Performance of Pulse Tube Refrigerators for a Wide Temperature Range

Abstract

Cooling performance of orifice pulse tube refrigerators was investigated in a wide temperature range from about 80 K to over 250 K to determine the feasibility of pulse tube refrigerators as refrigeration systems in that temperature range. Helium and nitrogen were used and compared as the working gas. P‐V work in the pulse tube refrigerator was estimated to determine the difference in performance between the two working gases based on energy flow in the refrigerator. Results revealed that the lowest wall temperature was 80 K for helium and 126 K for nitrogen, and that the refrigeration power for helium was over 1.5 times higher than that for nitrogen, even when operating conditions (e.g., frequency and orifice valve opening) were optimized for nitrogen. Moreover, it was found that the decrease in P‐V work through the regenerator for helium was also about 1.5 times larger than that for nitrogen, and that the oscillation of volume of gas element significantly affected the difference in P‐V work between the two working gases, whereas the phase difference between oscillations of pressure and displacement did not.