Investigation of the high efficiency pulse tube refrigerator with acoustic power recovery

The efficiency of conventional pulse tube refrigerator (PTR) is bounded due to the dissipation of acoustic power at the hot end. Thus, the acoustic power recovery is of great significance for improving the efficiency of the PTR, especially in the application of middle-high temperature zone and large cooling capacity. Based on an existing inertance tube pulse tube refrigerator (ITPTR), a pneumatic piston phase shifter is designed to shift the phase difference and recover part of the acoustic power. The acoustic impedance model and dynamic model are applied to theoretically analyze the work recovery pulse tube refrigerator (WRPTR). Parametric simulation and optimization of the pneumatic piston are performed with the help of the 1-D simulation software (Sage), and the experimental system of WRPTR is successfully built. Some experiments are performed on the experimental system and the experimental results are in good agreement with the simulation results. The experimental results show that the pneumatic piston phase shifter can recover the acoustic power well with a suitable phase relationship. A relative Camot efficiency of 20.8% is obtained at 170 K with 15 W cooling capacity. In addition, the pneumatic piston phase shifter is lighter and more compact, which is more advantageous in applications.