In this paper, coupled heat and mass transfer during the desorption process of a metal–hydrogen reactor (LaNi5–H2) is numerically investigated. To predict the dynamic behavior of this reactor, a new algorithm based on the lattice Boltzmann method (LBM) is proposed as a potential solver. Based on this algorithm, a computer code is developed using fortran 90. This algorithm is validated successfully by comparison with experimental data reported in the literature and results obtained by finite volume method (FVM). Using the developed code, the time–space evolutions of the temperature and the hydride density within the reactor are presented. In addition, the effect of some parameters (applied pressure, heating temperature, and overall heat transfer coefficient) on the dynamic behavior of the reactor is evaluated. Compared to the FVM, the proposed algorithm presents simple implementation on a computer and with reduced CPU time.

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The numerical instabilities associated with solidification and melting processes are mainly due to the transient temperature field in liquid and solid phases and characteristics of the front phase. To prevent these instabilities, a new model for the liquid fraction is proposed in the present article and is based on the analytical Heaviside step function's approximation. The efficiency of the current model is well verified with the numerical simulation of one-and two-dimensional heat conduction problems within regular geometries and is further noticed that the results agree well with the analytical solutions. It is also noted that the proposed model provides more accurate results when compared to the Meshless Local Petrov-Galerkin (MLPG) method and is competent to resolve the above said instabilities.To examine its accuracy for any 2D-arbitrarily-shaped enclosures, a new solidification problem within a more complex geometry was proposed. This problem can be used as a benchmark test for solidification/melting problems. The proposed model was applied to solve this problem and accurate results are obtained. Hence, the previously reported approaches,which are not even able to ensure discrete conservation at the interface, may be replaced by the proposed interface model.

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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