Continuous Boiling Phenomena of Sodium under Forced Convection by Direct Heating

Takahashi, Katsuro; Fujii-E, Yoichi; Suita, Tokuo

doi:10.1080/18811248.1972.9734920

Cited by 4 publications

(3 citation statements)

References 4 publications

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“…This could be the critical flux when, bubble detachment occurs. The prediction of such pulsating boiling phenomenon is in compliance with the findings from sodium boiling experiments reported by Katsuro et al [5]. The boiling simulation could be carried out only up to duration of 0.3 s.…”

Section: Sodium Boiling Simulationsupporting

confidence: 87%

“…To investigate the onset and propagation of sodium boiling within pin bundles, various experiments have been carried out by different authors. Some of previous experimental investigations of sodium boiling are Kikuchi et al, [1], Khafizov et al [2], Qiu et al [3], Zicheng et al [4] and Katsuro et al [5]. But since sodium experiments are expensive and involve safety concerns, large volumes of numerical simulations were also reported on sodium boiling.…”

Section: Introductionmentioning

confidence: 99%

“…Contrary to pressurized water and R12, sodium has large liquid to vapour density ratio and high thermal conductivity. In addition, from the sodium boiling experiment conducted by Katsuro et al [5], they found that except under certain special circumstances, sodium generally tend to show pulsating boiling phenomenon with either single bubble expulsion or slug type expulsion. Though CFD based boiling simulations using RPI model were reported for water and R12, its applicability to sodium is not reported in published literatures.…”

Section: Introductionmentioning

confidence: 99%

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CFD Simulation of Sodium Boiling in Heated Pipe using RPI Model

Raj¹,

Velusamy²

2017

World Congress on Momentum, Heat and Mass Transfer

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CFD prediction of sodium flow boiling in a 2-D asymmetric heated pipe is carried out using RPI wall heat flux partitioning model available in the commercial CFD code FLUENT. The two phase models are validated with published pressurized water and R12 flow boiling experimental data. The influence of radial mesh density on validation parameter is investigated. Void fraction, wall temperature and liquid temperature at different axial section are taken as the validation parameter for water experiment. Among the various parameters predicted, the void fraction of water at the outlet gave the largest deviation of 35% with experimental data. But its value is in close comparison near the location of boiling initiation. Further the void fraction calculated based on heat balance compares well with the CFD results. Radial distributions of void fraction, vapour velocity, bubble diameter at the end of heated section are the parameters compared with R12 experimental data. Except bubble diameter, all other parameters gave reasonably good comparison. But when invoking breakup and coalescence model the predicted value of bubble diameter value approaches experimental data. Finally, sodium boiling simulations were carried out with the chosen models. It was found that, unlike water and R12, in the case of sodium, stable boiling was not achieved and boiling is highly localized to the end of heated section. Periodic growth and re-condensation of sodium vapour is found. Further, temporal oscillation in the heat transfer coefficient up to 8% was observed in the boiling zone. During sodium bubble expansion the evaporative heat flux dominates and once the bubble detaches, the quenching heat flux dominates. Unlike pressurised water evaporative and quenching heat flux have almost equal participation in boiling region.

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Section: Sodium Boiling Simulationsupporting

confidence: 87%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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CFD Simulation of Sodium Boiling in Heated Pipe using RPI Model

Raj¹,

Velusamy²

2017

World Congress on Momentum, Heat and Mass Transfer

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Ejection Velocity and Residual Film during Initial Expulsion of Sodium in Direct Heated Channel

Takahashi

Fujii-E

Suita

1973

Journal of Nuclear Science and Technology

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Experimental Study of Steady-State Boiling of Sodium Flowing in a Single-Pin Annular Channel

Kikuchi¹,

Haga²,

Takahashi³

1975

Journal of Nuclear Science and Technology

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An experimental study was carried out on steady-state boiling of sodium flowing in the annular channel formed around a n electrically heated simulation of a fuel pin. In the present experiment, the inlet temperature and flow rate were held constant, and t h e heat flux was gradually increased up to t h e inception of boiling. Thereafter, the heat flux was further increased step by step until the surface temperature of the heater pin marked a sharp rise, indicating the occurrence of dry-out. Records were obtained of t h e changes brought by the increasing heat flux t o boiling phenomena, with particular reference to the behavior of the two-phase flow pattern and t o the characteristics of boiling noise, a s well a s of t h e frequency of bubble formation. It was made clear that there exists a region in which steady-state boiling will be established, and under these conditions the two-phase flow pattern changes sequentially f r o m bubbly flow to slug flow and then to annular flow. T h i s behavior of sodium boiling in a narrow channel is quite similar t o the case of water. With rising heat flux, t h e level of noise intensity associated with boiling first increased sharply to attain a maximum point, then decreased somewhat and remained constant thereafter until dry-out. T h e frequency of bubble formation depended on the size of the bubble. T h e product of bubble frequency and equivalent diameter was found to be constant.

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Continuous Boiling Phenomena of Sodium under Forced Convection by Direct Heating

Cited by 4 publications

References 4 publications

CFD Simulation of Sodium Boiling in Heated Pipe using RPI Model

CFD Simulation of Sodium Boiling in Heated Pipe using RPI Model

Ejection Velocity and Residual Film during Initial Expulsion of Sodium in Direct Heated Channel

Experimental Study of Steady-State Boiling of Sodium Flowing in a Single-Pin Annular Channel

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