International Journal of Research and Innovation on Science, Engineering and Technology (IJRISET)
International Journal of Research and Innovation in Thermal Engineering (IJRITE) DESIGN AND OPTIMIZATION OF WATER COOL CONDENSER FOR CENTRAL AIR CONDITIONER. Chitturi Nagavamsi Ravi Teja1, S.Raja Sekhar2. 1 Research Scholar, Department of Mechanical Engineering, Godavari Institute of Engineering And Technology, Andhra Pradesh, India. 2 AssociateProfessor, Department of Mechanical Engineering, Godavari Institute of Engineering And Technology, Andhra Pradesh, India.
Abstract Water-cooled chiller systems have typically been designed around entering condenser water temperatures of 85°F with a Optimization of Water - Cooled Chiller – Cooling Tower Combinations The warm water leaving the chilled water coils is pumped to the evaporator of the chiller, where the unwanted heat from the building is transferred by the latent heat of vaporization of the refrigerant. The compressor of the chiller then compresses the refrigerant to a higher pressure, adding the heat of compression in the process. The high pressure refrigerant then moves to the economical condenser water flow of 3.0 USGPM/ton and a 10°F denser, where the unwanted heat is rerange. In recent years, there has been considerable debate on the merits of designing around lower condenser water flow rates with a higher range in order to improve system lifecycle costs. However, two other parameters must also be considered in any analysis - approach and design wet bulb. The question to be answered is: What nominal condenser water flow rate and approach is best from a first cost standpoint as well as from a full load energy standpoint at any given wet bulb.
*Corresponding Author:
Central Air Conditioner System
Chitturi Nagavamsi Ravi Teja, Research Scholar,Department of Mechanical Engineering, Godavari Institute of Engineering And Technology, Andhra Pradesh, India. Email: chitturivamsi09@gmail.com
Central air conditioner unit is an energy moving or converted machines that are designed to cool or heat the entire house. It does not create heat or cool. It just removes heat from one area, where it is undesirable, to an area where it is less significant.
Year of publication: 2016 Review Type: peer reviewed Volume: III, Issue : I
Central air conditions has a centralize duct system. The duct system (air distribution system) has an air handler, air supply system, air return duct and the grilles and register that circulates warm air from a furnace or cooled air from central air conditioning units to our room. It returns that air back to the system and starts again.
Citation:Chitturi Nagavamsi Ravi Teja, Research Scholar "Design And Optimization of Water Cool Condenser For Central Air Conditioner." International Journal of Research and Innovation on Science, Engineering and Technology (IJRISET) (2016) 84-91
INTRODUCTION Refrigeration for personal comfort was first used in 1902. By 1997, 72% of all American households had air-conditioning and 47% of all households were cooled with central air. According to the Air-Conditioning and Refrigeration Institute (ARI), 81% of all new homes constructed were equipped with central air-conditioning in 1996. For a single family, detached home, the amount of energy dedicated to air-conditioning can be quite significant. In Atlanta, for example, air-conditioning accounts for approximately 19% of energy costs, which includes both gas and electricity, or 310 dollars per year. It also accounts for 32% of the total peak power demand of electricity in these homes. Obviously, improving the efficiency of residential air-conditioning units would decrease utility bills and pollution produced by the power generation.
It uses AC refrigerant (we may know it as Freon) as a substance to absorb the heat from indoor evaporator coils and rejects that heat to outdoor condenser coils or vice versa. Central air conditioner units used a blown, which is mounted indoor to a furnace to circular that cold air to the entire house through air distribution system (duct). It uses the same duct system for heating and cooling. Technical Data of Shell and tube Heat Exchanger: Heat duty = 345000 Kcal/hr Quantity of oil = 43.33 m3/hr Quantity of water = 200 m3/hr Cooling water inlet temperature, T1 = 32.00ºC Oil out let temperature, T2 = 45ºC Fouling factor on oil side = 0.0004 hrm2 ºC / Kcal Fouling factor on water side = 0.0002 hrm2 ºC/ Kcal Tube material =Admiralty brass Thermal conductivity of tube material= 104.12 Kcal/ hrmºC Number of tubes = 776 Number of passes = 4 Length of the tube = 2300mm Outside diameter of the tube do =15.875mm 84
International Journal of Research and Innovation on Science, Engineering and Technology (IJRISET)
Model graphs:
Thickness of the tube =1.245mm Inside diameter of the tube = 0.013385m Inside surface area of the tube = πxdi*L = Ai = πx(0.013385) * 2.3 = 0.0967m2 Outside surface area of the tube = π do*L =Ao = π x 0.015875*2.3 = 0.1147 m2 Ratio of outside to inside surface area = Ao/Ai = 1.1862 Number of baffles = 11 Baffle cut = 28% Type of cooler = Shell and tube heat exchanger Tube pitch/ type =20.64 mm/30º Baffle thickness = 6mm Shell inside diameter = 700mm Number of tubes per pass =776/4=196 Baffle pitch = 141mm
No. of passes vs Heat transfer
OIL PROPERTIES AT AVERAGE TEMPERATURE (53 ºC): Density = 850 Kg/m3 Specific heat =0.471 Kcal/Kg ºC Thermal conductivity =0.12925 Kcal/hrmºC Oil bulk viscosity = (μb)oil = 73 Kg/hr m Oil viscosity at tube wall temperature (μw)oil =159 Kg/ hr m WATER PROPERTIES AT AVERAGE TEMPERATURE (34 ºC): Density = 1000 Kg/m3 Specific heat = 1 Kcal/Kg ºC Thermal conductivity = 0.5425 Kcal/hrmºC Viscosity (μW) = 2.6 Kg/hr m
