The Effect of Surface Modification on Heat Transfer of Heat Exchanger

Abstract

This study mainly discussed the influence of different surface properties,namely an unmodified copper fin surface and a modified hydrophobic fin surface, on the heat transfer effect of heat exchangers with air velocity ranging from 0.5 m/s to 2.5 m/s and relative humidity of 60% and 90%. The researchers established the following conclusions based on the experiment results. The heat transfer and water removal rates of the two heat exchangers increased with an increase in wind velocity. When the inlet air velocity was increased from 0.5 to 2.5 m/s, the heat transfer and water removal rates of both heat exchangers were increased by approximately 90%.Under similar air velocity conditions, heat exchangers with hydrophobic surfaces constantly removed the condensed water droplets, thereby preventing the water droplets from causing surface thermal resistance. As a result, the condensation heat transfer effect of hydrophobic surfaces was greater than that of unmodified copper surfaces. Compared with heat exchangers with unmodified copper fin surfaces, heat exchangers with hydrophobic surfaces exhibited a 5.56% higher heat transfer efficiency.