Effect of Surface Nanostructures on Filmwise Condensation Heat Transfer
Surface with nanostructures was performed on copper substrate by hydrogen peroxide (H2O2) solution oxidation-etching treatment in this paper. The wetablility of the nanostructured copper surface and the smooth copper surface was investigated. And the steam condensation heat transfer characteristics on these surfaces were investigated experimentally. It is found that the surface with nanostructures shows a better hydrophilicity in the steam ambience. It is mainly resulted from the steam condensation in the cavities or ditches on the surface, and then a much more hydrophilic surface is formed. The experimental results have shown that the filmwise condensation heat transfer characteristics on these surfaces are worse, due to the hydrophilicity of the nanostructured surface. As the surface-free-energy-difference influences the heat transfer characteristics, a decrease of the surface-free-energy-difference, resulting from the more hydrophilic condensing surface, makes the heat transfer performance worse in the steam condensation process. The results demonstrated that the interface effect, such as liquid-solid free energy difference and the contact angle hysteresis, influences the heat transfer performance much,and the hydrophilicity of the nanostructured surface decreases the filmwise condensation heat transfer performance.
filmwise condensation surface nanostructures free energy difference
S.F. Wang Z. Lan X.H. Ma M.Z. Wang
Institute of Chemical Engineering, State Key Laboratory of Fine Chemicals, Dalian University of Technology, 116012 Dalian, China
国际会议
The 12th Asian Pacific Confederation of Chemical Engineering Congress(第十二届亚太化工联盟大会暨化工展览会)
大连
英文
2008-08-04（万方平台首次上网日期，不代表论文的发表时间）