No. of passes vs Heat transfer
Simulation of Heat Exchanger: In order to implement experimental data in the model, boundary conditions of each part of the system should bedetermined accurately. Oil cooler heat exchanger Oil circulates in a closed loop so the outlet and inlet oil temperatures are dependent and they can be correlated asfollows: Q = mw Sw(t2-t1) Manual Method Results: Number of passes
Ht Kcal/ hr-m2 ºC
Hs Kcal/ hr-m2 ºC
Uf Kcal/ hr-m2 ºC
Dp Kg/m2
1
2650
332
245
1432
2
4590
341
261
3645
4
8013.48
351.28
274.35
4178
6
11,144.68
364.45
290.14
14724
No. of passes vs Overall heat transfer coefficient
Results of Manual method This table represents the experimental results. in this the even number of passes increases the shell side heat transferor efficient, tube side heat transfer and overall heat transfer co efficient increases and pressure drop also increases.
No. of passes vs Pressure drop
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International Journal of Research and Innovation on Science, Engineering and Technology (IJRISET)
INTRODUCTION TO CREO PARAMETRIC (PRO-ENGINEER) Pro/ENGINEER Wildfire is the standard in 3D product design, featuring industry-leading productivity tools that promote best practices in design while ensuring compliance with your industry and company standards. Integrated CREO parametric CAD/CAM/CAE solutions allow you to design faster than ever, while maximizing innovation and quality to ultimately create exceptional products. Customer requirements may change and time pressures may continue to mount, but your product design needs remain the same - regardless of your project's scope, you need the powerful, easy-to-use, affordable solution that CREO parametric provides. ASSEMBLY PARTS OF HEAT EXCHANGERS:
Design view part of heat exchanger passage 6
“This is the total assembly part of HEAT EXCHANGER” The following parts were used to design the assemble parts to make a HEAT EXCHANGER. • SHELL.PRT • BUFFEL_PLATE.PRT • BUFFEL_PLATE.PRT • BUFFEL_PLATE1.PRT • BUFFEL_PLATE2.PRT • PATTERN.PRT • DOME.PRT INTRODUCTION TO ANSYS
Design view part of heat exchanger passage 1
ANSYS is general-purpose finite element analysis (FEA) software package. Finite Element Analysis is a numerical method of deconstructing a complex system into very small pieces (of user-designated size) called elements. The software implements equations that govern the behaviour of these elements and solves them all; creating a comprehensive explanation of how the system acts as a whole. These results then can be presented in tabulated or graphical forms. This type of analysis is typically used for the design and optimization of a system far too complex to analyze by hand. Systems that may fit into this category are too complex due to their geometry, scale, or governing equations. MATERIAL PROPERTIES Admiraltybrass:
Design view part of heat exchanger passage 2
Design view part of heat exchanger passage 4
Properties of Admiralty-Brass
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International Journal of Research and Innovation on Science, Engineering and Technology (IJRISET)
Copper:
Imported model of condenser of one pass
Analysis Results of condenser with Admiralty Brass: Thermal Analysis of Condenser with 1 passage with Admiralty –Brass:
Temperature result with one pass Properties of Copper
Copper -Aluminum alloy
Time vs Temperature with one pass
Properties of Copper-Aluminum Alloy
THERMAL ANALYSIS of a condenser with Admiralty Brass: Thermal Analysis of Condenser with 1 Passageof Admiralty Brass:
Heat flux result with one pass
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International Journal of Research and Innovation on Science, Engineering and Technology (IJRISET)
Analysis Results of condenser of four passages with Admiralty Brass:
Time vsHeat flux with one pass
Analysis Results of condenser of two passages with Admiralty Brass:
Temperature results with four passes
Temperature results with two pass
Time vsTemparature results with four passes
Time vs Temperature results with one pass
Heat flux results with four passes
Heat fluxresults with two pass
Time vs Heat fluxresults with four passes
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International Journal of Research and Innovation on Science, Engineering and Technology (IJRISET)
Analysis Results of condenser of six passages with Admiralty Brass:
THERMAL ANALYSIS of a condenser with Copper: Thermal Analysis of Condenser with 6 Passages with Copper:
Temperature results with six passes Temperature results with six passes
Time vsTemparature results with six passes
Heat fluxresults with six passes
Time vs Temperature results with six passes
Heat fluxresults with six passes
Thermal Analysis of Condenser with six Passageswith Cu-Al Alloy
Time vs Heat fluxresults with six passes
Temperature results with six passes
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International Journal of Research and Innovation on Science, Engineering and Technology (IJRISET)
Bar charts of results with Admiralty Brass:
Time vs Temperature results with six passes
Temparature with all passages
Heat fluxresults with six passes
OVERALL RESULTS AND DISCUSSION In this project work central air conditioner condenser (heat exchanger) has analyzed with the variation of 3 materials and 1/2/4/6 passages to suggest the optimum design material.
