基于G-M制冷机的大尺寸冷屏设计方法

介绍了基于Gifford-Mcmahon (G-M)制冷机的大尺寸冷屏的设计方法。该低温冷屏配合真空环境模拟室共同使用，为遥感卫星的星载遥感器等部件的红外定标试验提供20K的低温冷背景。该冷屏采用5台G-M制冷机进行制冷，外形尺寸达到1m×1m，是目前国内同类型冷屏中尺寸最大的。详细介绍了冷屏在容器内的安装布置、冷缩时的补偿等结构设计方法、冷屏的表面温度分布以及降温时间等计算分析。成功解决了大尺寸冷屏在低温环境下的冷缩补偿难题，试验结果表明:冷屏主要测点温度为15K，温度均匀性误差为±1K，达到并超过设计要求。 

Design method of large dimension cold shield based on G-M cryocooler

The design methods of the 20K large dimension cold shield based on Gifford-Mcmahon (G-M) cryocoolers used for infrared calibration test in space environment simulation test were introduced. The cold shield with 1m×1m boundary condition, the largest dimension in China, was cooled by five G-M cryocoolers. The installation and distribution of cold shield were introduced, and the method of compensator for contraction on cooling was also described in detail. The temperature distribution and cool-down time of cold shield surface were calculated and analyzed. The design of cold shield resolved the difficulty of compensator for contraction on cooling successfully. Test results showed that the temperature on the cold shield was 15K, and the temperature uniformity was ±1K. This indicated that the actual technical performance of the cold shield met and even exceeded the design requirements.