Boiling Heat Transfer and Critical Heat Flux
The phase change transition phenomenon from liquid phase to gas phase is called boiling. Boiling heat transfer is a heat transfer that transfers heat from the heat transfer wall surface to the fluid accompanied with vapor bubbles or vapor slugs under the conditions where wall surface temperature and the fluid temperature adjacent to the wall surface are high enough to generate the vapor phase. Boiling heat transfer is classified by the bulk fluid motion whether it is not forced to flow or it is forced to flow. The former is called pool boiling and its typical examples are boiling in a pot or a kettle. The latter is called flow boiling and its typical examples are boiling in a boiler, the reactor core of a boiling water reactor, and the steam generator of a pressurized water reactor.