 Critical heat flux

A limiting heat flux associated with a transition to a less effective boiling heat-transfer regime under specified conditions. Its value depends on fluid properties, pressure, flow, heating and geometry; a single number cannot be transferred indiscriminately between different flow passages.

Critical Heat Flux (CHF) is a key concept in thermodynamics and heat transfer, particularly in the field of boiling heat transfer. It refers to the maximum heat flux (the rate of heat transfer per unit area) that can be achieved during the boiling of a liquid before a dramatic drop in heat transfer efficiency occurs. Beyond this point, the liquid begins to transition to a vapor phase, and the heat transfer mechanism changes significantly.