A Superhigh Performance 40 K Pulse Tube Refrigerator with Miniaturized Active Phase Shifter

Compared to Stirling type refrigerants, Stirling type pulse tube refrigerators have no moving parts at the cold end, making the pulse tube refrigerator have the advantages of long life, high efficiency, and high reliability. The room temperature displacer with active control regulates the mass flow and pressure wave at the cold end of the pulse tube to optimize the performance of the pulse tube refrigerator. Both simulations and experiments have shown that the cooling efficiency of the pulse tube with room temperature displacer phasing is better than that of inertance tube with reservoir phasing in the 40 K temperature region. Adding the structure for power recovery to the active phase shifter can recover the acoustic work at the hot end of the pulse tube and improve the cooling efficiency. The gas load of the work recovery chamber can enhance the resonance efficiency of the displacer piston with micro weight for the same expansion chamber gas load. A cooling capacity of 4 W@ 40 K was obtained at 270 W electrical power with a miniaturized active phase shifter with power recovery. The relative Carnot efficiency is 9.63%. And a cooling capacity of 7 W @ 40 K was obtained at 600 W electrical power, with a relative Carnot efficiency of 7.58%.