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http://dx.doi.org/10.14346/JKOSOS.2020.35.3.96

Numerical Investigation on Experiment for Passive Containment Cooling System  

Ha, Hui Un (Central Research Institute, Korea Hydro & Nuclear Power Co., Ltd)
Suh, Jung Soo (Central Research Institute, Korea Hydro & Nuclear Power Co., Ltd)
Publication Information
Journal of the Korean Society of Safety / v.35, no.3, 2020 , pp. 96-104 More about this Journal
Abstract
The numerical simulations were conducted to investigate the thermal-fluid phenomena occurred inside the experimental apparatus during a PCCS, used to remove heat released in accidents from a containment of light water nuclear power plant, operation. Numerical simulations of the flow and heat transfer caused by wall condensation inside the containment simulation vessel (CSV), which equipped with 18 vertical heat exchanger tubes, were conducted using the commercial computational fluid dynamics (CFD) software ANSYS-CFX. Shear stress transport (SST) and the wall condensation model were used for turbulence closure and wall condensation, respectively. The simulation using the actual size of the apparatus. However, rather than simulating the whole experimental apparatus in consideration of the experimental cases, calculation resources, and calculation time, the simulation model was prepared only in CSV. Selective simulation was conducted to verify the effects of non-condensable gas(NC gas) concentration, CSV internal pressure, and wall sub-cooling conditions. First, as a result of the internal flow of CSV, it was observed that downward flow due to condensation occurred surface of the vertical tube and upward flow occurred in the distant place. Natural convection occurred actively around the heat exchanger tube. Due to this rising and falling internal flow, natural circulation occurred actively around the heat exchanger tubes. Next, in order to check the performance of built-in condensation model using according to the non-condensable gas concentration, CSV internal flow and wall sub-cooling, the heat flux values were compared with the experimental results. On average, the results were underestimated with and error of about 25%. In addition, the influence of CSV internal pressure and wall sub-cooling was small, but when the condensate was highly generated due to the low non-condensable gas concentration, the error was large compared to the experimental values. This is considered to be due to the nature of the condensation model of the CFX code. However, in spite of the limitations of CFD, it is valid to use the built-in condensation model of CFD for PCCS performance prediction from a conservative perspective.
Keywords
passive containment cooling system (PCCS); forced circulation; computational fluid dDynamics (CFD); wall condensation;
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Times Cited By KSCI : 2  (Citation Analysis)
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1 H. Uchida, A. Oyama and Y. Togo, "Evaluation of Post-accident Cooling Systems of Light-water Power Reactors," Proceedings of the Third International Conference on the Peaceful Uses of Atomic Energy, Geneva, Aug. 31-Sept. 9, 1964, 13, United Nations, New York, 93-104, 1964.
2 T. Tagami, "Interim Report on Safety Assessments and Facillities Establishment Project for June 1965", 1, Japanese Atomic Energy Research Agency, 1965.
3 A. A. Dehbi, "The Effect of Noncondensable Gases on Steam Condensation Under Turbulent Natural Convection Conditions", Massachusetts Institute of Technology, USA, PhD thesis, 1991.
4 H. Liu, N. E. Todreas and M. J. Driscoll, "An Experimental Investigation of a Passive Cooling Unit for Nuclear Plant Containment", Nuclear Engineering and Design, Vol. 199, No. 3, pp. 243-255, 2000.   DOI
5 J. Suh, "Numerical Investigation on Natural Circulation in a Simplified Passive Containment Cooling System", J. Korean Soc. Saf., Vol. 33, No. 3, pp. 92-98, June 2018.   DOI
6 B. Bae, S. Kim, Y. Park, H. Jun and K. Kang, "Investigation of Natural Circulation Characteristics in PCCS (Passive Containment Cooling System)", Transactions of the Korean Nuclear Society Spring Meeting, Jeju, Korea, May 17-18, 2018.
7 ANSYS, Inc., "ANSYS CFX-Solver Manager User's Guide", Canonsburg PA, USA, 2018.
8 ANSYS, Inc., "ANSYS CFX-Solver Theory Guide", Canonsburg PA, USA, 2018.
9 J. C. de la Rosa, A. Escriva, L. E. Herranz, T. Cicero and J. L. Munoz-Cobo, "Review on Condensation on the Containment Structures", Progress in Nuclear Energy, Vol. 51, pp. 32-66, 2009.   DOI
10 S. K. Park, M. H. Kim and K. J. Yoo, "Condensation of Pure Steam and Steam-Air Mixture with Surface Waves of Condensate Film on a Vertical Wall", International Journal of Multiphase Flow, Vol. 22, No.5, pp. 893-908, 1996.   DOI
11 M. Punetha and S. Khandekar, "A CFD Based Modelling Approach for Predicting Steam Condensation in the Presence of Non-condensable Gases", Nuclear Engineering and Design, Vol. 324, pp. 280-296, 2017.   DOI
12 J. Su, Z. Sun, G. Fan and M. Ding, "Experimental study of the Effect of Non-condensable Gases on Steam Condensation Over a Vertical Tube External Surface", Nuclear Engineering and Design, Vol. 262, pp. 201-208, 2013.   DOI