Enhancement of the metal hydride hydraulic pump efficiency by integrating a phase change material

Summary The combination of a metal hydride (MH) with a water pump has gained significant interest recently. However, the efficiency of such a system is low, as it requires a substantial quantity of heat from an external source to initiate the desorption process. Storing the heat generated by the absorption reaction (exothermic reaction) in a phase change material (PCM) and reusing it during the dehydration reaction (endothermic reaction) is a viable method to enhance the pump's efficiency. Thus, in the present study, the mathematical modeling and numerical simulation of a new configuration of a MH pump (MHP) equipped with a latent heat exchanger were investigated. The obtained results showed that using a PCM with MHP, as energy storage material, considerably enhances the performance of the pump. For example, with a heat transfer coefficient of 50 W/m2.K, an MH's thermal conductivity of 5.32 W/m. K, a PCM's thermal conductivity of 3 W/m. K, and pumping head of 25 m, it was noted that using Ba(OH)2‐8H2O with the pump as PCM decreases the pumping time by approximately 59% and allows for 17 times increase in overall efficiency over the case without PCM.