Abstract

The hot wire chemical vapor deposition method was applied for fabrication of hydrophobic fluoropolymer coatings on the surface of tubular heaters. The effect of hydrophobic surfaces (with static contact angle of 125°) on the local and integral heat transfer characteristics was studied during boiling of saturated water at atmospheric pressure, including high speed visualization. The heat transfer enhancement by 30% was observed in the range of low heat fluxes during boiling on the hydrophobic coated tubes. It was shown that the value of the bubble departure diameter and the nucleation site density significantly increased, and the bubble separation frequency was significantly reduced in comparison with the data obtained on the uncoated tube. The analysis of the operational characteristics of the synthesized coatings was carried out.

摘要

热丝化学气相沉积方法用于在管状加热器表面制备疏水性含氟聚合物涂层。在大气压下饱和水沸腾期间，研究了疏水表面（静态接触角为 125°）对局部和整体传热特性的影响，包括高速可视化。在疏水涂层管上沸腾期间在低热通量范围内观察到传热增强了 30%。结果表明，与未涂层管上获得的数据相比，气泡脱离直径和成核点密度的值显着增加，气泡分离频率显着降低。对合成涂层的操作特性进行了分析。