Simulation And Optimization Of Heat Transfer In Metal Hydride Tank

With the rapid development of world economy, the human beings demand for energy is increasing. However, fossil fuels increasingly drying up, looking for new alternative energy is imminent. As the most ideal substitute, Hydrogen has been the focus of international scholars. In the process of application and promotion of the hydrogen, Hydrogen storage is the key and difficult problem.This article will use the multi-physics simulation software COMSOL, and basic on the PDEs of metal hydride hydrogen storage system to establish the one-dimensional and two-dimensional finite element models and analysis the models. Then through the comparison analysis of the desorption process of metal hydride hydrogen storage of one dimensional model and analyzing the results of two-dimensional model, investigating the influence of dimensions of convergence. At last, we simply derivate and validate the heat and mass transfer on the weak form of PDEs, and discussed the weak-form of metal hydride hydrogen storage.First of all, based on the research of the basic principle of the metal hydride hydrogen storage, using the p- c- t curve to detailed analysis the phase change process of metal hydride hydrogen storage. Then, through the basic form of the three laws of thermodynamics, and analysis each part respectively in the hydrogen storage, and show their respective thermodynamic expressions. Further, studied the form of heat transfer and calculation method between the wall and the outside, the tank heat exchange device and the heat source of heat transfer calculation method. Then the coupling process are described, and provided a theoretical basis for modeling.Secondly, based on the one-dimensional and two-dimensional small scale hydrogen storage model, the one-dimensional model and two-dimensional model of the simulation results were analyzed. It is concluded that in the process that temperature, pressure and velocity of darcy trend of simulation results are basically identical, but at the end of the hydrogen storage condition is not consistent. through the analysis of this may be related to modeling process, a 1-d relative to 2-d, the difference of dimension will result in the loss of information, cause different hydrogen storage at the end of the state. Then, for one dimensional model and two-dimensional model in the simulation process. And the results of residual derivative was studied by means of drawing, Find a two-dimensional model in the process of calculating the residual of derivative gradually increase after short convergence, final approach to infinity. While one dimensional model after 50 s basic tends to converge to a fixed value. The results show that the one dimensional model in the research has a good adaptability to parameters.Finally, with a review of the weak form, put forward the solutions of hydrogen in weak form, then the basic heat transfer problems are weak form of deduction and analysis. Using Comsol respectively model and the weak form of the PDEs established model. Comparing the results, two kinds of model comparison results have more than 99% of the conformity degree. Further, the hydrogen storage in the PDEs are weak form is derived. Finally got the description of its weak-form, and the weak form of written form in the Comsol, The exploration of the theory for the improvement of the model has a certain reference value in the future.