Heat transfer characteristics of Marangoni condensation for ethanol–water mixtures on a horizontal plate

In this study, the heat transfer characteristics of Marangoni condensation for ethanol water mixtures on a horizontal surface were investigated experimentally. A wiper was adopted to remove the condensate on the condensing surface. During the time-series condensation process, a characteristic time was introduced to evaluate it. The characteristic time started with the wiper brushing through the center of the condensing surface and ended when the condensate stayed in a stable state, and the wiper did not work in this process. The results indicated that the characteristic time decreased with the increase in the initial vapor-to-surface temperature difference and increased slightly with the increase in the ethanol vapor concentration as a whole. Moreover, the time-series heat transfer coefficient decreased with the increase in vapor-to-surface temperature difference and ethanol vapor concentration. As the initial vapor-to-surface temperature difference decreased, the time-series heat transfer coefficient decreased and the characteristic curve became steeper. (C) 2015 Elsevier Ltd. All rights reserved.