A preliminary assessment on a two-phase steam condensation model in nuclear containment applications

In water-cooled nuclear power reactors, significant quantities of steam and hydrogen could be produced within the primary containment following the postulated design basis accidents (DBA) or beyond design basis accidents (BDBA). For accurate calculation of the temperature/pressure rise and hydrogen transport calculation in nuclear reactor containment due to such scenarios, wall condensation heat transfer coefficient (HTC) is used. In the present work, the adaptation of a commercial CFD code with the implementation of models for steam condensation on wall surfaces in presence of noncondensable gases is explained. Steam condensation has been modeled using the empirical average HTC, which was originally developed to be used for “lumped-parameter” (volume-averaged) modeling of steam condensation in the presence of noncondensable gases. The present paper suggests a generalized HTC based on curve fitting of most of the reported semiempirical condensation models, which are valid for specific wall conditions. The present methodology has been validated against limited reported experimental data from the COPAIN experimental facility. This is the first step towards the CFD-based generalized analysis procedure for condensation modeling applicable for containment wall surfaces that is being evolved further for specific wall surfaces within the multicompartment containment atmosphere.

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Effect of steam condensation on countercurrent flow limiting in nearly horizontal two-phase flow

Nuclear Engineering and Design ◽

10.1016/s0029-5493(99)00298-8 ◽

2000 ◽

Vol 196 (2) ◽

pp. 201-217 ◽

Cited By ~ 10

Author(s):

Moon-Hyun Chun ◽

Seon-Oh Yu

Keyword(s):

Two Phase Flow ◽

Countercurrent Flow ◽

Phase Flow ◽

Steam Condensation ◽

Two Phase

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CFD modelling of wall steam condensation by a two-phase flow approach

Nuclear Engineering and Design ◽

10.1016/j.nucengdes.2010.09.020 ◽

2011 ◽

Vol 241 (11) ◽

pp. 4445-4455 ◽

Cited By ~ 28

Author(s):

S. Mimouni ◽

A. Foissac ◽

J. Lavieville

Keyword(s):

Two Phase Flow ◽

Phase Flow ◽

Steam Condensation ◽

Cfd Modelling ◽

Two Phase

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Experimental Investigation of Steam Condensation in a Silicon Microchannel

2010 14th International Heat Transfer Conference, Volume 6 ◽

10.1115/ihtc14-22191 ◽

2010 ◽

Author(s):

A. Odaymet ◽

H. Louahlia-Gualous

Keyword(s):

Atmospheric Pressure ◽

Two Phase Flow ◽

Rectangular Cross Section ◽

Flow Patterns ◽

Experimental Investigations ◽

Phase Flow ◽

Steam Condensation ◽

Two Phase ◽

Mass Fluxes ◽

Study Heat Transfer

Experimental investigations of a two-phase flow were conducted to study heat transfer and various flow patterns of steam condensation in two different microchannels. Microchannels have a rectangular cross-section with hydraulic diameter of 305μm (depth of 310μm and width of 300μm) and 410.5μm (depth of 312μm and width of 600μm). The length of each microchannel is of 50 mm. The silicon microchannel is covered with a transparent thin Pyrex plate to view different flow patterns. Microthermocouples (K-type, 20μm) were placed in rectangular silicon grooves. Measurements are carried out for different inlet pressures and flow rates of steam while the outlet pressure of the microchannel is kept at atmospheric pressure. Plug/slug flow patterns are observed in the microchannel for different mass fluxes. Local surface temperatures along the microchannel corresponding of each two-phase flow structure are measured and analyzed.

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An Efficient Computational Scheme for Two-Phase Steam Condensation in the Presence of CO2 for Wellbore and Long-Distance Flow

ChemEngineering ◽

10.3390/chemengineering3010004 ◽

2019 ◽

Vol 3 (1) ◽

pp. 4 ◽

Cited By ~ 2

Author(s):

Akand Islam ◽

Alexander Sun ◽

Kamy Sepehrnoori

Keyword(s):

Oil And Gas ◽

Steam Injection ◽

Phase Changes ◽

Practical Significance ◽

Steam Condensation ◽

State Equations ◽

Long Distance ◽

Two Phase ◽

Phase Rule ◽

Thermodynamic Phase

Here we present an efficient and robust calculation scheme for two-phase, one-dimensional (1D) steady state steam condensation in the presence of CO2, based on conservation rules and thermodynamic phase relations. The mixing of fluids and phases is assumed to be homogeneous. Heat transfer is considered between the fluids and the ambient formations. For convenience, state equations are presented in terms of the entropy changes of individual phases, and the simple additive rule for the mixture. To monitor phase changes, the phase rule is checked. This investigation has practical significance for steam injection operation and long-distance pipe flow applications in the geothermal and mid- and up-stream oil and gas industries.

