Storage performance of a novel array metal hydride hydrogen storage reactor based on PCM thermal management

Abstract

Metal hydrides (MH) are an attractive option for solid hydrogen storage with the large thermal effects of their hydrogen absorption and desorption processes when used in reactors. Phase-change materials (PCM) have been used as thermal management media in the MH reactor. To further improve the performance of the reactor, this study proposed a novel PCM-based MH reactor with array layouts, aiming to construct a heat transfer interface with a high specific surface area. A mathematical model was constructed to elucidate the phenomenon of heat transmission and absorption reaction. It was found that an increase in the number of array units significantly increased the heat transfer area but had a limited impact on enhancing the absorption rate and heat transfer. Nevertheless, the array reactor with seven units had a significant 1.0 times increase in the absorption rate compared to the traditional reactor with only one array unit. Furthermore, the enhancement of thermal conductivity in MH/PCM and the elevation of hydrogen supply pressure have the potential to accelerate the reaction rate and heat transfer during absorption. The enhanced absorption pressure not only enhances the driving force of the reaction directly but also amplifies the temperature difference in heat transfer between PCM and MH. Consequently, this leads to a further improvement in heat transfer and reaction efficiency.