Experimental Research on Phase Angle of Hybrid Refrigerator Combining GM Gas Refrigeration Effect with Magnetic Refrigeration Effect in Liquid Helium Temperature Range

Cryogenic refrigeration technology in the liquid helium temperature range is the key technology supporting frontier science and technology.The current mainstream small-scale GM refrigerator has the problem of low efficiency.How to combine high-efficiency magnetic refrigeration technology to improve the efficiency of GM refrigerator in the liquid helium temperature range is the focus of current research.Based on previous work,this paper further investigated the hybrid refrigerator in the liquid helium range,and improved the cooling performance of the refrigerator by combining GM gas refrigeration effect with magnetic refrigeration effect.The second stage regenerator of the GM refrigerator was filled with three types of regenerative fillers including Pb,ErNi and EuTi_0.875Al_0.125O₃.The effect of magnetic refrigeration on the performance of the hybrid refrigerator was investigated.The influence of the phase angle of the hybrid refrigeration prototype was discussed.Under 1 Hz system frequency,when the phase angle is 60°,the two refrigeration effects of magnetic refrigeration and GM refrigeration have a most apparent positive super-imposition effect.The lowest no-load temperature is 3.66 K,which is 0.95 K lower than that of the GM refrigerator at the same frequency.