直流对室温排出器调相两级脉管制冷机的影响

脉管制冷机是小型低温制冷机中的研究热点, 调相机构对其制冷性能有重要影响. 室温排出器型调相机构既可以回收声功, 又能够增强调相能力, 逐渐受到了重视, 然而由于排出器活塞间隙的存在, 系统中形成了闭合气流环路, 带来Gedeon 声直流的影响. 本文基于阶梯室温排出器调相的液氢温区两级脉管制冷机, 考察直流量对于系统性能的影响. 模拟结果表明: 一定量的正向直流可提升20 K 制冷量高达80%以上; 然而排出器活塞间隙引入了负向直流, 增加活塞长度、减小活塞间隙, 可以一定程度抑制直流.

Effect of DC Flow on a Two-Sage Pulse Tube Cooler with Warm Displacer as the Phase Shifter

Pulse tube coolers are a hot topic in small scale coolers, and the phase shifter has a significant influence on cooling performance. The warm displacer becomes popular, vhich could not only recover acoustic power, but also enhance phase shifting ability. While DC flow (direct current flow) may occur in the system due to the clearance seal between the displacer piston and cylinder. Based on a twostage pulse tube cooler with stepped warm displacer as the phase shifter, the effect of DC flow on system performance is investigated in this paper. Simulation results indicated that with certain positive DC flow, the cooling power at 20 K could be improved by 80%; While, the clearance seal introduced negative DC flow, which could be suppporessed through increasing the piston length and reducing the gap.