20 K低温制冷机回热器结构设计

Structure Design of Regenerator for 20 K Cryocooler

20 K温区高效制冷是目前空间探测任务制冷的关键需求之一,斯特林/脉管复合制冷机是实现20 K温区高效制冷的重要技术手段。回热器作为复合制冷机的核心部件,其性能对制冷机的整机性能有决定性的影响。合理的设计方法和流程可以保证回热器的性能。20 K温区时回热器工质氦气和填料的物性与较高温区,如80 K温区,相比有很大区别,因此,不能简单套用较高温区回热器的设计方法,须对工作在20 K温区的回热器进行专门的结构设计。本文应用回热器模拟软件Regen3.2,设计了一个冷端温度为20 K的回热器,并对平均压力、相位角、冷端压比、填料种类等参数进行了优化,经过优化设计的回热器的COP超过0.035,20 K下制冷量为0.5 W。本研究为后续20 K温区高效斯特林/脉管复合制冷机的开发打下了基础,也为之后同类型回热器的设计提供了参考。

The requirement of high efficiency cooling method at 20 K temperature range plays an important role in the growing demand of aerospace refrigeration capacity.Stirling/pulse tube hybrid cryocooler shows great potential to achieve efficient refrigeration in 20 K temperature range.As the key component of the hybrid cryocooler,the regenerator greatly affects the overall cooling capacity of the cryocooler.So a reasonable design method is essential for ensuring the performance of the regenerator.Because of the difference between the thermodynamic properties of helium and regenerative material in 20 K temperature zone and that in higher temperature zone like 80 K,the design method for the regenerators working at rather high temperature zone cannot be simply applied.A dedicated design method and process for the 20 K regenerator is presented in this manuscript.By using the regenerator simulation software Regen3.2,parameters such as the average pressure,phase angle,cold end pressure ratio and packing type are optimized to achieve the highest COP.With the optimal design,the regenerator could reach a COP of over 0.035 and cooling capacity of 0.5 W at 20 K.This design of the regenerator presented in this manuscript lays a solid foundation for the further development of the high efficiency Stirling/pulse tube hybrid cryocooler.The presented method could also be used for the design of regenerators working at similar temperature range.