Experimental study of steady and transient subcooled flow boiling

نویسندگان

چکیده

This study aims to better characterize the heat transfer and flow structure in fully developed nucleate boiling regime a semi-annular duct. Experiments with refrigerant HFE7000 were performed range of Reynolds numbers from 13 000 40 500, subcoolings close 15 ?C, for constant heating power, wall temperature rates (linear increase temperature). With flux is well predicted by Chen-type correlation based on contribution due forced convection boiling, including effect liquid subcooling. A thin layer bubbles sliding along observed. The characteristic diameter increases decreases velocity its bubble diameters can be versus 3 dimensionless numbers: number flow, Jakob subcooling Boiling number. drag coefficient estimated measurements relative velocities good agreement recent numerical simulation Shi et al. [1] spherical moving shear flow. In experiments set temperature, non-homogeneity surface temperatures observed as high fluctuations fluxes. strongly degraded ( ? 60%) comparison power. Finally transient dT/dt investigated. For < 50 ?C.s?1, results are similar those Auracher Marquardt prediction provided.

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ژورنال

عنوان ژورنال: International Journal of Heat and Mass Transfer

سال: 2021

ISSN: ['1879-2189', '0017-9310']

DOI: https://doi.org/10.1016/j.ijheatmasstransfer.2020.120548