小型回热式低温制冷机中的冷端换热器在制冷量高效传输过程中起着至关重要的作用,而这一作用往往被忽视。研究发现,通过脉管冷端换热器的结构改进,液氦温区脉管制冷机在4.2 K温区的制冷量可以得到显著提高。实验结果表明,在压缩机输入功率分别为4.8 kW和6.0 kW的条件下,双向进气型二级脉管制冷机在4.2 K获得了760 mW和900 mW的制冷量,相应的制冷系数(COP)为1.58×10-4和1.50×10-4。该脉管制冷机在4.2 K获得的最大制冷量达960 mW。 Cold-side heat exchangers in small regenerative cryogenic refrigerators play a crucial role in the efficient transfer of cooling capacity, a function that is often overlooked. The study found that through the structural improvement of the cold-legged tube heat exchanger, the cooling capacity of the pulse tube refrigerator with liquid helium temperature in 4.2 K can be significantly improved. The experimental results show that with the input power of the compressor being 4.8 kW and 6.0 kW respectively, the two-way air-fed two-stage pulse tube refrigerator achieves the cooling capacity of 760 mW and 900 mW at 4.2 K, and the corresponding refrigeration coefficient ) Was 1.58 × 10 -4 and 1.50 × 10 -4. The MPC achieves a maximum cooling capacity of 960 mW at 4.2 K.