Collector Efficiency of the Double-Pass Solar Air Collectors with Fins

The experimental study on a forced-convective double-pass solar air collector with fins in the second channel has been conducted. The experiments were conducted by changing the parameters that influence the thermal efficiency of the collector. The efficiency of the solar collectors has been examined by changing the intensity of solar radiation and the mass flow rate. The results of this study suggest firstly, the double-pass solar collector with finned absorber has efficiency of more than 75% at a mass flow rate 0.072 kg/s and solar radiation at 788 W/m(2), and this study shown that finned absorber is 8 % more efficient than flat plate absorber. Secondly, the efficiency of solar collector is significant depending on the mass flow rate and solar radiation. The efficiency is increased proportional to mass flow rate and solar radiation. At the solar radiation at 423W/m(2) to 788W/m(2) increase efficiency is about 20-30%. At a mass flow rate varies from 0.04 kg/s to 0.083 kg/s, the efficiency increase is about 35% - 50%.