Numerical simulation of pre-cooling two-stage series pulse tube refrigerator at liquid hydrogen temperature
胡 栄沢, 朱 紹偉 （同済大）
Abstract:Two-stage series pulse tube refrigerator is the core component to achieve zero-boil-off storage of liquid hydrogen in liquid hydrogen stations. Its theoretical efficiency is close to the Carnot efficiency, with the double inlet as the phase shifter of the first cold head, the inertance tube and reservoir as the phase shifter of the second cold head. Double inlet supplies part of the input work to the second cold head and the first stage refrigeration capacity is transported to pre-cooling heat exchanger in the regenerator of second stage for higher efficiency at liquid hydrogen temperature. The 2D axisymmetric models were established to simulate the phase distribution of the refrigerator under different double inlet valve openings, operating frequencies and inertance tube sizes. The simulation results show that the double inlet valve opening influences the phase of the first cold head. The phase of the second cold head can be regulated to achieve the ideal state by adjusting the frequency. The optimal inertance tube size exists to obtain the ideal phase relation of the second cold head operating at an optimal frequency.