金属氢化物储氢器吸氢过程的数值分析

NUMERICAL ANALYSIS FOR HYDRIDING IN METAL HYDRIDE HYDROGEN STORAGE TANK

基于金属氢化物吸氢基本特性,建立圆柱形金属氢化物储氢器吸氢过程的一维数学物理模型。采用有限差分法对金属氢化物床体的传热传质进行计算。分别研究金属氢化物床体各处温度和氢含量在吸氢过程中的变化以及氢气压力、对流传热系数和金属氢化物床体径向厚度对金属氢化物吸氢过程的影响。计算结果表明:初始阶段金属氢化物床均匀吸氢,但随着氢化过程的进行,其中心区域的吸氢速率逐渐低于边缘区域;增加吸氢压力、提高对流传热系数均可促进储氢器的吸氢;金属氢化物床的径向厚度对吸氢速率影响很大,金属氢化物床越薄,氢化反应的速度越快。

Based on the principle of hydride adsorption, a one-dimensional mathematical model for hydriding in a cylindrical metal hydride hydrogen storage tank was established. The heat and mass transfer of metal hydride beds was computed by finite difference method. The variation in temperature and hydrogen concentration at different ra- dial positions of the hydride layer was analyzed during the process of hydriding. The effects of supply pressure, heat convection coefficient and hydride layer radial thickness on the hydriding was studied. It is shown that hydride for- mation initially takes place uniformly all over the metal hydride layer, but with the process of hydriding, the hydriding rate at the core region is gradually slower than one at surface region. The increase of supply pressure and heat convection coefficient can accelerate the hydriding of the hydrogen storage tank. The effect of hydride layer radial thickness is significant on the hydriding rate, and the thinner hydride layer, the higher the hydriding rate.