The theoretical analysis and experimental study on anti-frosting performance of surface characteristics

摘要

Different nucleation types of water drops were summarized, calculated and analyzed on the basis of classical nucleation theory, and experiments on horizontal cold surfaces were carried out under natural convection to examine the influences of hydrophobic surfaces on frost formation. Illustration of coefficient functions of energy barriers of different nucleation types indicates that the energy barrier to nucleation on a convex surface is relatively larger than that on a concave surface. If significant influences on water drop nucleation are expected of foreign surfaces, the ratio of the size of the foreign nucleus to the size of the critical nucleus of the new phase should vary within the range 0-1. If this ratio is larger than 10, there is no distinction for different heterogeneous nucleation types of water drops. The experiment results show that when there are no observable water drops develop at the early stage of frost formation, the frost crystals on the hydrophobic surface are even denser. If deposition of ice particles is dominant after frost formation starting, the frost growth on the hydrophobic surface and untreated surface is in the same pattern.