摘要
考虑蒸汽流速的影响,对Nusselt凝结换热模型进行修正,分别采用Nusselt模型和修正模型对自然循环条件下竖直管内层流膜状凝结时的换热特性进行计算并与实验结果比较。研究表明,管内凝结换热受蒸汽流速的影响不能忽略,蒸汽对液膜的剪切作用使液膜减薄,冷凝换热系数增大。由于修正模型合理地考虑了界面剪切力的影响,计算结果与实验相符。
Considering the effect of vapor velocity,the Nusselt theoretical formula for laminar film condensation is modified.By using the Nusselt formula and the modified model,the laminar flow condensation heat transfer characteristics inside a vertical tube are studied in a natural circulation system.The result shows that the effect of vapor velocity can not be neglected.The vapor shear decreases the liquid-film thickness and results in a increasing of condensation heat transfer compared to that calculated from Nusselt formula.The modified model considers the interface shear stress appropriately,so the calculated values agree well with the experiment results.
出处
《核动力工程》
EI
CAS
CSCD
北大核心
2010年第5期67-71,共5页
Nuclear Power Engineering
关键词
自然循环
管内冷凝
蒸汽流速
界面剪切力
Natural circulation
Condensation in tubes
Vapor velocity
Interface shear stress
