Analysis of heat and mass transfer in a porous solar thermochemical reactor

Abstract

Solar thermochemistry shows great potential as a viable solution for addressing the challenge of energy storage. The design of the reactor is still challenging the development and rapid upscaling of solar thermal conversion and storage processes. This study presents a novel reactor that capable of gas reheating and develops a comprehensive three-dimensional model that effectively couples the processes of heat transmission, gas flow and chemical reaction for the optimization of the reactor. It is demonstrated that the maximum thermal efficiency is 43.67% as the incident solar power is 3730 W, but it decreases as the temperature rises. The re-radiation loss at the reactor front face is found as a major factor affecting the reactor thermal efficiency. The result indicates that the thermal efficiency of the reactor is significantly improved as using the cutoff wavelength coating technology. As the cutoff wavelength is 1 μm, the average temperature of porous material increases from 1510.77 °C to 1634.87 °C at 60 min, and the reactor's thermal efficiency increases from 11.65% to 13.51%. This study provided comprehensive insights into heat and mass transfer in a porous solar thermochemical reactor.