Theoretical and Experimental Investigation of Stirling type Pulse Tube Cryocooler with a Cold Phase Shifter

In multistage pulse tube cryocooler (PTC) double-inlet valve offers an effective phase shift. However, it may generate a DC flow leading to an unsteady cooling performance. To overcome this, a gas coupled two-stage Stirling-type pulse tube cryocooler with an inertance tube has been designed and developed. The hot end heat exchanger, the inertance tube and the reservoir for the second stage, is precooled by the cold end of a separate single stage PTC. The effect of the inertance tube length, the pulse tube volume, the reservoir volume and the hot end temperature on the performance of the second stage of the two-stage PTC is investigated using Sage software and validated experimentally. A lowest temperature of 31.5 K is obtained with an input electric power of 200 W at 68 Hz. The experimental results are compared with theoretical results obtained by the Sage and are found in good approximations.