2-D mathematical modelling of hydrogen storage in metal hydrides

Abstract

In this study a numerical model which simulates heat and mass transfer processes of hydrogen absorption in LaNi5 is studied. Energy balance method is used for discretizing the heat equation. Transient heat conduction with convective boundary conditions is evaluated with explicit scheme. The analyses are conducted using MATLAB. Evaluation of temperature profiles and hydrogen mass that is being absorbed during hydriding are shown to be correlated with the experimental data and with the previous numerical studies. Since the hydriding reaction is exothermic, the rate of removal of heat released is critical in time needed to reach saturation in metal-hydride reactor. The effects of bed geometry, inlet hydrogen pressure, and metal porosity, initial bed temperature and the temperature of cooling fluid are investigated. Different cases are compared with the base case which is chosen to have similarities with conventional metal hydride tanks in reactor geometry and in thermophysical properties.