A theoretical heat transfer analysis of different indirectly-irradiated receiver designs for high-temperature concentrating solar power applications

Indirectly-irradiated receivers are widely used in most of the existing commercial concentrating solar power (CSP) plants. In order to compare the performances of the potential design strategies for the future high-temperature indirectly-irradiated receivers, a theoretical study has been conducted from a thermodynamic point of view. By analyzing the thermal circuit of the absorber wall, the roles of the heat flux through the wall and the total heat resistance have been observed to become more important to the receiver performances with increasing the concentration ratio. The influences of four parameters to the receiver performances have been analyzed: the convection heat transfer coefficient of the working fluid, the cavity shape factor, the thermal conductivity and the thickness of the absorber wall. Designing the absorber in a cavity shape has been proved to be an efficient way in enhancing the receiver performances by reducing the heat flux through the absorber wall. The advantage of the cavity receivers increases with increasing the concentration ratio, especially for gaseous working fluids which have relatively low heat transfer rates. The theoretical performance maps have been obtained for different potential design strategies, which will be helpful for making decisions in the future conceptual choice of receiver designs. (C) 2020 Elsevier Ltd. All rights reserved.

Automated summary

A theoretical study was conducted from a thermodynamic point of view to compare potential design strategies for future high-temperature indirectly-irradiated receivers. It was found that designing the absorber in a cavity shape can enhance receiver performance, especially for gaseous working fluids. The influence of heat flux through the wall and total heat resistance on receiver performance becomes more significant with increasing concentration ratio.