FRESNEL LENS SOLAR CONCENTRATOR TO UTILIZE THE EXTREME SOLAR INTENSITY IN HEAT EXCHANGER RECEIVERS

This work presents an experimental study of water heating using heat exchanger receivers with a fresnel lens concentrator. Two models of the heat exchangers are used, namely conical pipe and cubical tank heat exchangers, to investigate the thermal efficiency of different models. Each heat exchanger is resided at the focus of the fresnel lens, where the fresnel lens concentrator is controlled to track the solar light and maintain the focal stationery. The results showed that the highest thermal efficiency was recorded for the conical pipe heat exchanger where the efficiency was 30% when the intensity of the solar radiation was 1159 W/m(2) and the ambient temperature was 16 degrees C. Whereas the highest thermal efficiency of the cubical tank heat exchanger was 26% when the intensity of the solar radiation was 1197W/m(2) and the ambient temperature was 21 degrees C. Also, the results showed that the fresnel lens concentrator can be efficiently used to provide hot water during wintertime under Iraqi weather.