selective", this membrane should not allow large molecules or ions through the pores (holes), but should allow smaller components of the solution (such as the solvent) to pass freely.

1. Configuration with carbon filter at the end In this arrangement, the outlet from the hand pump is given into the preliminary filter cartridge. The losses occurring in the filter cause a considerable reduction in pressure of the flow. The fluid then flows into the sediment filter, where particles of size higher than 0.3 micron get caught up in it.The fluid from the sediment filter goes into the reverse osmosis membrane where the dissolved salts get removed from the water. The pressure of the flow is reduced considerably after this stage. The low pressure flow then goes into the carbon filter. The output from the filter is obtained at -5.78*104 Pascal. The figure 1 shows the analysis of this arrangement done in ANSYS FLUENT software.

D. SEDIMENT FILTER Sediment is any particulate matter that can be transported by fluid flow and which eventually is deposited as a layer of solid particles on the bed or bottom of a body of water or other liquid. Sedimentation is the deposition by settling of a suspended material. In a water plant these particles may be rust flakes from the water pipes, sand grains, small pieces of organic matter, clay particles, or any other small particles in the water supply. Water that has a high sediment level can change the aesthetic value of the finished beverage. It also can have a detrimental effect on the performance of your equipment. Sediment can cause blockages in the strainers, flow controls and even the solenoids inside your equipment III. MATERIALS AND METHODS The system uses a hand pump of suction type pre-filtration membrane, a sediment filter ,a pre-carbon filter (and an RO membrane. The hand pump used has a flow rate of 0.32 litres/second at the outlet. the pre-filtration membrane has

FIG 1

2. Configuration excluding carbon filter and sediment filter This configuration does not have a carbon and sediment filter in the arrangement. In this configuration, the output of the hand pump is fed to the preliminary filter cartridge. The losses occurring in this filter causes a considerable reduction

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to the pressure of the flow. The fluid from the preliminary filter then enters the RO membrane where the dissolved salts get removed. The pressure of water entering the RO filter is considerably higher than its specified inlet pressure as well as since there is no other filters to filter out particles other than the preliminary filter, it may cause damage to the RO membrane. This calls for more frequent replacement of the RO membrane. The output from the RO membrane is obtained at 8.59*105Pascal. The figure 2 shows the analysis of this arrangement done in ANSYS FLUENT software.

particles of size higher than 0.3 micron get caught up in it. The flow then enters the carbon filter. The output from the carbon filter is having sufficient pressure so as to be fed into the RO membrane where the dissolved salts and the micro-organisms present in the water are removed. . The output from the RO membrane is obtained at 2.24*105 Pascal. The figure 4 shows the analysis of this arrangement done in ANSYS FLUENT software.Table 1 shows the output values of different configurations

FIG 2 FIG 4 3. Configuration excluding Carbon filter In this arrangement, the outlet from the hand pump is given into the preliminary filter cartridge. The losses occurring in the filter cause a considerable reduction in pressure of the flow. The fluid then flows into the sediment filter, where particles of size higher than 0.3 micron get caught up in it.The fluid from the sediment filter goes into the reverse osmosis membrane where the dissolved salts and micro-organisms get removed from the water. The output from the RO membrane is obtained at 7.43*103 Pascal. The figure 3 shows the analysis of this arrangement done in ANSYS FLUENT software.

Configuration type Carbon filter at the end Pre-filtration and RO membrane only

Output pressure(Pascal) -5.78*104 8.59*105

Carbon filter not included

7.43*103

RO membrane at the end

2.24*105 TABLE 1

5. Final Geometry

FIG 3 4. Configuration with RO membrane at the end In this arrangement, the outlet from the hand pump is given into the preliminary filter cartridge. The losses occurring in the filter cause a considerable reduction in pressure of the flow. The fluid then flows into the sediment filter, where

The following graphs show the concentration of impurities and other parameters in comparison of proposed model with Aquaguard water purification system.

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concentration of certain impurities compared to commercially available models. The cost comparison with various commercially available products showed that the fabricated model was a cheaper alternative. The designed model provides drinking water without using electricity and is a cheap and energy saving option. REFERENCES 1.

V. CONCLUSIONS The fabricated model was designed based on the results of the analysis performed and it delivers pure drinking water at a high output pressure. The purity tests performed on the output from the system showed that there was a large reduction in the concentration of impurities. The output showed increased reduction in

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Courfia K. Diawara, Saidou N. Diop, Mouhamadou A. Diallo, Michel Farcy, André Deratani, “Performance of Nanofiltration (NF) and Low Pressure Reverse Osmosis (LPRO) Membranes in the Removal of Fluorine and Salinity from Brackish Drinking Water”, “Journal of Water Resource and Protection, 2011, 3, 912-917”. Srinivas Kushtagi, Padaki Srinivas, “Studies on chemistry and Water Quality Index of ground water in Chincholi Taluk, Gulbarga district, Karnataka India”

AN EXPERIMENTAL ANALYSIS ON SYNERGETIC EFFECT OF MULTIPLE NANOPARTICLE BLENDED DIESEL FUEL ON CI ENGINE Sajunulal Franc, Roshith Oommen George, Sachin Jacob James, Mathew John Abstract: Although the Compression Ignition Engines are a significant source of power, their detrimental emissions initiated the searches for alternative fuels that are renewable, safe and non-polluting. Even many researchers have put valid efforts in fuel modification, the current work describes the role of multiple nanofuel additives in diesel fuel. In this context, Aluminium oxide and Cobalt oxide nanoparticles are incorporated with the diesel fuel to investigate the performance, emission and combustion characteristics of a four stroke, single cylinder diesel engine. Experiments were carried out using five different additive combinations, neat diesel and diesel with some commercial additive for comparison. The experimental outcome revealed a substantial enhancement in brake thermal efficiency and a marginal reduction in harmful pollutants such as NOX, CO and smoke, for a particular nano additive proportion compared to that of neat diesel and commercial additive incorporated diesel.

I. INTRODUCTION Due to growth of population, high energy consumption and global warming concerns, it is having great importance for the green engineering sector. In this regard, even automobiles being one of the prior reasons for the environmental pollution and energy consumption, the design and improvement in engines have received substantial attention. Compression Ignition engines are considered as the prime mover not only in automobiles but also in power plants, industrial sectors and marine sector due to its reliable operation. So it is required in the present scenario to implement design and improvement of high energy efficient, low energy consumption and low hazardous emission diesel engines in automobiles. Government has also implemented stringent rules to engine manufactures and customers to follow emission norms to save the environment from the harmful emission. In this regard, various techniques have been employed such as fuel modification, engine design alteration and exhaust gas treatment and various researches have put their valid efforts to improve performance while reducing the pollutants in the compression ignition engines. Fuel modification techniques are widely adopted since it doesnâ&#x20AC;&#x2122;t require any major hardware modifications. Most of such fuel modification techniques are materialized by adding some fuel additives. Nanoparticle employs as one of the critical diesel additives due to its unique property which improve the fuel properties, combustion and reduce the level of deleterious pollutants. Nanoparticles are simplest form of structures of the order of nanometres. Nanoparticles are said to have amazing properties due to its smaller size and greater surface area to volume ratio. For the reason itself it has found various applications in the field of research and industries. Currently researches are

accelerated in the field of automobiles with application of nanoparticles. The present work is an advancement with the application of multiple nano additives in diesel fuels. The objective of the present investigation is to study the synergetic effect of multiple nanoparticle additives in a CI Engine in order to enhance the combustion characteristics, Improve the performance of engine, reduce the harmful emissions Global environmental and economic scenario itself clearly defines the scope of our present work. Due to the increased pollution and energy (fossil fuel) depletion it requires, less fuel consumption and more power along with the reduction of harmful emission from automobiles. By incorporating some combination of nanoparticles, it can bring out the requirements at low cost itself. When compared with the advantages obtained the cost is negligible and it could satisfy the impending emission regulations.

II. THEORY

A. NANOPARTICLES Nanoparticles are simplest form of structures of the order of nanometres ranging up to a size where they lose their unique properties. They can be available in different forms such as metals, metal oxides, and carbon nanotubes.. The current investigation is being proceeded with the desirable properties of the selected Alumina and Cobalt Oxide nanoparticles as a fuel additive Thermal conductivity is the most important parameter in the enhancement of thermal efficiency of an engine. Since alumina can bring out more uniform temperature distribution, it can bring about significant change emission levels. The unique property for the Alumina nanoparticles in bringing out desirable outcomes as a fuel additive is its ability to produce micro explosions in the cylinder, which in turn reduces the peak temperature. Cobalt Oxide acts as the better oxygen buffer in the role of a fuel additive. Thus the Oxygen atoms can moderate the combustion reaction so as to produce a cleaner combustion.As the temperature increases, the mobility of active oxygen atoms increases and the oxidation of CO become easier. The lattice oxygen on CO3O4 is more active than active oxygen and form bidentate carbonate which can oxidise CO to produce CO2. The present investigation is on the synergetic effect which the Alumina supported cobalt oxide could give as a potential fuel additive.

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III. EXPERIMENTAL METHODOLOGY

A. PREPERATION OF BLENDED FUEL

The investigation is carried out in an experimental setup as shown in figure 1. The set up consist of a single cylinder, four stroke, direct injection diesel engine coupled to an AC alternator for loading and an instrumentation system. The engine cooling was done by normal air cooling.

The diesel fuel was obtained from an approved dealer of Indian Oil Corporation Limited. The Alumina nanoparticles (40nm) were supplied by the manufacture M/s Plasma Chem, Berlin, Germany and CO3O4 nanoparticles (50nm) were supplied by M/s Sigma Aldrich, USA. The details specification of the particles are listed in table 2. Particle Manufacturer Shape Average size Full range Purity Appearance

Al2O3 Plasma Chem Spherical 40 nm 5-150 nm >99.8% White

CO3O4 Sigma Aldrich Spherical < 50 nm 10-150 nm 99.5% Black

TABLE 2 Particles Specifications

FIG 1 Experimental Setup

The instrumentation system includes AVL 444 Di-gas analyzer, AVL 415 smoke meter, Data acquisition system consisting of AVL pressure transducer (model: GH14D/H01) and AVL365C angle encoder. The AVL 444 Di-gas analyzer measures the exhaust emission such as NOX, CO, CO2, O2 and unburned HC. While the smoke opacity and soot concentration is measured by the AVL smoke meter. The details of engine technical specification and instruments are listed in table 1 Make & Model

Kirloskar, TAF 1

Type Bore x Stroke

Single cylinder, four stroke, air cooled, direct injection 87.5 x 110 mm

Compression Ratio

17.5:1

Swept volume

661cc

Combustion Chamber

Open hemispherical

Nozzle holes

3 holes

Spray hole diameter

0.25mm

Cone angle

110 degree

Rated output

4.4kW,1500 rpm

Injection timing

23oBtdc

Injection pressure

200 bar

TABLE 1 Engine Specifications

In general the nanoparticles possess excellent dispersion in all fluids such as water, ethylene glycol and oil to form stable suspensions for long periods, weeks or months. Hence for the present work ultrasonication technique was adopted to disperse both the particles in diesel fuel. This would help in preventing the agglumeration of particles. Both the particles were weighted separately in a predefined mass fraction and dispersed in the neat diesel with the aid of an ultrasonicator for 30 minutes .Thus the different nanoparticles blended diesel fuel (D5000, D0050, D3515, D2525, D1535) was prepared. Moreover the prepared samples were kept undisturbed and found to be stable for more than a week. IV. RESULTS AND DISCUSSIONS This section describes the combustion, performance and emission attribute of the diesel engine using virgin diesel, 5 blended samples namely D5000, D0050, D3515, D2525, D1535 and the sample with commercial diesel additive. The combustion characteristics are presented as heat release rate and cylinder pressure plotted against crank angle. The performance characteristics are plotted as brake thermal efficiency and specific fuel consumption against brake mean effective pressure. The emission parameters are plotted against load. A. COMBUSTION CHARACTERISTICS The variation of cylinder pressure and heat release rate was plotted with reference to crank angle for the tested fuels from no load to full load. Among the various test samples D3515 was found to have higher peak pressure. It was found that for the sample with Al2O3 and Co3O4 particles in equal proportion (D2525) shows a lesser value of peak pressure when compared with other fuel samples. At higher loads, the peak pressure was found to be higher for commercially available additive doped fuel than that of D2525. When compared with neat diesel, D2525 was showing similar and lesser trends in peak pressure. The figure 2 shows variation of cylinder pressure for the fuel samples at full load.

