压缩机驱动方式对主动调相型两级脉管阻抗特性影响研究

Influence of compressor driving method on acoustic impedance of two-stage pulse tube cryocooler with active piston phase shifter

对双压缩机驱动和单压缩机驱动两种驱动方式下,两级脉管的声阻抗特性和制冷效率随运行压力和运行频率的变化进行对比,研究了单压缩机驱动时冷指的声功分配和制冷效率。一台工作温区为20 K和80 K的主动调相型两级脉管制冷机,冷指入口声阻抗幅值随着运行频率的增加和运行压力的减少而减少。随着运行压力和运行频率的增加,一级制冷效率提升,二级制冷效率降低。单压缩机驱动时通过降低运行频率,选择最优的运行压力来改善第二级制冷性能,在40 Hz,2.8 MPa的运行参数下,400 W输入功时获得了0.37 W@20 K,6.7 W@80 K的制冷性能。

The acoustic impedances at the inlet of the two-stage cold finger and the cooling power at 20 K and 80 K are measured under different operating pressure and frequency,under the two driving modes of dual compressor drive and single compressor drive.The acoustic power distribution and cooling efficiency when driven by single compressor is studied.The first stage refrigeration efficiency is improved and the second stage refrigeration efficiency is decreased while increasing the operating pressure and frequency.The amplitude of acoustic impedance decreases with the increase of operating frequency and the decrease of operating pressure.To improve the refrigeration performance of the cryocooler while driven by single compressor,it’s suggested to choose a lower operating frequency and a appropriate operating pressure.Under the operating parameters of 40 Hz and 2.8 MPa,the cooling performance of 0.37 W@20 K and 6.7 W@80 K is obtained experimentally at 400 W input power.