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Research Papers: Heat and Mass Transfer

A Numerical Investigation on the Influence of Porosity on the Steady-State and Transient Thermal–Hydraulic Behavior of the PBMR

[+] Author and Article Information
Masoumeh Sadat Latifi

Department of Energy Engineering and Physics,
Amirkabir University of Technology,
424 Hafez Ave,
Tehran, Iran
e-mail: m.s.latifi@aut.ac.ir

Saeed Setayeshi

Department of Energy Engineering and Physics,
Amirkabir University of Technology,
424 Hafez Ave.
Tehran, Iran
e-mail: setayesh@aut.ac.ir

Giuseppe Starace

Department of Engineering for Innovation,
University of Salento,
Lecce 73100, Italy
e-mail: giuseppe.starace@unisalento.it

Maria Fiorentino

Department of Engineering for Innovation,
University of Salento,
Lecce 73100, Italy
e-mail: maria.fiorentino@unisalento.it

1Corresponding author.

Contributed by the Heat Transfer Division of ASME for publication in the JOURNAL OF HEAT TRANSFER. Manuscript received January 27, 2016; final manuscript received May 3, 2016; published online June 7, 2016. Editor: Portonovo S. Ayyaswamy.

J. Heat Transfer 138(10), 102003 (Jun 07, 2016) (9 pages) Paper No: HT-16-1034; doi: 10.1115/1.4033544 History: Received January 27, 2016; Revised May 03, 2016

The thermal–hydraulic phenomena in a pebble bed modular reactor (PBMR) core have been simulated under steady-state and transient conditions. The PBMR core is basically a long right circular cylinder with a fuel effective height of 11 m and a diameter of 3.7 m. It contains approximately 452,000 fuel pebbles. A three-dimensional computational fluid dynamic (CFD) model of the PBMR core has been developed to study the influence of porosity on the core performance after reactor shutdown. The developed model was carried out on a personal computer using ANSYS fluent 14.5. Several important heat transfer and fluid flow parameters have been examined under steady-state and transient conditions, including the coolant temperature, effective thermal conductivity of the pebble bed, and the decay heat. Porosity was found to have a significant influence on the coolant temperature, on the effective thermal conductivity of the pebble bed, on the decay heat, and on the required time for heat removal.

