基于斯特林制冷机的氦气氛高低温箱深冷试验研究

为了模拟航天产品试验所需极端温度环境和测试航天产品在较大升降温速率条件下的耐受能力,研制了区别于传统热真空罐的氦气氛高低温试验箱,其净空间尺寸为2m×2.2m,可以通过强制对流与辐射换热相结合的方式提高升降温速率.同时,以液氮和四缸两级斯特林制冷机为双冷源,对高低温箱的降温性能进行测试,考察了高低温箱内空间的降温极限以及达到多个目标温度的降温速率等.结果表明,在液氮与斯特林制冷机共同作用的条件下,通过氦气的强制对流、再将氦气抽除的技术手段,可使热沉温度降至-210℃以下.

Experimental Study on Cooling Performance of a Thermal Environment Simulation Chamber with Helium Atmosphere Based on a Stirling Cryogenerator

A 2 m×2.2 m high low temperature environment simulation chamber charged with helium gas was developed for testing aerospace products and their tolerance to high heating/cooling rate at extreme temperatures. The high cooling rate in the chamber was realized through a combination of forced convection and radiation heat transfer, which was significantly different from conventional thermal vacuum chambers. Using liquid nitrogen and a four cylinder, as well as the two stage Stirling cryogenerator as the cold sources, this paper conducted experimental study to test the results such as the achievable lower limit temperature and the cooling rates for approaching certain target temperatures. The Stirling cryogenerator enables the temperature of the heat sink to decrease to -210 ℃ when the chamber is precooled by liquid nitrogen, after which the helium gas inside is evacuated.