Performance Testing of Helium Valved Linear Compressor System Capable of Providing Compression Ratio Over 200

A Joule-Thomson cryocooler (JTC) with temperature around 2 K has great application potential, and the compression ratio is the key factor to limit the performance of the cryocooler. A valved linear compressor (VLC) system of super high compression ratio made by Shanghai Institute of Technology and Physics, Chinese Academy of Sciences (SITP) is always under development to meet the requirements and improve the performance of a JTC for emerging fields like quantum computing, deep-space exploration etc., which consists of four long-life valved linear compressors. This paper shows its development process and preliminary test. Based on the refrigeration performance indicator, the structural design is carried out, and the structural parameters of all stage compressors are obtained. The testing results show that the four-stage JT compressors achieve a compression ratio over 200, which can be conducive to improving the cooling capacity of a JTC. The VLC system of large compression ratio has compact structure and strong stability, which can meet the requirements of 1.5–2.5 K helium JTC for future space applications.