Tr 00062

IDL - International Digital Library Of Technology & Research Volume 1, Issue 5, May 2017

Available at: www.dbpublications.org

International e-Journal For Technology And Research-2017

Solar Heating System for Building – Water Heating, Pipe Dimension and Insulation over Pipe Satish Kumar Maurya1 & Dr. Jeeoot Singh2 1.P.G. Student, 2. Associate Professor Mechanical Engineering, Department, MMMUT Gorakhpur, India

Abstract: This paper presents the performance of a solar water heating system equipped with flat plate solar collector panels of numerically identical surface area but of different geometric configuration. The amount of heat acquired from collectors of solar energy depends primarily on the surface area that is exposed to the solar irradiance. The solar thermal water heaters with Thermo-syphon systems using Flat Plate Collectors (FPC) to heating water. The hot water supply through steel pipes and insulation must be necessary to saving heat energy, losses by atmosphere.

Polyethylene is the insulating material which is used to insulate over steel pipe. Approximately, 50% efficiency of the solar water heating system (SWHS) was gained when the insulation was used. They efficient and the cost effectiveness are according to the designs of the systems. The places and the climate of the buildings where they locate are the main considerations of the system design.

Keywords: flat plate collector, solar energy, residential buildings, steel pipe, insulating material, geometrical orientation.

1.

INTRODUCTION

One of the essential requirements in modern buildings is the uninterrupted provision of heating water. Flat plate collector absorbs radiated energy from sun and converts it into heat energy. A lot of work is being IDL - International Digital Library

done on solar collectors to increase efficiency of these systems. These systems can be used for hot water demands, space and room heating for household, large buildings, and power sector. A solar water heater consists of solar collector, hot water storage tank, control unit and pump station.

The hot water in storage tank heated by flat plate collector and supplied to building for different purposes. The storage tank is requiring of insulation to save heat energy otherwise heat will be transfer or loss to atmosphere. The supply of hot water through pipe at required location in building, the pipe is also require of insulation because at long distance transfer of hot water decreases its heat or water temperature drop, so for saving heat, insulation over pipe must necessary.

SWH can play vital role in reducing effects of environmental pollution caused by fossil fuels.

There are numerous types of the solar collector which are available commercially such as flat-plate collectors. The flat plate solar collector best fit for sunny and warm temperature zones, so during cold, cloudy, and breezy weather.

2. FLAT PLATE COLLECTOR: • A device may be used for absorb radiations to produce heat like water heater. The device in which 1|P a g e

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IDL - International Digital Library Of Technology & Research Volume 1, Issue 5, May 2017

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International e-Journal For Technology And Research-2017 the collection is achieved is called a flat-plate collector.

• The flat plate collector is usually held tilt in a fixed position and has no moving parts on a supporting structure, facing south if located in the northern hemisphere.

• The collector having a face area of 2 m2 with the length being usually larger than width and the temperature of hot water delivered ranges from 50 to 70o C. The storage tank being located above the level of the collector, if natural circulation is applied for heating small quantity of water.

• Absorber plate made of sheet metal and thickness range from 0.2 to 1 mm. Generally, Aluminium or Copper is used for both absorber plate and tube due to high thermal conductivity.

A.Insulated Container:A layer of insulation, which reduces conduction losses. An enclosure to contain the different elements.

B.Transparent Cover: These are one or more sheets made of glass for trapping the heat received by the absorber plate. It helps in reducing the convective and radiative heat losses.

C.Pipe/Tube: Flow tubes through which the heat transfer fluid circulates.

D.Absorber Plate: Absorber plate is used to grasp and absorb solar radiation. The plate is usually metallic (copper, aluminum or steel), sometimes plastics have been used in some low temperature applications.

4. DIRECTION OF FLAT PLATE COLLECTOR TILT ANGLE:

3. BASIC PARTS OF FLAT PLATE COLLECTOR: 5. STORAGE TANK:

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IDL - International Digital Library Of Technology & Research Volume 1, Issue 5, May 2017

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International e-Journal For Technology And Research-2017 The storage tank is located slightly at higher level with the solar collector which is located on stand. The cool water flow inside the tank and these water flows through collector. The collector heated this cool water due to low density of hot water than cool water, the hot water flow inside the tank. In storage tank, the hot water will up side and cool water will down side due to low and high density of water. The storage tank capacity is 1000 liters.

a descending water pipe. If the collector heats up the water, the water rises again and reaches the tank through an ascending water pipe at the upper end of the collector. The cycle of tank–water pipe–collector ensures the water is heated up until it achieves an equilibrium temperature. The consumer can then make use of the hot water from the top of the tank, with any water used being replaced by cold water at the bottom.

