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提出了蒸汽在固体表面上冷凝方式的表面自由能差判据 ,即冷凝温度下液体表面自由能与固体表面的表面自由能差大于 33.3mJ·m-2 时蒸汽在该表面上呈现滴状冷凝的必要条件 .当表面自由能差在 0与 33.3mJ·m-2范围内 ,表面强化冷凝传热的效果将取决于表面自由能差值的大小 ,差值越大 ,强化效果越明显 .这对深化表面涂层强化冷凝传热的机理以及选择传热表面涂层材料具有指导意义 .通过与文献报道实验结果的比较证实 ,该判据排除了静态接触角判据中测量温度的影响 .
The criterion for determining the surface free energy of the condensation of steam on the solid surface is proposed. That is, when the difference between the surface free energy of the liquid surface and the solid surface at the condensation temperature is more than 33.3 mJ · m -2, the steam shows drop condensation on the surface . When the surface free energy difference is in the range of 0 and 33.3 mJ · m-2, the effect of enhanced surface condensation heat transfer will depend on the difference of the surface free energy, and the larger the difference is, the more obvious the enhancement effect will be. It is instructive to deepen the mechanism of heat transfer enhancement of surface coatings and to select the heat transfer surface coating materials.Compared with the experimental results reported in the literature, this criterion ruled out the influence of the measurement temperature on the static contact angle criterion.