Numerical investigation of two discharging procedures of a metal hydride‐hydrogen storage tank

Abstract

Summary This article presents a numerical investigation of two discharging procedures of a metal hydride‐hydrogen storage tank (MH‐HST). The former is categorized as “simultaneous procedure” as the heating of the MH‐HST and the discharging of hydrogen from the same start simultaneously. The latter is categorized as “separated procedure” as the heating of the MH‐HST was carried out initially and the discharging of hydrogen from the same began only when the desired desorption temperature is attained. To the best of authors' knowledge, the separated procedure is simulated and compared for the first time with the simultaneous case. For the two procedures, the discharging process was carried out in two ways, that is, at constant and variable applied pressure. A computational model governing heat and mass transfer within the MH‐HST was developed and successfully validated with experimental data. The simulation results ascertain that the simultaneous procedure is faster than the separated procedure. For example, with a desorption pressure of 0.1 bar and a heating fluid temperature of 353 K, the “simultaneous procedure” provides a reduction of the discharging time by 57% in comparison with the “separated procedure.”

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“…Numerical results showed that increasing the thermal conductivity of the hydride bed has no important effect on the hydrogenation rate; however, it accelerated the convective cooling of the hydride bed. Two discharging procedures (simultaneous procedure and separated procedure) of an MH tank were investigated numerically by Askri et al 6 For the simultaneous procedure, the discharging process and the heating of the tank start simultaneously. For the second one, the discharging process starts only when the tank reaches the desorption temperature.…”