Effect of vapor pressure and vapor velocity on condensation heat transfer for low concentration ethanol and water mixture on a micro-minitube

In this present work, Marangoni condensation of ethanol-water vapor mixtures on a micro-vertical tube at different pressures and velocities had been studied, and observed the variation of condensation condition. The experiment results demonstrate that with the increase of subcooling, condensation heat transfer coefficient increase rapidly, heat transfer coefficient began to decrease after reaching the peak, decrease of curvature is relatively moderate, as the pressure increased, condensation heat transfer coefficient increased significantly in large subecooling. The effect of velocity was similar to the impact of pressure. Visualization experiments showed that pressure and flow rate had a great impact on the condensation rate.