An Inter-Phasing Pulse Tube Refrigerator for High Refrigeration Efficiency

Abstract

This chapter describes an inter-phasing pulse tube refrigerator with a new concept of a phase controller for increase in the overall refrigeration efficiency. In this pulse tube refrigeration system, there are two sets of the coolers one of which consists of a pulse tube and a regenerator. Pulse tube refrigerators,, require a phase controlling system located at the pulse tube hot end to obtain an optimum phase between the pressure fluctuation and the movement of the working gas in the pulse tube cold end to increase the regenerator performance. In the case of the double inlet and the four-valve pulse tube refrigerators, the additional compressor work is exhausted to get the optimum phase which reduces the overall performance of the refrigerator. The pulse tube hot ends of two coolers are connected by either an orifice valve or an on-off valve. Two coolers are operated 180 degrees out of phase only using one valved compressor. By controlling either a mass flow rate through the orifice or timing for the on-off valve, the phase between the pressure and the mass flow controlled by each other of two pulse tubes can be optimized. Test and analysis results of the performance of this inter-phasing pulse tube refrigerator are presented in comparison to that of other types of pulse tube refrigerators.