Intrinsic Behaviour of a Four Valve Pulse Tube Refrigerator

Abstract

The pulse tube refrigerator containing no moving parts in the cold section is more attractive for higher reliability, simpler construction and lower vibrations of mechanical and electromechanical origin than any other regenerator type refrigerator. This chapter reveals the effects of the oscillating flow phenomena of working gas inside the pulse tube on the thermal behavior of a four valve pulse tube refrigerator (FVPTR) in order to gain a better understanding of the real working conditions. It measures the pressure and temperature oscillations at various points. The oscillation behavior of the gas pressure is quite similar at all positions through the pulse tube. However, the one of the gas temperature changes with the location along the pulse tube dramatically. The amplitude of the temperature oscillation near the center of the pulse tube is larger than that at the ends. The phase of temperature oscillations in comparison to the pressure oscillations shifts over the length of the pulse tube. The observed data of the temperature and pressure behavior were used to identify typical loss mechanism of the FVPTR.