Heat flux with all passages
As per the analysis result tables & graphs has been produced as below for easy understanding: Admiralty Brass: TEMPERATURE
HEAT FLUX
1 PASSAGE
45.227
0.079431
2 PASSAGES
45.058
0.092678
4 PASSAGES
45.037
0.097065
6 PASSAGES
48.031
0.092771 Thermal Error with all passages
Copper: TEMPERATURE
HEAT FLUX
1 PASSAGE
45.626
0.57876
2 PASSAGES
45.070
0.25650
4 PASSAGES
45.052
0.70758
6 PASSAGES
48.232
0.23366
Bar charts of results with Copper:
Cu-Al Alloy: TEMPERATURE
HEAT FLUX
1 PASSAGE
45.234
0.19974
2 PASSAGES
45.063
0.23342
4 PASSAGES
45.044
0.24360
6 PASSAGES
48.232
0.23366
Temparature with all passages
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International Journal of Research and Innovation on Science, Engineering and Technology (IJRISET)
plications (IJERA). 3.THEORETICAL ANALYSIS OF THE PERFORMANCE OF DUAL PRESSURE CONDENSER IN A THERMAL POWER PLANT K.K.Anantha Kirthan, S. Sathurtha Mourian, P. Raj Clinton International Journal of Mechanical Engineering and Technology (IJMET).
Heat flux with all passages
4.PERFORMANCE ANALYSIS OF FINNED TUBE AIR COOLED CONDENSING UNIT OF SPLIT AIR CONDITIONER B. SREELAKSHMI, Advanced Engineering and Applied Sciences. 5.DESIGN ANALYSIS OF A FINNED-TUBE CONDENSER FOR A RESIDENTIAL AIR-CONDITIONER USING R-22 Emma May Sadler Georgia Institute of Technology 6.Optimizing Design & Control Of Chilled Water Plants Steven T. Taylor, P.E., Fellow ASHRAE ASHRAE Journal AUTHORS
Thermal error with all passages
CONCLUSION: This project deals with “DESIGN AND OPTIMIZATION OF WATER COOLED CONDENSER FOR A CENTRAL AIR CONDITIONING UNIT” In this project work central air conditioner condenser (heat exchanger) has analyzed with the variation of 3 materials and 1/2/4/6 passages to suggest the optimum design material.
Chitturi Nagavamsi Ravi Teja, Research Scholar, Department of Mechanical Engineering, Godavari Institute of Engineering And Technology, Andhra Pradesh, India.
Initially data collection and literature survey was conducted to understand the approach and methodology through this material, boundary & lode conditions was selected. 3d modeling and assembly for1/2/4/6 passages has been done and exported to Ansys for further investigation. Thermal analysis was conducted by varying 3 materials as per the analysis results material2 & 3(copper & copper -aluminum alloy) was showing better results than traditional material Admiralty brass. Copper is having more features than copper-aluminum alloy but while considering the cost better to go with copper-aluminum alloy with increased passages like 4 or 6 to improve performance.
S.Raja Sekhar, AssociateProfessor, Department of Mechanical Engineering, Godavari Institute of Engineering And Technology, Andhra Pradesh, India.
REFERENCES: 1. PERFORMANCE ANALYSIS ANDCALCULATION OFDIFFERENT PARAMETERS OFCONDENSER USING ANSYS FLUENT SOFTWARE Ram Mohan Gupta International Journal of Application or Innovation in Engineering & Management (IJAIEM) 2. PERFORMANCE ANALYSIS OF SURFACE CONDENSER UNDER VARIOUS OPERATING PARAMETERS Ajeet Singh Sikarwar1, Devendra Dandotiya2, Surendra Kumar Agrawal3 International Journal of Engineering Research and Ap91