Visualization Study on Onset of Nucleate Boiling for Natural Circulation Flow in a Narrow Rectangular Channel

Experiments on onset of nucleate boiling (ONB) have been performed for the natural circulation flow in a one-sided heated narrow rectangular channel. With fast camera putting into use, the visualization study was conducted to capture the location of ONB. The experiments were performed at pressure of 0.2 MPa and 0.3 MPa, with subcooling temperature ranging from 40 to 60 K, and heating flux ranging from 70 to 220 kW/m2. Differing from conventional channel, the superheats of wall surface in the narrow rectangular channel needed for ONB is larger, and can be predicted with Thom’s correlation in developed flow region. Moreover, the superheat needed for ONB will decrease for the existence of entrance effect. The visualization study indicated that the traditional determination of ONB will bring in more error. In this study, valuable data and image have been provided for the error analysis of ONB.

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Experimental investigation of flow and heat transfer for natural circulation flow in an inclined narrow rectangular channel

Progress in Nuclear Energy ◽

10.1016/j.pnucene.2017.04.004 ◽

2017 ◽

Vol 98 ◽

pp. 266-276 ◽

Cited By ~ 8

Author(s):

Chunping Tian ◽

Ming Yan ◽

Jianjun Wang ◽

Xiaxin Cao ◽

Changqi Yan ◽

...

Keyword(s):

Heat Transfer ◽

Experimental Investigation ◽

Natural Circulation ◽

Rectangular Channel ◽

Circulation Flow ◽

Flow And Heat Transfer

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Research on Natural Circulation Flow Oscillation Experiment in Narrow Rectangular Channel

Volume 4: Computational Fluid Dynamics (CFD) and Coupled Codes; Decontamination and Decommissioning, Radiation Protection, Shielding, and Waste Management; Workforce Development, Nuclear Education and Public Acceptance; Mitigation Strategies for Beyond Design Basis Events; Risk Management ◽

10.1115/icone24-60679 ◽

2016 ◽

Author(s):

Tao Zhou ◽

Xiaolu Fang ◽

Liang Liu ◽

Yaoxin Wang ◽

Zejun Xiao

Keyword(s):

Mass Velocity ◽

Natural Circulation ◽

Rectangular Channel ◽

Density Wave ◽

Low Flow ◽

Circulation Flow ◽

Flow Oscillation ◽

Flow Pulsation ◽

Wave Instability ◽

Oscillation Phenomenon

A narrow rectangular natural circulation experimental system is used to research flow pulsation occurred during the experiment. During the experiment, the flow pulsation phenomenon is found in narrow rectangular channels. When compared with density wave instability, it is found that the flow pulsation has certain characteristics of density wave instability, but at the same time, there will be a transient low flow phenomenon, which is a unique flow oscillation phenomenon in the narrow rectangular channel. The mechanism of flow oscillation phenomenon is analyzed, on this basis, a forecast equation of mass velocity is put forward. Forecast equation of mass velocity is used to calculate the natural circulation mass flow rate. Calculation results are in good agreement with the experimental results, which proves that the forecast equation of mass velocity is correct, provides control and prevention theory basis for natural circulation flow instability in narrow rectangular channel.

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Study of Two-Phase Natural Circulation Cooling of Core Catcher System Using Scaled Model

Journal of Thermal Science and Engineering Applications ◽

10.1115/1.4030249 ◽

2015 ◽

Vol 7 (3) ◽

Cited By ~ 1

Author(s):

Shripad T. Revankar ◽

Kiwon Song ◽

B. W. Rhee ◽

R. J. Park ◽

K. S. Ha ◽

...

Keyword(s):

Pressure Drop ◽

Void Fraction ◽

Natural Circulation ◽

Rectangular Channel ◽

Water System ◽

Scaling Analysis ◽

Circulation Flow ◽

Two Phase ◽

Decay Heat ◽

Core Catcher

A two-phase natural circulation cooling has been proposed to remove melted core decay heat by external core catcher cooling system during sever accident scenario. In this paper, two types of the core catcher cooling loops, one with heated loop and the other adiabatic loop simulated with air water system are analytically studied. First, a scaling analysis was carried out for natural circulation flow in a closed loop. Based on the scaling analyses, simulation of two-phase natural circulation is carried out both for air–water and steam–water system in an inclined rectangular channel. The heat flux corresponding to the decay heat is simulated with steam generation rate or air flux into the test section to produce equivalent flow quality and void fraction. Design calculations were carried out for typical core catcher design to estimate the expected natural circulation rates. The natural circulation flow rate and two-phase pressure drop were obtained for different heat inputs or equivalent air injection rates expressed as void fraction for a select downcomer pipe size. These results can be used to scale a steam water system using scaling consideration presented. The results indicate that the air–water and steam water system show similar flow and pressure drop behavior.

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Experimental Study on Natural Circulation Flow in Rectangular Channel Under Rolling

Proceedings of The 20th Pacific Basin Nuclear Conference ◽

10.1007/978-981-10-2314-9_70 ◽

2017 ◽

pp. 771-780

Author(s):

Jiangwen Wang ◽

Puzhen Gao ◽

Chong Chen

Keyword(s):

Experimental Study ◽

Natural Circulation ◽

Rectangular Channel ◽

Circulation Flow

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Research on the Occurring Location of ONB in Narrow Rectangular Channel Under Natural Circulation by Factorial Analysis Method

Volume 3: Thermal-Hydraulics ◽

10.1115/icone24-60651 ◽

2016 ◽

Author(s):

Shi Qi ◽

Tao Zhou ◽

Baixu Chen ◽

Zejun Xiao

Keyword(s):

Natural Circulation ◽

Rectangular Channel ◽

Nucleate Boiling ◽

Factorial Analysis ◽

Important Influence ◽

Gap Size ◽

Analysis Method ◽

The Third ◽

Natural Circulation Loop ◽

Factor Interaction

This paper describes the research on the location of Onset of Nucleate Boiling (ONB) in Natural circulation. Selecting the narrow rectangular natural circulation loop as the research object, the occurring location of ONB is analyzed by experiment. By the method of factorial analysis, the influences of different factors and the factor interaction to the location of ONB are studied. The results show that, the inlet subcooling has the biggest influence, whose contribution percentage is 49.8%. The second important influence is the gap size, whose contribution percentage is 25.2%. The third important influence is the heat flux, whose contribution percentage is 24.4%. The influence of factor interaction to the location of ONB are negligible.

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AN EXPERIMENTAL DETERMINATION OF ISOLATED BUBBLE ACOUSTICS IN A NUCLEATE BOILING SYSTEM

10.1615/ihtc5.230 ◽

1974 ◽

Cited By ~ 3

Author(s):

G. E. Robinson ◽

Frank W. Schmidt ◽

H. R. Block ◽

G. Green

Keyword(s):

Experimental Determination ◽

Nucleate Boiling

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Relationship between the system of Astronomical constants and the radar determinations of the Astronomical Unit

Symposium - International Astronomical Union ◽

10.1017/s0074180900104930 ◽

1965 ◽

Vol 21 ◽

pp. 153-175

Author(s):

D. O. Muhleman

Keyword(s):

Error Analysis ◽

Astronomical Unit ◽

Astronomical Constants

This paper is devoted to an exact discussion of the determination of the astronomical unit with radar and to an extensive error analysis of the technique. Theoretical relationships between the constants are used to construct a consistent set of numerical values of constants based on these results.

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