Experimental Study on Condensation heat transfer of Ethanol-Water Mixtures on a Vertical Mini-tube

摘要

Experiments were carried out to investigate condensation of ethanol-water vapor mixtures on a vertical mini-tube with outer diameter of 1.032mm. The length, inter diameter of the tube was 110mm, 0.727mm, respectively. The tests were performed at a wide range of ethanol concentrations (Cv=0%, 1%, 2%, 5%) and varied velocity of vapor (Uv=2m/s, 4m/s,6m/s) and pressure (Pv=31.2kPa,47.4kPa,84.5kPa). With the change of the vapor-to-surface temperature difference, the heat transfer coefficients revealed nonlinear characteristics with the peak values under all ethanol mass fractions of vapor. The heat transfer coefficients decreased with increasing ethanol mass fraction of vapor.