Stabilization of flow boiling in microchannels using pressure drop elements and fabricated nucleation sites

Abstract

Heat transfer during flow boiling in minichannels and microchannels is intimately linked to the liquid-vapor phase distribution in the channels. The vapor phase exists as nucleating bubbles, dispersed bubbles, elongated bubbles, an annular core, or all dispersed droplets. A detailed analysis of various structures, supported by high speed video images is carried out and the effects on the associated heat transfer rates are discussed. This information provides insight into the flow boiling mechanisms and guidance for future research in this area.