A Model for Analyzing Ideal Double Inlet Pulse Tube Refrigerators

Abstract

The analysis starts with considerations for optimizing the flow rates applied to both ends of an ideal gas double inlet pulse tube with cold and warm end temperatures T _c and T _w . It is argued that operation with periodic gas flows having equal voluminal amplitudes and finite phase shift is advantageous. In this case, the temperature in the adiabatically cycled gas column proves to rise exponentially from T _c to T _w , and in small amplitude approximation, this temperature distribution is constant in time.

In the next step, the paper presents a numerical procedure and also an analytical solution to calculate the gross refrigeration power as well as the instantaneous heat flows at different positions of such systems. Additionally, the swept volumes and the work of both warm end compressors and also the displacements of the gas within the pulse tube are calculated as functions of pulse tube volume, regenerator dead volume, temperature, pressure, phase shift and others. The numerical procedure is applicable to arbitrary wave forms of the gas flows. Examples are given for harmonic and for rectangular wave forms.