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B. PERFORMANCE CHARACTERISTICS The variation of brake thermal efficiency with respect to break mean effective pressure is shown in figure 4. It is observed that brake thermal efficiency of samples with particle additives show significant increase in brake mean effective pressure. The samples especially D2525 shows a constantly higher brake thermal efficiency in all loads, particularly at higher loads.

FIG 2 Variation of Pressure with Crank Angle

Similar results were obtained when the heat release rate was plotted against the crank angle for the test fuels. Figure 3 shows the heat release rate Vs crank angle at half load and full load for the fuel samples. It was found that heat release rate for the sample with equal proportion of both the particles was lesser when compared with other samples and commercial additive. At higher loads sample D2525 have similar and better results with neat diesel.

FIG 4 Brake Thermal Efficiency Vs BMEP

This could be due to the better combustion characteristics which allowed more fuel to interact with air. Even the Co3O4 particles which supplied sufficient active oxygen helps in enhancing the efficiency. Similar trend was obtained in case of specific fuel consumption. Figure 5 shows the change in brake specific fuel consumption with respect to bmep. The specific fuel consumption was found to be decreasing at medium loads. This could be due to proper mixing of air with fuel and shortened ignition delay effort. It means that at medium loads, a lesser amount of fuel was consumed for producing a same amount of work when compared to the neat diesel.

FIG 3 Variation of Heat Release with Crank Angle

This could be due to the improved ignition which has accelerated the combustion. This leads to better catalytic activity. Thus the pressure of nano sized particles in the diesel has enhanced the ignition and produced low heat release rate when compared with other sample and especially the commercial additive. Due to the greater surface area- volume ratio, the nanoparticles could have improved the fuel- air mixing and leading to shorter ignition delay.

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FIG 5 Specific Fuel Consumption Vs BMEP

C. EMISSION CHARACTERISTICS For a compression ignition engine, the major emission consists of oxides of nitrogen, carbon monoxide, unburned hydrocarbons and smoke.

It is a serious concern to note the percentage of carbon monoxide. It is shown in figure 8 that the CO emission marginally decreases with D2525 sample and possess a great extent of difference with neat diesel and commercial additive doped diesel.

FIG 6 Variation of NOX with load

The variation of NOX with respect to load is shown in figure 6. At higher loads NOX emissions show a marginal decrease with sample D2525. The better combustion characters associated with sample, such as lower heat released caused the reduction in oxides of nitrogen. Also it is noticeable that at every load; NOX emissions produced by sample D2525 are lower compared to neat diesel and commercial additive. The variation of HC emissions for the particle doped diesel fuels, neat diesel and commercial additive added fuel is depicted in figure 7. It can be inferred from the figure that, even at medium and higher loads, the HC emissions showed a significant reduction with nanoparticles. Especially the sample with equal amount of both particles, D2525 showed an almost constant emission rates at lower to higher loads. This is because Al2O3 helps in lower loads while CO3O4 helps in higher loads.

FIG 8 Variation of CO with load

There was a slight reduction in smoke opacity level for D2525 sample at all loads and particularly at higher loads. This could be due to better fuel- air mixing in presence of Al2O3 and CO3O4 nanoparticle which have led to improved combustion. The variation of smoke opacity for the neat diesel, particle blended diesel and additive samples are illustrated in fig 9.

FIG 9 Variation of Smoke Opacity with load

FIG 7 Variation of HC with load

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V. CONCLUSIONS The present work was an experimental investigation of performance, combustion and emission characteristics of a single cylinder four stroke direct injection diesel engine using Al2O3 - CO3O4 nanoparticles blended diesel fuel. The fuel samples were made with five different proportions of additives. The combustion, performance and emission characteristics of these samples were studied and compared with that of neat diesel and diesel which is doped with commercial diesel additive. The results were in supportive with application of nanotechnology in the area of internal combustion engines for improving performance and reducing emission. The conclusions of investigations are as follows: 1. The alumina- cobalt oxide nanoparticles blended diesel fuel was stable for more than a week under idle conditions. 2.

Due to the shortened ignition delay effect of nanoparticles blended diesel fuel the peak pressure and peak heat release rate was reduced.

There was a noticeable improvement in the brake thermal efficiency of the particle blended sample. Especially when the Al2O3 and CO3O4 nanoparticles where blended in equal ratio, the results were satisfactory. There was a reduction in specific fuel consumption when compared to neat diesel.

There was a marginal reduction of NOX, HC, CO and smoke emissions for D2525 sample. HC emissions were found to have 15-20% reduction when compared with neat diesel and 20-25% reduction with commercial additive additive doped diesel at full load. The CO emission kept above 20% marginal decrease than neat diesel in lower and medium loads. NOX emissions were also found to be lesser when compared at all loads conditions. The smoke opacity and soot concentration were also satisfactory for the sample.

[4] J. Sadhik Basha & R. B. Anand., " An Experimental Study in a CI Engine Using Nanoadditive Blended Waterâ&#x20AC;&#x201C;Diesel Emulsion Fuel", International Journal of Green Energy Volume 8, Issue 3, 2011.DOI:10.1080/15435075.2011.557844

VI. REFERENCES [1] Mu-Jung Kao, Chen-Ching Ting, Bai-Fu Lin, and TsingTshih Tsung, "Aqueous Aluminum Nanofluid Combustion in Diesel Fuel" Journal of Testing and Evaluation, Vol. 36, No. 2 Paper ID JTE100579 [2] Sadhik Basha, J., "An Experimental Analysis of a Diesel Engine Using Alumina Nanoparticles Blended Diesel Fuel," SAE Technical Paper 2014-01-1391, 2014, DOI:10.4271/2014-01-1391. [3] V. Sajith, C. B. Sobhan, and G. P. Peterson., "Experimental Investigations on the Effects of Cerium Oxide Nanoparticle Fuel Additives on Biodiesel" Advances in Mechanical Engineering Volume 2010, Article ID 581407, 6 pages DOI:10.1155/2010/581407

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MODELING AND ANALYSIS OF NONPNEUMATIC TYRES WITH HEXAGONAL HONEYCOMB SPOKES Vinay T V, Kuriakose J Marattukalam, Sachu Zachariah Varghese, Shibin Samuel, Sooraj Sreekumar

Abstract: A pneumatic tyre is made of an airtight inner core filled with pressurized air. Pneumatic tyre have been dominant in the world market due to many advantages like low mass design, low vertical stiffness and low contact pressure. However, it have certain disadvantages like the possibility of a flat while driving, complex manufacturing procedure, the required maintenance for proper internal air pressure. Hence Non-Pneumatic tyres are introduced to overcome these disadvantages. Non-pneumatic tyres (NPT) are introduced with a compliant cellular solid spoke component which functions as air of a pneumatic tire. This project investigates hexagonal honeycomb spokes for NPT tire under macroscopic uni-axial loading. The spokes of an NPT undergoes tension-compression cycle while the tyre rolls. The spokes of an NPT is required to have both stiffness and resilience, which are conflicting requirements. Three types of honeycomb spokes are designed in AUTOCAD, namely A, B and C. Three dimensional models are created in CATIA. The mass of the designed tyres are found out. ANSYS finite element analysis is used to study about the deformation and stresses developed in different type of honeycomb spokes. Type C honeycomb spokes are found to be better considering both fatigue resistance and lower mass design.

I. INTRODUCTION A tyre is a ring shaped vehicle component that covers the wheel's rim to protect it and enable better vehicle performance. A pneumatic tyre is made of an airtight inner core filled with pressurized air. Most tyres, such as those for automobiles and bicycles, provide traction between the vehicle and the road while providing a flexible cushion that absorbs shock. The pneumatic tyre was first introduced in 1888 by Dunlop, since then has been dominant in the world tyre market for more than 100 years due to four major advantages it has over a rigid wheel: (i) low energy loss on rough surfaces, (ii) low vertical stiffness, (iii) low contact pressure, and (iv) low mass. However it has some disadvantages like: (i) The possibility of a blowout or a flat while driving, (ii) The required maintenance for proper internal air pressure, and (iii) the complicated manufacturing procedure. Thus non pneumatic tyres (NPT) were developed which overcome these disadvantages. When the non-pneumatic tyre is put to the road, the spokes absorb road impacts the same way air pressure does in pneumatic tyres. The thread and shear bands deform temporarily as the spokes bend, then quickly spring back into shape. Airless tyres can be made with different spoke tensions, allowing for different handling characteristics. More pliant spokes result in a more comfortable ride with improved handling. The lateral stiffness of the tyre is also adjustable.

However, you can’t adjust such a tyre once it has been manufactured. The objective of the present investigation is to study about the constituent materials of an NPT and to conduct static structural analysis on designed models. Masters IG and et al. (1996), presented a model about the elastic deformations in honey combs [1]. A theoretical model has been developed for predicting the elastic constraints of honeycombs based on the deformation of the honey comb cells by flexure, stretching ad hinging. The model has been used to derive expressions for the tensile moduli, shear moduli and Poisson’s ratios. Examples are given of Structures with a negative Poisson’s ratio. Tonuk E. and et al. (2001), constructed a detailed finite element model of a radial automobile tyre and its characteristics are studied [2]. The stress strain relationship of rubber is modeled. Validity of various simplifications is checked. Balawi S and et al. (2008), investigated different properties of honeycomb structure [3]. The modeling of the effective properties of these honeycomb cores is of key importance to predict the overall mechanical response of the sandwich structures. In particular, the in-plane elastic moduli were studied by analytical and numerical means and correlated with experimental results for aluminum hexagonal or regular honeycombs. It is found that the flexibility of the honeycomb increases with cell angle. Stefano Gonella and et al. (2008), conducted a study about the equivalent in-plane properties for hexagonal and auxetic lattices, through the analysis of partial differential equations associated with their homogenized continuum models [4]. The adopted homogenization technique interprets the discrete lattice equations according to finite differences formalism, and it is applied in conjunction with the finite element description of the lattice unit cell. II. PROBLEM DEFENITION AND BACKGROUND Non-pneumatic tyres generally have higher rolling resistance and provide much less suspension than similarly shaped and sized pneumatic tyres. Other problems for airless tyres include dissipating the heat buildup that occurs when they are driven. NPT’s are often filled with compressed polymers (plastic), rather than air. Considering the NPT structure, the spokes undergo tension–compression cyclic loading while the tyre rolls. Therefore, it is important to minimize the local stresses of spokes that is, the spokes should be fatigue resistant. In this project we designed NPT based on hexagonal honeycomb

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spokes. Honeycombs have been primarily used in lightweight sandwich structures for which a high out-of-plane stiffness is desired. A honeycomb structure is an array of hollow cells formed between thin vertical walls. Two dimensional prismatic cellular materials of periodic microstructures are called honeycombs. Different types of honeycomb structures are: square, hexagonal, kagome, triangle, mixed squares and triangles, and diamond shape. Triangular, Kagome, and diamond cell honeycombs are good for high modulus structural designs. Square and hexagonal cell honeycombs are known to be good for flexible structural designs. Hexagonal cell structures are known to be flexible in both axial and shear loadings. Also, hexagonal honeycombs can easily be tailored to have targeted in-plane properties by changing the cell angle, the cell wall thickness, and the cell length. The spokes of an NPT are required to have both stiffness and resilience under cyclic tension–compression loading. In general, stiffness and resilience are conflicting requirements if a material has a high modulus, it shows a low elastic strain limit, and vice versa. The challenge, then, is to design materials that have both high stiffness and high resilience. Finite element analysis (FEA) has been utilized extensively in the simulation of tyre models due to its capability to solve complicated structural behaviors combining the nonlinearity of a material and geometry. FEA is often used to verify design integrity and identify critical locations on components without having to build the part or assembly. The different types of NPT geometry are created using CATIA and AUTOCAD. The analysis is done by modeling the structure into thousands of small pieces (finite elements).In this study, ANSYS WORKBENCH is used for a numerical experiment with NPTs having hexagonal honeycomb spokes. III. STUDY ABOUT THE CONSTITUENT MATERIALS OF NPT The Non-pneumatic tyre is designed using following constituent parts, which are hub, honeycomb spokes, outer ring and thread. The function of hub is to provide a rigid support to the honeycomb spokes. The honeycomb spokes are the key component of the NPT, which replaces the air-filled pneumatic tyres. The spokes of an NPT should have both stiffness and resilience under cyclic compression loading. The function of outer ring is to enforce the thread rubber to be deformed by shear. The thread provides the necessary traction between the road and the vehicle.