The collector then heats up the cold water again.

6. STORAGE TANK INSULATION:

Due to higher temperature differences at higher solar irradiances, warm water rises faster than it does at lower irradiances. Therefore, the circulation of water adapts itself almost perfectly to the level of solar irradiance. A thermosiphon system‟s storage tank must be positioned well above the collector, otherwise the cycle can run backwards during the night and all the water will cool down. Furthermore, the cycle does not work properly at very small height differences. In regions with high solar irradiation and flat roof architecture, storage tanks are usually installed on the roof.

In general terms, the more thermal insulation will better since it reduces standby heat loss. Hot water tank is available with various insulation ratings but it is possible to add layers of extra insulation in the form of a blanket or 'jacket' on the outside of an uninsulated, hot water tank to reduce heat loss, to increase energy efficiency and, in extreme conditions, the hot water tank itself might be wholly enclosed in a specially constructed insulated space.

The most commonly available type of water heater blanket is fiberglass insulation with a vinyl film on the outside, the insulating blanket being wrapped around the tank fixed in place with tape or straps, adding insulation to an already well insulated tank may cause condensation leading to rust, mould, or other operational problems so some air flow must be maintained, usually by convection caused by waste heat. Most modern hot water tank have applied polyurethane foam (PUF) insulation.

Thermosiphon systems operate very economically as domestic water heating systems, and the principle is simple, needing neither a pump nor a control.

However, thermosiphon systems are usually not suitable for large systems, that is, those with more than 10 m² of collector surface. Furthermore, it is difficult to place the tank above the collector in buildings with sloping roofs, and single circuit thermosiphon systems are only suitable for frost-free regions.

7. THERMOSIPHON SYSTEM:

Thermosiphon System [adopted from 4]

For storing water, a storage tank is needed. A very simple way of doing this, making use of gravity is shown in above the thermosiphon system. The principle of the thermosiphon system is that cold water has a higher specific density than warm water, and so being heavier will sink down. Therefore, the collector is always mounted below the water storage tank, so that cold water from the tank reaches the collector via IDL - International Digital Library

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IDL - International Digital Library Of Technology & Research Volume 1, Issue 5, May 2017

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International e-Journal For Technology And Research-2017

8.CALCULATION: The quantity of solar energy striking the Earth's surface (solar constant) averages about 1,000 watts per square meter under clear skies, depending upon weather conditions, location and orientation. However on the solar flat plate collector (FPC) available at present you will only gain roughly 15-20% efficiency at best. For flat plate collector, the useful heat gain (Qu) can be calculated by,

9. FLOW RATE: The suitable flow rate used in this project was set to 1000 liters per hour in major pipe and 100 liters per hour in minor pipes, Working fluids is allowed to flow steady enough to ensure the heat from the absorber plate is transferred uniformly. Temperature difference between the inlet and the outlet are easily measurable when the fluid temperature is already in steady state condition. The velocity of water inside pipe will be depending on the height of storage tank. In this project we use more bend pipes, Where bend loss is affect to velocity of water inside pipe. The pipe may be horizontal, vertical and inclined in direction. The velocity of water inside pipe used in this project was set to 0.1 m/sec.

10. DIMENSION OF PIPE: A.Major Pipe: The major steel pipe is connected from hot water tank.

The major pipe is require to discharge 1000 liters water per hour.

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IDL - International Digital Library Of Technology & Research Volume 1, Issue 5, May 2017

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International e-Journal For Technology And Research-2017

B.Minor Pipe: The minor steel pipes are connected to major pipe. The minor pipe installed in 10 rooms and each room is requiring to 100 liters water per hour.

