Metal hydride reactor with triply periodic minimal surface structure for hydrogen storage solution

Abstract

Metal hydride (MH) shows high effectiveness in storing hydrogen due to its relatively low temperature, low- pressure, and high volumetric hydrogen density. However, it also has been reported that its gravimetric density is low due to the weight of the MH itself. It has been shown that the MH reactor is not suitable for mobile application unless its reactor also acts as a body frame compensating its weight. Triply periodic minimal surface (TPMS) structures show a great potential as heat-exchanger (HE) with its extended surface properties per volume and reinforced structure nature that is designed to bear mechanical load. These properties have a promising application as hydrogen carrier solution especially in MH hydrogen storage. Excellent arrangement has been found due to high storage density and heat transfer performance on removing the heat from MH during hydrogen absorption process and heating the MH to release the hydrogen. In this study, TPMS-HE is adopted as MH reactor and a mathematical model has been developed to analyze and improve its performance on absorption time of hydrogen. Modeling and analysis in fluid dynamics are validated with the existing reference data from experiment. Different parameters on cooling conditions are compared to natural convection. As the results, improvement on cooling condition can improve the absorption rate and time. Moreover, due to its application simplicity, a forced air convection as cooling solution seems preferable for this type of MH reactor.