Characteristics of a 1.6 W Gifford-McMahon Cryocooler with a Double Pipe Regenerator

[摘要] This paper focuses on the second stage regenerator of a 4 K Gifford-McMahon (G-M) cryocooler. A three-layer layout of lead (Pb), HoCu2and Gd2O2S spheres in the second stage regenerator derives a good performance at 4 K. After some modifications, we confirmed that the cooling power of 1.60 W at 4.2 K was achieved by using this three-layer layout. A two-stage G-M cryocooler is RDK-408D2 (SHI) and a compressor is C300G (SUZUKISHOKAN) with a rated electric input power of 7.3 kW at 60 Hz. In order to further improve, a double pipe regenerator was applied to the second stage regenerator. As a double pipe, a stainless steel pipe with thin wall was inserted in the coaxial direction into the second stage regenerator. The helium flow in the second stage regenerator is expected to be non-uniform flow because of the distribution of helium density and the imperfect packing of regenerator material. The double pipe regenerator is considered to have an effect of restraining the non-uniform flow. From the experimental results, the second stage cooling power of 1.67 W at 4.2 K and the first stage cooling power of 64.9 W at 50 K were achieved.

[发布机构] Department of Electronic-Mechanical Engineering, National Institute of Technology, Oshima College, Yamaguchi; 742-2193, Japan^1;National Institute of Materials Science, Tsukuba; 302-0003, Japan^2

[效力级别] 物理学 [学科分类] 材料科学（综合）

[关键词] Cooling power;Double pipes;G-m cryocooler;Helium density;Input power;Non-uniform flows;Regenerator materials;Stage cooling