Investigation on phase shifter of a 10 W/70 K inertance pulse tube refrigerator

A 10 W/70 K inertance pulse tube refrigerator (IPTR) has been developed for cooling infrared focal-plane array in a space mission. To investigate the influences of the phase shifter (inertance tube and reservoir) on the cooling performance, simulation models of the IPTR were built and experimental studies were conducted. The effects of reservoir volume and the surface roughness inside the inertance tube on cooling performance of the IPTR were investigated in detail. The optimized parameters of the phase shifter were developed to improve the cooling performance of the IPTR. The results show that a large reservoir volume reduces the optimal operating frequency, decreases the losses in the regenerator and improves the cooling performance of the IPTR. Because of the small surface roughness inside the stainless steel inertance tube, the input electric power of the IPTR is decreased, with a cooling power of 10 W at 70 K. The IPTR achieves 14.75% of the relative Carnot efficiency at 70 K by optimizing the inertance tube and reservoir.