Thermal performance analysis of free-falling solar particle receiver and heat transfer modelling of multiple particles

Abstract

Obtaining the detailed transient heat transfer process between particles is one of the most important key factors to comprehensively understand the thermal conversion performance of the solar particle receiver. To present a clear understanding of heat transfer, a detailed two-dimensional transient numerical simulation of the solar particle receiver integrated with the Monte Carlo Ray Tracing method and the Finite Element Method is presented in this paper. The solar radiation flux distribution throughout the free-falling solar particle receiver is simulated by considering Monte Carlo Ray Tracing and the transient heat transfer in the circular particle process in the receiver is calculated using the Finite Element Method. Moreover, based on the coupling model, considering the transient heat transfer process inside the particles, the effects of different particle sizes, radiation fluxes, void ratio, and particle residence time on the temperature distribution and thermal performance of the solar particle receiver are also studied. The results show that the transient heat transfer process inside the single particles slightly affected the average outlet temperature of the receiver and the solar thermal energy conversion efficiency. A better outlet temperature and thermal conversion efficiency can be obtained when solid particles with a diameter of 0.2 ~ 0.4 mm in the experiment are used. This study provides basic theoretical insights and support for further research on the thermal performance, structural design, and optimization of the solar particle receiver.