DOI QR코드

DOI QR Code

Plant-scale experiments of an air inflow accident under sub-atmospheric pressure by pipe break in an open-pool type research reactor

  • Donkoan Hwang (Division of Advanced Nuclear Engineering, POSTECH) ;
  • Nakjun Choi (Division of Advanced Nuclear Engineering, POSTECH) ;
  • WooHyun Jung (Department of Mechanical Engineering, POSTECH) ;
  • Taeil Kim (Department of Mechanical Engineering, POSTECH) ;
  • Yohan Lee (Division of Advanced Nuclear Engineering, POSTECH) ;
  • HangJin Jo (Division of Advanced Nuclear Engineering, POSTECH)
  • 투고 : 2022.09.20
  • 심사 : 2023.01.25
  • 발행 : 2023.05.25

초록

In an open-pool type research reactor with a downward forced flow in the core, pipes can be under sub-atmospheric pressure because of the large pressure drop at the reactor core in the atmospheric pool. Sub-atmospheric pressure can result in air inflow into the pipe from the pressure difference between the atmosphere and the inside of the pipe, which in a postulated pipe break scenario can lead to the breakdown of the cooling pump. In this study, a plant-scale experiment was conducted to study air inflow in large piping systems by considering the actual operational conditions of an advanced research reactor. The air inflow rate was measured, and the entrained air was visualized to investigate the behavior of air inflow and flow regime depending on the pipe break size. In addition, the developed drift-flux model for a large vertical pipe with a diameter of 600 mm was compared with other correlations. The flow regime transition in a large vertical pipe under downward flow was also studied using the newly developed drift-flux model. Consequently, the characteristics of two-phase flow in a large vertical pipe were found to differ from those in small vertical pipes where liquid recirculation was not dominant.

키워드

과제정보

This work was supported by a National Research Foundation of Korea (NRF) grant funded by the Korean government (Ministry of Science and ICT). (2020R1A4A3079853).

