CFD for subcooled flow boiling: Simulation of DEBORA experiments

In this work we investigate the present capabilities of CFD for wall boiling. The computational model used combines the Euler/Euler two-phase flow description with heat flux partitioning. Very similar modelling was previously applied to boiling water under high pressure conditions relevant to nuclear power systems. Similar conditions in terms of the relevant non-dimensional numbers have been realized in the DEBORA tests using dichlorodifluoromethane (R12) as the working fluid. This facilitated measurements of radial profiles for gas volume fraction, gas velocity, liquid temperature and bubble size. After reviewing the theoretical and experimental basis of correlations used in the model, give a careful assessment of the necessary recalibrations to describe the DEBORA tests. It is then shown that within a certain range of conditions different tests can be simulated with a single set of model parameters. As the subcooling is decreased and the amount of generated vapour increases the gas fraction profile changes from wall to core peaking. This is a major effect not captured by the present modelling. Some quantitative deviations are assessed as well and directions for further model improvement are outlined.

[1]  P. Griffith,et al.  The mechanism of heat transfer in nucleate pool boiling—Part I: Bubble initiaton, growth and departure , 1965 .

[2]  Peter Griffith,et al.  THE MECHANISM OF HEAT TRANSFER IN NUCLEATE POOL BOILING. Technical Report No. 19 , 1962 .

[3]  Ulrich Grigull,et al.  Heat Transfer in Boiling , 1977 .

[4]  F. White.  Viscous Fluid Flow , 1974 .

[5]  F. Menter.  Two-equation eddy-viscosity turbulence models for engineering applications , 1994 .

[6]  Yassin A. Hassan,et al.  A two-equation turbulence model of turbulent bubbly flows , 2001 .

[7]  Eckhard Krepper,et al.  Use of models for lift, wall and turbulent dispersion forces acting on bubbles for poly-disperse flows , 2007 .

[8]  D. Drew,et al.  Theory of Multicomponent Fluids , 1998 .

[9]  D. Kenning,et al.  Subcooled flow boiling at high heat flux , 1985 .

[10]  Henryk Anglart,et al.  CFD prediction of flow and phase distribution in fuel assemblies with spacers , 1997 .

[11]  Nikolay Ivanov Kolev.  UNIQUENESS OF THE ELEMENTARY PHYSICS DRIVING HETEROGENEOUS NUCLEATE BOILING AND FLASHING , 2006 .

[12]  B. Mikic,et al.  A New Correlation of Pool-Boiling Data Including the Effect of Heating Surface Characteristics , 1969 .

[13]  Boštjan Končar,et al.  Wall function approach for boiling two-phase flows , 2010 .

[14]  Robert Cole,et al.  A photographic study of pool boiling in the region of the critical heat flux , 1960 .

[15]  W. E. Ranz,et al.  Evaporation from drops , 1952 .

[16]  M. Ishii.  Thermo-fluid dynamic theory of two-phase flow , 1975 .

[17]  Janusz A. Szymczyk,et al.  Flow field around growing and rising vapour bubble by PIV measurement , 2005, J. Vis..

[18]  Etienne Manon,et al.  Contribution à l'analyse et à la modélisation locale des écoulements bouillants sous-saturés dans les conditions des réacteurs à eau sous pression , 2000 .

[19]  Michael Z. Podowski,et al.  MULTIDIMENSIONAL EFFECTS IN FORCED CONVECTION SUBCOOLED BOILING , 1990 .

[20]  V. I. Tolubinsky,et al.  VAPOUR BUBBLES GROWTH RATE AND HEAT TRANSFER INTENSITY AT SUBCOOLED WATER BOILING , 1970 .

[21]  I. Zun,et al.  The transverse migration of bubbles influenced by walls in vertical bubbly flow , 1980 .

[22]  B. A. Kader.  Temperature and concentration profiles in fully turbulent boundary layers , 1981 .

[23]  Wei Yao,et al.  Prediction of Parameters Distribution of Upward Boiling Two-Phase Flow With Two-Fluid Models , 2002 .

[24]  H. J. Ivey.  Relationships between bubble frequency, departure diameter and rise velocity in nucleate boiling , 1967 .

[25]  Günter Brenn,et al.  Modelling of the Near-Wall Liquid Velocity Field in Subcooled Boiling Flow , 2005 .

[26]  Eckhard Krepper,et al.  CFD simulation of convective flow boiling of refrigerant in a vertical annulus , 2008 .

[27]  A. K. Agrawal,et al.  Shape of liquid drops moving in liquid media , 1966 .

[28]  Eckhard Krepper,et al.  CFD modelling of subcooled boiling—Concept, validation and application to fuel assembly design , 2007 .

[29]  Hidesada Tamai,et al.  Transverse migration of single bubbles in simple shear flows , 2002 .

[30]  N. Zuber,et al.  Drag coefficient and relative velocity in bubbly, droplet or particulate flows , 1979 .

[31]  J. Converti,et al.  A model for turbulent polydisperse two-phase flow in vertical channels , 2003 .

[32]  G. Cubizolles,et al.  LOCAL MEASUREMENTS ON FLOW BOILING OF REFRIGERANT 12 IN A VERTICAL TUBE , 2001 .

[33]  Michio Sadatomi,et al.  Momentum and heat transfer in two-phase bubble flow—I. Theory , 1981 .