Numerical Simulation on Heating Effects during Hydrogen Absorption in Metal Hydride Systems for Hydrogen Storage

Abstract

A 2-D numerical simulation model was established based on a small-sized metal hydride storage tank, and the model was validated by the existing experiments. An external cooling bath was equipped to simulate the heating effects of hydrogen absorption reactions. Furthermore, both the type and the flow rate of the cooling fluids in the cooling bath were altered, so that changes in temperature and hydrogen storage capacity in the hydrogen storage model could be analyzed. It is demonstrated that the reaction rate in the center of the hydrogen storage tank gradually becomes lower than that at the wall surface. When the flow rate of the fluid is small, significant differences can be found in the cooling liquid temperature at the inlet and the outlet cooling bath. In areas adjacent to its inlet, the reaction rate is higher than that at the outlet, and a better cooling effect is produced by water. As the flow rate increases, the total time consumed by hydrogen adsorption reaction is gradually reduced to a constant value. At the same flow rate, the wall surface of the tank shows a reaction rate insignificantly different from that in its center, provided that cooling water or oil coolant is replaced with air.

Experimental and numerical study of temperature evolution and hydrogen desorption process on an amorphous alloy Mg50Ni50

“…The proposed model, which describes the H 2 diffusion through the hydride bed, is based on energy balances for the hydrogen-heating model, mass balances for H 2 diffusion model, and heat exchanger metal hydride bed model. In our case, adsorption kinetics depends on pressure is taken into consideration to valid the proposed mathematical model [ [13] , [14] , [15] , [16] ].…”

“…In the extensive exploration of Mg-based alloys conducted to date, despite occasional conflicting results in certain studies, specific elements have emerged as particularly promising due to their notable hydrogen storage capacity. Several experimental and theoretical investigations have delved into the hydrogen desorption characteristics of various Mg-based alloys [ [12] , [13] , [14] , [15] , [16] , [17] , [18] , [19] , [20] ]. Notably, Orimo et al [ 21 ] focused on examining the H 2 storage properties of the Mg 50 Ni 50 alloy in its amorphous state.…”

Metal-Hydride-Based Hydrogen Storage as Potential Heat Source for the Cold Start of PEM FC in Hydrogen-Powered Coaches: A Comparative Study of Various Materials and Thermal Management Techniques

“…The process of hydrogen uptake from the materials is an exothermic process, with large amounts of heat produced [11,12]. The materials' temperature during the storage naturally tends to increase and, due to the low thermal conductivity of the metal hydride powders, the temperature remains at high levels [13]. The temperature increase negatively affects the kinetics of the hydrogenation process [14] as the higher temperature also increases the equilibrium pressure P eq .…”