Metal Hydride Hydrogen Storage: Numerical Simulation and Experimental Study

This study investigates hydrogen storage in LaNi₅ metal hydrides (MH) through combined numerical simulation and experimental analysis. MH materials offer high volumetric hydrogen density and inherent safety due to reversible exothermic absorption and endothermic desorption reactions, but low thermal conductivity limits charging and discharging rates. Computational fluid dynamics simulations were performed using two-dimensional axisymmetric models in ANSYS Fluent, incorporating a fully coupled conjugate heat transfer model and heat and mass transfer. Key parameters examined include the number and arrangement of internal cooling fins, heat transfer fluid flow rate, hydrogen inlet pressure, and fin material. Experiments employed a pipe-shaped stainless-steel reactor containing 93 g of LaNi₅ powder, with temperature monitored by a four-point thermocouple and precautions taken to prevent material degradation. Numerical results show that staggered fins, higher HTF Reynolds numbers, increased hydrogen pressure, and copper fins significantly reduce hydrogen charging time. Experimental measurements validated the absorption and desorption behaviour, confirming the accuracy of the computational models. These findings highlight the importance of thermal management and reactor design in enhancing MH hydrogen storage performance. Future studies will explore parametric effects on heat generation, absorption efficiency, and hydrogen storage capacity, supporting the practical deployment of MH-based hydrogen and thermal energy storage systems.