Abstract
The main objective of this investigation is to identify the ratio of expansion and contraction during hydrogen sorption process by a direct observation of the volumetric changes of LaNi5 granular bed in a transparent metal-hydride reactor. In addition to this, a two-dimensional mathematical modeling is developed. The originality of this model is that it considers the change in the specific volume of the bed (deformable powder bed). The computational results are validated with the experimental data. This numerical investigation analyses the effects of variation of thermo-physical properties, and geometrical dimensions on heat and mass transfer occurring in the deformable bed. The experimental results indicate a significant change in the specific volume of granular media associated to charging and discharging process, approximately 17.77 vol% and 8.16 vol%, respectively. Also, the validity of the assumption that neglects the change in volume of the bed is discussed.
•An experimental test rig was established to determine the expansion and the contraction ratios of the metal hydride bed.•A mathematical model for a deformable powder bed has been developed.•The validity of the assumption that neglects the change in volume of the bed was discussed.