Experimental investigation of double pass solar water heater by using reflector

Abstract A new concept of double pass solar water heater using reflector has been introduced in this paper to improve its thermal efficiency. Here the design, construction, and performance scrutiny of double pass solar water have been discussed. The consequence of the mass flow rate on the outlet temperature, thermal performance, and overall performance has been analyzed. Moreover, the performance result has been compared with the single-pass solar water heater. The data are taken for a different mass flow rate of 0.0022 kg/s, 0.0028 kg/s, 0.0033 kg/s, 0.0039 kg/s and 0.0044 kg/s from 9 a.m. to 4 p.m. at an interval of 30 min. The maximum efficiency obtained for a higher mass flow rate of 0.0044 kg/s is 50.26%. The maximum efficiency for other mass flow rates is 47.61%, 47.98%, 48.82%, and 48.89%, respectively. All these efficiencies are found in the middle of the day around 12.00 p.m.–1.00 p.m. as the maximum solar radiation is observed in that period. Though the sunlight radiation is not much higher in this month for the same mass flow rate, the efficiency of double pass solar water heater using reflector is much greater than a conventional single-pass solar water heater.