The nature of microbubble emission under subcooled water boiling

Model of the heat exchange in boiling emulsions with low-boiling disperse phase at the solid wall

“…The value of the exponent α is found by final according to a priori accepted views about important characteristics of nucleation under the influence of external pulses. For example, for 0   , when droplets are gas bubbles critical size [6,7], the relation (6) is applicable for aqueous emulsions. The other limiting case 1   corresponds to the emulsions containing organic liquids [8], where there are no gas bubbles.…”

Experimental investigation of transition process from nucleate boiling to microbubble emission boiling under transient heating modes

“…Tange et al, Hattori and Ueno performed statistical investigation on microbubbles in MEB, showed that increasing liquid subcooling would decrease the microbubble size and intensify the jet process. Zeigarnik et al analyzed the components of the microbubbles from collapsed vapor films in MEB and deemed that they were the mixture of vapor and noncondensable gases. Recently, Inada et al experimentally studied boiling of a liquid droplet on a small heating surface to clarify the process of subcooled liquid rushing to the heating surface.…”

The dynamics of a vapour bubble growth under the boiling of a subcooled liquid in low volumes

“…Normal bubbles "evacuation" [23] from the heating wall with their going beyond the viscous sublayer is missing. Ejection phenomenon of numerous small (10-80 mm) bubbles (called "microbubble emission") at the subcooled boiling water under the high heat fluxes has been explained by releasing of the rest of air on the superheated surface and in the boundary layer of the liquid [24]. This air has not been removed by deaeration.…”

“…Modeling representations of the boiling of the subcooled water under forced flow have been studied and also a comprehensive analysis has been conducted [18][19][20][21][22][23][24]. It is found that at subcooling temperatures over 50 • the hydraulic resistance coefficients equal under the boiling and forced convection of a single-phase liquid at non-isothermal flow.…”

“…This air has not been removed by deaeration. The influence of the mode parameters (heat flux and subcooling to the saturation temperature) on the sound characteristics of the resulting vapor-air -water mixture in the boiling process in a large volume has been established [24].…”