Effects of channel dimension, heat flux, and mass flux on flow boiling regimes in microchannels

Abstract

ABSTRACT

A comprehensive flow regime map for microchannel flow boiling with quantitative transition criteria

“…As mentioned in the introduction, a systematic investigation of boiling flow patterns and heat transfer with respect to microchannel dimensions and mass flux was recently performed by the authors [16,17] and it was shown that confinement effects are present below a threshold value of channel cross-sectional area for a fixed mass flux [17]. In the present work, a criterion is developed for the existence of physical confinement in microchannel boiling based on channel dimensions, mass flux and fluid properties.…”

“…In recent work by the authors [15][16][17], the effects of microchannel dimensions and mass flux on flow boiling regimes and heat transfer rates were investigated. Experiments were conducted with the perfluorinated dielectric fluid, Fluorinert FC-77, over a wide range of channel dimensions and mass fluxes.…”

“…The microchannel width, aspect ratio, and hydraulic diameter in these experiments ranged from 100 µm to 5850 µm, 0.27 to 15.55, and 96 µm to 707 µm, respectively, and the mass flux ranged from 225 to 1420 kg/m 2 s. The dependence of the boiling heat transfer coefficient on vapor quality was also investigated in detail for a number of refrigerants [18]. In [16], two types of flow regime maps were developed, one on mass flux-vapor quality coordinates and the other on vapor-liquid superficial velocity coordinates. However, the flow regime maps represented in these coordinate systems depend on channel dimensions, and therefore, individual maps were developed for each channel size.…”

Fundamental issues, mechanisms and models of flow boiling heat transfer in microscale channels

“…29 Liu and Garimella [78] Tran et al [70] and Owhaib et al [71]. As already mentioned, it is very important to understand the heat transfer trends and mechanisms by observing the flow phenomena and flow regimes [76]. These studies have provided good examples but systematic studies in this aspect are needed to better understand the heat transfer mechanisms.…”

Cooling Performance of a Two-Phase (Vapor-Liquid) Flow-Cooling System

“…[4,5] The coolant flow is driven by a pump to provide a convective effect on the boiling surface, in addition to the heat transfer by boiling bubbles.…”