Pool boiling refers to boiling under natural convection conditions. Heat transfer characteristics of pool boiling is usually given by the so-called boiling curve which has the nucleate, transition, and film boiling regions. Nucleate boiling is a very efficient mode of heat transfer, but there exists the maximum heat flux for nucleate boiling. Film boiling is not efficient from the viewpoint of heat transfer because the boiling surface is covered by a vapor film. There exists the minimum heat flux which can sustain film boiling, and the transition boiling curve intervening between the nucleate and film boiling regions has a negative slope. Pool boiling heat transfer is one of complicated heat transfer phenomena because it relates to the following elementary processes; molecular kinetics of phase change, supersaturation of mother phase, interfacial stability, dynamics of contact line, nucleation and growth of new phase, and interfacial morphology. This overview presents the outline of pool boiling heat transfer in relation to such elementary processes.
