液氦温区大冷量GM制冷机仿真及参数分布研究

Simulation and parameter distribution study of high-capacity GM cryocoolers working in liquid helium temperature

为提高液氦温区GM制冷机制冷效率,加快产品迭代速度,采用Sage仿真软件对鹏力超低温生产的一台KDE420两级GM制冷机进行了整机建模,该制冷机由两台KDC6000V压缩机并联驱动,模拟结果显示该制冷机一、二级分别可获得71.6 W@50 K、2.6 W@4.2 K制冷量,与实验测试结果基本一致。同时对模型中整机(火用)损失情况、膨胀机内温度和(火用)流分布等进行了系统分析。分析表明:进入二级回热器的(火用)占一级膨胀腔(火用)的69.5%,二级回热器铅丸段温度梯度过高,通过优化二级回热填料可进一步提高制冷性能。

To improve the cooling efficiency of GM cryocoolers working in liquid helium temperature and accelerate the product iteration speed,a comprehensive simulation of a two-stage GM cryocooler manufactured by CSIC Pride(Nanjing)Cryogenic Technology Co.,Ltd.was carried out by Sage.The cryocooler was driven by two KDC6000V compressors in parallel.Simulation results show that the first and second stage cooling capacities are 71.6 W@ 50 K and 2.6 W@ 4.2 K respectively,which are basically consistent with the experimental results.The total exergy loss,temperature and exergy flow distribution in the expansion chamber are analyzed by the simulation model.The analysis shows that the exergy flow entering the second heat exchanger accounts for69.5% of the exergy flow in the first expansion chamber,and the temperature gradient along the lead of the second regenerator is too high,which points out the direction for further improvement.