基于CFD方法的低温泵热力学设计与数值仿真研究

Thermal Design and Evaluation of Cryopump:A Simulation and Experimental Study

通过CFD数值仿真的方法对低温泵一级冷阵和二级冷阵降温过程以及稳态平衡过程的热力学情况进行了研究。研究针对低温泵不同的运行工况,导热柱的设置以及冷屏厚度等因素的影响,分析了各种情况下低温泵的温度分布情况。同时文章还对低温泵降温过程分别采用稳态物性和变化物性进行计算,分析物性的定性温度以及低温泵一级冷阵的结构对计算结果的影响。针对DN400低温泵建立测试系统进行降温情况的测试,通过测试和仿真计算的结果进行对比,确认了设计和分析方法的有效性,降温时间的计算误差约为7%。

The temperature field and heat flow,from cooling-down to steady state in the newly-developed cryopump comprising the 1 stand 2 ndcryo-cooling arrays,were empirically approximated,mathematically modeled,theoretically analyzed,numerically simulated and experimentally measured with the lab-built test platform equipped with DN400 cryopump for thermal design optimization. The influence of the rather complicated cooling-down conditions,including but not limited to the 1 stcryo-cooling array structure,thermal rod setting,radiation shield thickness,operating modes,thermal properties of components materials and large temperature ranges involved,on the refrigeration and time evolution of temperature distribution of the newly-designed cryopump was investigated. The simulated and tested results were found to be in good agreement. For example,when it comes to the cool-down time,the discrepancy between the simulation and measurement was about 7%.