Investigation of step piston pulse tube refrigerator

• The step piston type pulse tube refrigerator is confirmed by experiment. • A thermo acoustic model is developed to explain its working mechanism. • The effect of inertance tube and buffer is investigated by experiment. • 60 W cooling power at 128 K with 13.6 % efficiency is achieved. The step piston pulse tube refrigerator (SPPTR) utilizes just a single moving part and one cold head to achieve the recovery of the expansion work at the hot end of the pulse tube. Its structure is simple and exhibits high intrinsic efficiency in the high-temperature zones. This paper completed the first experimental validation of SPPTR. A thermoacoustic model of SPPTR was developed to elucidate the mechanism of SPPTR. The study explored the effects of inertance tube dimension and buffer volume on the performance of the SPPTR through both experiment and thermoacoustic model approaches. SPPTR obtained 60 W cooling power at 128 K with 13.6 % efficiency, signifying the emergence of a new work recovery type pulse tube refrigerator.