低温容器在水蒸气膜态凝结前后的绝热效果分析  

ANALYSIS OF THE INSULATION EFFECT OF CRYOGENIC VESSELS BEFORE AFTER THE FORMATION OF FILM CONDENSATION OF WATER VAPOR

作　　者：陈明[1] 鲁雪生[2] 刘翔[3] 

机构地区：[1]清华大学热能工程系,北京100084 [2]上海交通大学制冷与低温实验室,上海200030 [3]清华大学建筑技术科学系,北京100084

出　　处：《真空与低温》2003年第2期119-123,共5页Vacuum and Cryogenics

摘　　要：绝热失效严重影响了低温容器的经济和安全运行。膜态凝结的出现是绝热失效最直接的表现。提出了用低温容器表面温度与空气露点温度的比较来判别低温容器的绝热是否失效的方法。理论上,分析了低温容器表面水蒸气膜态凝结出现前后的换热机理。在一个高真空多层绝热低温容器上进行了实验,测量并分析了水蒸气膜态凝结前后低温容器表面温度和液氮蒸发速度的变化。理论分析和实验均验证该方法对于判别绝热效果的有效性和可行性。The insulation failure seriously affects the economic and safe operation of cryostats. The formation of the film condensation is the direct representation of the insulation failure. A method using the comparison of the temperature of the cryogenic vessel outer surface with the drew\|point temperature of the air to judge the effectiveness of the cryogenic vessel vacuum is proposed. The heat transfer mechanics before and after the film condensation formation was analyzed theoretically. Experiments were carried out on a high vacuum and multiliayer insulation cryogenic vessel. The surface temperature and evaporation rates of liquid nitrogen before and after the film condensation formation were measued and analyzed. The validity and practicability of this method in judging the insulation effect is proved by results of the theoretical analysis and experimental study.

关 键 词：低温容器 水蒸气 膜态凝结 绝热效果 空气露点温度 表面温度 换热机理 贮运设备 

分 类 号：TB658[一般工业技术—制冷工程]