CFD simulation of DEBORA boiling experiments

• Autorzy: Rzehak R. , Krepper E.
• Języki publikacji: EN

Abstrakty

EN

In this work we investigate the present capabilities of computational fluid dynamics for wall boiling. The computational model used combines the Euler/Euler two-phase flow description with heat flux partitioning. This kind of modeling 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, bubble size and liquid temperature as well as axial profiles of wall temperature. After reviewing the theoretical and experimental basis of correlations used in the ANSYS CFX model used for the calculations, we give a careful assessment of the necessary recalibrations to describe the DEBORA tests. The basic CFX model is validated by a detailed comparison to the experimental data for two selected test ca cases. Simulations with a single set of calibrated parameters are found to give reasonable quantitative agreement with the data for several tests within a certain range of conditions and reproduce the observed tendencies correctly. Several model refinements are then presented each of which is designed to improve one of the remaining deviations between simulation and measurements. Specifically we consider a homogeneous MUSIG model for the bubble size, modified bubble forces, a wall function for turbulent boiling flow and a partial slip boundary condition for the liquid phase. Finally, needs for further model developments are identified and promising directions discussed.

Słowa kluczowe

EN

computational fluid dynamics simulation; heat flux partitioning; subcooled flow boiling; two-fluid model

PL

obliczeniowa mechanika płynów; przechłodzenie; symulacja

• Wydawca: Wydawnictwo Instytutu Maszyn Przepływowych PAN ; Komitet Termodynamiki i Spalania PAN
• Czasopismo: Archives of Thermodynamics
• Rocznik: 2012
• Tom: Vol. 33, no. 1
• Strony: 107--122
• Opis fizyczny: Bibliogr. 31 poz.,Rys., tab.,

Twórcy

autor

Rzehak R.

autor

Krepper E.

