Abstract
We have previously proposed the Reactor Train System (RTS) for efficient solar thermochemical hydrogen (STCH) production, which utilizes a counter-flow radiative heat exchange system with moving reactors. RTS reactors are heated with indirect infrared radiation, which is markedly different from current experimentally demonstrated solar receiver-reactors. In this work we present a design study of a prototype reactor, including a high-fidelity heat transfer model with component dimensions informed by mechanical stress modeling. This model was used to subject different variants of the reactor to a heating cycle, and reactor performance metrics such as hydrogen productivity and component temperatures were compared. We report that thermal performance improves when smaller structural components are used, and when active cooling losses are reduced. Our findings show that indirectly heated reactors have unique design considerations, and conventional concentrated solar receivers perform poorly even with a high-temperature window. Strategies for improving the performance of indirectly irradiated thermochemical reactors are identified.
