级间热桥的传热特性对于热耦合型多级脉管制冷机的制冷温度和制冷效率均具有重要影响。采用铜丝编织带和铜箔连接的3种热桥进行对比实验,研究了热桥的传热特性对热耦合二级Stirling型脉管制冷机性能的影响。采用改进后的热桥,以氦气作为工质,在总输入电功率为400W,以及优化的工作频率和充气压力条件下,热耦合二级Stirling型脉管制冷机实现了12.96K的无负荷制冷温度,并可同时在23.1K和100.8K分别提供0.4W和6W的制冷量。
The cooling temperature and the efficiency of a thermally coupled multistage pulse tube refrigerator are significantly influenced by the heat transfer characteristics of the heat bridge. To investigate the effect of heat transfer characteristics of heat bridge on the refrigeration performance of a thermally coupled two-stage Stirling-type pulse tube refrigerator, contrastive experiments with three types of heat bridges were performed. With the modified heat bridge and 400 W total electric input power, a no-load cooling temperature of 12.96 K had been attained by the prototype, which is able to simultaneously supply the cooling powers of 0.4 W at 23.1 K and 6 W at 100.8 K.