The hub of an NPT should provide a rigid frame. Aluminium alloy, AL 7075-T6 is selected as the hub. Zinc is the primary alloying element in AL7075-T6. It is strong, with strength comparable to many steels, and has good fatigue strength and average machinability. However, its relatively high cost limits its use to applications where cheaper alloys are not suitable. 7075 aluminium alloy's composition roughly includes 5.6–6.1% zinc, 2.1-2.5% magnesium, 1.2– 1.6% copper, and less than half a percent of silicon, iron, manganese, titanium, chromium, and other metals. The T6 alloy is heat treated and artificially tempered. Its applications are; Aircraft fittings, gears and shafts, fuse parts, meter shafts and gears, missile parts, regulating valve parts, worm gears, keys, aircraft, aerospace and defence applications, bike frames. T6 temper 7075 has the following properties: density, ρ = 2800 kg/m3, Modulus, E = 72 GPa, and Poisson’s ratio, υ = 0.33, Yield strength = 500 MPa. A 1 mm thick aluminum alloy is used for the inner hub. The outer radius of the hub is taken as 217mm, as shown in Figure 1.

Fig.2 Honeycomb Spokes

Polyurethane is used as the constituent material of the honeycomb spokes. Polyurethane is a unique material that offers the elasticity of rubber combined with the toughness and durability of metal. Polyurethane has good resilience and stiffness. The properties of Polyurethane are: density, ρ = 1200 kg/m3, modulus, E = 32 MPa, shear modulus, G = 10.81 MPa, and poisons ratio, υ = 0.49 and Yield strength = 140 MPa. In the Figure 2, the spokes of TYPE A is shown, whose dimensions is specified later. The radius of the spokes is taken as 317mm.

Fig.3 Outer Ring

Fig.1 Hub

The outer ring is made of high strength steel, AISI 4340. This enforces the thread rubber to be deformed by shear. Without the outer ring, the edges of the spokes over the contact zone with the ground would buckle and cause an undesirable nonlinear effect of the honeycombs.

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The properties of AISI 4340 are density, ρ = 7800 kg/m3, modulus, E = 210 GPa, poisons ratio, υ = 0.29 and yield strength = 470 MPa. The thickness of outer ring is taken as 0.5 mm. The outer radius of the outer ring is 317.5 mm, as shown in Figure 3.

spokes. The other material properties and dimensions remains the same.

Fig.5 Hexagonal Notations

Fig.4 Thread

The thread component is made of a synthetic rubber. The function of thread is to provide necessary traction between road and tyre. The thread should have a good grip on various terrains. Synthetic rubber, invariably a polymer, is any type of artificial elastomer mainly synthesised from petroleum by products. An elastomer is a material with the mechanical (or material) property that it can undergo much more elastic deformation under stress than most materials and still return to its previous size without permanent deformation. The properties of rubber are: density, ρ = 1043 kg/m3, modulus, E = 11.9 MPa, sheer modulus G = 4 MPa, poisons ratio, υ = 0.49 and yield strength = 16Mpa. The thickness of thread is taken as 15mm. The outer radius of thread is 332.5 mm, as shown in Figure 4. TABLE I PROPERTIES OF THE CONSTITUENT PARTS OF NPT

Part

Hub

Spokes

Material

AL 7075T6 2800

Density Ρ,kg/m3 Youngs Modulus E (MPa) Poisons Ratio,υ Yield Strength (MPa)

Thread

Polyure thane 1200

Outer Ring AISI 4340 7800

72000

210000

11.9

0.33

0.49

0.29

0.49

500

140

470

Rubber 1043

Hexagonal honeycombs are modeled with the cell wall thickness, t, vertical cell length, h, the inclined cell length, l, and the cell angle, θ, as illustrated in Figure 5. When designing honeycombs, numerous configurations are available with cell angle, θ, cell height, h, and cell length, l. The dimensions of the honeycomb spokes are chosen arbitrarily. Here we are considering three different types of hexagonal spoke. TABLE II DIMENSIONS OF HONEYCOMB SPOKES

NPT Type Type A Type B Type C

l (mm)

h(mm)

26.25 29.65 37.21

36.66 28.52 16.74

θ (degree) 15.76 31.50 47.14

t (mm) 3.2 3.8 4.2

The Table II shows the dimensions of the three types of NPT, which are modelled. Only regular honeycombs are considered, i.e. those with a positive poisons ratio. The ratio of the inclined cell length to the cell height, l/ is the critical factor to design in-plane flexible structures for simple tension–compression loading. Therefore, the cell angle may not be important when designing the in plane flexible structures. In other words, the in-plane flexure behavior of auxetic honeycombs may not be greatly different from that of regular honeycombs. Auxetic honeycombs are those with a negative poisons ratio. It has more stiffness in lateral direction under loading, compared to regular spokes. Cell angle, θ is the important dimension in designing a fatigue resistant honeycomb. As the cell angle, θ increases the flexibility of hexagonal honeycomb increases.

Fig. 6 Proposed model

Type A Type B Type C Fig.6 Suggested honeycomb design in AUTOCAD

The properties of the constituent parts of an NPT is summarised in the Table I. IV. MODELLING OF DIFFERENT TYPES OF NPT Three types of non-pneumatic tyres are studied, namely Type A, B and C. The models of the NPT’s are created in AUTOCAD and CATIA. The difference between the Type A, B and C are in the variation of dimensions of the honeycomb

The Figure 6 shows the suggested types of NPT design in AUTOCAD. Two dimensional models are created in AUTOCAD. The 2D modeling involves steps like sketching, rotating, explode etc. The explode function in AUTOCAD is very helpful in structural analysis. Explode command allows to break a compound object into its components separately, so the properties could be individually modified. Objects that

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can be exploded include blocks, circles etc. The 2D model is then imported into CATIA.

Type A

hub is 750N, 1500N, 3000N and 9000N. The corresponding deformed shapes and Von-Mises stress is found out. The deformed shapes and stress distribution of Type A, B and C under a load of 3000N is shown. The summarized results are shown in the Table III.

Type B Type C Fig.7 Suggested honeycomb design in CATIA

The Figure 7 shows the suggested types of NPT design in CATIA. Three dimensional models are created in CATIA. The 3D modeling involves various steps like sketching, padding etc. The material properties of the constituent parts are defined in CATIA inorder to find out the mass of designed tyres. The designed 3D models are then imported into ANSYS WORKBENCH for static structural analysis.

Fig.9 Total Deformation of Type A under 3000 N

V. RESULTS AND ANALYSIS The models that are created in AUTOCAD are imported into ANSYS WORKBENCH. It is finite element analysis software, which is used for static structural analysis. The three types of NPTâ&#x20AC;&#x2122;s are imported into the WORKBENCH, and the corresponding material data are defined. The bonding operation in WORKBENCH is used to produce a bonding between all the components. The element type of hub, outer ring and spokes are defined.

Fig.10 Von-Mises Stress of Type A under 3000 N

Fig.8 Meshed Model

The constituent parts of the NPT are properly meshed. Cubical mesh is used for meshing since all the components are symmetrical. The mesh size is set as medium. The number of elements in the three models is around 15000. The meshed model is shown in Figure 8. While the vertical displacement loading is applied at the hub center, the horizontal displacement of the bottom center on the thread is set to zero so that a deformed geometry can be maintained to be symmetric with respect to the plane perpendicular to the road surface. The load is applied at the hub of the NPT. All degrees of freedom of a line of contact at the bottom of the thread is set as zero. The load applied at the

Fig.11 Total Deformation of Type B under 3000 N

The Von-Mises stress in Type B is found to be lesser than that of Type A. So Type B spokes are more fatigue resistant than Type A spokes. For example, consider the Type

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A and B under 3000 N load at hub, Figures 10 and 12. The maximum Von-Mises stress in Type A is found to be 18.469 MPa, while in Type B is only 14.92 MPa.

the top portion of the tyre. The deformation is very small under small loading. The Von-Mises stress is found to be maximum at the edges of the spokes which are in contact with the outer ring. TABLE III SUMMARIZED RESULTS

NPT type

TYPE A

TYPE B Fig.12 Von-Mises Stress of Type B under 3000 N

TYPE C

Condition

Max. Von-Mises stress (MPa) Max Deformation(mm) Max. Von-Mises stress (MPa) Max Deformation(mm) Max. Von-Mises stress (MPa) Max Deformation(mm)

750 N at Hub 4.61

1500 N at Hub 9.234

3000 N at Hub

0.022

0.044

0.088

3.732

7.463

14.92

0.012

0.025

0.0512

1.815

3.631

7.262

0.004 5

0.009

0.018

18.469

9000 N at Hub 55.40 6 0.264 9 44.78 0.153 9 21.78 9 0.054

From the results obtained, we can infer that the Von mises stress is lesser for Type C than A and B. which means that Type C is better design in terms of fatigue resistance. It can carry more load without much deformation. The lower local stresses of the Type C spokes are favorable in designing fatigue resistant spokes due to the lower cyclic stresses. The lower Von-Mises stress in Type C is due to the higher cell angle. Because as cell angle increases, flexibility increases leading to lesser local stresses.

Fig.13 Total Deformation of Type C under 3000 N

Fig.15 The total mass of Nptâ&#x20AC;&#x2122;s when the lateral width is set to be 225 mm

Fig.14 Von-Mises Stress of Type C under 3000 N

The Von-Mises stress in Type C is found to be much lower than that of Type A and B, which turns out to be better for the fatigue resistant design of honeycomb spokes. For example, for 3000 N at the hub, Figure 14, the maximum Von-Mises stress in Type C is found to be 7.26 MPa which is lower than that of an NPT with Type A and B spokes. From the deformation of the NPT under load, Figures 9, 11 and 13, we can infer that the maximum deformation is at

The total mass of NPTs with the honeycomb spokes when the lateral width is set to be 225 mm is found from CATIA, Figure 15. The mass can be found out after assigning all the material properties to the constituent parts of NPT. The mass of the hub, outer ring and the thread is same, only the mass of the spokes is a variable. The mass of the tyre increases as the cell wall thickness of spokes increase. The Type C is found to be of higher mass. The mass of Type C is about 14% higher than that of Type A. Inorder to design a tyre for both, low mass and high fatigue resistant honeycomb

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spokes, a higher modulus elastomer as a base material with the Type C spokes is preferable. VI. CONCLUSIONS In this project, the cellular spoke geometries for a Non pneumatic tyre were studied with regular honeycomb spokes. Non pneumatic tyres are the tyres that are not supported by air pressure. The Non pneumatic tyres overcome many disadvantages over conventional tyre like possibility of a catastrophic damage, required maintenance of proper internal air pressure and complex manufacturing procedure. The constituent materials of a hexagonal honeycomb spokes were studied. Different types of hexagonal honeycomb spokes are modelled and their static structural analysis was conducted. The total mass of the designed models were found out from CATIA. It is seen that Type C have 14% higher mass than that of Type A. This increase in mass is due to increase in cell wall thickness. The major conclusion is that the honeycomb spokes with a higher cell angle magnitude show lower local stresses, which is good for a fatigue resistant spoke design. Here Type C has lowest local stresses than A and B. The maximum VonMises stress is found to be at the edges of the spokes i.e. at the contact between spokes and the outer ring. The NPT based on hexagonal honeycomb spokes can be used to replace a conventional pneumatic tyre. REFERENCE [1]

Masters IG and Evans KE, “Models for the elastic deformation of honeycombs”, Compos Struct, Vol. 35, 1996, pp. 403–22.

[2]

Tonuk E and Unlusoy YS, “Prediction of automobile tire cornering force characteristics by finite element modeling and analysis”, Comput Struct, Vol. 79, 2001, pp. 1219–32.

[3]

Balawi S and Abot JL., “A refined model for the effective in-plane elastic moduli of hexagonal honeycombs”, Compos Struct, Vol. 84, 2008, pp. 25-42.

[4]

Gonella S and Ruzzene M, “Homogenization and equivalent in-plane properties of two dimensional periodic lattices”, Int J Solid Struct, Vol. 45, 2008, pp. 2897–915.

[5]

Jaehyung Ju and Joshua D. Summers, “Design of Honeycombs for Modulus and Yield Strain in Shear”, Journal of Engineering Materials and Technology, Vol. 134, 2012, pp. 110-126.

