DC flow may exist in a pulse tube cryocooler if a closed loop is formed by double inlet, etc. It has been found that, given the right amount and the right direction, DC flow may be favorable to the cooling performance of a PTC working at liquid hydrogen temperature and liquid helium temperature with Stirling type or G-M type PTC. In case of Vuilleumier type PTC, which is driven by a thermal compressor, none has been studied. In this paper, the effects of DC flow on a Vuilleumier type PTC working around 10 K have been studied through numerical analysis. In the simulation, the software SAGE is utilized to study the DC flow with a double-inlet module capable of adjusting the DC flow rate. The dependence of performance for thermal compressor on DC flow was firstly investigated. Then the influence of DC flow on the cooling performance was studied, including the cold end enthalpy, cooling capacity, expansion efficiency for pulse tube, etc. Main factors affecting the pulse tube expansion efficiency was distinguished. Finally, the operating parameters effects on cooling performance with varying DC flow rate were carried out. It is found that certain amount of DC flow is beneficial to the system performance with the optimum ratio between DC flow rate and AC flow rate amplitude lying within the approximate range from 0.05% to 0.08%.

如果通过双入口等形成闭环，则脉冲管低温冷却器中可能存在直流电。已经发现，在正确的数量和正确的方向下，直流电可能会有利于在以下温度工作的PTC的冷却性能。斯特林型或GM型PTC的液态氢温度和液态氦温度。对于由热压缩机驱动的Vuilleumier型PTC，尚未进行任何研究。本文通过数值分析研究了直流电流对工作在10 K附近的Vuilleumier型PTC的影响。在仿真中，使用SAGE软件通过一个能够调节DC流量的双入口模块来研究DC流量。首先研究了热压缩机性能对直流流量的依赖性。然后研究了直流流量对冷却性能的影响，包括冷端焓，冷却能力，脉冲管膨胀效率等。区分了影响脉冲管膨胀效率的主要因素。最后，进行了操作参数对不同直流流量下冷却性能的影响。发现一定量的直流流量有利于系统性能，直流流量和交流流量幅度之间的最佳比例在大约0.05％至0.08％的范围内。