Experimental optimization of phase for a 20 K thermally-coupled two-stage high-frequency pulse tube cryocooler

Abstract With the rapid advancement of space technology, there is a continuous increase in demand for long-wave infrared detection devices, leading to higher requirements for two-stage pulse tube cryocoolers operating at liquid hydrogen temperatures. The performance of the cryocoolers is closely related to the inertance tube size. In order to improve a two-stage thermally-coupled pulse tube cryocooler’s performance in the liquid hydrogen temperature range, this study conducted phase optimization experiments, analyzed the effects of different inertance tube combinations on the cryocooler’s performance. The optimal operation frequency, power factor, no-load cooling temperature, cooling capacity and rCOP were compared for cryocoolers with different inertance tube combinations. After preliminary optimization, the cryocooler achieved 586 mW/20 K cooling power with a total electric power consumption of 185 W, resulting in a rCOP of 4.43%.