Rationalization of existing mechanistic models for the prediction of water subcooled flow boiling critical heat flux

Celata, Gian Piero; Cumo, M.; Mariani, Andrea; Simoncini, Michela; Zummo, Giovanni

doi:10.1016/0017-9310(94)90035-3

“…For the DNB with low subcooling or saturated condition, the critical enthalpy models were proposed by Weisman and Pei (1983) and Tong (1968), in which the heat transfer coefficient from the interface of bubbly layer to liquid core was estimated by correlations derived from their experiments. For the DNB with high subcooling, the liquid sublayer dryout models were proposed by Katto (1992), Lee and Mudawar (1983) and Celata et al (1994), in which the bubble diameter, the thickness of liquid sublayer and the length of vapor blanket were determinant for the sublayer dryout.…”

Section: Mechanismmentioning

confidence: 99%

Critical Heat Flux in Subcooled Flow Boiling of Water

Chen¹

2012

An Overview of Heat Transfer Phenomena

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“…Lee and Mudawar 14) proposed a liquid sublayer dryout model where the CHF occurs when the liquid sublayer beneath the vapor bracket moving along the heating surface dries out. Katto 15) and Celata et al 16) also proposed similar CHF models, but the formation mechanism and the thickness of the liquid sublayer are quite different among these models.…”

Section: Introductionmentioning

confidence: 99%

Critical Heat Flux and Near-Wall Boiling Behaviors in Saturated and Subcooled Pool Boiling on Vertical and Inclined Surfaces

Sakashita¹,

Ono²,

NYUI³

2009

J. Nucl. Sci. Technol.

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The mechanism of the critical heat flux (CHF) where the departure from nucleate boiling (DNB)-type boiling transition takes place has not been fully elucidated. In this paper, we examine the trigger mechanism of the CHF for saturated and subcooled pool boiling on vertical and inclined surfaces based on measurements of the liquid-vapor behaviors near heating surfaces by using a conductance probe. The angle of inclination was varied from 90 (vertical) to 170 (facing almost horizontally downwards). The probe signals and the void fraction distributions showed that a liquid layer remains beneath the vapor masses moving upward along the heating surface at high heat fluxes near the CHF. The thickness of the liquid layer was determined from the location where the probe signals corresponding to the vapor masses disappeared. The thickness of the liquid layer formed on the vertical surface increased with increasing degree of subcooling, which may be the cause of the increases in CHF with increasing degree of subcooling. The measurements of saturated boiling on the inclined surface confirmed that the orientation of the heating surface greatly affects the period it takes for vapor masses to pass, but it negligibly affects the liquid layer thickness. This suggests that the decrease in CHF with increasing angle of inclination is primarily caused by the lengthening of the duration of vapor mass passage.

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“…Lee and Mudawar 14) proposed a liquid sublayer dryout model where the CHF occurs when the liquid sublayer beneath the vapor bracket moving along the heating surface dries out. Katto 15) and Celata et al 16) also proposed similar CHF models, but the formation mechanism and the thickness of the liquid sublayer are quite different among these models.…”

Section: Introductionmentioning

confidence: 99%

Critical Heat Flux and Near-Wall Boiling Behaviors in Saturated and Subcooled Pool Boiling on Vertical and Inclined Surfaces

Sakashita

¹

,

Ono

²

,

NYUI

³

2009

Journal of Nuclear Science and Technology

17

0

View full text Add to dashboard Cite

The mechanism of the critical heat flux (CHF) where the departure from nucleate boiling (DNB)-type boiling transition takes place has not been fully elucidated. In this paper, we examine the trigger mechanism of the CHF for saturated and subcooled pool boiling on vertical and inclined surfaces based on measurements of the liquid-vapor behaviors near heating surfaces by using a conductance probe. The angle of inclination was varied from 90 (vertical) to 170 (facing almost horizontally downwards). The probe signals and the void fraction distributions showed that a liquid layer remains beneath the vapor masses moving upward along the heating surface at high heat fluxes near the CHF. The thickness of the liquid layer was determined from the location where the probe signals corresponding to the vapor masses disappeared. The thickness of the liquid layer formed on the vertical surface increased with increasing degree of subcooling, which may be the cause of the increases in CHF with increasing degree of subcooling. The measurements of saturated boiling on the inclined surface confirmed that the orientation of the heating surface greatly affects the period it takes for vapor masses to pass, but it negligibly affects the liquid layer thickness. This suggests that the decrease in CHF with increasing angle of inclination is primarily caused by the lengthening of the duration of vapor mass passage.

show abstract

Rationalization of existing mechanistic models for the prediction of water subcooled flow boiling critical heat flux

Cited by 163 publications

References 21 publications

Critical Heat Flux in Subcooled Flow Boiling of Water

Critical Heat Flux in Subcooled Flow Boiling of Water

Critical Heat Flux and Near-Wall Boiling Behaviors in Saturated and Subcooled Pool Boiling on Vertical and Inclined Surfaces

Critical Heat Flux and Near-Wall Boiling Behaviors in Saturated and Subcooled Pool Boiling on Vertical and Inclined Surfaces

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