Topology optimization on fin structure used in solar thermochemical heat storage reactor

Abstract

Thermochemical heat storage (TCHS) has the advantages of high energy density and low heat loss. In this study, parabolic trough concentrator (PTC) technology is combined with TCHS reactor. A numerical model of photothermal coupled energy storage process is established for PTC-TCHS. The fins of the reactor are designed by topology optimization method to reduce the temperature difference and improve the TCHS performance. Firstly, the effect of fin volume fraction on TCHS performance is analyzed, and the most reasonable fin volume fraction of 15 % is derived. After that, performance of the reactor with topological fins is compared with other empirically designed fins. The results show that the topological fins were effective in reducing the temperature difference by 37 %, 19.9 % and 8.5 % compared to straight, horizontal and curved fins. Meanwhile, the topological fin has the shortest reaction time of 6980 s and the highest thermal efficiency of 76.7 %. Finally, the effects of different operating conditions of DNI and reactant porosity on the topological fin reactor are explored. Under different operating conditions, the topological fin reactor always has better applicability and superiority, which demonstrate the reliability of the topology optimization method for fin design of solar thermochemical heat storage reactor.