35K两级高频脉管制冷研究:Ⅰ.理论分析

Study on high frequency two-stage pulse tube refrigeration at 35K: Part Ⅰ. Theoretical analysis

针对空间35K温区探测器的冷却需要，基于回热器数值计算软件REGEN3．2，成功设计了一台两级高频脉管制冷机．该制冷机采用热耦合的级间布置和惯性管调相方式，其中第二级脉管热端的惯性管和气库置于第一级脉管的冷头下，即冷惯性管，较好地解决了第二级脉管内小声功流条件下相位调节的难题．给出了第二级脉管制冷机的详细设计方法，讨论了第二级回热器填料、长度、充气压力对脉管制冷机性能的影响．计算表明，在80～35K，40Hz下，采用500目不锈钢丝网作为回热器时的制冷性能优于铅丸回热材料，充气压力在1．25MPa下可以获得较好的制冷性能．

For the requirements of detectors cooling at 35 K in space application, a two-stage Stirling-type pulse tube cryocooler （PTC） was successfully designed based on the regenerator simulation software known as REGEN3.2. The two-stage Stirling-type PTC was thermally coupled and an inertance tube was used as phase shifter in the system. In order to obtain a relative large phase at low acoustic power for the second stage of this system, a cold inertance tube and the reservoir at the second stage of the hot end of pulse tube, which was precooled by the cold end of the first stage pulse tube, was introduced in this sys- tem. This work presented the detail design information and discussed the effects of regenerator material, regenerator length and charging pressure on the performance of the second stage of the cryocooler. The calculation results showed that 500 mesh stainless steel is the best regenerator material and its coefficient of performance （COP） is much higher than that of the lead sphere at 80- 35 K and 40 Hz. The charging pressure of 1.25 MPa is suggested for the experiment system.