Abstract Coaxial pulse tube cryocoolers are the configuration of choice as they allow better access to the cold head. Hence, a previously built and tested in-line pulse tube cryocooler which uses an active displacer for phase control has been modified into a coaxial configuration. The active displacer allows the mass flow and the pressure pulse at the cold end of the pulse tube to be easily adjusted for optimum performance. The displacer also allows the expansion power at the warm end of the pulse tube to be recovered in order to operate more efficiently. A numerical Sage model is used to demonstrate this by examining the work flows throughout the cryocooler and it is shown that more than 6% of the power required to drive the cryocooler comes from the warm end of the pulse tube via the displacer. When using an inertance tube or orifice, this expansion power is dissipated as heat which is why using a displacer can lead to a more efficient cryocooler. Moreover, the effect of changing the displacer phase and stroke on cryocooler performance and pressure characteristics is examined both experimentally and numerically.

中文翻译：

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带主动置换器的同轴斯特林脉冲管低温冷却器

摘要 同轴脉冲管低温冷却器是首选配置，因为它们可以更好地接近冷头。因此，使用主动置换器进行相位控制的先前构建和测试的直列式脉冲管低温冷却器已被修改为同轴配置。主动置换器允许轻松调整脉冲管冷端的质量流量和压力脉冲，以获得最佳性能。置换器还允许恢复脉管热端的膨胀功率，以便更有效地运行。数值 Sage 模型用于通过检查整个低温冷却器的工作流来证明这一点，结果表明驱动低温冷却器所需的功率中有 6% 以上来自脉冲管的热端，通过置换器。使用惯性管或孔板时，这种膨胀能力会以热量的形式消散，这就是为什么使用置换器可以提高制冷器效率的原因。此外，通过实验和数值研究了改变置换器相位和冲程对低温冷却器性能和压力特性的影响。