Analysis On Heat Removal Factor For Cavity Receiver Of A Linear Solar Concentrator And Its Utilization

Linear parabolic trough collector (PTC), as one type of the medium-temperature solar collectors, has a high operation temperature, and can be widely used in areas such as power generation, refrigeration and air conditioning, space heating and desalination. In this paper, a new cavity receiver structure that can be used in solar PTC has been proposed. Different from the traditional receiver, the new one is not restricted by the sealing form between metal and evacuated glass tube, and can suppresse the radiation and convection loss through the heat exchange principal of the cavity. Thus the new type of receiver has a better performance and lower price.In this paper, four types of cavity receiver are analyzed in detail. The four types of cavity receiver are triangle, square, circular and semicircular in shape. Expressions of heat removal factor, efficient factor and time constant of the four types of cavity receiver have been deduced and test for trough solar collector system has been set up. Their thermal performances have been compared through test and theoretical calculation .And then the best structure is obtained. Mathematical model for the trough solar collector with triangular cavity receiver is formulated and used together with the test results to optimize the structure. At last, a solar heating, thermal storage and refrigeration system with trough solar collector which uses the new type of cavity receiver is set up. The influences of each component on the solar thermal efficiency are analyzed. The results show that the parabolic trough solar system using cavity receiver in the typical condition, when the temperature is 150℃,the efficiency can reach 46%,and the storage efficiency can reach 81.2% when using the Explicit storage.