Experimental thermal performance and enviroeconomic analysis of serpentine flow channeled flat plate solar water...

The thermal performance of a flat plate solar water collector (FPSWC) depends on the amount of solar energy absorbed by the absorber, the quantity of heat transferred to the heat transfer fluid (HTF), and the fluid residence time in the collector. In this real-time experimental study, the thermal efficiency of the serpentine flow channeled FPSWC is compared with that of a conventional collector. The heat transfer coefficients (HTC) and heat loss coefficients of both configurations are evaluated at three different water mass flow rates (0.0083 kg/s, 0.0167 kg/s, and 0.025 kg/s). The results show that the serpentine flow channeled collector offers higher energy and exergy efficiencies of 78.9% and 6.47%, respectively, at a mass flow rate of 0.025 kg/s due to the continuous surface contact of the HTF with the absorber plate. The conventional collector yields energy and exergy efficiencies of 66.28% and 4.58%, respectively, at similar operating conditions. The peak HTC of the serpentine flow collector is 210 W/m²K, which is 27.3% higher than that of the conventional collector at a maximum flow rate. The maximum HTC is observed at a higher mass flow rate and lower absorber temperature. The heat loss increases when solar radiation intensity increases; the HTC reaches its peak value at the maximum solar radiation intensity. The proposed collector shows a cleaner production of hot water with a lower payback period when compared to a conventional collector, as evident from the enviroeconomic analysis. The findings can contribute to more successful deployments of solar thermal systems.