MODELING HEAT AND MASS TRANSFER IN METAL HYDRIDE-BASED HYDROGEN STORAGE SYSTEMS USING THE FINITE VOLUME METHOD

Integrated hydrogen systems need technology to store hydrogen (H₂) for many applications. Conventionally, hydrogen can be kept either in the gaseous state (under 500-700 bars) or as a liquid at cryogenic temperature (almost 20 K). Alternatively, metal hydrides (MH)-based storage of hydrogen is currently the state-of-the-art approach to storing hydrogen that offers both safety and higher storage efficiency. However, the main challenge in the MH is the low thermal conductivity that limits the heat transfer during the exothermic adsorption and endothermic desorption processes. This ultimately leads to slow reaction rates and ultimately to higher charging and discharging durations. To improve the performance of MH-based hydrogen storage systems, it is crucial to optimize the heat and mass transfer mechanisms within the MH bed. This work is an attempt to model the heat and mass transfer phenomena during the adsorption process of hydrogen. The governing equations are discretized based on Finite Volume Method and Euler’s implicit method is used for time integration. This method offers a robust and customizable numerical approach that can examine the performance of a broad range of metal hydrides and system configurations for varying environmental conditions. This will enable the modeling and optimization of heat and mass transfers, aimed at reducing the charging and discharging times of these systems. The analyzed parameters include temperature, equilibrium pressure, and average reacted fraction of hydrogen during the adsorption process. The reacted fraction profile from the inhouse developed 2D axis symmetrical model is validated with the experimental data reported in the literature.