Intensive cooling metallic bodies with low thermal conductivity in film boiling of ethanol

Zabirov, A R; Yagov, V. V.; Kanin, Pavel K.

doi:10.1088/1742-6596/891/1/012014

Cited by 6 publications

(5 citation statements)

References 6 publications

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“…8b). The following opportu-nity for the development of events is considered in [11]. Natural convective upward flow develops in the subcooled liquid at the interface with the vapor film.…”

Section: Resultsmentioning

confidence: 99%

“…After the occurrence of contact, two scenarios for the development of the process are possible: the recovery of the vapor film or its collapse with a subsequent transition to the intensive cooling mode. According to [11], the "choice of scenario" is determined by the ratio of the heat flux caused by the intense evaporation of liquid in the zone of three-phase contact to the heat flux due to the unsteady heat conduction from the volume of the cooled body. In this way, the following dimensionless complex is determined to within a numerical factor: Here, ρ, c, and λ are the density, heat capacity, and thermal conductivity of the metal; t 0 is the characteristic time of contact of the liquid with the protrusions of the surface roughness; and ΔT 0 is the difference between the average surface temperature ( ) and T lim .…”

Section: Resultsmentioning

confidence: 99%

“…This conclusion is confirmed by strong effect of the thermal effusivity coefficient of a metal on the temperature of the cooled surface at which this mode begins: when stainless steel balls are immersed in water with a temperature of 30°C, intensive cooling is observed almost immediately at T w > 700°C, whereas the corresponding T w values for nickel and copper balls were noticeably lower [9]. Based on these results, an approximate model was proposed for an emergence of the intensive cooling mode that takes into account the effect of subcooling and properties of a coolant, as well as superheat of the surface of the cooled sample and its thermal effusivity [11]. The model is confirmed by the newly discovered regimes of intense film boiling of deeply subcooled ethanol at pressure P ≥ 0.5 MPa in the process of cooling of the stainless-steel ball, presented in this paper.…”

Section: Heat and Mass Transfer And Physical Gasdynamicsmentioning

confidence: 99%

“…It is found that in water subcooled by ΔT sub > 20-30 K, microbubble boiling occurs when the samples made of materials with very different properties (stainless steel, nickel, and copper) are cooled. As far as is known, the temperature of a cooled ball is measured in such experiments at the center and at several points on the surface rather than at one point only in [7][8][9][10][11][12][13]. The presence of several surface thermocouples enables us to determine reliably the temperature of occurrence of the intensive cooling mode, the velocity of the cooling front propagation over the surface, and the rate of the ball cooling.…”

Section: Heat and Mass Transfer And Physical Gasdynamicsmentioning

confidence: 99%

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Effect of Coating by a Carbon Nanostructure on Heat Transfer with Unsteady Film Boiling

et al. 2019

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We present the results of an experimental study of heat transfer regimes during cooling in water of high-temperature, heated steel balls with a technically smooth and modified surface. The modification consisted of the application of a finely dispersed carbon coating to the surface followed by electron beam treatment. When the samples are placed in subcooled water, an intensive heat transfer regime occurs on the both samples; it appeared upon film boiling with heat fluxes on the surface up to 6 MW/m 2 . The heat flux values based on the initial cooling thermograms were obtained from a one-dimensional inverse heat conduction problem. The carboncoating leads to a decrease in the surface temperature, which corresponds to the transition to the intensive cooling mode, whereas the intensive cooling mode itself is identical for samples with the different surface treatments. Experimental results confirm the approximate model proposed for the conditions for the occurrence of the intensive cooling regime during film boiling of a subcooled liquid.

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“…8b). The following opportu-nity for the development of events is considered in [11]. Natural convective upward flow develops in the subcooled liquid at the interface with the vapor film.…”

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Heat and Mass Transfer And Physical Gasdynamicsmentioning

confidence: 99%

Section: Heat and Mass Transfer And Physical Gasdynamicsmentioning

confidence: 99%

See 2 more Smart Citations

Effect of Coating by a Carbon Nanostructure on Heat Transfer with Unsteady Film Boiling

et al. 2019

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“…It is very important when we deal with alcohols, because their viscosity increase dramatically when liquid temperature drop. Another interesting results were obtained on water-ethanol mixtures [11].Using liquid mixtures instead of pure components can be considered as a convenient way to investigate influence of the liquid properties. Experiments demonstrated that with ethanol concentration decreasing the process of boiling strengthened and duration of cooling decreased.…”

Section: Introductionmentioning

confidence: 99%

Pressure influence on film boiling of mixtures

Zabirov¹,

Yagov²,

Kanin³

et al. 2019

Proceedings of the 6th International Conference on Fluid Flow, Heat and Mass Transfer (FFHMT'19)

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A unique experimental work was carried out to study the laws governing the cooling of subcooled water-ethanol mixtures under pressures up to 0.5 MPa. The great intensification of quenching was recorded with increasing pressure and mass fraction of water in ethanol. At some conditions the transition temperature to the intensive boiling regime noticeably exceeded the critical temperature of the liquid (when direct liquid-solid contact is impossible).

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