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Powerless Air Conditioning with Integrated Water Heating Nishin Asharaf , Nicku Abhraham , Sajin Chacko , Shijo George , Tom Mathew

Abstractâ&#x20AC;&#x201D;

The planet is progressively marching towards a serious electric energy crisis, owing to an escalating desire of electric energy becoming greater than its supply. We have always accepted that the energy we make use of each day is not unrestricted, still we take it for granted. So it is better to utilize the available resources. Among these solar energy is the most abundant and cheap resource available. So here we use only solar energy for the cooling of buildings and also for water heating. In this project, we utilize only solar power for the cooling process and also for water heating. The cooling process proceeds as the temperature of atmosphere increases by sun rays. This can also be used as a room heater in winter condition by proper adjustment. The main highlight of our project is that only solar energy is utilized for the cooling and heating process. No other external power sources are used. Our product is ecofriendly and pollution less. This can also installed at remote areas where electricity is not available and in regions where atmospheric temperature is high e.g. Rajasthan. It is well suited for middle class family as it requires only initial investment and less maintenance cost. No separate water heater is required for domestic purpose

I. INTRODUCTION Space cooling and refrigeration are highly energyintensive processes. Cooling demands in various sectors are maximum mainly during day time when solar energy is also prevalent; this is more so in the hot summer season. Most parts of India get abundant sunshine throughout the year. Solar cooling/refrigeration is, therefore, the most relevant application for our country, especially in view of the rapidly increasing demand for energy and shortage of electric power. It is estimated that cooling consumes about 35,000 MW of electricity for various end-uses. Part of this is from conventional power plants in areas where electricity is easily available and the rest is being generated through DG sets which consume a significant amount of highly subsidized diesel leading to noise and air pollution, besides heavy CO2 emissions. Apart from this, in rural areas, where such options are not available, 30â&#x20AC;&#x201C;40% of agricultural produce is being destroyed due to lack of proper post harvest cooling facilities. Thus, resorting to solar cooling not only mitigates energy shortage and environmental pollution, but also contributes to the reduction of food spoilage. The applications of cooling include domestic refrigeration, comfort/ space cooling in

various sectors, industrial refrigeration and process cooling, cold storages with deep freezing, etc. The capacity range of systems varies from a few Watts to thousands of kilo Watts. Solar cooling/air-conditioning systems have the potential to catering to all the above sectors. However, this is an emerging technology and faces many growth barriers, which are different from other heating and cooling technologies. The demand of air conditioning is increasing due to the effect of climate change and global warming. If we still rely on the conventional electric air conditioning but electricity is generated from fossil fuels, the greenhouse gas emission would continuously worsen global warming; in turn the demand of air conditioning would be further increasing. In subtropical cities, air conditioning is a standard provision for buildings. However, air conditioning would commonly take up half of building electricity consumption. The development of renewable energy is on the rise worldwide because of the growing demand on energy, high oil prices, and concerns of environmental impacts. In recent years, progress on solar-powered air conditioning has increased as nowadays, air conditioning system is almost a must in every building if we want to have a good indoor comfort inside the building. Therefore, this project focuses in the design and construction of a direct current (DC) air conditioning system integrated with solar parabolic focusing collector using angularly placed mirrors and photovoltaic (PV) system with mechanized sun-tracking system which consists of PV panels, solar charger and batteries. The air conditioning system can be operated on solar and can be used in non-electrified areas. As we all known, solar energy is cost effective, renewable and environmentally friendly. Air conditioning is defined as the simultaneous processing of temperature, humidity, purification and distribution of air current in compliance with the requirement of space needing air conditioning. In general, air conditioning which also can be known as refrigeration is defined as any process of heat removal. To produce the process, it requires energy where the sources are commonly gas and electricity. With increasing gas and electricity tariffs, solar energy becomes attractive once the system has been installed. As one of the sources of renewable energy, solar energy is likely the most suitable system for installation in sub-tropical countries. The most common globally, preferred type of thermally driven technology is evaporative cooling. The

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system, which has simpler capacity control, mechanism, easier implementation, high reliability, silent operation, long life and low maintenance cost was a genuine candidate for efficient and economic use of solar energy for cooling applications. But in this project concentrates on development and improvement of a normal air conditioner unit using steam condensation and evaporative cooling sidewisely using solar energy and electricity generated from the PV system. Utilizing solar energy to run the air conditioning system is a practical technique to replace conventional electricity. In order to obtain a feasibility of the air conditioning system using solar, a lot research and testing have been initiated to learn and discover the design and operation of the air conditioning and solar water heating system which is consist of PV system. D.M. Whaley describes the design, construction and initial experimental performance testing of a novel integrated solar thermal system prototype for the provision of space cooling and dehumidification, space heating and domestic water heating.[1]. Luis Carlos Herrera Sosa research found that in arid climates, evaporating water is the best cooling technique possible.[2].Morgado Baca I. evaluates Evaporative Cooling (EC) strategy efficiency, in which water is used as coolant.[3]. Concentrated solar power technology constitute an interesting option to meet a part of future energy demand, especially when considering the high levels of solar radiation and clearness index that are available particularly in India. In this work, we study a medium temperature parabolic trough solar collector used to drive a cooling and water heating installation. Solar steam generating systems using parabolic trough concentrators have been in use for the past decade in several countries in the world. During the past years, various R & D efforts have been put into use to improve the performance. Parabolic-trough solar water heating is a well-proven technology that directly substitutes renewable energy for conventional energy in water heating. Parabolic-trough collectors can also drive absorption cooling systems or other equipment that runs off a thermal load. There is considerable potential for using these technologies in India. II. PROJECT OBJECTIVES

IV. THEORY A. Evaporative Cooling System Evaporative cooling involves heat and mass transfer, which occurs when water and the unsaturated air water mixture of the incoming air are in contact. This transfer is a function of the differences in temperatures and vapor pressures between the air and water. Heat and mass transfer are both operative in the evaporative cooler because heat transfer from the air to the water evaporates water, and the water evaporating into the air constitutes mass transfer. Heat inflow can be described as either latent or sensible heat. Whichever term is used depends on the effect. If the effect is only to raise or lower temperature, it is sensible heat. Latent heat, on the other hand, produces a change of state, e.g., freezing, melting, condensing, or vaporizing. In evaporative cooling, sensible heat from the air is transferred to the water, becoming latent heat as the water evaporates. The water vapour becomes part of the air and carries the latent heat with it. The air dry-bulb temperature (DBT) is decreased because it gives up sensible heat. The air wet-bulb temperature (WBT) is not affected by the absorption of latent heat in the water vapour because the water vapour enters the air at the air wet-bulb temperature. Theoretically, the incoming air and the water in the evaporative cooler may be considered an isolated system. Because no heat is added to or removed from the system, the process of exchanging the sensible heat of the air for latent heat of evaporation from the water is adiabatic. Evaporative cooler performance, therefore, is based on the concept of an adiabatic process. The minimum temperature that can be reached is the wet bulb temperature of the incoming air. Wet pads provide a large water surface in which the air is moistened and the pad is wetted by dripping water. The direct evaporative cooling process works essentially with the conversion of sensible heat in latent heat. The surrounding ambient air is cooled by evaporation of the water from the wet surface of the panel to the air. The addition of water vapour to the air increases its latent heat and relative humidity. If the process is adiabatic, this increase of the latent heat is compensated by a reduction of the sensible heat and consequent reduction of the dry bulb temperature of air.

The demand of air conditioning is increasing due to the effect of climate change and global warming. If we still rely on the conventional electric air conditioning but electricity is generated from fossil fuels, the greenhouse gas emission would continuously worsen global warming; in turn the demand of air conditioning would be further increasing. However, air conditioning would commonly take up half of building electricity consumption. So we aimed to develop a new hybrid power-less air conditioning system and an in built water heating system attached to it by utilizing free energy source. Also we aimed to develop an environment friendly and low cost air conditioning and water heating system.

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V. LAYOUT OF THE SYSTEM

VI. WORKING OF THE SYSTEM

VII. COMPONENTS OF THE SYSTEM

In this project, we utilize only solar power for the cooling process and also for water heating. The cooling process proceeds as the temperature of atmosphere increases by sun rays. A solar parabolic concentrator with a mechanized sun tracking is used for heating of water inside a copper pipe which is placed at the focus of the concentrator. The mirrors of the concentrator are correctively positioned, so that the sun rays falling on the concentrator is directed towards the focus of the concentrator. This causes the heating of water inside the copper tube to a temperature of more than 350 degree Celsius and produces superheated steam which is mixed with the air from the room. This mixture is then expanded through a duct which condenses the steam. The high pressure mixture is then passed to an evaporative cooler which consist of moist fibers which causes the cooling of the mixture.

A. Solar Parabolic Concentrator The Parabolic Trough Concentrator (PTC) is a solar concentration technology that converts solar beam radiation into thermal energy in their linear focus receiver. This type of concentrator is commonly provided with one-axis solar tracking to ensure that the solar beam falls parallel to its axis. In our system a medium range concentrator ranging from about 85 to 250 °C is used. It consists of about 16 mirrors equally spaced along the circumference of the solar concentrator. Each mirror so angled so that the light incident on it is reflected towards the focus. Each mirror is properly angled by using a laser reflection process. The sides of the concentrator are covered by Aluminum foil so that light transmitted through the mirrors are again reflected towards the center. A copper tube of about 50mm diameter is placed at focus of the concentrator. The sides and top surfaces of the concentrator are covered by a reflective film so that light incident is reflected back and so heat loss by convection can be reduced. The concentrator is properly directioned by using a mechanized sun tracking system.      

The passage to the evaporator is coated with coolant material which lowers the temperature of the incoming air without affecting its pressure. This cooled air is then passed to the room which is at a lower pressure. The vents of the evaporator are coated with dehumidifiers such as silica gel and a sheet coated with lithium chloride or lithium bromides is rolled inside the evaporator chamber. In this system cooling effect is produced by both steam condensation and evaporative cooling. This is how the cooling effect is produced. This can also be used as a room heater in winter condition by proper adjustment. The required level of water inside the concentrator is maintained by a reservoir which is attached to concentrator pipe (copper). A metallic pipe is used to connect the concentrator and reservoir. As the temperature of water in the concentrator increases, the temperature of water in the reservoir also increases by convection. This hot water can be utilized for domestic purposes.

Length of the concentrator = 1000 cm Diameter of the concentrator = 55 cm Diameter of the copper tube = 50 mm Width of mirrors = 5 cm Length of the mirrors = 100 cm Reflectivity of the mirrors = 0.73

Fig 1 Orientations of mirrors in the concentrator

The orientation of mirrors in the concentrator is shown in figure 1. It consists of about 16 mirrors equally spaced along the circumference of the solar concentrator. Each mirror so angled so that the light incident on it is reflected towards the focus. Each mirror is properly angled by using a laser reflection process. The fabricated model of the solar concentrator with mechanized sun tracking systems is as shown in figure 2

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Fig 2 Solar Parabolic concentrator

B. Evaporative Cooling Chamber It consist of layers of cooling pad, a sheet coated with lithium bromide and water sprayer. The cooling pad is made of coconut fiber and cotton due to its good water holding capacity. The cooling pad is timely sprayed with water by using a sprayer. A sheet coated with lithium bromide / lithium chloride is rolled in and out of the chamber .The sheet rolled so that water absorbed by the sheet is regularly dried outside by using the heat from sunlight.

Fig 4 Inlet duct of the Evaporative chamber

The evaporative chamber is filled with layers of cooling pad which is regularly sprayed with water by a sprayer. The cooling pad is made of coconut fibre and cotton due to their high water holding capacity .the dimension of the layer of cooling pad used is about 45×45×45 cm. The cooling pad used in the proposed system is as shown in figure 5.

Fig5 Cooling pad used in the fabricated system Fig 3 Evaporative Chamber

The fabricated model of the evaporative cooling chamber is as shown in the figure 3.The dimensions of the chamber designed is .05×.05×.05 m. It mainly consist of evaporative cooling pad which is regularly water sprayed by using a sprayer. The chamber has two ducts on its either sides. The duct at the inlet of the chamber is designed for steam condensation and the other duct at the outlet is for proper air flow to the cooling space. The shape of the duct designed at the inlet of the evaporative chamber is as shown in figure 4.

