An investigation of direct condensation of steam jet in subcooled water

Chun, Myung‐Suk; Kim, Yeon-Sik; Park, Jee-Won

doi:10.1016/0735-1933(96)00077-2

Cited by 198 publications

(116 citation statements)

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“…Empirical correlations of the steam jet lengths were proposed by several workers (Chun et al, 1996;Kerney et al, 1972;Stanford et al, 1972;Weimer et al, 1973) for various steam mass #uxes and pool temperatures. However, the correlations for high-steam mass #ux conditions did not agree with each other.…”

Section: Introductionmentioning

confidence: 99%

“…A number of experimental studies (Chun et al, 1996;Cumo and Ferrari, 1974;Fukuda, 1982;Young et al, 1974;) were performed to establish the empirical correlations of the heat transfer coe$cients for various steam mass #uxes and pool temperatures. The heat transfer areas were obtained with the assumption of a smooth interface between steam and water in the calculation of heat transfer coe$cients.…”

Section: Introductionmentioning

confidence: 99%

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Experimental study on stable steam condensation in a quenching tank

Kim

Bae

Song

et al. 2001

Int. J. Energy Res.

139

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SUMMARYExperimental study on direct contact condensation (DCC) of a stable steam discharging into a quenching tank with sub-cooled water has been performed for "ve di!erent sizes of horizontal nozzles over a wide range of steam mass #ux and pool temperature conditions. Two di!erent steam jet shapes (conical and ellipsoidal) were typically observed, depending on the steam mass #ux and the pool temperature. The steam jet expansion ratios, the dimensionless steam jet lengths, and the average heat transfer coe$cients were determined and the e!ects of steam mass #ux, pool temperature, and nozzle diameter on these parameters were discussed. Empirical correlations for the dimensionless steam jet length and the average heat transfer coe$cient as a function of steam mass #ux and condensation driving potential were established. The axial and radial temperature distributions in the steam jet and in the surrounding pool water were measured and the e!ects of steam mass #ux, pool temperature, and nozzle diameter on these parameters were also discussed.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Experimental study on stable steam condensation in a quenching tank

Kim

Bae

Song

et al. 2001

Int. J. Energy Res.

139

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“…In this work the regime map presented by Chun et al 32 is taken as a reference for explaining steam condensation phenomena based on the steam flux and pool temperature. We can find from the regime map (Figure 7) that the steam condensation in the present case was occurring either in chugging regime (C) or in transient chugging regime (TC) depending upon water pool temperature.…”

Section: Photographic Studymentioning

confidence: 99%

“…Different regimes of steam condensation, which essentially discusses steam jet formation and breakup mechanism with respect to steam flux and pool temperature, are identified by many researchers. [30][31][32] The mechanism of steam bubble/ jet formation is based on relative rates of momentum of steam (steam flux) and rate of condensation of steam. When the momentum (steam flux) associated with the steam is high enough to push the liquid water away it forms the longer steam (vaporous) jet but the stability of the jet i.e.…”

Section: Photographic Studymentioning

confidence: 99%

Steam bubble cavitation

et al. 2008

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in Wiley InterScience (www.interscience.wiley.com).Generating hydrodynamic/ acoustic cavitation (Gogate et al.) for a useful purpose encompasses the following energy transformation steps: (1) Burning fuel in boiler. (2) Expanding the steam in a turbine generator. (3) Using electrical output from the generator to: (a) Pump water through a mechanical constriction (hydrodynamic cavitation), or (b) Operate ultrasonic transducer (acoustic cavitation). The combined loss, which is the mathematical product of each of the above step efficiencies, lowers the overall efficiency. An energy efficient method for generating useful cavitation is presented here. It suggests direct injection of steam (I) into sub-cooled water to produce cavitation, thereby eliminating the inefficiencies of the remaining steps (II and III). Cavitation produced by this technique was experimentally and numerically shown to produce collapse conditions similar to hydrodynamic/acoustic cavitation. Direct steam injection cavitation coupled with acoustic cavitation, exhibited 4-16 times greater energy efficiency as compared to acoustic cavitation alone. Similar effects have been numerically speculated for hydrodynamic cavitation.

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“…Many researchers have looked at the condensation of steam discharged into pools and many complex models have been developed to predict pressure oscillations and the distance required for complete condensation of the steam (Chun et al, 1996, Weimer et al, 1973, Kudo et al, 1974, Cumo et al, 1978, Tin et al, 1982, Simpson & Chan, 1982, Nariai & Aya, 1986. For our purposes the important result from this work is that the steam is (12) condensed over a short distance (0.4 to 1.5 times the vent diameter) so that we can look at the liquid exiting the condensation region for its effects on the pool thermal behavior (Fig.…”

Section: Steam Discharge Jetmentioning

confidence: 99%

Mixing Processes in High-Level Waste Tanks - Final Report

Peterson¹

1999

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RESEARCH OBJECTIVE AND SUMMARY OF RESULTSMixing and transport in large waste-tank volumes is controlled by the multidimensional equations describing mass, momentum and energy conservation, and by boundary conditions imposed at walls, structures, and fluid inlets and outlets. For large enclosures, careful scaling arguments show that mixing is generated by free buoyant jets arising from the injection of fluid or buoyancy into the enclosure, and by temperature and/or concentration gradients generated near surfaces by heat and mass transfer at walls, cooling tubes, and liquid-vapor interfaces. For large enclosures like waste-tank air spaces, scaling shows that these free and wall jets are generally turbulent and are generally relatively thin.When one attempts to numerically solve the multi-dimensional mass, momentum, and energy equations with CFD codes, very fine grid resolution is required to resolve these thin jet structures, yet such fine grid resolution is difficult or impossible to provide due to computational expense. However, we have shown that the ambient fluid between jets tends to organize into either a homogeneously mixed condition or a vertically stratified condition that can be described by a one-dimensional temperature and concentration distribution. Furthermore, we can predict the transition between the well-mixed and stratified conditions. This allows us to describe mixing processes in large, complex enclosures using one-dimensional differential equations, with transport in free and wall jets modeled using standard integral techniques. With this goal in mind, we have constructed a simple, computationally efficient numerical tool, the Berkeley Mechanistic Mixing Model (BMIX), which can be used to predict the transient evolution of fuel and oxygen concentrations in DOE high-level waste tanks following loss of ventilation, and validate the model against a series of experiments. The experiments have been done with both water and air as working fluid.Using a scaled water tank experiment, the question of the dilution of a ceiling plume of ambient air entering the waste tank at the ventilation penetrations at the top of the waste tank is addressed (see reference [2] included with this final report). The water tank experiments model flow exchange similar to the exchange between the waste tank and the ambient air by partitioning the water tank in two equal sized horizontal compartments with two penetrations. The upper compartment is filled with denser sugar or salt water and the bottom compartment is filled with pure water. When the experiment is started the unstable density potential creates an upward buoyant jet though one penetration and a downward plume in the other. Measurements of buoyant jet dilution in the bottom compartment of the water experiment is accomplished using a new measurement technique using diffraction of a sheet of laser light to measure the density profile in the bottom compartment. Also flow patterns and mixing are observed using dye introduced into the downward directed buoyant jet. ...

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An investigation of direct condensation of steam jet in subcooled water

Cited by 198 publications

References 10 publications

Experimental study on stable steam condensation in a quenching tank

Experimental study on stable steam condensation in a quenching tank

Steam bubble cavitation

Mixing Processes in High-Level Waste Tanks - Final Report

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