Thermodynamic Analysis of G-M/J-T Helium Refrigeration Cycle for a Cryoadsorption Test Facility

Abstract

A cryoadsorption test facility is developing for upgrade the cryopump of EAST neutral beam injector. To provide an optional cryogenic supply plan for the test facility, a Gifford-McMahon (G-M)/Joule-Thomson (J-T) helium refrigeration cycle is designed. In this paper, the influence of stage temperature of two-stages G-M cryocooler and J-T heat exchanger effectiveness on the performance of the cycle is thermodynamically analyzed. The results of the analysis make it clear that, for the cycle precooling power input, the temperature of cryocooler stages plays a very important role on cycle performance. And different operational J-T heat exchanger effectiveness and its thermal characteristics in the refrigeration cycle are also discussed.