摘要
了解析湿过程中冷凝水对换热器翅片侧换热和压降的影响机制,需要首先建立湿工况下翅片表面冷凝水滴形成及运动过程的模型。本文通过对翅片表面上冷凝水滴的形成和运动机制进行分析,建立水滴形成过程的传质传热模型以及接触角模型,并结合VOF界面追踪方法来描述气液相界面、计算表面张力,从而预测冷凝水滴在竖直翅片表面形成及运动过程。通过实验对模型的可靠性进行了验证:对于传热系数,模型计算结果与实验数据平均误差为6.9%,模型对于96%的实验数据点预测误差在±15%以内;对于传质系数,模型计算结果与实验平均误差为12.1%,模型对于91%的实验数据点预测误差在±20%以内;对于翅片表面水滴形成和运动过程,模型计算结果与可视化实验结果能够较好地吻合。
In order to predict the performance of tube-finned heat exchangers under dehumidifying condition,the behavior of condensing liquid droplet on vertical plain-fin surfaces should be known.The objective of this article is to develop a model for liquid droplet condensation and motion on vertical plain-fin surfaces.To achieve this goal,the mechanisms of droplet condensation and motion are analyzed firstly.Then the equations for predicting the heat and mass transfer rate during the water condensation are established,and a Volume of Fluid-Continuous Surface Force model with varying contact angles along the contact line is developed to predict droplet movement.The prediction ability was verified by the experimental data,and verification results show that:the simulation results of jhagree with 96% of the experimental data within the deviation of±15%,and the mean deviation is 6.9%;the simulation results of jmagree with 91% of the experimental data within the deviation of ±20%,and the mean deviation is 12.1%.
出处
《化工学报》
EI
CAS
CSCD
北大核心
2014年第S2期140-147,共8页
CIESC Journal
关键词
翅片表面
液滴
冷凝
运动
数值模型
fin surface
liquid droplet
condensation
motion
numerical model
