Abstract:The heat transfer characteristics of nucleate boiling are significantly higher than that of single-phase heat transfer. Nucleate boiling is widely used in related systems and equipment in many fields such as aviation, aerospace, navigation, electronics, energy, power, air conditioning, refrigeration, and biomedicine. The latent heat of vaporization in boiling heat transfer can take away a large amount of heat, and the bubbles create a disturbance, which can enhance heat transfer. The initial bubble characteristics are an important factor affecting the heat transfer characteristics of nucleation boiling, and the surface structure on the heated wall has a very important influence on the formation of the initial bubbles. The surface structure can change the bubble characteristic parameters, such as the temperature of onset of nucleate boiling, bubble diameter, and nucleation site density, etc. Therefore, understanding the bubble characteristic parameters on the structured surfaces is significant to the development of the enhanced boiling heat transfer mechanism. Three kinds of single crystal silicon wafers with different scale microstructures and the same specific surface area were prepared. A set of nucleation boiling visualization microscopic observation experimental platforms to observe the dynamic process of bubble growth was built. Nucleation boiling test was performed. The experimental results showed that the microstructure on the heating surface could promote the growth of bubbles and the effect might be associated with the structural scale.