4 K节流制冷机预冷温度及压力特性影响研究

空间4 K JT节流制冷是实现深空探测任务的关键技术之一。基于4 K温区开式节流制冷机实验台，理论分析末级预冷温度及高压压力对理论最大制冷量的影响，给出不同工况下最优末级预冷温度及最优高压压力的选择。开展实验测试验证理论计算。分别测试了末级预冷温度为15 K时，五种高压压力（0.829、1.103、1.775、1.837和2.154 MPa）以及高压压力1.773 MPa时三种不同预冷温度（11.5、15.0和18.0 K）下的最大制冷性能，实验结果变化趋势与理论值吻合较好。预冷温度及压力特性影响研究为后续节流系统整体压缩机及预冷机最优状态耦合匹配奠定基础。

Study on precooling temperature and pressure characteristics of 4 KJoule-Thomson cryocooler

Space 4 K Joule-Thomson (JT) throttling cooling is one of the key technologies for deep space exploration missions. Based on the existing experimental system of a precooled 4 K JT cryocooler, the effects of the precooling temperature and the high pressure on the maximum cooling capacity are analyzed theoretically. Then, the optimal precooling temperature and high pressure under different working conditions are involved. The experimental studies are developed to verify the theoretical calculations. The maximum cooling performance were tested under five different high pressures (0.829 MPa, 1.103 MPa, 1.775 MPa, 1.837 MPa, and 2.154 MPa) at the final pre-cooling temperature of 15 K and three different pre-cooling temperatures (11.5 K, 15.0 K and 18.0 K) at high pressure 1.773 MPa. The trend of the experimental results is in good agreement with the theoretical values. The study on the influence of precooling temperature and pressure characteristics will be helpful for optimizing the coupling matching of the compressor and precooling cooler for the 4 K JT system.