Theoretical analyses and experimental verifications of a four-stage Stirling-type pulse tube cryocooler reaching 3 K

摘要

This paper conducts theoretical analyses and experimental verifications of a four-stage Stirling-typepulse tube cryocooler (SPTC) aimed at reaching 3 K for low-Tc superconducting devices and deepspace explorations. A computational fluid dynamics (CFD) model is built for the SPTC, in which theirreversible losses in the regenerator are studied and cooling performances simulated. The entropygenerations caused by three types of losses including pressure drop, axial heat conduction andineffective heat transfer are calculated quantificationally and the distributions of them are presented.The four-stage SPTC is then worked out and tested. The experimental results indicate that, byusing He-4 and He-3, it reaches no-load temperatures of 4.2 K and 3.5 K, respectively. The SPTC isexpected to reach 3 K by matching with a larger capacity compressor.