Numerical analysis of a built‐in thermal storage system of metal hydride and nanoparticles enhanced phase change material and nanofluid

Abstract

SummaryThis study presents the numerical investigation of the performance improvement of Metal Hydride (MH) bed equipped with nano‐enhanced phase change material (NePCM) jacket for heat reaction recovery via U‐tube heat exchanger using Nanofluid. In this study, Mg2NiH6 is used as an MH bed, sodium nitrate (NaNO₃) as heat storage medium (PCM), and sodium‐potassium nitrate (60% NaNO₃‐40% KNO₃) as a heat transfer fluid (HTF). A computational model for this system is developed and validated. Furthermore, the hydriding of the MH bed, the melting of NePCM, and the overall heat transfer characteristics are simulated. With this model, the effect of a few types of nanoparticle additives on the hydriding process is investigated. The nanoparticles of iron oxide (Fe2O3) and copper oxide (CuO) are dispersed at various concentrations (to a range of 0‐1.5 wt.%) in the HTF. Further, CuO and graphene nanoparticles are added to the PCM to a range of 0 to 5 wt.%. The simulation shows that a reduction of hydriding process time by 33.5% is possible by using this MH‐Nanofluid‐NePCM system in comparison with a conventional MH bed system. The use of nanoparticles in the HTF, at an optimum flow rate, did not show a significant effect on the enhancement of the hydriding process. Also, the results show that CuO‐PCM composite has a greater impact in decreasing the time of complete hydriding relative to graphene‐PCM composite.