C. Primary Water Tank Primary tank is the main tank of the house. It is connected to the secondary tank and the evaporative chamber. D. Secondary Water Tank It is the tank containing the hot water. It is connected directly to copper pipe of the concentrator. The water for secondary tank is from the primary tank. The level of water in the concentrator is maintained by maintaining the water level in the secondary tank by using a float valve. The dimension of the secondary tank used is 25×25×50 cm. the fabricated secondary tank is as shown in the figure 6.

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=.03*1.004*(30-23) = 211.09 J Total heat transfer through the cooling pad Q*.45 = 211.09 Q=0.46899 Heat transfer through the cooling pad = q*0.45*0.45 = Q q=2.316 kJ/m2 Heat transfer rate of the cooling pad material per unit area =2.316 kJ/m2 Rational cooling efficiency= Total Cooling effect Total heat input = 211.09 = 0.43 495 Rational cooling efficiency =0.43 IX. RESULTS AND DISCUSSIONS Fig 6 Fabricated secondary hot water tank

E. Solar Photovoltaic Panel The solar photovoltaic panel used in the system is 100 W panel. The solar panel is only power source used in the system to drive the blower, sun tracking system motors and motors used to roll the lithium bromide coated sheets. VIII. CALCULATIONS

Fig 7 The variation of solar intensity in a day

Average solar radiation intensity Area of each mirror of concentrator Total area of the mirror Reflectivity of the glass used

=500W/m2 =.05*1=.05 m2 =16*0.05=0.8 m2 =0.73

Fig 8 Fabricated model of the system

Intensity of solar radiation at peak time =900W/m Total solar energy incident on the mirror=900*.8=720W Total solar energy reflected by mirror =720*0.73=525.6W Absorptivity of copper =0.94 Total heat generated in the concentrator pipe =0.94*525.6 = 495W =495J/s Temperature at the exit T2=23 deg. celsius Total heat transfer across the system =-mCp(T2-T1)

The fabricated model of the proposed system is as shown in the figure 8. A cabin of size about 3Ă&#x2014;3Ă&#x2014;5.5 ft was fabricated as the cooling space. The side wall of the model shows the blower which is used for the suction and flow of the hot air from the room to the system. Two pipes are provided inside the cabin for getting the hot and cold water.

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   



Solar cooling systems with intermittent heat storage for institutions and other establishments working during day time Integrated hybrid solar systems both for heating and cooling to work in all seasons High heat storage air conditioning and water heating systems Increasing cost of electricity and its non availability on a 24×7 hour basis at many places Decreasing cost of solar electricity through photovoltaic which has come down to around Rs 8/per unit from the earlier price of Rs 18/- per unit about 3 years back. REFERENCES

Fig 9 CFD analysis of the air and steam flow through the pipe

It is clear from the figure 9 that the steam air superheated mixture condenses at the exit of the duct. The design and analysis of the proposed system was done and designed system is fabricated and the analysis of the fabricated model was conducted. In the analysis part it was found that the steam condenses at the inlet of the evaporative chamber. Also from calculations it was found that rational cooling efficiency was about 0.43. From the analysis of the fabricated model it was found that the temperature of the cabin was reduced to about 25 degree Celsius and the temperature of the hot water was about 50 degree Celsius. X. CONCLUSIONS A constant temperature about 25℃ is obtained in the cabin which is almost human comfort temperature. And for water heating about 50℃ is obtained at the hot water tank. Rational cooling efficiency of 0.43 is obtained and is greater when compared to the existing system whose rational cooling efficiency is about 0.3 to 0.4. This can also be used as a room heater in winter condition by proper adjustment. The main highlight of our project is that only solar energy is utilized for the cooling and heating process. No other external power sources are used. Our product is ecofriendly and pollution less. This can also installed at remote areas where electricity is not available and in regions where atmospheric temperature is high e.g. Rajasthan. It is well suited for middle class family as it requires only initial investment and less maintenance cost. No separate water heater is required for domestic purpose.

[1]. D.M. Whaleya, W.Y. Samana, A.T. Alemua, “Integrated Solar Thermal System for Water and Space Heating, Dehumidification and Cooling”, Energy Procedia, vol.57, 2014, pp. 2590 – 2599 [2]. Luis Carlos Herrera Sosa, Gabriel Gómez-Azpeitiab, “Cooling Average Potential of Evaporative Cooling System in Dry Warm Climate”, Energy Procedia, vol. 57, 2014 , pp. 2554 – 2563 [3]. Morgado Baca I.a, Melero Tur S.a, Neila Gonzalez J.a, Acha Román C.a , “Evaporative cooling efficiency according to climate conditions” , Procedia Engineering, vol.21 ,2011, pp. 283 – 290 [4]. José Roberto García Chávez, “Application of Combined Passive Cooling and Passive Heating Techniques to Achieve Thermal Comfort in a Hot Dry Climate”, Energy Procedia, vol. 57, 2014, pp. 1669 – 1676

FUTURE SCOPE Keeping in view the present status and cost of electricity/diesel and other fossil fuels fuel and also the available solar technologies, there seems to be a vast potential of solar cooling as per following factors:

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DESIGN AND ANALYSIS OF 3D BLADES FOR WELLS TURBINE Shyjo Johnson, Sriram S Kumar, Tom B Thachuparambil, Vivek Joseph John , G.Anil Kumar

Abstract- Wells turbine is a self rectifying air turbine which is widely used in oscillating water column energy converter. The Wells turbine will always rotate in the same direction irrespective of the direction of the oscillating airflow. Furthermore the Wells turbine has a simple configuration and structure. This is why the Wells turbine is very commonly used for conversion of wave energy. At present 2-dimensional blades are being used for the conversion of wave energy. We are proposing 3-dimensional blades that can improve the steady characteristics of the current wells turbine. The effect of 3-dimensional blade on the turbine characteristics has been analyzed based on different inlet velocities and steady characteristics were found out. Further, the aim of the use of 3-dimentional blade for Wells turbine is to prevent flow separation on the suction surface near tip, which is a major drawback in the case of existing one. The chord length is constant with radius and the blade thickness increases gradually from hub to tip. The blade profiles are NACA0015 at hub, NACA0020 at mean radius and NACA0025 at tip.

energy conversion. However, according to the previous studies, the current Wells turbine has inherent disadvantages such as lower efficiency, poorer starting characteristics and higher noise level in comparison with conventional turbines. On the other hand, in order to overcome these weak points, a number of self-rectifying air turbines with different configurations have been proposed .Rather, different we are concentrating on the design of a three dimensional blade, in place of the existing 2 dimensional one.

The performance of wells turbine with 3-dimensional blades has been compared with those of original Wells turbine, i.e., the turbine with 2-dimensional blades. As a result, it has been concluded that both the efficiency and turbine characteristics can be improved by the use of 3-dimensional blade. Keywordsâ&#x20AC;&#x201D; wells turbine, oscillating water column, steady characteristics, stall

INTRODUCTION

Several of the wave energy devices being studied under any wave energy program make use of the principle of an oscillating water column (OWC). In such wave energy devices an oscillating water column due to wave motion is used to drive an oscillating air column, which is converted into mechanical energy. The energy conversion from an oscillating air column can be achieved by using a system of non-return valves for rectifying the airflow, together with a conventional turbine. However, such a system is complicated and difficult to maintain, and the average cycle efficiency in an oscillating airflow is likely to be considerably smaller. The non-return valves can be eliminated by the use of a self rectifying air turbine, which inherently provides a unidirectional rotation for an alternating airflow. The â&#x20AC;&#x153;Wells turbineâ&#x20AC;? is of this type and is one of the simplest and probably the most economical turbines for wave

Fig 1 Outline diagram of wells turbine Figure 1 shows the conversion of energy taking place inside a wells turbine. The potential hydro energy of ocean waves is converted to pneumatic energy. This pulsated air passes through a turbine blade and is converted to mechanical energy. The turbine is coupled to a generator which converts the mechanical energy into electrical energy Figure 2 shows the outline of wells turbine. In this study, in order to enhance the characteristics of Wells turbine for wave energy conversion, the effect of 3-dimensional (3D) blade on the turbine characteristics has been investigated analytically under steady flow conditions. The chord length is constant with radius and the blade profile changes gradually from hub to tip in the study. The aim of 3D blade is to prevent flow separation on the suction surface near tip and to gain much energy at tip.

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Fig 2 Wells turbine The blade profiles are NACA0015 at hub, NACA0020 at mean radius and NACA0025 at tip. And then, the characteristics of Wells turbine with 3-dimensional have been compared with those of the original Wells turbine, i.e., the turbine with 2-dimensional (2D) blade.

Sea-wave energy power plants experienced a renewed interest after the introduction of the Wells turbine. In fact, the Wells turbine is commonly adopted in OWC wave energy converters, where, due to the wave motion, the pressure at the inlet of the vertical duct generates pressure fluctuations in the plenum thus producing an oscillating air-flow able to drive a turbine. At present two dimensional blades are being utilized for the conversion of mechanical energy, which has its own disadvantages. It includes poor starting characteristics of the turbine, lower efficiency and the problem of flow separation at the suction surface. In order to overcome these disadvantages 3 dimensional blades are designed which helps to overcome the disadvantages of current one. The three dimensional blades are of two types namely 3D-A and 3D-B,which are classified according to the blade profiles arrangement at the hub, mean radius and tip. IV.

II. OBJECTIVES The first objective of our project is to design three dimensional blades using CATIA V5 for wells turbine in place of existing two dimensional blades. A blade is called 2D because the blade thickness is constant with radius and has uniform cross section. Blade profiles such as NACA0015 or NACA0020 or NACA0025 can be used. The existing two dimensional blades have certain drawbacks such as poor starting characteristics, lower efficiency and problem of flow separation at suction surface. The above drawbacks could be overcome by three dimensional blades. Secondly, to compare the steady characteristics of the current 2Dimensional blade with 3Dimensional blades. Turbine performance under steady flow conditions is evaluated by, Turbine efficiency, Torque coefficient, Pressure drop coefficient against axial velocity

DESIGN OF TURBINE BLADE

The effective energy conversion is possible due to the use of the self-rectifying axial Wells turbine. The turbine blades have symmetrical profiles (commonly four digit double zero NACA profiles).In order to investigate the characteristics of wells turbine NACA0015 with constant chord length for 2D blades and for 3d blades with NACA0015,NACA0020 and NACA0025.The details of 2D blades and 3D blades are shown on table 1 Table 1 Specifications of blade

III. PROBLEM DEFINITION AND BACKGROUND Analyses of the flow through the Wells turbine have been carried out by means of analytical, and numerical methods. The flow domain is divided into annular elements where the two-dimensional assumption is used; the lift and drag coefficients are obtained either from experimental data for isolated airfoils. In the last years, thanks to the development achieved in CFD, the numerical simulation of the three-dimensional turbulent flows, such as that through a Wells turbine, became practicable and several numerical studies on the flow-field through Wells turbine have been presented. In consideration of the low sea wave frequencies, previous works have carried out the fluid dynamic analysis of such a turbine by means of a quasi-steady approach. Recently, hysteretic phenomena have been detected under oscillating flow conditions, especially when the oscillating flow amplitude grows.

Figure 3 shows the dimensions of wells turbine experimental setup. The airfoil used in wells turbine are symmetrical airfoils.

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Fig 5 Pressure contour at 5m/s for 3D blade Fig 3 Dimensions of wells turbine The design of wells turbine has done in CATIA v5 .the design of turbine rotor are shown below:

We are analyzing 2D, 3D-A and 3D-B type of blades by giving different inlet velocities such as 3, 5, 7 and 9m/s. As a result force acting on the turbine, area and the net torque acting on the turbine can be obtained from the fluent software. Based on the above values steady characteristics such as flow coefficient, pressure drop coefficient and efficiency can be calculated. The turbine performance under steady flow conditions is evaluated by turbine efficiency, torque coefficient and pressure drop coefficient against flow velocity and is being tabulated as shown in table 2: Table 2 Steady characteristics of turbine

(a) 3D-B blade

(b) 3D-A blade Fig 4 3D blade profile RESULT AND DISCUSSION

The analysis of wells turbine has done using ANSYS14. We used Moving Reference Frame (MRF) method to analyze the turbine. MRF method is a method used to analyze rotating bodies. The boundary conditions are inlet velocity was varied in the order of 3 to 9 m/s and outlet pressure as gauge pressure and the speed of rotation is limited to 2000 rpm using speed governor. For the analysis of 3D-A blade results are calculated at 2000rpm using MRF method. The pressure contour obtained shown in the below Fig .The maximum pressure was found to be 473.5pa

axial

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From the graph shown below it can be infer that as velocity increases torque coefficient increases.

