直线型和同轴型脉管制冷机在90 K的对比分析

Comparative analysis of in-line and coaxial pulse tube cryocoolers at 90 K

直线型和同轴型脉管制冷机被广泛应用于空间领域,尤其是同轴型脉管制冷机。同轴型脉管制冷机结构紧凑且使用便利,而直线型脉管制冷机结构简单且制冷效率高。目前,对于两类脉管制冷机的理论比较研究相对较少,因此开展相应的比较研究很有意义。本文分析了两款不同结构的单级脉管制冷机(直线型和同轴型)。通过建立一维数值模型分析两款制冷机相关热力学参数的不同之处,从机理上揭示了不同结构会导致不同的制冷性能。通过比较两款制冷机的能量流及声功阻抗图,开展实验对两款制冷机性能进行测试和分析。结果表明:在相同的输入功率时,直线型脉管制冷机具有更高的制冷效率,而同轴型脉管制冷机可以达到更低的制冷温度(原因在于同轴型冷指的脉冲管置于回热器内部,会被回热器预冷)。通过比较发现,模拟数据和实验结果具有较好的一致性。

Linear and coaxial pulse tube cryocoolers(PTCs)are widely used in space,especially coaxial PTCs.The coaxial PTC has a compact structure and is more convenient to use,while the linear structure is simple with high cooling efficiency.At present,the research on the difference between the two PTCs based on theoretical re⁃search is relatively rare.Therefore,it is very valuable to carry out some comparative studies between the two PTCs.Two kinds of Stirling-type single-stage PTCs(in-line and coaxial type)are analyzed due to their different structures in this paper.One-dimensional numerical model is established to analyze the changes of the relevant thermodynamic parameters in the two cryocoolers.The mechanism is revealed that different structural changes could lead to different cooling performance.The differences between the PTCs are compared by analyzing the en⁃ergy flows,acoustic impedance networks.Also,two experimental setups are established,and the performance of the two pulse tube cryocoolers is tested and analyzed.The results show that the in-line cryocooler has higher cool⁃ing efficiency,and the coaxial one could reach lower cooling temperature at the same input power because the pulse tube is placed in the regenerator of the coaxial system and precooled by the regenerator.By comparing the simulation data with the experimental results,it is found that there is a good consistency.