【摘要】 目的：液氦温区Gifford-McMahon(GM)脉管制冷机以其长寿命和低振动等优势逐渐成为量子科技和低温物理等尖端科学领域的理想制冷源，但现有旋转阀部件中的不可逆损失严重限制了其在液氦温区的制冷效率。本文旨在提升液氦温区GM脉管制冷机的制冷性能。针对GM脉管制冷机的关键部件旋转阀，本文开发了以泄露损失和流阻损失为指标的(火用)损评估方法，优化了旋转阀的结构并基于实验进行了验证，以期为液氦温区高效大冷量的GM脉管制冷机的开发提供参考。创新点：1.通过交变流动旋转阀(火用)损失方程，构建以泄露损失和流阻损失为指标的GM脉管制冷机旋转阀(火用)损评估方法；2.搭建实验测试平台，对旋转阀烟损失进行定量测算；3.完整开展从(火用)损失理论分析到旋转阀关键部件优化再到实际制冷机性能提升的闭环研究。方法：1.通过理论分析，推导获得旋转阀内(火用)损失特性与操作参数的定量关系(公式(2)～(6));2.分别搭建旋转阀泄漏流量测试平台(图3)和(火用)损失评估平台(图5)，并根据实验平台定量分析不同运行频率、充气压力和负载对旋转阀(火用)损失分布的影响；3.通过Sage软件计算旋转阀流阻损失对脉管制冷机制冷性能的影响情况(图9)，并结合实际工艺扩大现有旋转阀的流通面积；4.通过旋转阀(火用)损失分析和脉管制冷机性能测试的方法验证所述理论。结论：1.在液氦温区GM脉管制冷机内的旋转阀中，流阻损失占97.5%以上，泄露损失只占2.5%，因此流阻损失是主要的(火用)损失；2.旋转阀流通面积扩大1.5倍后其内流阻显著降低，且压缩机输出(火用)可提高1.2～1.5倍；3.使用低流阻旋转阀驱动同一台制冷机冷头时，脉管制冷机可获得0.78 W@4.2 K制冷量，且制冷性能提高约16.4%。更多还原

【Abstract】 Gifford-McMahon-type pulse-tube cryocoolers(GM-PTCs) working at liquid helium temperatures are promising in quantum technology and cryogenic physics for their high reliability and minimal vibration. These features stem from the fact that there are no extra moving parts introduced into the system. The rotary valve is a key component in GM-PTCs that transfers the output exergy from the compressor to the cold head. Because a low Carnot efficiency of 1.58% is achieved at liquid helium temperatures, optimizing the rotary valve is crucial for improving the efficiency of GM-PTCs. In this regard, an exergy-loss analysis method is proposed in this paper to quantitatively obtain the leakage loss and viscosity loss of a rotary valve by experimental measurements. The results show that viscosity loss accounts for more than 97.5% of the total exergy loss in the rotary valve, and that it is possible to improve the structure of the rotary valve by expanding the flow area by 1.5 times. To verify the method, the cooling temperature and power of a remote two-stage GM-PTC were monitored, with original or optimized rotary valves installed. The experimental results show that compared to the original rotary valve, the optimized rotary valve can improve the cooling efficiency of a GM-PTC by 16.4%, with a cooling power of 0.78 W at 4.2 K.更多还原