高真空多层绝热夹层稀薄气体传热分析  

Heat transfer analysis of rarefied gas with high vacuum multilayer insulation in annular space

作　　者：王鑫 陈叔平[1] 朱鸣[2] 吴宗礼 赵高逸 刘亚楠 Wang Xin;Chen Shuping;Zhu Ming;Wu Zongli;Zhao Gaoyi;Liu Yanan(College of Petrochemical Engineering,Lanzhou University of Technology,Lanzhou 730050,China;China Special Equipment Inspection and Research Institute,Beijing 100029,China)

机构地区：[1]兰州理工大学石油化工学院,兰州730050 [2]中国特种设备检测研究院,北京100029

出　　处：《低温与超导》2021年第12期1-6,41,共7页Cryogenics and Superconductivity

基　　金：国家重点研发计划(2017YFC0805601)资助。

摘　　要：为研究多层绝热夹层稀薄气体传热特性及其对绝热性能的影响,建立了全压力范围气体导热模型,分析了气体种类、真空度、层密度、温度等因素对绝热夹层气体导热系数的影响规律。同时,结合直接蒙托卡罗(DSMC)方法验证了模型的准确性。结果表明:温度对气体导热系数影响显著,真空度高于20 Pa时导热系数随温度的升高而逐渐减小,低于20 Pa时逐渐增大;随真空度、层密度的增大,气体导热系数减小,适当提高夹层真空度与多层绝热层密度有利于降低残余气体导热;全压力范围内氢气的导热系数最大,氩气最小,采用必要的物理化学方法除氢、利用氩气置换夹层中残留空气有助于改善绝热性能。A heat conduction model of gas within full pressure range was established to study the heat transfer characteristic of rarefied gas in annular space with multilayer insulation and its influence on thermal insulation performance.The effects of gas type, layer density, vacuum degree and temperature on the thermal conductivity of insulating interlayer gas were analyzed. Meanwhile, the accuracy of the model was verified by direct simulation Monte Carlo(DSMC) method. The results show that the temperature has a great effect on the thermal conductivity of gas.The thermal conductivity gradually decreases with the increase of temperature when the vacuum value is more than 20 Pa, and gradually increase when the vacuum value is less than 20 Pa. With the increase of vacuum degree and layer density, the thermal conductivity of gas gradually decreases. It is beneficial to reduce the heat conduction of interlayer residual gas by properly increasing interlayer vacuum degree and multilayer insulation density.The thermal conductivity of hydrogen is the highest within full pressure range, and that of the argon is the lowest. Necessary physical and chemical methods can be used to remove hydrogen and to replace the residual air in the interlayer with argon, which are helpful to improve the thermal insulation performance.

关 键 词：稀薄气体 DSMC 气体导热系数 温度 真空度 层密度 

分 类 号：TB711[一般工业技术—真空技术] TK124[动力工程及工程热物理—工程热物理]