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Two-Phase Flow and Heat Transfer during Steam Condensation in a Converging Microchannel with Different Convergence Angles

Advances in Mechanical Engineering ◽

10.1155/2013/372898 ◽

2013 ◽

Vol 5 ◽

pp. 372898 ◽

Cited By ~ 1

Author(s):

Ben-Ran Fu ◽

T. H. Chang ◽

Chin Pan

Keyword(s):

Heat Transfer ◽

Two Phase Flow ◽

Phase Flow ◽

Steam Condensation ◽

Two Phase ◽

Flow And Heat Transfer

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A Dynamic Film Model of the Pulsating Heat Pipe

Journal of Heat Transfer ◽

10.1115/1.4003759 ◽

2011 ◽

Vol 133 (8) ◽

Cited By ~ 28

Author(s):

Vadim S. Nikolayev

Keyword(s):

Heat Transfer ◽

Heat Pipe ◽

Capillary Tube ◽

Numerical Code ◽

Oscillating Flow ◽

Pulsating Heat Pipe ◽

Two Phase ◽

Thermally Induced ◽

Film Evaporation ◽

Condensation Model

This article deals with the numerical modeling of the pulsating heat pipe (PHP) and is based on the film evaporation/condensation model recently applied to the single-bubble PHP (Das et al., 2010, “Thermally Induced Two-Phase Oscillating Flow Inside a Capillary Tube,” Int. J. Heat Mass Transfer, 53(19–20), pp. 3905–3913). The described numerical code can treat the PHP of an arbitrary number of bubbles and branches. Several phenomena that occur inside the PHP are taken into account: coalescence of liquid plugs, film junction or rupture, etc. The model reproduces some of the experimentally observed regimes of functioning of the PHP such as chaotic or intermittent oscillations of large amplitudes. Some results on the PHP heat transfer are discussed.

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Steam-Side Characterisation of a Modular Air-Cooled Condenser

Volume 6: Energy, Parts A and B ◽

10.1115/imece2012-87846 ◽

2012 ◽

Cited By ~ 5

Author(s):

A. O’Donovan ◽

R. Grimes ◽

E. J. Walsh ◽

J. Moore ◽

N. Reams

Keyword(s):

Pressure Drop ◽

Power Plants ◽

Modular Design ◽

Cooling Water ◽

Quantitative Relationship ◽

Alternative Methods ◽

Steam Condensation ◽

Two Phase ◽

Frictional Pressure Drop ◽

Large Level

Diminishing fossil fuel reserves and a growing collective environmental awareness has led to the development of alternative methods of power generation such as Concentrated Solar Power (CSP). Although almost all existing CSP plants currently use water-cooled condensers, limited water supplies in the designated desert regions for such power plants, the high costs associated with providing cooling water and environmental considerations will all restrict the future use of water-cooled condensers. Air-cooled condensers (ACCs) are therefore proposed, despite evidence to suggest that they suffer from significant inefficiencies [1]. It has been suggested that a modular design, addressed in this paper, could offer solutions to issues with current ACC technologies. To fully characterise the modular ACC design it is necessary to quantify the steam-side characteristics. A series of tests were performed under vacuum conditions representative of an operational condenser. The condenser vacuum was measured for a series of incremental fan rotational speeds, to determine both the qualitative and quantitative relationship between fan speed and condenser pressure. Results indicate that for a given steam mass flow rate, the condenser pressure decreases with increasing fan rotational speed. Furthermore, the choice of vacuum pump, used to displace air leakages, was shown to have a significant influence on the steam-side response. Larger displacement-capacity vacuum pumps permit lower condenser pressures. The steam condensation pressure drop through the condenser tubes was also measured. Results for the measured pressure drop revealed a large level of momentum recovery, which is not uncommon in steam condensation processes. Experimental frictional pressure drops were determined and these compared favourably with certain two-phase frictional pressure drop correlations. In particular, the Lockhart & Martinelli correlation was found to be most capable of predicting the frictional pressure drop trends encountered during testing. The large level of agreement between the measurements and predictions provide confidence in future use of the Lockhart & Martinelli correlation to predict frictional pressure losses.

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