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建立内置螺旋换热管的金属氢化物反应器的3维数学模型,其特点是耦合了螺旋管内载热流体温度变化对反应过程的影响。根据所建模型并采用多物理场软件对反应器传热及反应过程进行数值模拟,分析了不同操作参数下反应器的传热性能与吸氢反应特性。结果表明:吸氢反应过程可划分为3个阶段,第1阶段主要受氢气压力影响,第3阶段主要受传热过程控制,其间为过渡段;氢气压力的减小能降低反应速率和床层平均温度,当其低至0.6 MPa时,反应速率显著降低;载热流体温度的升高使传热温差减小,从而导致反应速率降低,当其高至323 K时,反应已不能彻底进行;床层中,靠近螺旋管壁处温度较低,反应更为充分,但远离管壁的区域换热性能较差,反应较缓慢,由此指出了换热结构的改进方向。
A 3-D mathematical model of a metal hydride reactor with a built-in spiral heat exchange tube is established, which is characterized by the coupling of the influence of the temperature change of the heat transfer fluid in the spiral tube on the reaction process. The heat transfer and reaction process of the reactor were numerically simulated according to the model and using multiphysics software. The heat transfer performance and hydrogen absorption reaction characteristics of the reactor under different operating parameters were analyzed. The results show that the process of hydrogen absorption can be divided into three stages, the first stage is mainly affected by the pressure of hydrogen, the third stage is mainly controlled by the heat transfer process, and the transition period is between. The decrease of hydrogen pressure can reduce the reaction rate and the bed When the temperature is as low as 0.6 MPa, the reaction rate decreases remarkably. The increase of the temperature of the heat transfer fluid decreases the heat transfer temperature difference, which leads to the decrease of the reaction rate. When the reaction temperature is up to 323 K, the reaction can not be completely carried out. In the bed, the temperature near the spiral wall is lower and the reaction is more adequate. However, the area far away from the wall has poor heat exchange performance and slow response, indicating the improvement direction of the heat exchange structure.