Numerical investigation of hydrogen absorption in an annulus-disc metal hydride reactor

This work involves a numerical investigation of two-dimensional coupled heat and mass transfer processes in a LaNi₅-based annulus-disc reactor, during hydrogen absorption using the commercial software FLUENT 6. Temperature and amount of hydrogen absorbed profiles inside the metal hydride bed, variation of average bed temperature and hydrogen storage capacity are presented for different reactor design configurations and different cooling tube radii, respectively. The numerical simulations revealed that the hydriding process time for the LaNi₅ alloy depends on the configuration and geometrical dimensions of the tubular heat exchange device, and the overall hydride formation moreover. The question of minimizing the hydriding time is reduced to the accommodation of the amount of heat removed from the bed reactor, for that reason the system must be efficiently cooled for a quicker absorption process. A good agreement was found between the present computational results and the experimental data reported in the literature.