10K单级脉管制冷机性能研究

Performance Study of a Single-Stage Pulse Tube Cooler at 10 K

20K温区大功率低温制冷机在超导体冷却、液氢无损贮存和低温泵等方面有着广阔的应用前景。为了探索单级脉管制冷机的极限制冷温度同时提高脉管制冷机在20K温区的制冷量,本文开展了计算模拟和实验研究。回热器模拟软件REGEN3.2的模拟结果显示,在不同的冷端质量流量下,单级脉管制冷机所能达到的最低制冷温度均为9.5K。在此基础上,本文设计了一台单级脉管制冷机,对回热器冷端10～80K温区的回热材料作了进一步优化。采用由不锈钢丝网、铅丸和稀土磁性蓄冷材料Er3Ni构成的复合式回热器,该单级脉管制冷机获得了10.9K的最低制冷温度,这是目前公开报道的单级脉管制冷机最低制冷温度。该制冷机在20.9K可获得20W的制冷量或在29.9K可获得40W的制冷量,输入功率为7.5kW。

20 K high power cryocoolers have promising applications for superconductor cooling, liquid hydrogen storage, cryopump and so on. In order to explore the lowest attainable refrigeration temperature and improve cooling performance at the temperature around 20 K for a single-stage G-M type pulse tube cooler （PTC）, numerical and experimental study were further performed. Simulation results with REGEN3.2 showed that the lowest attainable refrigeration temperature can reach 9.5 K. Based on the simulation results, a single-stage G-M type pulse tube cooler was designed and fabricated. The cold part of the regenerator at the temperature range of 10～80 K was further optimized. Based on hybrid regenerator consisted of stainless steel mesh, Pb spheres and Er3Ni, a lowest temperature of 10.9 K was achieved, which is a new record for the single stage pulse tube cooler. With an input power of 7.5 kW,the cooler can provide cooling power of 20 W at 20.9 K or 40 W at 29.9 K.