Influences of Ambient Temperature on Dual-Temperature-Zone Pulse Tube Refrigerator with Acoustic Power Recovery Phase Shifter

Pulse tube refrigerators are widely used in space detection and quantum computing due to their low vibration output at the cold end and high reliability. Dual-temperature-zone pulse tube refrigerators can simultaneously achieve dual cooling temperatures. However, in the actual application scenario, the cooling performance is largely affected by the ambient temperature zones, which limits applications in complex environments. In this study, based on the dual-temperature-zone pulse tube refrigerator with an active acoustic power recovery phase shifter, the influence characteristics of the ambient temperature on the gas spring of the phase shifter, inlet acoustic power of the cold finger, and dual-temperature cooling capacities are investigated. Unlike the conventional piston-type phase shifter, which has only an expansion chamber, the acoustic power recovery phase shifter has an acoustic power recovery chamber at the back end of the piston, which can recover the expansion acoustic power from the hot end of the pulse tube. Compared to the traditional piston-type phase regulator containing only an expansion chamber, when the ambient temperature increases from 253 K to 333 K, the maximum change in the total gas spring stiffness of the piston in the acoustic power recovery phase shifter is only 2 630 kg/s², and the level of impact could be reduced by 86.1%, which shows that the acoustic power recovery phase shifter has a higher adaptability to the ambient temperature. The experiment shows active control of cooling capacities in dual-temperature zones by adjusting the piston motion of the phase shifter at ambient temperatures of 253 K and 333 K.