Experimental study on thermal performance of U-type evacuated glass tubular solar collector with low inlet temperature

摘要

U-type evacuated glass tubular solar collectors are increasingly used for solar-assisted heat pump system for space heating, and it is an ideal choice as an evaporator for this system. The temperature of the working fluid in such kind of collectors is commonly lower than that of the ambient air. However, it was rarely reported in literatures. In this paper, the thermal performance of the U-type evacuated glass tubular solar collector is studied-experimentally under conditions where the temperature of the working fluid is lower than that of ambient air.