含不凝气蒸汽在锯齿形表面的凝结传热特性  

Condensation heat transfer characteristics of steam containing non-condensable gas on sawtooth surface

作　　者：闫吉庆 王效嘉 田茂诚[2] YAN Jiqing;WANG Xiaojia;TIAN Maocheng(Shenhua Engineering Technology Co.,Ltd.,Beijing 100007,China;School of Energy and Power Engineering,Shandong University,Jinan 250061,Shandong,China)

机构地区：[1]中国神华国际工程有限公司,北京100007 [2]山东大学能源与动力工程学院,山东济南250061

出　　处：《山东大学学报（工学版）》2020年第6期129-134,共6页Journal of Shandong University（Engineering Science）

摘　　要：为了在含不凝气蒸汽凝结过程中获得更高的热效率,提出新型锯齿形强化板并建立其二维模型,使用Fluent软件对锯齿形强化板和相同规格波纹板的凝结传热特性进行对比研究。建立可同时计算不凝气层及液膜层的凝结传热模型并在数值模拟中通过用户自定义函数进行编译,模型的可靠性通过和相同工况下的试验进行对比得到验证。数值模拟得到两种板型表面的两相流动及热质交换特征,发现相比于波纹板,锯齿形板能够显著提高不凝气层的紊流度,利于相界面处传热传质过程的进行;锯齿形板的液膜会在波节的齿峰处产生周期性的断裂后在下游壁面上重新形成并在波谷处达到最大厚度;相比于波纹板,在所研究工况内锯齿形板的换热能力总体提高60%以上。To obtain higher thermal efficiency in the condensation process of steam containing non-condensing gas,a new sawtooth heat transfer strengthening plate was proposed and its two-dimensional model was established.The difference of condensation heat transfer characteristics between serrated plate and corrugated plate with the same specification was analyzed by Fluent software.A condensation heat transfer model to calculate both non-condensable gas layer and liquid film layer at the same time was established and compiled by user defined functions in the numerical simulation.The model reliability was verified by comparing with the experimental values in the same working conditions.The two-phase flow and heat and mass transfer characteristics of different plate surfaces are obtained,and the results showed that compared with the corrugated plate,the sawtooth plate could significantly improve the turbulence of the non-condensable gas layer,which was beneficial to the heat and mass transfer process on the liquid film surface.The liquid film of the sawtooth plate would be periodically fractured at the tooth peak of the wave node and then re-formed on the downstream wall surface and reached the maximum thickness at the trough.Compared with the corrugated plate,the heat transfer capacity of the sawtooth plate was improved by more than 60%.

关 键 词：锯齿形板 数值模拟 凝结传热 不凝气 液膜 

分 类 号：TK124[动力工程及工程热物理—工程热物理]