Maximum torque coefficient is found out to be for 3D-A which is 0.16 at 9m/s when compared to other two blades.

seems that the turbine characteristic in the case of 3D-A which the blade thickness increases with radius is better than the case of 2-dimensional blade. The turbine characteristics such as pressure drop coefficient, torque coefficient and efficiency is found to be higher for 3D-A blade. The maximum efficiency was found to be 66.32% for 3D-a blade. Further, it can be concluded that the stall characteristic in the case of 3-dimensional blade depends on the profile at tip than that at hub. REFERENCES

Fig 6 Variation of torque coefficient with axial velocity From the graph shown below it can be infer that as axial velocity increases pressure drop coefficient increases. For 3D-A blade it is found out that there is slight increase in pressure drop coefficient with increase in axial velocity

[1] David G. Dorrell1 and Min-Fu Hsieh, “Performance of Wells Turbines for use in Small-Scale Oscillating Water Columns”, ISOPE Conference, 1-6 July, 2007 [2] Masami Suzuki, “Design Method of Wave Power Generating System with Wells Turbine”, Proceedings of the Twelfth (2002) International Offshore and Polar Engineering Conference Kitakyushu, Japan, May 26–31, 2002 [3] M. Torresi , S. M. Camporeale , P. D. Strippoli and G. Pascazio “ Accurate numerical simulation of a high solidity Wells turbine”, Renewable Energy, vol. 33, issue 4, 2008, pp. 735-747

Fig 7 Variation of pressure drop coefficient with axial velocity From the graph, efficiency increases with axial velocity and efficiency for 3D-A is found to be more than other two blades. Max efficiency for 3D-A is found to be 66.32%

Fig 8 Variation of efficiency with axial velocity VI.

CONCLUSIONS

In this study, the effect of 3-dimensional blade on turbine characteristics was investigated analytically under steady flow conditions, in order to enhance the performance of Wells turbine for wave energy conversion. As the results, it

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DESIGN AND ANALYSIS OF HEAT EXCHANGER FOR AUTOMOTIVE EXHAUST BASED THERMOELECTRIC GENERATOR [TEG] Rakesh Rajeev, Richu Lonappan Jose, Rohan Mathai Chandy, Thomas Lukose, Er.Nandu S

Abstract- In internal combustion engines the thermal efficiency is around 30 %, roughly 30% of the fuel energy is wasted in exhaust gases, and 30% in cooling water and 10% are unaccountable losses. Efforts are made to catch this 30 % energy of exhaust gases. If this waste heat energy is tapped and converted into usable energy, the overall efficiency of an engine can be improved. Thermoelectric modules which are solid state devices that are used to convert thermal energy to electrical energy from a temperature gradient and it works on principle of Seebeck effect.

Most of the worldwide increase in oil demand will come from the transport sector. The transport sector will share 54% of global primary oil consumption in 2030 compared to 47% today and 33% in 1971. The share of oil products in transportation sector of energy consumption will remain almost constant over the projection period (WEO, 2004). In gasoline powered internal combustion engines; around 30% of the fuel energy is wasted in the form of exhaust gases, and 30% in coolant as shown in figure 1.

This paper demonstrates the potential of thermoelectric generation. A hot side heat exchanger as well as cold side heat exchanger was designed and analysed. After certain analytical studies it is found that heat exchanger positioned between catalytic converter and muffler has higher surface temperature. Thermoelectric modules of Bismuth Telluride (Bi2Te3) were selected according to the temperature difference between exhaust gases side (between catalytic converter and muffler) and the engine air conditioner evaporator as cold side. A circular heat exchanger with fins was designed and the thermo electric modules were placed on the heat exchanger for performance analysis. The study showed that energy can be tapped from engine exhaust. Keywordsâ&#x20AC;&#x201D; Seebeck Effect, Thermoelectric Generator, Heat Exchanger, Thermoelectric Materials, Bismuth Telluride .

Fig.1 World Marketed Energy Use by Fuel Type 1980 â&#x20AC;&#x201C; 2030, (IEO, 2006)

INTRODUCTION

The "Energy Crisis" has become a major challenge in front of engineers across the globe due to rapidly increasing demands and consumption of energy. For almost two hundred years, the main energy resource has been fossil fuel and will continue to supply much of the energy for the next two and half decades. Worldwide oil consumption is expected to rise from 80 million barrels per day in 2003 to 98 million barrels per day in 2015 and then to 118 million barrels per day in 2030.

One potential solution is the usage of the exhaust waste heat of combustion engines. This is possible by the waste heat recovery using thermoelectric generator. A thermoelectric generator converts the temperature gradient into useful voltage that can used for providing power for auxiliary systems such as minor car electronics. As shown in the figure 2, the proposed system consists of one hot side heat exchanger and one cold side heat exchanger. Between the two heat exchangers the thermoelectric modules (TEG) are placed. The exhaust gas from engine passes through hot side heat exchanger and air condition refrigerant passes through cold

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side heat sink. According to the principle of Seebeck effect, thermoelectric modules convert the heat into useful electricity.

generation of an exhaust TEG (thermoelectric generator) depends on heat energy and thermoelectric conversion efficiency. However, there are compatibility problems among TEG, CC (catalytic converter) and muf (muffler). The present work tried to vary the installation position of TEG and propose three different cases. Case 1: TEG is located at the end of the exhaust system; case 2: TEG is located between CC and muf; case 3: TEG is located upstream of CC and muf. To theoretically determine voltage developed using TEG. That is by Seebeck effect the voltage produced is given by the equation V = α (TH-TC) Where α is the difference in Seebeck coefficient of two leg materials and has the units of V/K, and TH and TC are the hot and cold side absolute temperatures both measured in Kelvin.

Fig.2. Thermoelectric Waste Heat Recovery as a Potential Energy Efficiency Option in Ground Vehicles

The driving principle behind thermoelectric generation is the known as the Seebeck effect. Whenever a temperature gradient is applied to a thermoelectric material, specifically metals or semiconductors, the heat passing through is conducted by the same particles that carry charge. The movement of charge produces a voltage. The junctions of the different conductors are kept at different temperatures which cause an open circuit electromotive force (e.m.f) to develop as follows: V = α( TH - TC ) Where α is the difference in Seebeck coefficient of two leg materials and has the units of V/K, and are the hot and cold side absolute temperatures both measured in Kelvin. A German Physicist, Thomas Johann Seebeck, discovered this effect in the early 1800s

III. DESIGN A. DESIGN OF COLD SIDE HEAT EXCHANGERS The cold side heat exchanger is designed according to the following specifications given below. This design does not develop any back pressure which will distort the air conditioning system. Outer diameter of pipe, d Height of fin, h = 0.25d Breadth of fin, b = 0.5d Width of fin, w = 0.75xPipe length

An important unit less constant to evaluate the performance of thermoelectric materials is the thermoelectric figure of merit, ZT. It describes the effectiveness of a specific thermoelectric material in terms of its electrical and thermal material properties. The figure of merit is expressed as ZT for materials has remained below 1 for decades, but in recent years, ZT of new materials has reached values greater than 2. II. OBJECTIVES The main objective of this project is to design and analyse the heat exchangers for Thermo Electric Generator [TEG]. The TEG has two sides’ one hot side and cold side. The hot side is selected as the exhaust system and the cold side is selected as automobile air condition evaporator side. The heat exchangers are placed in the hot side and cold side as mentioned above. In this project two modules of thermo electric materials [Bi2Te3] are placed in series.

The above designed heat exchanger is developed to a 3 Dimensional model by using Solidworks software as shown in figure 4. The figure 4 is designed with 2.54cm diameter which is common size of AC evaporator tube. In figure 4 the design is extruded to 2.54cm.

To determine the best installation positions for heat exchangers in exhaust system of automobiles. The power

The figure 4 shows the three-dimensional view of the cold heat exchanger developed in Solidworks software.

Fig.3.Design of cold side heat exchanger

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Fig.4. 3D model of cold side heat exchanger (Extrude 2.54cm)

A. DESIGN OF HOT SIDE HEAT EXCHANGER Fig.7. Heat exchanger installed between catalytic converter and muffler

The figure 7 shows the installation position of heat exchanger in exhaust system. It was found out that the heat exchanger placed between catalytic converter and muffler has high temperature gradient in exhaust system.

Fig.5. Design of hot side heat exchanger

The hot side heat exchanger is designed. It is designed as it doesn’t distort the flow of exhaust gas. This design does not develop any back pressure which will distort the exhaust system.

The heat exchanger is placed between the catalytic converter and muffler because if it was placed after the muffler effective temperature would not be obtained as when the exhaust gases passes through muffler it expands and temperature gets decreased. Thus effective temperature would not be obtained. If it was placed before the catalytic converter the velocity of exhaust gas is very high that heat transfer does not take place effectively. Hence it was observed that the best position to place the heat exchanger was between catalytic converter and muffler, because at this point the velocity is less and also more heat transfer takes place. Even if back pressure occurs the exhaust gases enters only the catalytic converter which creates no harmful effects. IV. ANALYSIS The analyses of heat exchangers are done on Ansys software. Ansys is numerical analysis software. The boundary conditions of heat exchangers placed in exhaust system [between catalytic converter and muffler] which is the hot side and the heat exchanger on evaporator of air condition as cold side are shown in tables 5.1 and 5.2. A.

Fig.6. 3D model of hot side heat exchanger (Extrude 10cm)

The above designed heat exchanger is developed to a 3 Dimensional model by using Solid works software as shown in figure 6. The figure 5 is designed with 7.5cm diameter which is common size of AC evaporator tube. In figure 6 the design is extruded to 10cm.

COLD SIDE HEAT EXCHANGER

The boundary conditions of cold side heat exchanger placed in evaporator of air condition system are given in table 1. The temperature of AC ranges from 0 ºC to -4ºC.Thus we take -4 ºC is taken. Velocity is considered as 0.02m/s. The analysis done with the given boundary conditions and is meshed to finite element size. The governing equations are continuity equation, energy equation, momentum equation and k-ɛ equation as the flow is turbulent.

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C .ANALYSIS OF COLD SIDE HEAT EXCHANGER

Table 1 .Boundary Condition of cold side heat exchanger

TURETEMPERATURE [K] 269

VELOCITY [m/s] .02

In Ansys software the outlet boundary condition is opening option and the interface is coupled wall. B.

Heat exchanger placed in the ac evaporator. A portion of evaporator is removed and the heat exchanger is placed. The boundary conditions are applied and governing equations were given. Analysis is done and the results are obtained.

HOT SIDE HEAT EXCHANGER

The boundary conditions of cold side heat exchanger placed in exhaust system [between catalytic converter and muffler] are given in table 2. The temperature of AC ranges from 400 ÂşC -1100ÂşC.Thus we take 600K , 750 K, 900K and 1200K is taken. Velocity is considered as 10m/s. In an automobile exhaust the velocity of exhaust gases ranges from 8-20m/s. Hence we use 10m/s as a moderate value. The analysis done with the given boundary conditions and is meshed to finite element size. The governing equations are continuity equation, energy equation, momentum equation and k-É&#x203A; equation as the flow is turbulent Table 2 Boundary Condition of hot side heat exchanger.

Sl.No:

TEMPERATURE [K]

VELOCITY [m/s]

650

750

900

1200

Fig.8 Analysis of cold side heat exchanger

The figure 8 shows the analysed cold side heat exchanger. When 269K and velocity 0.02m/s boundary condition were given almost 269K was obtained on the surface of heat exchanger. This temperature obtained at surface was conducted to the cold side of TEG with the help of suitable conducting materials. The temperature obtained from cold side heat exchanger will not sustain for long, so the temperature should make use of quickly. Hence the TEG module was placed near to cold side, in an appropriate place between catalytic converter and muffler. D. ANALYSIS OF HOT SIDE HEAT EXCHANGER

CALCULATION Heat exchanger is placed in the exhaust system .A portion is removed and heat exchanger is placed. Analysis is done and the results are obtained. The heat exchanger installation position is between the catalytic converter and muffler.

