ESTS0023 COMPBRN3.
COMPBRN3, Modelling of Nuclear Power Plant Compartment Fires
NAME OR DESIGNATION OF PROGRAM, COMPUTER, DESCRIPTION OF PROGRAM OR FUNCTION, METHOD OF SOLUTION, RESTRICTIONS ON THE COMPLEXITY OF THE PROBLEM, TYPICAL RUNNING TIME, UNUSUAL FEATURES OF THE PROGRAM, RELATED AND AUXILIARY PROGRAMS, STATUS, REFERENCES, MACHINE REQUIREMENTS, LANGUAGE, OPERATING SYSTEM UNDER WHICH PROGRAM IS EXECUTED, OTHER PROGRAMMING OR OPERATING INFORMATION OR RESTRICTIONS, NAME AND ESTABLISHMENT OF AUTHORS, MATERIAL, CATEGORIES
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| Program name | Package id | Status | Status date |
|---|---|---|---|
| COMPBRN3 | ESTS0023/02 | Tested | 30-JUN-1994 |
Machines used:
| Package ID | Orig. computer | Test computer |
|---|---|---|
| ESTS0023/02 | IBM PC | PC-80486 |
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3. DESCRIPTION OF PROGRAM OR FUNCTION
COMPBRN3 is a deterministic fire hazards program designed for use in probabilistic analysis of fire growth in a particular room. This analysis is required when assessing the risk associated with fires in nuclear power plants. An air entrainment model is included which consists of a plume entrainment model, a wall jet entrainment model, and a model for the doorway mixing effect. Output available includes the total heat release rate of the fire, the temperature and thickness of the hot gas layer formed near the compartment ceiling, the mass burning rate for individual fuel elements, the surface temperature of the elements, and the thermal heat flux at user-specified locations.
COMPBRN3 is a deterministic fire hazards program designed for use in probabilistic analysis of fire growth in a particular room. This analysis is required when assessing the risk associated with fires in nuclear power plants. An air entrainment model is included which consists of a plume entrainment model, a wall jet entrainment model, and a model for the doorway mixing effect. Output available includes the total heat release rate of the fire, the temperature and thickness of the hot gas layer formed near the compartment ceiling, the mass burning rate for individual fuel elements, the surface temperature of the elements, and the thermal heat flux at user-specified locations.
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4. METHOD OF SOLUTION
A quasi-static approach is followed to simulate the process of fire growth during the pre-flashover period in an enclosure. The compartment is modeled as two zones (or control volumes) which divide it into two distinct, homogeneous, stably-stratified regions. The hot gases accumulating under the ceiling due to fire plume entrainment and negative buoyancy are defined as the upper layer (the ceiling hot gas layer). The lower region is assumed to be thermally inert and contains relatively quiescent cool air, which remains at ambient conditions at all times. These regions are separated by a thermal interface with uniform height inside the room and a higher elevation at the doorway. At each time-step, the hot gas layer model computes the thermal interface heights, the hot gas layer temperature, and the heat fluxes to fuel elements by solving several coupled mass and heat steady-state balance equations by a Newton-Raphson iteration scheme. Correlations are used to determine the convective heat transfer in the buoyant plume of hot gases above the flames. The COMPBRN3 steady-state models and submodels are taken from the fire research literature.
A quasi-static approach is followed to simulate the process of fire growth during the pre-flashover period in an enclosure. The compartment is modeled as two zones (or control volumes) which divide it into two distinct, homogeneous, stably-stratified regions. The hot gases accumulating under the ceiling due to fire plume entrainment and negative buoyancy are defined as the upper layer (the ceiling hot gas layer). The lower region is assumed to be thermally inert and contains relatively quiescent cool air, which remains at ambient conditions at all times. These regions are separated by a thermal interface with uniform height inside the room and a higher elevation at the doorway. At each time-step, the hot gas layer model computes the thermal interface heights, the hot gas layer temperature, and the heat fluxes to fuel elements by solving several coupled mass and heat steady-state balance equations by a Newton-Raphson iteration scheme. Correlations are used to determine the convective heat transfer in the buoyant plume of hot gases above the flames. The COMPBRN3 steady-state models and submodels are taken from the fire research literature.
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6. TYPICAL RUNNING TIME
NESC executed the sample problem in 1 minute on an IBM PC/AT with a math coprocessor.
NESC executed the sample problem in 1 minute on an IBM PC/AT with a math coprocessor.
ESTS0023/02
NEA-DB ran the test case included in this package on a66-MHz PC/486 in about 2 seconds of clock time.
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8. RELATED AND AUXILIARY PROGRAMS
COMPBRN3 supersedes the earlier COMPBRN codes. COMPBRN3 employs a different air entrainment model and better numerical scheme to solve for the properties of the ceiling hot gas layer; incorporates a number of changes to the plume heat transfer, mean plume temperature correlation, cylindrical shape factor, and vertical fuel cell calculations, and includes added error checking and user-friendly features.
COMPBRN3 supersedes the earlier COMPBRN codes. COMPBRN3 employs a different air entrainment model and better numerical scheme to solve for the properties of the ceiling hot gas layer; incorporates a number of changes to the plume heat transfer, mean plume temperature correlation, cylindrical shape factor, and vertical fuel cell calculations, and includes added error checking and user-friendly features.
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10. REFERENCES
- COMPBRN3, NESC No. 1105, COMPBRN3 IBM PC Version Flexible Disk
Cartridge, Description and Implementation Information,
NESC Note 89-21 (December 7, 1988).
- N.O. Siu:
COMPBRN - A Computer Code for Modeling Compartment Fires
NUREG/CR03239 (UCLA-ENG-8257), (1983).
- COMPBRN3, NESC No. 1105, COMPBRN3 IBM PC Version Flexible Disk
Cartridge, Description and Implementation Information,
NESC Note 89-21 (December 7, 1988).
- N.O. Siu:
COMPBRN - A Computer Code for Modeling Compartment Fires
NUREG/CR03239 (UCLA-ENG-8257), (1983).
ESTS0023/02, included references:
- Vincent Ho, Nathan Siu, G. Apostolakis and G.F. Flanagan:COMPBRN III - A Computer Code for Modeling Compartment Fires
NUREG/CR-4566, ORNL/TM-10005 (July 1986).
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ESTS0023/02
NEA-DB implemented the program on a DELL 466/L 66-MHZ 80486 with 8 MBytes of RAM. The executable generated with a Lahey compiler has a file size of 418,664 bytes. The executable generated with Microsoft compiler has a file size of 192,648 bytes.[ top ]
ESTS0023/02
The program was implemented under MS-DOS version 6.2. The source code was compiled both with the Lahey F77L-EM/32 Version 5.20 and the Microsoft Version 5.1 Fortran compiler.[ top ]
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ESTS0023/02
| File name | File description | Records |
|---|---|---|
| ESTS0023_02.001 | Information file | 101 |
| ESTS0023_02.002 | COMPBRN3 Fortran 77 source | 2926 |
| ESTS0023_02.003 | COMPBRN3 Lahey executable | 0 |
| ESTS0023_02.004 | COMPBRN3 Microsoft executable | 0 |
| ESTS0023_02.005 | Sample problem input | 22 |
| ESTS0023_02.006 | Sample problem output | 2609 |
| ESTS0023_02.007 | DOS file-names | 6 |
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- G. Radiological Safety, Hazard and Accident Analysis
- H. Heat Transfer and Fluid Flow
Keywords: fires, gases, heat transfer, nuclear facilities, probabilistic sys assessment, risk assessment, safety.