航天应用的制冷机系统

A CRYOCOOLING SYSTEM FOR SPACE APPLICATION

介绍冷却４×２２ 元 Ｈｇ Ｃｄ Ｔｅ 红外探测器的集成组件的斯特林制冷系统。这是一种单级的牛津型的斯特林制冷机。其特点是采用膜片弹簧支撑、音圈电机驱动、差动变压器的位移传感器和间隙动密封技术。制冷机的最低制冷温度４３ Ｋ， 降温时间２０ ｍ ｉｎ， 其压缩机功耗约３０ Ｗ。制冷机系统采用双机屏蔽轴向对置排列， 以减小系统机械振动和对探测器的电磁干扰。制冷机通过柔性冷链（汇流排）冷却红外探测器组件。系统在８０ Ｋ 时对探测器提供的冷量大于３０ ｍ Ｗ，制冷机功耗４５ Ｗ。冷链温差为２５ Ｋ， 探测器等效温度灵敏度０２ Ｋ。

In this paper a miniature single stage Stirling Cryocooler for use to cool a 4×22 pixels HgCdTe infrared detector is introduced.A concept of the cryocooler is based on the“Oxford type”Stirling refrigerator which is characterized by flexure suspension springs,linear driving motors and clearance seals without wear of seal materials for long term operation.The cooling tests show that the lowest temperature at the cold head is 43K,the cooldown time is 20 minutes and the power consumption of the compressor is about 30W. To reduce the mechanical disturbance,the back to back arrangement of two refrigerators is adopted in system configuration,and the effect of magnetoelectrical disturbance(MED)of the refrigerators on the detector is also significantlv reduced by ME shielding.The cooling power is transmitted from the cold head to the detector through flexure cold chains.This system can offer not less than 300mW cooling power to the detector at 80K and the power consumption is 45W.The temperature difference between the two ends of the cold chain is 2 5K and the equivalent temperature sensitiviy of the detector is less than 0 2K.