基于分子动力学的充气压力影响脉管制冷机性能机理研究

The Mechanism of the Influence of Inflation Pressure on the Performance of Pulse Tube Refrigerator based on Molecular Dynamics

为了进一步探究脉管制冷机的内部运行机理,基于分子动力学仿真对脉管内气体交变流动进行了分析研究。研究结果表明:当充气压力增大时,脉管内压比、质量流量增大,冷端最低制冷温度下降,热端温度上升,但对压力波、温度波和质量流量波相位没有影响。在不考虑压缩机级后换热器和回热器的情况下,在压缩机出口处,压力波超前流速波的相位角大约为90°,超前质量流量波大约72°,温度波领先流速波大约72°,领先质量流量波大约72°;在远离压缩机的远端,压力波则落后于流速波大约72°,落后于质量流量波大约72°,温度波则落后流速波大约90°,落后于质量流量波大约72°;无论在热端还是冷端,压力波与温度波均几乎同相。

In order to further explore the internal operating mechanism of the pulse tube refrigerator,the alternating flow of gas in the pulse tube was analyzed and studied based on molecular dynamics simulation.The research results show that when the inflation pressure increases,the pressure ratio and mass flow in the pulse tube increase,the minimum refrigeration temperature at the cold end drops,and the temperature at the hot end rises,but it has no effect on the phases of the pressure wave,temperature wave and mass flow wave.Without considering the heat exchanger and regenerator at the rear of the compressor stage,at the compressor outlet,the phase angles of the pressure wave leading the velocity wave and mass flow wave are about 90°and 72°respectively,and the phase angles of the temperature wave leading the velocity wave and mass flow wave are about 72°equally;at the far end away from the compressor,the phase angles of the pressure wave lagging behind the velocity wave and mass flow wave are about 72°equally,while the phase angles of the temperature wave lagging behind the velocity wave and mass flow wave are about 90°and 72°respectively.The pressure wave and temperature wave are almost in phase regardless of whether they are on the hot end or on the cold end.