Re = Ď VD Âľ Where Re â&#x20AC;&#x201C; Reynolds number V- Velocity of flow D- Diameter of pipe Ď â&#x20AC;&#x201C; Density Âľ - Coefficient of viscosity At 600K: Ď = 0.5905đ?&#x2018;&#x2DC;đ?&#x2018;&#x201D;/ đ?&#x2018;&#x161;3 V = 10đ?&#x2018;&#x161;/đ?&#x2018; D = 0.05đ?&#x2018;&#x161; Âľ = 0.00003054đ?&#x2018; đ?&#x2018; /đ?&#x2018;&#x161;2 Re = Ď VD = 0.5905*10*0.05 = 9667.64 >4000 Âľ 0.00003054 (Since Reynolds number is greater than 4000 the flow is Turbulent) Thus k-epsilon equation is used. \ In Ansys software the outlet boundary condition is given opening option and the interface coupled wall.

Fig.9. Analysis of hot side heat exchanger at 600K

The figure 9 shows the analyzed cold side heat exchanger. When 600K and velocity 10m/s boundary

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condition were given almost 487K was obtained on the surface of heat exchanger

Fig.11. Analysis of hot side heat exchanger at 1200K

Fig.10. Analysis of hot side heat exchanger at 750K

The figure 10 shows the analyzed cold side heat exchanger. When 750K and velocity 10m/s boundary condition were given almost 493K was obtained on the surface of heat exchanger.

Fig.13. Analysis of heat exchanger placed between catalytic converter and muffler

V Fig.11. Analysis of hot side heat exchanger at 900K

The figure 11 shows the analyzed cold side heat exchanger. When 900K and velocity 10m/s boundary condition were given almost 512K was obtained on the Surface of heat exchanger. The figure 12 shows the analysed cold side heat exchanger. When 1200K and velocity 10m/s boundary condition were given almost 642K was obtained on the surface of heat exchanger The figure 13 shows the analysis of heat exchanger installed between the catalytic converter and muffler. From [1] we studied that heat exchanger placed between catalytic converter and muffler has the maximum heat transfer. Thus maximum temperature difference is obtained at this position. In this case a boundary condition of 750K temperature and 10m/s velocity and we obtained a temperature of 587K at the surface of heat exchanger.

RESULTS

The results obtained from the analysis were tabulated in the table 3 and 4. The table 3 shows boundary condition temperature with obtained surface temperature. The table 4 shows the temperature difference and voltage obtained by using Seebeck equation. As temperature increases voltage obtained also increases. Table 3. Temperature obtained from analyssi

Set No:

TEMPERATURE (K)

MAXIMUM HOT SIDE TEMPERATURE (K)

SURFACE TEMPERATURE (K)

1 2 3 4

600 750 900 1200

487 493 512 642

From table 4 a graph plotting voltage and temperature difference as shown in figure 6.1 which provide

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us the results. As from table we can see that the voltage obtained is very low. But future studies are done to improve this voltage obtained. In this analysis the thermo electric modules of two bismuth telluride are placed parallel. Hence the voltage obtained doubles. Table.4 Output Voltage Obtained

Set No :

Temperature (K)

Hot Side Temperature Th (K)

Cold Side Temperature Tc (K)

Voltage (V) V=α(Th-Tc)

1 2 3 4

600 750 900 1200

487 493 512 642

269 269 269 269

0.189 0.275 0.361 0.534

0.5

The current study focuses on the structural optimization of the heat exchanger and the coolant system to improve the efficiency of the vehicular exhaust gas heat. In the later study the way of the simulation modeling and the infrared experimental verification that has been introduced in this article needs to be combined with the heat transfer theory, to make further structural design and optimization to improve the overall exhaust heat utilization. The main advantage of using TEG is that it does not have a any moving parts.

Voltage (V)

0.4 Voltage Vs Temperature Difference

0.2 0.1

As temperature increases voltage produced also increased as voltage is proportional to the temperature difference. It is also analyzed that heat exchanger installed between catalytic converter and muffler obtained more uniform flow distribution, higher surface temperature and lower back pressure than in other cases. In this work, the heat exchanger attached with the TEGs for recovering waste heat from an automotive exhaust pipe is analyzed. According to the agreement between the infrared experimental results and the CFD simulation results, an aluminium fin type heat exchanger is selected to form the hot side. It can reduce the thermal resistance and obtain a relatively high surface temperature and uniform temperature distribution to improve the efficiency of the TEG.

0.6

0.3

limitation is that Bi2Te3 becomes distorted after 900ºC. That is after 900 ºC tellurium vaporizes at this temperature.

0 218

224

243

373

Temperature Difference (K)

Fig.14. Voltage Vs Temperature difference

From the figure 14 Voltage vs Temperature difference we can infer that voltage increases as temperature difference increase. That is voltage is proportional to temperature difference. Hence if we obtain more temperature more voltage can be produced. VI.

CONCLUSIONS

An Automobile Exhaust Thermoelectric System was designed and analyzed for the waste heat recovery of an automobile engine. The hot side is exhaust system and cold side as AC evaporator. The cold side heat exchanger analysis was done at a temperature of 269K. The hot side heat exchanger was analyzed at temperatures 600K, 750K, 900K, and 1200K. The temperature of heat exchanger surface was obtained and was tabulated. The voltage produced by the TEG was calculated from the temperature difference obtained from hot and cold side heat exchanger analysis. A voltage against temperature difference graph was plotted. It was found that the voltage increase as temperature difference increases. But a

More power could also be extracted by improving the exhaust gas heat exchanger. However with the current design the hot junction temperatures at or above 250oC were allowed for the given material of TEG (Bi-Te) and results were obtained. Results show that voltage, current, power developed and efficiency of the system increase with the increase in engine speed. Hence the AETEG system traps the waste heat of exhaust gases from engine & generates useful power which can be used to charge the car battery, to power auxiliary systems and minor car electronics. As AETEG reduces the wastage of energy, it improves the overall efficiency of vehicle. TEG system can be profitable in the automobile industry REFERENCES [1] Prathamesh Ramade, Prathamesh Patil, Prof. Santosh Trimbake , “Automobile Exhaust Thermo-Electric Generator Design and Performance Analysis”, Case Studies In Thermal Engineering, Vol. 4 , 2014, pp. 682-691. [2] X. Liu, Y.D. Deng, S. Chen, W.S. Wang, Y. Xu, C.Q. Su , “A case study on compatibility of automotive exhaust thermoelectric generation system, catalytic converter and muffler ”, Case Studies In Thermal Engineering, Vol. 2 ,2014 ,pp. 62-66. [3] C.Q. Sun, W.S. Wang, X. Liu, Y.D. Deng ,“Simulation and experimental study on thermal optimization of the heat exchanger for automotive exhaust-based thermoelectric generators ”, International Journal of Emerging Technology and Advanced Engineering, Vol. 8, 2014 ,pp. 85-91 .

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SOLAR DISTILLATION Ken Toms Pothen,NevinSaju Varghese, Nidhish Thomas Jacob, Sachin Mathew, Nikhil Ninan

other calamities. This results in a very challenging situation for individuals to prepare for such circumstances, and keep themselves and their families safe from diseases and toxic chemicals present in untreated water. Everyone wants to find out the solution for above problem with the available sources of energy in order to achieve pure water. Fortunately there is a solution for these problems, a technology that is not only capable of removing a very wide variety of contaminants in just one step, but also simple, costeffective and environment friendly.

Abstract-There is an important need for pure water in many developing countries. Often, water sources are brackish or contain harmful bacteria and therefore cannot be directly used for drinking purpose. Only 1% of Earth's water is in a fresh, liquid state, and the rest is polluted by toxic chemicals and other contaminants. For this reason purification of water supplies is extremely important. To overcome this problem we use solar distillation. Solar distillation is a simple method for obtaining pure water. The major limitations on the use of this method are low productivity per unit installation area, the need for large installation areas and variability of the energy source.

Solar energy technologies include solar heating, solar photovoltaic, solar thermal electricity and solar architecture, which can make significant contributions for solving some of the most acute problems the world now faces. Solar energy is the radiant light and heat from the sun. We have always used solar energy since humans existed.

In our project we are making a new design to increase the amount of distilled water obtained from solar still method. We are using a flat plate collector for initial heating of impure water. We also make use of heating coil to provide the additional heating. Heating coils are powered by solar energy. Condensation takes place by passing hot vapours through a cooling tank. In this project, the quality of both untreated and treated water will be noted.

Solar technologies are broadly characterized as either passive solar or active solar depending on the way they capture, convert and distribute solar energy. Active solar techniques include the use of photovoltaic panels and solar thermal collectors to harness the energy. Passive solar techniques include orienting a building to the sun, selecting materials with favourable thermal mass or light dispersing properties, and designing spaces that naturally circulate air. In 2011, the International Energy Agency said that the development of affordable, inexhaustible and clean solar energy technologies will have huge long term benefits. It will increase countries energy security through reliance on an indigenous, inexhaustible and independent resource. It will enhance sustainability, reduce pollution and lower the costs of mitigating climate change.

I.INTRODUCTIONTO SOLAR DISTILLATION Fresh water is the essence of life and is the most important constituent of the environment. Water is a basic requirement for domestic, industrial and agriculture purposes. Supplying fresh and healthy water is still one of the major problems in different parts of the world especially in arid remote areas. The combined effect of continuous increase in world population, together with the increasing industrial and agricultural activities all over the world contributes to the water contamination. There is almost no water left on earth that is safe to drink without purification. Only 1% of earth's water is in a fresh, liquid state, and rest is polluted by toxic chemicals and other contaminants. For this reason, purification of water supplies is extremely important. Moreover, purification systems are easily damaged or compromised by disasters and

In our project we are new design to improve the performance of solar still. Traditional solar stills make use of direct sun energy to carryout evaporation

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of the input water. In this design we first use direct sunlight and then use a heating coil to provide the additional heating of the vapours coming out from the tube. Condensation takes place by passing water through the tubes to a cooling tank. Thus the amount of purified water produced increases.

were conducted. From these data, initial design was articulated. The initial design was discussed with our guide, and following changes were made in the design based on his feedback: 1. Cost of the entire system was considered and decisions were made to access the components easily to reduce the cost. 2. Design was simplified so that the device can be used easily. Thus the reliability of system increases and the maintenance costs are also reduced. 3. The design was also modified in such a way that the efficiency of system increases.

Our main aim is to increase the amount of purified water. In this project, the quality of both untreated and treated water will be noted. Other objectives are: 1. 2. 3. 4.

To purify water from virtually any source To obtain relatively inexpensive method of water purification To obtain easy to use method To provide clean useful drinking water without an external energy source

III.PRIMARY DESIGN The main components of this project are given below 1. Solar panel 2. Copper tube 3 .Gate valve 4. Flat plate collector 5 .Battery 6 .Cooling tank 7. Heating element

This method can be used in industries for many industrial processes. It is having laboratory use for analytical work. It has application in hospitals and dispensaries for sterilization. It is used in garages and automobile workshop for radiator and battery maintenance. Solar distillation is used to produce drinking water and to produce pure water for lead acid batteries, laboratories, hospitals and in producing commercial products such as rose water. It is recommended that drinking water has 100 to 1000 mg/l of salt to maintain electrolyte levels and for taste.

10 Watt solar panel was selected for our project. These 10 Watt Solar Panels are useful when we require small power. The 10W panel kit doesn't require a charge controller if the battery to be used is larger than 70Ah. Copper tubing is most often used for the supply of hot and cold tap water, and as refrigerant line in heating, ventilation and air conditioning systems. Copper offers a high level of resistance to corrosion, but is becoming very costly.The reason for selecting copper tube is that they can withstand a temperature of 400ยบC. An alternative for copper tube is aluminium tube, but the main problem associated with aluminium tube is that water cannot be used for testing. This is because of the formation of oxides on the walls of the tube. Specifications: Diameter of tube=10mm, Length of tube =14.21m.

The solar distillation systems are mainly classified as passive solar still and active solar still. Passive Solar Stills: In a passive still the distillation takes place purely by direct sun light. The single slope and double slope solar stills are the conventional low temperature solar stills. They are operating at a temperature below 60ยบC. The single slope solar still is more versatile and efficient than the double slope.Active Solar Stills: In an active solar still, an extra thermal energy is fed to the water in the basin to create a faster rate of evaporation. Further the active solar stills are classified as: 1. High temperature distillation solar stills: hot water is fed into the basin from a solar collector panel. 2. Pre-heated water application solar stills: hot water is fed into the basin at a constant flow rate. 3. Nocturnal production solar stills: hot water is fed into the basin once in a day.

