Heat Transfer Analysis and Waste Heat Recovery of Specially Designed Heat Exchanger used in Hybrid Solar Water System

The amount of heat extracted from bottom surface of PV module of hybrid solar water system is strongly influenced by air gap between bottom surface of module and top surface of heat exchanger. The heat transfer analysis between these two surfaces and waste heat recovery of specially designed heat exchanger used in hybrid solar water system are studied in this research work for latitude of Mumbai. For this configuration, outside heat transfer coefficient of stagnant air was calculated and found to be 50 W/m(2) (0)k. By using desired equations and correlations, air gap between these surfaces was found to be 0.53 mm. For this air gap at highest electrical power point condition, with solar radiation of 918 W/m(2) and mass flow rate of 0.035 kg/sec, the system was able to generate a combined power with PV/T efficiency of 53.7 % and PV efficiency of 11.7 %. Experimental results showed that increase in heat transfer from these surfaces was strongly influenced by the air gap.