‘SOLAR WATER HEATING SYSTEM WITH PHASE CHANGE MATERIAL’ SEMINAR REPORT ON ‘SOLAR WATER HEATING SYSTEM WITH PHASE CHANGE MATERIAL’ SUBMITTED BY : Mr. GADHAVE PITAMBAR SUBHASH ROLL NO. 3010H04 G.S.MOZE COLLEGE OF ENGINEERING, Balewadi

INTRODUCTION Energy is essential for the existence of human life and plays vital role in the progress of the nation. So it has become a need to harness alternate and renewable energy sources. Today India has one of the highest potential for the effective use of renewable energy sources . Solar energy being simple to use, clean, non polluting and inexhaustible has received wide spread attention in recent times. Phase Change Material (PCM) is one of the techniques to store this thermal energy in the form of latent heat.

PHASE CHANGE MATERIAL The storage unit stores the heat in PCM.s during the day and supplies hot water during the night and overcast periods. Result in higher efficiency of the solar collector system. SELECTION OF PCM :- Thermal properties - High latent heat of transition, Good heat transfer. Physical properties - High density, Small volume change. Chemical properties - Long-term chemical stability, No toxicity. Economics – Abundant, Available, Cost effective.

APPLICATIONS OF PCM Increase hot water efficiency in solar water heaters • Capture waste heat in boiler industry • Cold storage/cold chain applications for horticulture • Bio-Pharmaceuticals and vaccine transport • Food / Poultry / Meat transport at specific temperatures • Thermal wear for adverse climatic conditions • Can be used as a room heater, same device / trolley can also be used as a cooler in summer • Backup for room warmers / fireplace and so on

ADVANTAGES OF PCM • Very High Latent Heat • Can be tailor made for specific temperature requirements • Easy handling and can be encapsulated in a variety of mediums • Cheap and high stability over long periods of time • Stable performance over repeated phase change cycles • Limited / No supercooling • Low / No flammability • Non toxic.

CLASSIFICATION OF PCM

Paraffin’s Paraffin is safe, reliable, predictable, less expensive and non- corrosive. These are hydrocarbons & waxes at room-temperature. Paraffin waxes are cheap and have moderate thermal energy storage density Paraffin wax is the most commonly used commercial organic heat storage PCM .

Solar water heater with PCM During day time, the raised hot water which absorbs the energy from the Sun will be stored in a tank.

WORKING When the tank is partially filled by PCM, the PCM will start to melt by absorbing the energy heat from hot water. In the evening, in the absence of solar energy, the Temperature of the Hot water reduces by loss of heat to the environment. When the temperature decreases paraffin will start to freeze. During its freezing, it will give up the heat to the water, and maintain the water’s temperature at not less than 580C (for paraffin) . This increases the efficiency of the solar water heater by allowing availability of hot water at nights.

Solar tanks : – PCM tanks with inner core, The PCM tanks have two groups by the construction: – PCM tanks with inner core, – PCM tanks with inner balls.

EXPERIMENTAL SET –UP 1. Solar flat plate collector; 2. Pump; 3 & 4. Flow control valves; 5. Flow meter; 6. TES tank; 7. PCM capsules; 8. Temperature indicator; TP & Tf . Temperature sensors

CALCULATION OF SOLIDIFICATION During the discharging of the tank the PCM solidifies to the inner surface of the tube. Thermal conductivity is given by, λPCM - coefficient of thermal conductivity of the paraffin λw - coefficient of thermal conductivity of the tube d1 - inner diameter of the solid paraffin layer on the inner surface of the tube d2 - inner diameter of the tube d3 - outer diameter of the tube tw1 - temperature of the phase change tw3 - temperature of the outer surface of the tube

EXPERIMENTAL RESULTS Irradiation, energy yield and air temperature in a typical summer day

Comparing the temperature in a conventional solar tank and a PCM- tank with paraffin.

Comparing the temperature in a conventional solar t ank and a PCM- tank with salt

Comparison of System Efficiency

CONCLUSION Hence the systems with PCM are viable option for solar heat energy storage. Possessing considerable advantages over the systems without PCM, it can be used as an alternative to current domestic sensible solar water heating technologies.

REFERENCES Atul Sharma, V. V. Tyagi, C.R. Chen and D. Buddhi, Review on thermal energy storage with pase change materials & applications. Istvan Peter Szabo, Design of an experimental phase change material solar tank. Atul Sharma, Ashu Sharma, Nirdesh Pradhan and Biswarup Kumar, Performance evaluation of a solar water heater having built in lantent heat storage unit. Phase change Material in heating and cooling applications. C. V. Papade & N. M. Morkhane, Solar water heating system with phase change material.

THANK YOU