Enhancing absorption performance in metal hydride hydrogen storage: Implementation of fins and a water jacket

This study investigates the flow and heat transfer characteristics of a Metal Hydride (MH) hydrogen storage device featuring internal fins and a water jacket for improved hydrogen storage performance. The MH is modelled as a porous medium, with computational fluid dynamics used to analyse transient heat and mass transfer, incorporating a conjugate turbulent heat transfer model for the water jacket. Investigations covered fin arrangements (in-line and staggered), materials (stainless-steel and copper), water flow rates (Re = 5100–22000), and hydrogen inlet pressures (5–20 bar). Results show that staggered copper fins and higher flow rates or pressures significantly reduce hydrogen absorption time: staggered fins with Re = 5100 reduce absorption time by 30 %, Re = 22000 achieves further 27 % reduction, and increasing inlet pressure to 20 bar decreased it by 61 %. However, increased fin numbers and pressures introduce challenges such as pressure drop and reactor mass. Four reactor designs were assessed, highlighting trade-offs in performance.