Effects on the cooling performance of the gas distribution in the two-stage thermal-coupled pulse tube cryocooler.

This paper presents the theoretical investigations on the gas distribution happening in the thermal-coupled two stage pulse tube cryocooler (TSPTC) which only contains one compressor. The dynamic characteristics of the mass flow rate and the pressure in the regenerator, the pulse tube and the inertance tube are analysed, and the governing equations are deduced. The power transmitted by the thermal bridge and the cooling capacities of both stages are investigated. A thermal-coupled TSPTC, which can provide cooling capacity at 30~35 K and 50~100 K simultaneously, is modified and simulated to investigate the influencing factors of the gas distribution. With the increase of the first stage’s cooling temperature, the second stage’s inlet mass flow rate increases, while the cooling capacity decreases. With the increase of one stage’s cooling efficiency, the other stage’s cooling efficiency decreases. Thus, the both stage can’t achieve the optimal performances, simultaneously.