设计了直线型脉管制冷机的低温回热 器，搭建了该回热器的低温在机交变流动压降实验平台，开 展了压降和冷端压比变化规律实验研究，比较了输入功、频 率、制冷温度和充气压力对回热器压降的影响。结果表明，脉 管制冷机的运行频率越小，制冷温度越低，回热器的压降越大；充 气压力为3.0 MPa时的回热器压降大于3.2 MPa时；回 热器的冷端压比越大，比卡诺效率越高；通过增加回热器的冷端压 比可提高脉管制冷机的效率。

An in-line pulse tube cryocooler regenerator is designed. An experimental platform for in-line low temperature oscillatory flow pressure drop is established for the regenerator. Experimental study is carried out for the pressure drop and the change rule of pressure ratio at the cold end. The influences of input power, frequency, cooling temperature and initial pressure on the pressure drop of the regenerator are analyzed. The results show that the lower the operating frequency of the crycooler is, the lower the cooling temperature is and the greater the pressure drop of the regenerator is. The pressure drop under the initial pressure of 3.0 MPa is greater than that under the initial pressure of 3.2 MPa. The higher the pressure ratio at the cold end is, the higher the relative Carnot efficiency is. By increasing the pressure ratio at the cold end of the regenerator, the efficiency of the pulse cryocooler can be improved.