• Helmholtz-Zentrum Dresden-Rossendorf, Pob 510119, D-01314 Dresden, Germany,

Bibliografia

• [1] ISHII M.: Thermo-fluid Dynamic Theory of Two-phase Flow, Eyrolles, Paris 1975.
• [2] KURUL N., PODOWSKI M.Z.: Multidimensional effects in forced convection subcooled boiling. In: Proc. 9th Int. Heat Transfer Conf., Jerusalem, Israel, 1990, Vol. 2, Paper 1-Bo-04.
• [3] KURUL N., PODOWSKI M.: On the modeling of multidimensional effects in boiling channels. In: ANS Proc. 27th Natl. Heat Transfer Conf., Minneapolis, MN, USA, 1991, 30.
• [4] KREPPER E. et al.: Modelling of subcooled boiling – concept, validation and application to fuel assembly design. Nucl. Eng. Des. 237(2007), 716–731.
• [5] BARTOLOMEJ G.G., CHANTURIYA V.M.: Experimental study of true void fraction when boiling subcooled water in vertical tubes. Thermal Eng. 14(1967), 123–128 (translated from Teploenergetika 14(1967), 80–83).
• [6] KREPPER E., RZEHAK R.: CFD for subcooled flow boiling: Simulation of DEBORA experiments. Nucl. Eng. Des. 241(2011), 3851–3866.
• [7] GARNIER J. et al.: Local measurements on flow boiling of refrigerant 12 in a vertical tube. Multiphase Sci. and Technol. 13(2001), 1–111.
• [8] YAO W., MOREL C.: Prediction of parameters distribution of upward boiling twophase flow with two-fluid models. In: Proc. 10th Int. Conf. Nuclear Engineering, Arlington, Virginia, USA, 2002, Paper ICONE-10-22463.
• [9] YAO W., MOREL C.: Volumetric interfacial area prediction in upward bubbly twophase flow. Int. J. Heat Mass Transfer 47(2004), 307–328.
• [10] BOUCKER M. et al.: Towards the prediction Of local thermal-hydraulics in real PWR core conditions using Neptune_CFD_software. Workshop on Modeling and Measurements of Two-Phase Flows and Heat Transfer in Nuclear Fuel Assemblies, KTH Stockholm, Sweden, 2006.
• [11] MOREL C., LAVIEVILLE J.M.: Modeling of multisize bubbly flow and application to the simulation of boiling flows with the NEPTUNE CFD code. Science and Technology of Nuclear Installations (2009), 953527.
• [12] KADER B.A.: Temperature and concentration profiles in fully turbulent boundary layers. Int. J. Heat Mass Transfer 24(1981), 1541–1544.
• [13] WINTTERLE T.: Development of a Numerical Boundary Condition for the Simulation of Nucleate Boiling at Heated Walls. PhD. thesis, University of Stuttgart, 2004.
• [14] MIKIC B.B., ROHSENOW W.M.: A new correlation of pool-boiling data including the fact of heating surface characteristics. Trans. ASME J. Heat Transfer 91(1969), 245–250.
• [15] RANZ W.E., Marshall W.R.: Evaporation from drops. Chem. Eng. Prog. 48(1952), 141–146.
• [16] ANGLART H. et al.: CFD prediction of flow and phase distribution in fuel assemblies with spacers. Nucl. Eng. Des. 177(1997), 215–228.
• [17] ISHII M., ZUBER N.: Drag coefficient and relative velocity in bubbly, droplet or particulate flows. AIChE J. 25(1979), 843–855.
• [18] TOMIYAMA A. et al.: Transverse migration of single bubbles in simple shear flows. Chem. Eng. Sci. 57(2002), 1849–1858.
• [19] BURNS A.D. et al.: The Favre averaged drag model for turbulence dispersion in Eulerian multi-phase flows. In: Proc. 5th Int. Conf. on Multiphase Flow, Yokohama, Japan, 2004, Paper 392.
• [20] MENTER F.: Two-equation eddy-viscosity turbulence models for engineering applications. AIAA J. 32(1994), 1598–1605.
• [21] SATO Y. et al.: Momentum and heat transfer in two-phase bubble flow-I. Int. J. Multiphase Flow 7(1981), 167–177.
• [22] TOLUBINSKY V.I., KOSTANCHUK D.M.: Vapour bubbles growth rate and heat transfer intensity at subcooled water boiling. Heat Transfer 1970. In: Proc. 4th Int. Heat Transfer Conf., Paris, France, 1970, Vol. 5, Paper B-2.8.
• [23] KOLEV N.I.: Uniqueness of the elementary physics driving heterogeneous nucleate boiling and flashing. Nucl. Eng. Technol. 38(2006), 175–184.
• [24] KREPPER E. et al.: The inhomogeneous MUSIG model for the simulation of polydispersed flows. Nucl. Eng. Des. 238(2008), 1690–1702.
• [25] LUCAS D. et al.: Condensation of steam bubbles injected into subcooled water. In: Proc. 13th Int. Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-13), Kanazawa City, Japan, 2009, Paper N13P1097.
• [26] PRINCE M.J., BLANCH H.W.: Bubble coalescence and break-up in air-sparged bubble columns. AIChE J. 36(1990), 1485–1499.
• [27] LUO H., SVENDSEN H.F.: Theoretical model for drop and bubble breakup in turbulent dispersions. AIChE J. 42(1996), 1225–1233.
• [28] RAMSTORFER F. et al.: Modelling of the near-wall liquid velocity field in subcooled boiling flow. In: Proc. ASME Summer Heat Transfer Conf., San Francisco, California, USA, 2005, Paper HT2005-72182.
• [29] KONCAR B., KREPPER E.: CFD simulation of convective flow boiling of refrigerant in a vertical annulus. Nucl. Eng. Des. 238(2008), 693–706.
• [30] KLAUSNEr J. et al.: Vapor bubble departure in forced convection boiling. Int. J. Heat Mass Transfer 36(1993), 651–662.
• [31] ANSYS CFX-Solver Theory Guide, Release 12.1. ANSYS Inc., 2009.