Design and Performance Analysis of a Novel Concentrating Solar Water Heater for Building Applications

Flat plate solar collectors are widely used in residential applications. However, the collector’s efficiency dramatically drops during the winter time when the hot water is mostly needed. This is due to the reason that the solar radiation hits the absorber plate collector at a lower angle. This study aims to investigate a novel low/medium temperature non-tracking Parabolic Trough Collector (PTC). Such system is considered as a good alternative option to provide hot water and space heating compared to the conventional flat plate and evacuated tube collectors. Within the scope of this study, several related variables such as solar radiation, heat gain of the system and thermal efficiencies of PTC are tested under Mediterranean climate and compared to the previous studies. The investigated system consists of a low temperature PTC collector, storage tank, flow meter and circulation pump. Experimental work has been carried out in the first and the third week of April in Famagusta during the early spring season where solar radiation was limited due to the rain and cloudy sky. Water is circulated between two storage tank and solar collector with two different flow rates which are 15 L/h and 20 L/h. Temperature sensors are installed tin the system to measure inlet and outlet temperatures of the collector as well as the tank and ambient temperatures. Furthermore, the intensity of the solar radiation is measured by the pyrometer and data is stored. According to the results, the overall thermal efficiency of the system with 15 L/h and 20 L/h was found 44% and 33% respectively. Furthermore, useful energy gain of the PTC is obtained as 285.24 W and 233.69 W, while the average solar radiation is about 654.51 W and 723.31 W for the flow rates of 15 L/h and 20 L/h respectively. Keywords: Solar Energy, Domestic Hot water, Water Heating, Parabolic Tr