论文部分内容阅读
基于镁/氢化镁热化学储热系统,建立了二维非稳态数学模型。对吸氢放热过程中的传热传质现象进行了数值模拟,主要研究了壁面温度和反应床当量导热系数对系统反应速率的影响。结果表明,放热过程中存在最佳的壁面温度使反应速率达到最快,过高或者过低的壁面温度都将使反应床的温度偏离理论上的最佳值,从而降低反应速率。针对不同当量导热系数的反应床,最佳壁面温度也不相同;反应床的当量导热系数并非越大越好,应该根据具体的边界温度以及氢气压力情况进行合理的选择以获得最佳的反应速率。
Based on the magnesium / magnesium hydride thermochemical heat storage system, a two-dimensional unsteady mathematical model was established. The heat and mass transfer phenomenon during hydrogen absorption and exothermic process was numerically simulated. The effects of wall temperature and equivalent bed thermal conductivity on the reaction rate were studied. The results show that the best wall temperature exists in the exothermic process to maximize the reaction rate. If the wall temperature is too high or too low, the temperature of the reaction bed will deviate from the theoretical optimum and the reaction rate will decrease. For the reaction bed with different equivalent thermal conductivity, the optimal wall temperature is not the same. The equivalent thermal conductivity of the reaction bed is not as good as possible. The optimum reaction rate should be selected according to the specific boundary temperature and hydrogen pressure.