The paper presents a Computational Fluid Dynamics (CFD) methodology to model gas-liquid boiling flow in a full scale 5 × 5 rod bundle with spacer grid typical in Pressurized Water Reactor (PWR) fuel rod bundle. The CFD modeling method is developed based on the STAR-CCM+ CFD code, including the Eulerian-Eulerian two-fluid model and the improved wall heat partitioning model. The OECD/NRC PWR Sub-channel and Bundle Tests (PSBT) are used as a numerical benchmark to assess the simulation quantitatively. The simulated geometry is a full scale of 5 × 5 fuel rod bundle with 17 spacers, including 7 mixing vane spacers (MV), 8 simple spacers (SS) and 2 non-mixing vane spacers (NMV). The present simulated results are in good agreement with the experimental results, the average error of the simulated cross-section void fraction is less than 20%. Based on the simulations, the axial distributions of second flow intensity, the rod surface temperature, bulk fluid temperature, and the void fraction are discussed. The results show that the spacer grid structures, especially the mixing vane, play an essential part in spreading the bubbles, reducing the void fraction and the rod surface temperature.
The support provided by OECD/NEA and JNES is grateful acknowledged. The data used in this study is from OECD/PSBT benchmark of OECD/NEA and JNES.
Author contributions: All the authors have accepted responsibility for the entire content of this submitted manuscript and approved submission.
Research funding: None.
Conflict of interest statement: The authors declare no conflicts of interest regarding this article.
Bartolomei, G.G. and Chanturiya, V.M. (1967). Experimental study of true void fraction when boiling subcooled water in vertical tubes. Therm. Eng. 14: 123–128.Search in Google Scholar
Bartolomei, G.G., Brantov, V.G., and Molochnikov, Y.S. (1982). An experimental investigation of true volumetric vapor content with subcooled boiling in tubes. Therm. Eng. 29: 132–135.Search in Google Scholar
Burns, A.D., Frank, T., and Hamill, I. (2004). The Favre averaged drag model for turbulent dispersion in Eulerian multi-phase flows. In: Proceedings of the 5th international conference on multiphase flow, Yokohama.Search in Google Scholar
Colombo, M. and Fairweather, M. (2016). Accuracy of Eulerian-Eulerian, two fluid CFD modeling models of subcooled boiling flows. Int. J. Heat Mass Tran. 103: 28–44, https://doi.org/10.1016/j.ijheatmasstransfer.2016.06.098.Search in Google Scholar
Cong, T.L., Zhang, R., Chen, L.J., Zhang, X., and Yu, T. (2018). Studies on the subcooled boiling in a fuel assembly with 5 by 5 rods using an improved wall boiling model. Ann. Nucl. Energy 114: 413–426, https://doi.org/10.1016/j.anucene.2017.12.058.Search in Google Scholar
Garnier, G., Manon, E., and Cubizolles, G. (2001). Local measurements on flow boiling of refrigerant 12 in a vertical tube. Multiph. Sci. Technol. 13: 1–111, https://doi.org/10.1615/MultScienTechn.v13.i1-2.10.Search in Google Scholar
Goodheart, K., Alleborn, N., and Chatelain, A. (2013). Analysis of the interfacial area transport model for industrial 2-phase boiling flow applications. In: The 15th international topical meeting on nuclear reactor thermal hydraulics, Pisa.Search in Google Scholar
Krepper, E., Koncar, B., and Egorov, Y. (2007). CFD modeling of subcooled boiling-concept, validation and application to fuel assembly design. Nucl. Eng. Des. 237: 716–731, https://doi.org/10.1016/j.nucengdes.2006.10.023.Search in Google Scholar
Krepper, E. and Rzehak, R. (2011). CFD for subcooled flow boiling: simulation of DEBORA experiments. Nucl. Eng. Des. 241: 3851–3866, https://doi.org/10.1016/j.nucengdes.2011.07.003.Search in Google Scholar
Kocamustafaogullari, G. and Ishii, M. (1995). Foundation of the interfacial area transport equation and its closure relation. Int. J. Heat Mass Tran. 38: 481–493, https://doi.org/10.1016/0017-9310(94)00183-V.Search in Google Scholar
Kurul, N. and Podowski, M.Z. (1990). Multidimensional effects in forced convection subcooled boiling. In: Proceeding of the 9th international heat transfer conference, Israel.10.1615/IHTC9.40Search in Google Scholar
Mimouni, S., Lavieville, J., Seiler, N., and Mathieu, G. (2011). Combined evaluation of second order turbulence model and polydispersion model for two phase boiling flow and application to fuel assembly analysis. Nucl. Eng. Des. 241: 4523–4636, https://doi.org/10.1016/j.nucengdes.2010.12.028.Search in Google Scholar
Ranz, W.R. (1952). Evaporation from drops part I & II. Chem. Eng. Prog. 48: 141–173.Search in Google Scholar
Ren, B., Dang, Y., Gan, F.J., and Yang, P. (2020). CFD simulation of subcooled boiling flow in PWR 5 × 5 rod bundle. Kerntechnik 86: 38–47, https://doi.org/10.1515/KERN-2020-0061.Search in Google Scholar
Rubin, A., Schoedel, A., and Avramova, M. (2012). OECD/NRC Benchmark based on NUPEC PWR subchannel and bundle tests(PSBT). Volume I: experimental database and final problem specifications report NEA/NSC/DOC(2012)1.US NRC. OECD Nuclear Energy Agency, Pairs.Search in Google Scholar
Tomiyama, A., Kataoka, I., Zun, I., and Sakaguchi, T. (1998). Drag coefficients of single bubbles under normal and micro gravity conditions. JSME Int. J.-Ser. B Fluids Therm. Eng. 41: 472–479, https://doi.org/10.1299/JSMEB.41.472.Search in Google Scholar
Waite, B.M., Shaver, D.R., and Podowski, M.Z. (2015). Mechanistic modeling of two phase flow around spacer grids with mixing vanes. In: The 16th international topical meeting on nuclear reactor thermal hydraulic, Chicago.Search in Google Scholar
© 2022 Walter de Gruyter GmbH, Berlin/Boston