The function of a gate valve is to ensure a straight line flow of a liquid where minimal restriction is desired.A battery, which is actually an electric cell, is a device that produces electricity from a chemical reaction. A battery consists of two or more cells connected in series or parallel.The specifications of the battery: Nominal voltage: 12V, Nominal capacity: 7 Ah.Heating Element converts electricity into heat energy. Electric current that passes through the element encounters resistance, resulting in heating of the element. This process is independent of the direction of current flow. In this project nichrome was chosen as the heating element. Nichrome 80/20 is an ideal material, because it has relatively high resistance and

II.METHODOLOGY At first, we found out different ways to attain fresh water. Then we analysed the costs which are incurred by different methods. The result of the analysis was discussed by our team and brain storming sessions

159

forms an adherent layer of chromium oxide when it is heated for the first time. A typical flat-plate collector is a metal box with a glass or plastic cover (called glazing) on top and a dark-coloured absorber plate on the bottom. The sides and bottom of the collector are usually insulated to minimize heat loss.Sunlight passes through the glass and strikes the absorbing surface, which heats up surface. Absorber surfaces are commonly painted with selective coatings, which absorb and retain heat better than ordinary black paint. It was found that for maximum annual yield, the optimum collector inclination for a flat plate collector is 20Âş. Glass wool or fibreglass insulation is manufactured from melted glass spun. It can be either be in the form of a flexible mat or fine fibres. Glass wool is used as the insulation material inside the box. This is done to prevent the escape of heat which is absorbed in. Glass to be used on the surface of the box is transparent ordinary glass. Silicon paste is used for pasting glass on to the upper surface of the walls. The glass entraps the heat inside the box and prevents the heat from escaping to the surroundings. The cover can be either glass or plastic.

Fig. 2: Primary Layout Working Impure water enters the copper tube at the inlet of the box. Copper tube is placed inside the box and the box acts like a flat plate collector. Sun light passes through the glass surface placed on top of the box and strikes on the copper tubes and it gets heated up. The low temperature impure water gets heated and gets converted into vapour. At the exit of box a heating coil is present which is powered by using the heat from the sun which is stored in a battery. Heating coil ensures that only vapours passes through copper tubes at the exit. The hot vapours are made to pass through a cooling tank. Copper tubes inside cooling tank act as cooling coils and cold water is circulated inside the cooling tank. The hot vapours will be condensed to the liquid state by absorption of heat by the cold water inside the cooling tank. The distilled water is then collected in a vessel at the exit of the cooling tank.

Fig. 1: Flat plate collector Glass is more preferable than plastic because plastic degrades in the long term use due to ultra violet rays from the sunlight and is more difficult for water to condense onto it. Specification of mild steel box: 1.The collector inclination for a mild steel box is 21Âş. 2 .Dimension of box is 1mx0.5m x0.125m 3. 4mm thick transparent glass is placed on the box.

Fig. 3: CAD model of primary design However this model is not feasible since a continuous power source is required to heat the heating element. A more powerful solar panel was required for continuous charging of the battery, so an alternative method was found out.

Cooling tank contains water used for condensation of hot vapours coming through the copper tubes. It is kept after heating coils. Cold water in the tanks absorbs the heat from the hot vapours passing through the copper tubes. This results in condensation of hot vapours. Copper tubes act as cooling coils. Water is passed though one hole on the cooling tank and exits through a hole on the opposite end. Water available for cooling is taken from a pipe.

IV.FINAL DESIGN In order to overcome the problems faced by primary design, an alternative solution was found out. A parabolic reflector was used to concentrate the sunâ&#x20AC;&#x2122;s rays on to the copper tube at the exit of flat plate

160

collector. As it failed to charge the battery continuously; heating coil, solar panel and battery were removed.

Fig 5: CAD Model of Final Design V.RESULTS AND DISCUSSION

The main components are given below 1. Copper tube 2. Flat plate collector 3. Cooling tank 4. Gate valve 5. Parabolic Reflector

The experimental values regarding the quality of the water before and after the testing are noted and the efficiency of solar still is calculated. Temperatures obtained are shown in below table.

A parabolic reflector is a reflective surface used to collect or project energy such as light, sound or radio waves. It has the shape of a circular paraboloid, i.e., the surface generated by a parabola revolving around its axis. The parabolic reflector transforms an incoming plane wave traveling along the axis into a spherical wave converging toward the focus. Conversely, a spherical wave generated by a point source placed in the focus is reflected into a plane wave propagating as a collimated beam along the axis. Diameter of the reflector is 48 cm and the focal length of reflector is 28 cm.

Time

9:00am

Inlet temp. (ยบC)

Exit temp. Of flat plate collector without Reflector(ยบC)

Exit temp. of flat plate collector with Reflector(ยบC)

Outlet Temp. (ยบC)

2 10:00am

52 2

Fig. 4: Final Layout

11:00am

12:00pm

102

1:00pm

101

Working

5 2:00pm

A reflector is used to concentrate the sun light on to the copper tube at the exit of flat plate collector. The temperature of the copper tube at the exit of collector rises and as a result the impure vapour liquid coming out of the collector gets heated to high temperatures. This hot vapour is made to pass through a cooling tank. Copper tubes acts like cooling coils inside cooling tank. The hot vapours will be condensed to the liquid state.

55 5 4

3:00pm

48 8

Water quality before and after conducting the experiment are tested. It can be noted that pH value of tested water increases from 6.7 to 6.9. Chloride content, dissolved oxygen and total hardness were found to decrease after the conduct of the experiment. There were no bacteria present in the water which was tested. VI.EFFICIENCY CALCULATION OF SOLAR STILL

161

Q u = mCp Î&#x201D;T

(Ô&#x17D;Îą)e- effective transmittance-absorptance product

Qu - heat gained by working fluid in W (J/s)

Ô&#x17D; - transmittance of the glass cover =0.92

m - mass flow rate in kg/s

đ?&#x203A;ź - absorptance of the absorber(black paint)=0.96

Cp - Specific heat of water = 4.18kJ/kgK

Ď d - diffuse reflectance of the cover, which can be estimated by calculating reflectance Ď for an incident angle of 60Âş denoted by Î¸1

Î&#x201D;T â&#x20AC;&#x201C; average temperature-atmospheric temperature in K

tan ( ď ą 1 ď&#x20AC; ď ą 2 )

sin ( ď ą 1 ď&#x20AC; ď ą 2 )

ď ˛ ď&#x20AC;˝

m ď&#x20AC;˝ ď ˛ď&#x201A;´Aď&#x201A;´ v

Ď -density of liquid in kg/m3

2 tan ( ď ą 1 ď&#x20AC;Ť ď ą 2 ) 2

ď&#x20AC;Ť

2 sin ( ď ą 1 ď&#x20AC;Ť ď ą 2 ) 2

Î&#x2DC;2- Angle of refraction

A-area of cross section of the collecting tank in m2

sin ď ą 1

v is the velocity of flow in m/s

sin ď ą 2 ď&#x20AC;˝

Discharge = volume/time

n -refractive index of transparent glass cover =1.5

Q ď&#x20AC;˝

0 . 001

sin 60

sin ď ą 2 ď&#x20AC;˝

= 2 . 94 ď&#x201A;´ 10 2 . 94 ď&#x201A;´ 10

ď&#x20AC;5

1 .5

= 35.24Âş

m3/s

tan ( ď ą 1 ď&#x20AC; ď ą 2 )

sin ( ď ą 1 ď&#x20AC; ď ą 2 )

ď&#x20AC;˝ Area ď&#x201A;´ Velocity

ď ˛ ď&#x20AC;˝

= (3.14 x 0.1 x v)/4

2 tan ( ď ą 1 ď&#x20AC;Ť ď ą 2 ) 2

tan ( 60 ď&#x20AC; 35 . 24 )

ď&#x20AC;Ť

2 sin ( ď ą 1 ď&#x20AC;Ť ď ą 2 )

v = 3.745 x 10-3m/s

ď&#x20AC;˝

2 tan ( 60 ď&#x20AC;Ť 35 . 24 ) 2

sin ( 60 ď&#x20AC; 35 . 24 ) 2

ď&#x20AC;Ť

2 sin ( 60 ď&#x20AC;Ť 35 . 24 ) 2

m ď&#x20AC;˝ ď ˛ď&#x201A;´Aď&#x201A;´ v

= 0.1412 = (1000 x 3.14 x 0.012 x 3.745 x 10-3)/4

( ď ´ď Ą ) e ď&#x20AC;˝

= 2.94 x 10-4 kg/s Q u ď&#x20AC;˝ mC p ď &#x201E; T

ď&#x20AC;˝

-4

= (2.94 x 10 x 4.18 x 1000 x (63-30)) = 40.55W

ď ´ď Ą 1 ď&#x20AC; (1 ď&#x20AC; ď Ą ) ď ˛ d

0 . 92 ď&#x201A;´ 0 . 96 1 ď&#x20AC; (1 ď&#x20AC; 0 . 96 ) ď&#x201A;´ 0 . 1412

= 0.888

Qi=HT Ac(Ô&#x17D;Îą)e

Value of HT= 6.67 kWh/mÂ˛day, at Kottayam, Kerala

Qi- incident solar energy in W

1 kWh/mÂ˛day = 1,000 W x 1 hour / (1 mÂ˛ x 24 hours)

HT - total solar radiation on the flat plate collector in W/m2

= 41.67 W/mÂ˛ Q i ď&#x20AC;˝ H T A c ( ď ´ď Ą ) e

Ac - area of the collector in m2

( ď ´ď Ą ) e ď&#x20AC;˝

Q i = 6.67 x 41.67 x 1 x 0.5 x 0.888

ď ´ď Ą 1 ď&#x20AC; (1 ď&#x20AC; ď Ą ) ď ˛ d

= 123 W

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distilled water obtained in this process can also be increased.

Efficiency, 

Qu Qi



Fresh water produced by a solar still would be one of the best solutions to supply fresh water to villages and arid regions. Solar energy is the best alternative compared to any other heating energy sources. It can be concluded that use of solar distillation promises to enhance the quality of life, and health standards in remote areas.

40 . 55 123

= 32.97% Cost analysis of this project is shown in the table below.

VIII. REFERENCE SL

PARTS

QTY

SPECIFICATION

NO.

[1] V. Sivakumar, E.GanapathySundaram, “Improvement techniques of solar still efficiency”: A Review, (2013) 246-264.

COST (Rs.)

Cooling Tank

Copper Tube

0.2m x 0.2m x0.2m

500

14m x10mm

4000

[2] Prof Alpesh Mehta, ArjunVyaas, NithinBodar,“Design of Solar Distillation System”, International Journal of Advanced Science and Technology Vol. 29, (2011).

Reflector

45cm dia

200

Mild Steel Box

1m x 0.5m x 0.125m

2000

Glass

4mm thick

195

Total cost:

[3] Shobha.B.S, Vilas Watwe, Rajesh A.M, “Performance Evaluation of a Solar Still Coupled to an Evacuated Tube Collector type Solar Water Heater”, International Journal of Innovations in Engineering and Technology Vol. 1 Issue 1 ( 2012). [4] Amitava Bhattacharyya, “Solar Stills for Desalination of Water in Rural Households”, International Journal of Environment and Sustainability| Vol. 2 No. 1, (2013) 21‐30.

6895

[5] AayushKaushal, Varun, Renewable and Sustainable Energy Reviews 14, International Journal of Advanced Science and Technology (2010).

VII. CONCLUSION

[6] M. KoilrajGnanadason, P. Senthil Kumar, G.Jemilda, S.Sherin Jasper, “Effect of Nanofluids in a Modified Vacuum Single Basin Solar Still”,International Journal of Scientific & Engineering Research Volume 3, (2012).

This project is dealing with design, fabrication and analysis of an effective method of solar distillation. The initial design comprised of heating coil which is heated by the solar energy trapped and converted by the solar panel. Solar power from the panel is transferred to the heating coil through the battery. However on further study it was found that this method was not feasible as battery had to be continuously charged by using a high power solar panel, so we modified the design.Solar panel, solar battery and the heating coil were removed. A parabolic reflector was used to focus the high intensity solar radiation on the copper tube at the exit of the flat plate collector. A cooling tank was used to cool the vapour at a fast rate, thereby a cost effective solar distillation was fabricated. The analysis of solar still was conducted, its efficiency was calculated and was found to be 32.97%. If the flow rate of water inside the cooling tank is increased, the amount of

[7] A.E. Kabeel, “performance of solar still with a wick concave evaporation surface”, Twelfth International Water Technology Conference, (2008).

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