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References

International Atomic Energy Agency, 2006, “ Status of Innovative Small and Medium Reactor Designs 2005,” IAEA, Vienna, Austria, Report No. IAEA-TECDOC-1485.
Matzner, D. , 2004, “ PBMR Project Status and the Way Ahead,” 2nd International Topical Meeting on High Temperature Reactor Technology, Beijing, China, Sept. 22–24.
International Atomic Energy Agency, 2013, “ Evaluation of High Temperature Gas Cooled Reactor Performance,” IAEA, Vienna, Austria, Report No. IAEA-TECDOC-1694.
Venter, P. J. , Mitchell, M. N. , and Fortier, F. , 2005, “ PBMR Reactor Design and Development,” Proceedings of the 18th International Conference on Structural Mechanics in Reactor Technology (SMiRT 18), Beijing, China, Aug. 7–12, International Association for Structural Mechanics in Reactor Technology, Raleigh, NC.
Lee, J.-J. , Yoon, S.-J. , Park, G.-C. , and Lee, W.-J. , “ Turbulence-Induced Heat Transfer in PBMR Core Using LES and RANS,” J. Nucl. Sci. Technol., 44(7), pp. 985–996. [CrossRef]
Viljoen, C. F. , van Rooyen, W. J. , and Mtyobile, V. , 2006, “ The Use of CFD in the Design of PBMR Test Facilities,” Proceedings HTR2006: 3rd International Topical Meeting on High Temperature Reactor Technology, Johannesburg, South Africa, Oct. 1–4.
Oh, C. H. , Kim, E. S. , Sherman, S. , Kim, J. H. , and NO, H. C. , 2008, “ Application of Gamma Code Coupled With Turbomachinery Models for High Temperature Gas-Cooled Reactors,” The 12th International Symposium on Transport Phenomena and Dynamics of Rotating Machinery (ISROMAC12), Honolulu, HI, Paper No. ISROMAC12-2008-20224.
Eskom Ltd., 2000, “ PBMR Safety Analysis Report,” Document No. 001929-207/4, Rev. B, 6-17 (PBMR).
Fumizawa, M. , Kaneko, Y. , and Izumi, M. , 2008, “ Porosity Effect in the Core Thermal Hydraulics for Ultra High Temperature Gas-Cooled Reactor,” Journal of Systemics, Cybernetics and Informatics, 6(6), pp. 86–92.
Mkhosi, M. M. , 2007, “ Computational Fluid Dynamics Analysis of Aerosol Deposition in Pebble Beds,” M.S., dissertation, Ohio State University, Columbus, OH.
Ferng, Y. M. , and Chen, C. T. , 2011, “ CFD Investigating Thermal-Hydraulic Characteristics and Hydrogen Generation From Graphite Water Reaction After SG Tube Rupture in HTR-10 Reactor,” Appl. Therm. Eng., 31(2011), pp. 2430–2438. [CrossRef]
Auwerda, G. J. , Zheng, Y. , Lathouwers, D. , and Kloosterman, J. L. , 2011, “ Effect of Non-Uniform Porosity Distribution on Thermal Hydraulics in a Pebble Bed Reactor,” CNS Paper No. NURETH-14.
du Toit, C. G. , and Rousseau, P. G. , 2012, “ Modeling the Flow and Heat Transfer in a Packed Bed High Temperature Gas-Cooled Reactor in the Context of a SYSTEMS CFD Approach,” ASME J. Heat Transfer, 134(3), p. 031015. [CrossRef]
Reitsma, F. , Strydom, G. , de Haas, J. B. M. , Ivanov, K. , Tyobeka, B. , Mphahlele, R. , Downar, T. J. , Seker, V. , Gougar, H. D. , Da Cruz, D. F. , and Sikik, U. E. , 2006, “ The PBMR Steady-State and Coupled Kinetics Core Thermal-Hydraulics Benchmark Test Problems,” Nucl. Eng. Des., 236(2006), pp. 657–668. [CrossRef]
Oh, C. , Kim, E. , Schultz, R. , Patterson, M. , and Petti, D. , 2009, “ Thermal Hydraulics of the Very High Temperature Gas Cooled Reactor,” 13th International Topical Meeting on Nuclear Reactor Thermal Hydraulics, Kanazawa, Japan, Sept. 27–Oct. 2, Paper No. NURETH-13.
Ergun, S. , 1952, “ Fluid Flow Through Packed Columns,” Chem. Eng Process., 48(2), pp. 89–94.
Macdonald, I. F. , El-Sayed, M. S. , Mow, K. , and Dullien, F. A. L. , 1979, “ Flow Through Porous Media: The Ergun Equation Revisited,” Ind. Eng. Chem. Fundam., 18(3), pp. 199–208. [CrossRef]
Kaviany, M. , 1995, Principles of Heat Transfer in Porous Media, Springer, New York.
Griveau, A. , 2007, “ Modeling and Transient Analysis for the Pebble Bed Advanced High Temperature Reactor (PB-AHTR),” University of California, Berkeley, CA, M.S. Project Report No. UCBTH-07-001.
Petersen, H. , 1970, The Properties of Helium: Density, Specific Heats, Viscosity, and Thermal Conductivity at Pressures From 1 to100 bar and From Room Temperature to About 1800, Danish Atomic Energy Commission, Risö, Report No.224.
