Enhancement of the thermal energy storage capacity of a parabolic dish concentrated solar receiver using phase change materials

摘要

The enhancement of the thermal storage capacity of a solar receiver using phase change materials (PCMs) to give inertial balance is experimentally investigated in this research study. A parabolic dish collector with a reflector aperture area of 16m(2) is used to test the performance of the solar receiver. Sugar alcohols are selected as phase change materials for their properties of medium melting point, high latent heat and medium phase change temperature. The PCMs are filled in the receiver as thin layers to capture the peak radiation and store the heat depending on the temperature distribution and collection efficiencies on the solar receiver. Outdoor tests are conducted at different flow rates of heat transfer fluid through the solar receiver. The PCM in the solar receiver ensures a uniform heat output during a short discontinuity of solar radiation due to the thermal buffering effect of the solar receiver. The average energy and exergy efficiencies of the receiver with multiple PCMs are 66.7% and 13.8%, respectively, for the HTF flow rate of 80 kg/h. The solar receiver acts as a thermal battery for meeting thermal needs even after sunset.