AN EXPERIMENTAL STUDY ON POST-CHF HEAT TRANSFER FOR LOW FLOW OF WATER IN A $3\times3$ ROD BUNDLE

  • Published : 2005.10.01

Abstract

An experimental study on post-CHF heat transfer has been performed with a $3\times3$ rod bundle using a vertical steam-water two-phase flow at low flow conditions. The effects of various parameters on the post-CHF heat transfer are investigated and the reasons for the parametric effects are discussed. As the heat transfer regime changes from CHF to post-CHF, the radial wall temperature distribution is changed depending on the pressure and the mass flux conditions. The superheat of the fluid increases considerably with an increase of the wall temperature (or heat flux) and with a decrease of the mass flux. This implies, indirectly, a strong thermal non-equilibrium at high wall temperature and low mass flux conditions. In order to improve the prediction accuracy of the existing post-CHF correlations, it is necessary to perform more experiments, particularly direct measurement of the vapor superheat, and to modify the correlation by considering a strong thermal non-equilibrium at low flow and low pressure conditions.

Keywords

References

  1. G. F. Hewitt, J. M. Delhaye and N. Zuber, Post Dryout Heat Transfer, CRC Press, Inc., Boca Raton, Florida (1992)
  2. J. C. Chen, 'A Short Review of Dispersed Flow Heat Transfer in Post-Dryout Boiling,' Nucl. Eng. Design, 95, 375 (1986) https://doi.org/10.1016/0029-5493(86)90062-2
  3. D. C. Groeneveld, 'Post-Dryout Heat Transfer: Physical Mechanisms and a Survey of Prediction Methods,' Nucl. Eng. Design, 32, 283 (1975) https://doi.org/10.1016/0029-5493(75)90099-0
  4. D. C. Groeneveld and S. R. M Gardiner, 'A Method of Obtaining Flow Film Boiling Data for Subcooled Water,' Int. J. Heat Mass Transfer, 21, 17 (1978) https://doi.org/10.1016/0017-9310(78)90068-6
  5. Y. Koizumi, H. Kumamaru, T. Yonomoto and K. Tasaka, 'Post-Dryout Heat Transfer of High-Pressure Steam-Water Two-Phase Flow in Single Rod Channel and Multi Rod Bundle,' Nucl. Eng. Design, 99, 157 (1987) https://doi.org/10.1016/0029-5493(87)90117-8
  6. H. Kumamaru, Y. Koizumi and K. Tasaka, 'Investigation of Pre- and Post-Dryout Heat Transfer of Steam-Water Two-Phase Flow in a Rod Bundle,' Nucl. Eng. Design, 102, 71 (1987) https://doi.org/10.1016/0029-5493(87)90268-8
  7. M. Akiyama, A. Inoue, M. Ohishi et al., 'Study on Post-BT Heat Transfer in a Full Scale BWR (8x8) Rod Bundle,' Nucl. Eng. Design, 117, 341 (1989) https://doi.org/10.1016/0029-5493(89)90183-0
  8. D. C. Groeneveld, 'Post-Dryout Heat Transfer at Reactor Operating Conditions,' AECL-3281, Atomic Energy of Canada Limited (1973)
  9. A. F. Varone and W. M. Rohsenow, 'Post Dryout Heat Transfer Prediction,' Proc. of the Joint Japan-USA Two-Phase Flow Conf., Lake Placid, New York, USA, Aug. (1984)
  10. C. Unal, K. Tuzla, J. C. Chen, S. Neti and O. Badr, 'Convective Film Boiling in a Rod Bundle: Axial Variation of Nonequilibrium Evaporation Rates,' Int. J. Heat Mass Transfer, 31[10], 2091 (1988) https://doi.org/10.1016/0017-9310(88)90119-6
  11. C. Unal, K. Tuzla, A. F. Cokmez-Tuzla and J. C. Chen, 'Vapor Generation Rate Model for Dispersed Drop Flow,' Nucl. Eng. Design, 125, 161 (1991) https://doi.org/10.1016/0029-5493(91)90075-S
  12. S. Y. Chun, S. K. Moon, H. J. Chung, M. K. Chung and M. Aritomi, 'An Experimental Study on Heat Transfer Characteristics Just Before Critical Heat Flux in Uniformly Heated Vertical Annulus Under a Wide Range of Pressures,' J. of the Korean Nuclear Society, 34[4], 269 (2002)
  13. ANSI/ASME PTC 19.1, ASME Performance Test Codes, Supplement on Instruments and Apparatus, Part 1, Measurement Uncertainty, ASME, New York (1985)
  14. H. C. Hottel and A. F. Sarofim, Radiative Transfer, McGraw-Hill, New York (1967)
  15. S. K. Moon, S. Y. Chun, S. Cho, J. K. Park and W. P. Baek, 'An Experimental Study on the Low Flow CHF in Vertical Rod Bundle with Non-Uniform Axial Heat Flux Distribution,' Proc. of the 10th Int. Topical Meeting on Nuclear Thermal Hydraulics (NURETH-10), Seoul, Korea, Oct. 5-11 (2003)
  16. D. Evans, S. W. Webb and J. C. Chen, 'Axially Varying Vapor Superheats in Convective Film Boiling,' Journal of Heat Transfer, 107, 663 (1985) https://doi.org/10.1115/1.3247475
  17. S. Nijhawan, J. C. Chen, R. K. Sundaram and E. J. London, 'Measurement of Vapor Superheat in Post-Critical-Heat-Flux Boiling,' Journal of Heat Transfer, 102, 465 (1980) https://doi.org/10.1115/1.3244324
  18. R. S. Dougall and W. M. Rohsenow, 'Film Boiling on the Inside of Vertical Tubes with Upward Flow of the Fluid at Low Qualities,' MIT Report No. 9079-26, Massachusetts Institute of Technology (1963)
  19. K. G. Condie, S. J. Bengston and S. L. Richlein, 'Measurement of Axially Varying Nonequilibrium in Post-Critical-Heat-Flux Boiling in a Vertical Tube,' NUREG/CR-3362, U.S. Nuclear Regulatory Commission (1983)
  20. D. C. Groeneveld and G. G. J. Delorme, 'Prediction of Thermal Non-Equilibrium in the Post-Dryout Regime,' Nucl. Eng. Design, 36, 17 (1976) https://doi.org/10.1016/0029-5493(76)90138-2
  21. D. C. Groeneveld, L. K. H. Leung et al., 'A Look-Up Table for Fully Developed Film-Boiling Heat Transfer,' Nucl. Eng. Design, 225, 83 (2003) https://doi.org/10.1016/S0029-5493(03)00149-3