Launder, B. E. , and Spalding, D. B. , 1973, “ The Numerical Computational of Turbulent Flows,” Comp. Method Appl. Mech. Eng., 3(2), pp. 269–289. [CrossRef]
Celik, I. B. , 1999, Introductory Turbulence Modeling, West Virginia University, Morgantown, WV.
Benenati, R. F. , and Browsilow, C. B. , 1962, “ Void Fraction Distribution in Beds of Spheres,” AIChE J., 8(3), pp. 359–361. [CrossRef]
Du Toit, C. G. , 2008, “ Radial Variation in Porosity in Annular Packed Beds,” Nucl. Eng. Des., 238(11), pp. 3073–3079. [CrossRef]
Vortmeyer, D. , and Schuster, J. , 1983, “ Evaluation of Steady Flow Profiles in Rectangular and Circular Packed Beds by a Variational Method,” Chem. Eng. Sci., 38(10), pp. 1691–1699. [CrossRef]
Hoogenboezem, T. A. , 2006, Heat Transfer Phenomena in Flow Through Packed Bed, Master's thesis North-West University, Potchefstroom, South Africa.
Latifi, M. S. , and Setayeshi, S. , 2016, “ Effects of Porosity on Thermal-Fluid Phenomena in PBMR Core,” J. Therm. Eng. (in press).
Auwerda, G. J. , 2014, “ Core Physics of Pebble Bed High Temperature Nuclear Reactors,” Ph.D. dissertation, Delft University of Technology, Delft, The Netherlands.
Klerk, A. , 2003, “ Voidago Variation in Packed Bed Beds at Small Column to Particle Diameter Ratio,” AIChE J., 49(8), pp. 2022–2029. [CrossRef]
Riberio, A. M. , Neto, P. , and Pinho, C. , 2010, “ Mean Porosity and Pressure Drop Measurements in Packed Beds of Monosized Spheres: Side Wall Effects,” Int. Rev. Chem. Eng., 2(1), pp. 40–46.
Zhai, T. , 2003, “ LOCA and Air Ingress Accident Analysis of a Pebble Bed Reactor,” MIT Ph.D. thesis, Massachusetts Institute of Technology, Cambridge, MA.
Pantankar, S. V. , 1980, Numerical Heat Transfer and Fluid Flow, 1st, ed., Hemisphere Publishing, Washington, DC.
Ferziger, J. H. , and Peric′, M. , 2002, Computational Methods for Fluid Dynamics, 3rd, ed., Springer, Berlin.
ANSYS Inc., 2012, “ FLUENT R14.5 User's Guide,” ANSYS, Canonsburg, PA.
DIN, 1990, “ Berechnung der Nachzerfallsleistung der Kernbrennstoffe von Hochtemperatur-reaktoren mit kugelförmigen Brennelementen,” Deutsches Institut für Normung e.V., Germany, Standard No. DIN 25485.
Bakx, T. , 2011, “ Testing a Nuclear Pebble-Bed Reactor Model in OpenFOAM,” B.S. thesis, Delft University of Technology, Delft, The Netherlands.

Figures

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Fig. 1

The vertical power distribution profile

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Fig. 2

Porosity variation as a function of distance from wall

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Fig. 3

The simplified geometry used in the computations

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Fig. 4

Grid independence test

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Fig. 5

Comparison between the DIN 25,485 standard calculation and CFD results

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Fig. 6

Porosity effect on the average temperature across the axial position of the core under steady-state conditions

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Fig. 7

Porosity effect on the coolant thermal conductivity across the axial position of the core

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Fig. 8

Porosity effect on the average temperature across the axial position of the core under transient conditions

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Fig. 9

Porosity effect on the ratio of unsteady to steady-state temperature

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Fig. 10

The porosity effect on the effective thermal conductivity of the pebble bed across the axial position of the core: (a) under steady-state condition and (b) under transient condition

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Fig. 11

Contour plots of the effective thermal conductivity of the pebble bed along the radial direction at the height of 5.5 m of the core in different porosities: (a) ε = 0.36, (b) ε = 0.39, and (c) ε = 0.43

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Fig. 12

The porosity effect on the behavior of the decay heat at various time periods: (a) 2 hrs < t < 20 hrs, (b) 100 hrs < t < 1100 hrs, and (c) 50 weeks < t < 330 weeks

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