填充二氧化碳的低温真空管道绝热性能研究  

Study on thermal insulation performance of cryogenic vacuum pipes filled with carbon dioxide

作　　者：许张良 谭宏博[1] 吴昊 Xu Zhangliang;Tan Hongbo;Wu Hao(Department of Energy and Power Engineering,Xi’an Jiaotong University,Xi’an 710049,China)

机构地区：[1]西安交通大学能源与动力工程学院,西安710049

出　　处：《低温工程》2022年第3期13-18,共6页Cryogenics

基　　金：国家重点研发计划资助项目(2020YFB1506203)。

摘　　要：填充二氧化碳(CO_(2))的真空绝热结构在低温下因其真空度提升而改善绝热性能,有望被用于低温工程的绝热层。建立并验证了填充空气和CO_(2)的真空绝热板的热导率计算模型,并比较采用空气和CO_(2)填充时真空绝热板的绝热性能;针对有填充材料的真空绝热层建立了表观热导率计算模型,预测了不同条件下管道绝热层的表观热导率。结果表明,当其它条件相同且填充物为玻璃纤维时,填充气体为CO_(2)的真空绝热层的表观热导率低于填充空气的绝热层;相较于二氧化硅气凝胶,绝热层内填充玻璃纤维的绝热性能更佳;当CO_(2)填充压力为10 Pa时、绝热层平均温度为140 K时,表观热导率小于1 mW/(m·K);当CO_(2)填充压力为100 Pa、绝热层平均温度为210 K时,该结构用于LNG输运管道绝热层的表观热导率约为聚异氰脲酸酯硬泡(PIR)的1/10。预制的CO_(2)冷凝真空绝热结构在低温工程领域(如低温液体输送管道)具有较好的应用前景。The vacuum insulation structure filled with carbon dioxide(CO_(2))can improve its thermal insulation performance at low temperature because of its higher vacuum degree,and is expected to be used as an insulation layer in cryogenic engineering.The thermal conductivity calculation model of vacuum insulation panels filled with air and CO_(2)was set up and verified,and the insulation performance of vacuum insulation panels filled with air and CO_(2)was compared.A calculation model of equivalent thermal conductivity of a vacuum insulation layer with filling material was also established to predict the equivalent thermal conductivity of the insulation layer under different conditions.The results show that when other conditions are the same and the filling material is glass fiber,the equivalent thermal conductivity of the vacuum insulation layer filled with CO_(2)gas is lower than that filled with air.Compared with silica aerogel,the insulation layer filled with glass fiber has a better thermal insulation performance.The equivalent thermal conductivity is less than 1 mW/(m·K)as the CO_(2)filling pressure is 10 Pa and the average temperature of the insulation layer is 140 K.Under a filling pressure of 100 Pa and an average temperature of 210 K,the equivalent thermal conductivity of the insulation layer used for LNG transportation pipelines is about 1/10 of that filled with rigid foam of polyisocyanurate(PIR).The prefabricated CO_(2)condensation vacuum insulation structure has a good application prospect in cryogenic engi-neering(such as cryogenic liquid conveying pipelines).

关 键 词：二氧化碳冷凝真空绝热 低温真空管道 绝热性能 表观热导率 

分 类 号：TB61[一般工业技术—制冷工程] TB663