两级同轴型脉管制冷机回热器与脉管壁换热影响的模拟与实验

针对同轴型结构的两级脉管制冷机,采用热力学方法分析了回热器与脉管壁间换热作用对制冷机性能的影响。发现当脉管内热量通过壁面传向回热器时,脉管冷端焓流将增大,进而提升脉管冷指的制冷量。对设计的一台两级同轴型高频脉管冷指进行了数值模拟。模拟结果表明相同结构参数及输入下,引入回热器与脉管壁间的径向换热作用,低温级制冷量由原先的0.55 W@30 K提升至1.39 W@30 K,而对高温级的影响却小到可以忽略。

Simulation and experiments on effect of heat transfer between regenerator and pulse tube in a two-stage coaxial pulse tube cryocooler

For coaxial type two-stage pulse tube cryocooler,thermodynamic method are used to analyze the impact of heat transfer between the regenerator and pulse tube on the cooling performance of the cooler.The heat that flows from the pulse tube to the regenerator leads to the increase of enthalpy flow at the cold end of the pulse tube,and the cooling power increases at the same time.A one-dimensional model of a newdesigned two-stage coaxial pulse tube cryocooler is built.The simulation shows that when heat transfer between the regenerator and the pulse tube is introduced into the model,the cooling power of the second stage increases from 0.55 W@30 K to 1.39 W@30 K,however the effect on the first stage can is negligible.