Double inlet pulse tube refrigerators: an important improvement

Abstract

The main purpose of this paper is to reveal how the pulse tube in a pulse tube refrigerator works and to look at why the mass flow rate through the regenerator is so large, why the refrigeration power per unit mass flow rate through the regenerator is so low, how to reduce the mass flow rate through the regenerator and how to increase the refrigeration power per unit mass flow rate through the regenerator. On the basis of the theoretical analysis, a modified version called the double inlet pulse tube refrigerator is suggested, which has a second inlet at the hot end of the pulse tube connected to the pressure wave generator. Numerical analysis and experimental results confirm that the double inlet pulse tube refrigerator has improved performance over the orifice pulse tube refrigerator.