11. INSULATING MATERIAL: In this paper, we will use polyethylene foam to insulate over steel pipes for both major and minor pipes. These properties are Polyethylene Foam:  Polyethylene is a flexible plastic foamed insulation that is widely used to prevent freezing of domestic water supply pipes and to reduce heat loss from domestic heating pipes.  It is usually a mixture of similar polymers of ethylene with various values of n and the chemical formula (C2H4)n.  Polyethylene is of low strength, hardness and rigidity, but has a high ductility and impact strength as well as low friction.  The thermal-conductivity of HDPE (high-density polyethylene) and LDPE (low-density polyethylene) are 0.50 w/mk and 0.33 w/mk respectively.

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IDL - International Digital Library Of Technology & Research Volume 1, Issue 5, May 2017

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International e-Journal For Technology And Research-2017 plants in the sunnier places [11]. As the energy production from the CSP is not sufficient to the demand, the solar-hybrid energy systems are the trend in the short-term development. For the long-term development, the solar power tends to be the major energy source.

14. CONCLUSION:

CRITICAL RADIUS CASES: 1. If, R1 < Rc The heat transfer increases by adding insulation till R2 = Rc. If insulation thickness is further increased, the rate of heat loss will decrease from this peak value.

This happens when R1 is small and Rc is larger then the thermal conductivity of the insulation K is high (poor insulating material) and heat transfer co-efficient h is low.

2. If, R1 > Rc The heat transfer decreases by adding insulation. This happens when R1 is large and Rc is small then the thermal conductivity of the insulation K is low (good insulating material) and heat transfer co-efficient h is high.

13. THE FUTURE OF SOLAR THERMAL ENERGY: The passive and active solar will become the main source of low temperature heating systems. The integration of solar energy into the building is a trend of the building energy development. The tendency of designing energy efficient and cost effective building is the main direction in the next few decades [9]. For the electricity, it will rely on the concentrating solar power (CSP). Refer to the experts, a minimum reduction of 50% of greenhouse gases have to be achieved in the coming fifty to a hundred years in order to protect the global climate [10]. According to some studies, the number of CSP plants around the world will increase. The CSP plants will be mainly built in the sunny areas. In the less sunny places, there will be mixing of local energy production with less contribution of CSP electricity from nearby CSP IDL - International Digital Library

In this study, the simulations demonstrated the solar thermal water heater (STWH) on the residences. The hot water supply at the rate of 1000 liters/hour in buildings. There are requiring to 155 solar flat plate collectors for heating these water. The comparison of without insulation and with insulation is of great importance. Without insulation knew a 50% of energy losses in the transfer pipe. As a result, the energy stored in the hot water tank reaches 167.2 MJ/hour.

Thanks to the insulation of transfer pipe. Still, even though there is insulation the reduced losses are high.

The problem goes back to the long pipe that connects the tank with the collector.

15. REFERENCES: 1. M. S. Hossain, R. Saidur, H. Fayaz, N. A. Rahim, M. R. Islam, J. U. Ahamed, and M. M. Rahman, 'Review on solar water heater collector and thermal energy performance of circulating pipe,„ Renew Sustain. Energy Rev., vol. 15, no. 8, pp. 3801–3812, 2011.

2. S.P. Sukhatme, "Solar Energy- Principles of Thermal Collection and Storage", 2008, the McGrawHill Companies.

3. http://iniflex.com/Benefits.html 4. http://www.appropedia.org/Thermosiphon 5. S. IRFAN SADAQ, S. NAWAZISH MEHDI, ISHRATH M.M, AFROZ MEHAR, NBV. LAKSHMI KUMARI, “PERFORMANCE ANALYSIS OF SOLAR FLAT PLATE COLLECTOR” Third IRF International Conference, 2015, India, ISBN: 978-9382702-74-0.

6.http://www.engineersedge.com/heat_transfer/convec tive_heat_transfer_coefficients__13378.htm 7. R.K. RAJPUT, “Heat And Mass Transfer”, 2006, S. Chand & Company Limited.

8.https://en.wikipedia.org/wiki/Hot_water_storage_tan k.

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International e-Journal For Technology And Research-2017 9. U.S. Department of Energy - Energy Efficiency & Renewable Energy, web page:http://www.eere.energy.gov/ 10. Werner W. and Gottfried P., 2000, Technology Portrait Thermal Solar Energy, source: energytech.at, web page:http://energytech.at/solar/portrait.html 11. Technology Roadmap - Concentrating Solar Power, source: International Energy Agency (iea).

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