참고문헌

  1. D. Jo, J. Park, H. Chae, Development of thermal hydraulic and margin analysis code for steady state forced and natural convective cooling of plate type fuel research reactors, Prog. Nucl. Energy 71 (2014) 39-51. https://doi.org/10.1016/j.pnucene.2013.11.006
  2. H. Yoon, Y. Choi, K. Seo, S. Kim, Discharge header design inside a reactor pool for flow stability in a research reactor, Nucl. Eng. Technol. 52 (10) (2020) 2204-2220. https://doi.org/10.1016/j.net.2020.04.006
  3. K. Seo, I. Kim, K.-J. Park, M. Jung, H. Yoon, S. Kim, et al., An analysis of air-water flow phenomena due to a pipe break under sub-atmospheric pressures using TRACE, Nucl. Eng. Des. 374 (2021), 111064.
  4. I.K. Park, H.Y. Yoon, H.B. Park, Numerical approach to siphon break phenomena in a research reactor pool using the CUPID code, Nucl. Eng. Des. 326 (2018) 133-142. https://doi.org/10.1016/j.nucengdes.2017.11.001
  5. R. Kong, S. Kim, S. Bajorek, K. Tien, C. Hoxie, Effects of pipe size on horizontal two-phase flow: flow regimes, pressure drop, two-phase flow parameters, and drift-flux analysis, Exp. Therm. Fluid Sci. 96 (2018) 75-89. https://doi.org/10.1016/j.expthermflusci.2018.02.030
  6. N. Zuber, J.A. Findlay, Average Volumetric Concentration in Two-phase Flow Systems, 1965.
  7. H. Goda, T. Hibiki, S. Kim, M. Ishii, J. Uhle, Drift-flux model for downward two-phase flow, Int. J. Heat Mass Tran. 46 (25) (2003) 4835-4844. https://doi.org/10.1016/S0017-9310(03)00309-0
  8. D. Barnea, O. Shoham, Y. Taitel, Flow pattern transition for vertical downward two phase flow, Chem. Eng. Sci. 37 (5) (1982) 741-744. https://doi.org/10.1016/0009-2509(82)85034-3
  9. K. Kawanishi, Y. Hirao, A. Tsuge, An experimental study on drift flux parameters for two-phase flow in vertical round tubes, Nucl. Eng. Des. 120 (2-3) (1990) 447-458. https://doi.org/10.1016/0029-5493(90)90394-D
  10. T. Hibiki, M. Ishii, One-dimensional drifteflux model for two-phase flow in a large diameter pipe, Int. J. Heat Mass Tran. 46 (10) (2003) 1773-1790. https://doi.org/10.1016/S0017-9310(02)00473-8
  11. X. Shen, R. Matsui, K. Mishima, H. Nakamura, Distribution parameter and drift velocity for two-phase flow in a large diameter pipe, Nucl. Eng. Des. 240 (12) (2010) 3991-4000. https://doi.org/10.1016/j.nucengdes.2010.01.004
  12. Z. Li, G. Wang, M. Yousaf, X. Yang, M. Ishii, Flow structure and flow regime transitions of downward two-phase flow in large diameter pipes, Int. J. Heat Mass Tran. 118 (2018) 812-822. https://doi.org/10.1016/j.ijheatmasstransfer.2017.11.037
  13. C. Lu, R. Kong, S. Qiao, J. Larimer, S. Kim, S. Bajorek, et al., Frictional pressure drop analysis for horizontal and vertical air-water two-phase flows in different pipe sizes, Nucl. Eng. Des. 332 (2018) 147-161. https://doi.org/10.1016/j.nucengdes.2018.03.036
  14. G. Wang, Z. Li, M. Yousaf, X. Yang, M. Ishii, Experimental study on vertical downward air-water two-phase flow in a large diameter pipe, Int. J. Heat Mass Tran. 118 (2018) 919-930. https://doi.org/10.1016/j.ijheatmasstransfer.2017.11.065
  15. C. Dong, T. Hibiki, Drift-flux parameter modeling of vertical downward gas-liquid two-phase flows for interfacial drag force formulation, Nucl. Eng. Des. 378 (2021), 111185.
  16. S.H. Kang, H.S. Ahn, J.M. Kim, H.M. Joo, K.-Y. Lee, K. Seo, et al., Experimental study of siphon breaking phenomenon in the real-scaled research reactor pool, Nucl. Eng. Des. 255 (2013) 28-37. https://doi.org/10.1016/j.nucengdes.2012.09.032
  17. S.H. Kang, K.-Y. Lee, G.C. Lee, S.H. Kim, D.Y. Chi, K. Seo, et al., Investigation on effects of enlarged pipe rupture size and air penetration timing in real-scale experiment of siphon breaker, Nucl. Eng. Technol. 46 (6) (2014) 817-824. https://doi.org/10.5516/NET.03.2014.037
  18. H. Kim, J.-P. Park, D. Jang, D. Kim, Y.-G. Jung, S.-K. Park, et al., Development of phenomena identification and ranking tables (PIRTs) to implement research reactor-specific capability in SPACE code, Ann. Nucl. Energy 138 (2020), 107206.
  19. M.A. Hoq, M.M. Soner, M. Salam, S. Khanom, S. Fahad, Assessment of n-16 activity concentration in Bangladesh atomic energy commission triga research reactor, Nucl. Eng. Technol. 50 (1) (2018) 165-169. https://doi.org/10.1016/j.net.2017.11.006
  20. K.-Y. Lee, H.-G. Yoon, An Innovative Passive Residual Heat Removal System of an Open-Pool Type Research Reactor with Pump Flywheel and Gravity Core Cooling Tank, vol. 2015, Science and Technology of Nuclear Installations, 2015.
  21. K. Usui, Vertically downward two-phase flow,(II) Flow regime transition criteria, J. Nucl. Sci. Technol. 26 (11) (1989) 1013-1022. https://doi.org/10.1080/18811248.1989.9734422
  22. J. Jia, A. Babatunde, M. Wang, Void fraction measurement of gas-liquid two-phase flow from differential pressure, Flow Meas. Instrum. 41 (2015) 75-80. https://doi.org/10.1016/j.flowmeasinst.2014.10.010
  23. K. Usui, K. Sato, Vertically downward two-phase flow,(I) Void distribution and average void fraction, J. Nucl. Sci. Technol. 26 (7) (1989) 670-680. https://doi.org/10.1080/18811248.1989.9734366
  24. Y. Xue, H. Li, C. Hao, C. Yao, Investigation on the void fraction of gas-liquid two-phase flows in vertically-downward pipes, Int. Commun. Heat Mass Tran. 77 (2016) 1-8. https://doi.org/10.1016/j.icheatmasstransfer.2016.06.009
  25. O. Kashinsky, V. Randin, Downward bubbly gas-liquid flow in a vertical pipe, Int. J. Multiphas. Flow 25 (1) (1999) 109-138. https://doi.org/10.1016/S0301-9322(98)00040-8
  26. N. Clark, J. Van Egmond, E. Nebiolo, The drift-flux model applied to bubble columns and low velocity flows, Int. J. Multiphas. Flow 16 (2) (1990) 261-279. https://doi.org/10.1016/0301-9322(90)90058-Q
  27. K. Isao, I. Mamoru, Drift flux model for large diameter pipe and new correlation for pool void fraction, Int. J. Heat Mass Tran. 30 (9) (1987) 1927-1939. https://doi.org/10.1016/0017-9310(87)90251-1
  28. J.P. Schlegel, P. Sawant, S. Paranjape, B. Ozar, T. Hibiki, M. Ishii, Void fraction and flow regime in adiabatic upward two-phase flow in large diameter vertical pipes, Nucl. Eng. Des. 239 (12) (2009) 2864-2874. https://doi.org/10.1016/j.nucengdes.2009.08.004