Coupling model of solar PTC and LHS unit(I): model validation and performance analysis

The coupling model of solar parabolic trough collector(PTC)and latent heat storage(LHS)unit was established and the coupled simulation code was self-developed. The influence of temperature undulation of heat transfer fluid(HTF)in the outlet of collector caused by the unsteady state change of solar radiation intensity in a whole day on heat storage performance of LHS unit was investigated. And the comparative investigation of the LHS performance with two different LHS(single PCM and multiple PCM)methods was performed. The results showed that due to the effect of unsteady solar radiation, the heat storage rate decreased at first, and then it increased until reaching a relative maximum value. After that it decreased again. The total heat storage capacity increased with time and reached a maximum value, and then it slowly decreased. The single PCM completely melted at 14∶18 and the heat storage capacity reached the maximum value at 16∶00; and the multiple PCMs completely melted at 13∶45 and the heat storage capacity reached the maximum value at 15∶14. The results validate that the heat storage rate can be enhanced by using multiple PCMs.