Numerical simulation of thermal property effect of heat transfer plate on bubble growth with microlayer evaporation during nucleate pool boiling

It is well known that during nucleate boiling, a large amount of energy can be transferred under relatively small temperature difference between the heat transfer surface and fluid, indicating that high efficiency of heat transfer can be achieved. However, the mechanism of nucleate boiling is still not well elucidated owing to the complexity of the phenomenon. The thermal properties of heat transfer plate, which is directly in contact with the microlayer, may have a significant impact on heat transfer and evaporation characteristics of the microlayer. A volume of fluid (VOF) method based algorithm, in which the experimentally measured microlayer structure was taken into account, has been developed to simulate micro layer evaporation and single bubble behavior. The influence of thermal conductivity of heat transfer plates on the contribution of microlayer evaporation was examined. It was concluded that more efficient heat supply to the heat transfer surface can be achieved for the heat transfer plate with higher thermal conductivity. Microlayer evaporation occupied approximately 30-70% of the bubble volume, indicating that microlayer evaporation is a principal mechanism of boiling heat transfer. (C) 2017 Elsevier Ltd. All rights reserved.