Heat Transfer Analysis of Dropwise Condensation on Superhydrophobic Copper Surface

摘要

The heat transfer coefficient of condensation is increased by modifying the bare copper condensing substrate into a superhydrophobic surface which exhibit the property of high water repellence that will make a contact angle about 160° ± 2°. Simple solution immersion and thermo solution immersion methods are used to prepare the superhydrophobic surfaces on the copper plates. The superhydrophobic nature on the copper plates are obtained by immersing the plates into the solution of 0.003 - 0.007M ethanol and myristic acid then heating the plates in the solution at 40 - 65℃ for 2 - 5 hours. The contact angle of water droplet is measured on the obtained superhydrophobic copper surfaces which gives the maximum contact angle of 162° and average value of 160° ± 2° with low inclination angle of 2°. The maximum contact angle is obtained by adjusting the composition of the solution, temperature of the solution and immersion time to 0.005M, 45° and 3 hours respectively. Further the prepared superhydrophobic copper surface is experimented for dropwise condensation and the values of vapour temperature, surface temperature and heat transfer coefficient are compared with the bare copper surface.