蒸气流速对存在温度梯度的竖直壁面Marangoni凝结换热的影响研究

EFFECT OF VAPOR VELOCITY ON MARANGONI CONDENSATION HEAT TRANSFER ON VERTICAL SURFACE WITH TEMPERATURE GRADIENTS

本文以水-酒精混合蒸气为工质,对蒸气流速对存在温度梯度的竖直壁面Marangoni凝结换热特性的影响进行了实验研究。结果表明:混合蒸气凝结换热系数随蒸气流速的增加而增加,但换热系数对流速的敏感性随酒精蒸气浓度不同而有所区别,在酒精蒸气浓度较低时,流速使换热系数的增加较为明显。对比流速对溶质Marangoni凝结换热特性的的影响,流速对温度梯度和浓度梯度共同驱动的Marangoni凝结换热影响要弱一些。

The effect of vapor velocity on Marangoni condensation heat transfer for water-ethanol mixture vapor on a vertical surface with temperature gradients was researched. The results showed the heat transfer coefficients increased with the increase of vapor velocities. The sensitivity of heat transfer coefficient to vapor velocity depended on the ethanol vapor concentration. At the low range of ethanol vapor concentration, the effect of vapor velocity on heat transfer coefficient was much significant. For the mixture vapor with higher ethanol vapor concentration, the effect became weak. Compared to the effect of vapor velocity on the heat transfer coefficient of solutal Marangoni condensation, the effect of vapor velocity on that of Marangoni condensation driven by temperature and concentration gradients was much weak.