An Experimental and Analytical Study of Influential Parameters of Parabolic Trough Solar Collector

Energy plays a vital role in all human life activities. Due to the problems caused by fossil fuels in recent decades such as global warming, greenhouse gas emissions, ozone depletion, etc., the use of renewable and clean energy has been considered. An experimental facility for the acquisition of reliable data from Parabolic Trough Solar Collectors (PTCs) was established to develop a robust analytical model. A wide range of Heat Transfer Fluid (HTF) flow rates (۰.۰۳۷۲-۰.۱۰۷۲ kg/s) and solar radiation (۴۰۰-۹۰۰ W/m۲) were used to determine PTC parameters such as the outlet temperature of HTF loss and temperature distribution. Vacuum conditions in the receiver were considered effective in terms of thermal efficiency. Also, three types of HTF including two oil fluids (Syltherm ۸۰۰ and S۲) and water were examined. The temperature distribution showed that when Syltherm ۸۰۰ or S۲ passed through the absorber tube, the outlet temperature was higher than water: ۲.۸۴ % for Syltherm ۸۰۰ and ۳.۷۲ % for S۲. Since the absorber tube temperature was much higher than water, the heat loss in this condition was considered for oil HTF. Of note, the results demonstrated that use of the vacuum tube could diminish heat loss for the oil HTF. The effect of solar intensity increases from ۶۰۰ W/m۲ to ۹۰۰ W/m۲ on the maximum temperature of the receiver tube indicated that when Syltherm ۸۰۰ was used as an HTF, this temperature increased by ۳۵.۱ % (from ۱۶۷ °C to ۲۱۹ °C), while this percentage was ۳۲.۷ % and  ۶.۸ % for S۲ and water, respectively.

Keywords:

solar collector , PTC , Heat transfer fluid , Vacuum Tube , Analytical Study