Study on G-M type pulse tube cryocooler with a novel active gas distribution system

Abstract

In order to overcome the disadvantages of a traditional gas distribution system of G-M type pulse tube cryocoolers, a novel active gas distribution system with a middle stage reservoir is proposed. Different from the traditional intake and exhaust processes, the refrigeration cycle with the active gas distribution system consists of an intake process from the middle stage reservoir, an intake process from the compressor, an exhaust process to the middle stage reservoir and an exhaust process to the compressor. Theoretical analysis shows that the active distribution system may significantly reduce the power consumption of the compressor due to the reduction of irreversible losses during the intake and exhaust processes. The self-made pulse tube cooler with the active gas distribution system was tested. Experimental results show that the active gas distribution system decreases the power consumption by 27% and entropy generation by 37% when the proportion of opening time of the middle stage reservoir is 30%. The cryocooler reaches a lower refrigeration temperature with minor decrease of cooling power. Besides, the active gas distribution system may increase the life time for valves.