Numerical investigation on performance enhancement of metal-hydride hydrogen tank using electromagnetic induction heating

Due to their large volumetric storage capacity for hydrogen at safe, moderate temperatures and pressures, metal hydrides have received much attention by researchers. Since one of the major controlling factors of the storage process is heat transfer from/to the metal hydride bed, several methods to improving heat transfer have been published. In the present work, electromagnetic induction is investigated numerically as a new heating method to enhance the performance of metal-hydride hydrogen tanks. A two-dimensional mathematical model that describes the dynamic behavior of a LaNi5 hydrogen tank encircled by a copper coil crossed by an alternating current was developped and successfully validated with experimental data. Numerous numerical simulations are performed using this model, and the results reveal that electromagnetic induction can shorten the hydrogen tank's discharging time by 87 % when compared to the heat transfer fluid approach. Furthermore, by raising the desorption temperature from 303 K to 353 K, the discharging time may be reduced by 73 %. The rapidity of the discharging process is unaffected significantly by raising the desorption temperature above 353 K, though. For desorption pressures lower than 0.1 bar, the same effect was observed. Studying the impact of the coil's number of turns per unit length revealed that by increasing this parameter from 640 to 3200, the discharging time is considerably reduced. Nevertheless, increasing this number above 3200 has a negligible impact on the metal-hydride hydrogen tank's dynamic behavior.