Numerical Study of Hydrogen Desorption in an Innovative Metal Hydride Hydrogen Storage Tank

Efficient heat transfer is the key to hydrogen desorption in a metal hydride-based hydrogen storage system. In this study, a three-dimensional transient-state computational fluid dynamics (CFD) model is developed for describing the hydrogen desorption related heat/mass transfer phenomena inside a metal hydride-based hydrogen storage tank. The model involves flow, heat, and mass transfers related to hydrogen desorption in the storage tank. The model is validated against the temperature evolution data reported in the literature. The model is applied to a hydrogen storage tank where LaNi5 is used as a metal hydride in the tank. The typical thermochemical phenomena related to the hydrogen desorption process are illustrated, including temperature evolution and hydrogen-to-metal-atomic ratio (H/M) during desorption. Further, several new tank designs are proposed and evaluated including embedding heating tube, copper fins, and/or aluminum foam for promoting heat transfer efficiency and hydrogen desorption efficiency. The simulation results indicate that the new design of embedding heating tubes, embedded copper fins, and aluminum foam additives shows the highest desorption performance in terms of both heating rate and hydrogen desorption rate, where the desorption rate is improved by 50% compared to the other designs. This model is a cost-effective tool for designing, optimizing, and scaling up hydrogen tank.