1 / 28

Computer Fluid Dynamic Simulation of Fire and Evacuation Scenarios for Large Experiments of Physics

Computer Fluid Dynamic Simulation of Fire and Evacuation Scenarios for Large Experiments of Physics. 5 th HEP Technical Safety Forum at SLAC 11-15 Apr 2005. Topics. Introduction CFD Codes Validation Applications Evacuation Codes Validation Applications. …For structural integrity

shada
Download Presentation

Computer Fluid Dynamic Simulation of Fire and Evacuation Scenarios for Large Experiments of Physics

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. CERN - European Organization for Nuclear Research Computer Fluid Dynamic Simulation of Fire and Evacuation Scenarios for Large Experiments of Physics 5th HEP Technical Safety Forum at SLAC 11-15 Apr 2005

  2. Topics • Introduction • CFD Codes • Validation • Applications • Evacuation Codes • Validation • Applications CERN - European Organization for Nuclear Research

  3. …For structural integrity Long term wall temperatures Hot gases temperatures …For life protection Early stage visibility Smoke dilution & composition Gas temperatures (Radiant heat) How to assess fires ..let’s begin with the answer which we need; we want to know:… Walls and objects Surface Temperature plot Gas Temperature slice plot Mixture fraction Iso-surface plot Gas Velocity vector plot CERN - European Organization for Nuclear Research

  4. The idea is : To run fully instrumented small scale real fire tests (record fire power, T, p, soot, chemical species and concentration) to obtain results by interpolation of the real fire tests by means of semi-empirical equation Bigger precision and extrapolation of the small scale tests are possible, to a certain extent (*), with Computational Flow Dynamic (CFD) How to assess fires (continued) …a glance at the CFD method… (*) CFD growing precision and validation means chance to downsize real test on materials and money saved! CERN - European Organization for Nuclear Research

  5. Market Survey CFD Codes (most referenced) Here are reported the most referenced &used CFD codes for Smoke transport-diffusion modeling • FDS – (National Institute of Science and Technology –MD-US) (free) • Phoenics (Concentr. Heat and Momentum Ldt, GB) (100-2000eu) • Fluent (Fluent Inc. GB) (price requested) • Flow3d (Flow Science Inc. NM-US) • Smartfire (University of Greenwich) (2500eu edu) • Jasmine (Ies Limited GB) (12000eu ) • Sofie (University of Cranfield – GB) (150eu) • CFX Gen.Purpose Dedicated CERN - European Organization for Nuclear Research

  6. Heiss Dampf Nuclear Reactor at Karlsrhue ~50, fully instrumented oil, propane, cables fire tests in the dismantled reactor vessel (20m large, 50 m high) FDS2 was back-validated against these data at Maryland University Memorial Tunnel Fire Test in US ~100 fully instrumented oil fire and ventilation tests FDS2 was back-validated against these data at CERN ValidationValidation effort at CERN and elsewhere on FDS2 Large scale test, well representative of large experiment halls Long tunnel test, well representative of Accelerator Tunnels CERN - European Organization for Nuclear Research

  7. FDS2 Validation • Heiss-Dampf Reaktor Karlsruhe Gasoil 2-4 MW fire (Test T52) Propane 1 MW fire (Test T51) CERN - European Organization for Nuclear Research

  8. HDR Propane TEST T51 Data comparison ~5% ~11% FIRE room ceiling level layer Doorway ceiling level layer Doorway temperature profile FIRE room floor level layer ~15% ~100% CERN - European Organization for Nuclear Research

  9. HDR TEST T52 OIL 2 MW Data comparison Fire room temperature ~27% More on the geometry O2 ~8% Upper Hatch temperature Doorway temperature ~45% ~12% Doorway velocity ~14% CERN - European Organization for Nuclear Research

  10. FDS2 MEMORIAL TUNNEL FIRE TEST VALIDATION The Memorial tunnel test program has provided a huge amount of raw data on road tunnel fire 8m high Flight view inside tunnel Tests 850m long 8m large CERN - European Organization for Nuclear Research

  11. CASE T501: 20 MW Natural Ventilation – (Temperature) 16’ from ignition TEMPERATURES OBSERVED: ~150-300F = 80-150C ~150-300F = 80-150C FDS2 RESULT CERN - European Organization for Nuclear Research

  12. Validation Overall Judgment • The average results of the FDS2 in different situations(*) is as follows : • Long term quasi steady Gas temperatures • errors of the order of 20-30% of the DT • Gas Concentration • large errors, of ~ 1 orderof magnitude • Velocity of transients, like smoke layers descentand movement • errors of the order of 40-60 %. • (*)different situations: • small room-small fire, • small room-big fire, • high bay-small fire, • high bay-big fire, tunnel fire, • pre-flashover, post-flashover, • poor ventilation, rich ventilation, • etc……!!!!!! CERN - European Organization for Nuclear Research

  13. Evacuation Simulation M. Survey • Evacuation simulation codes: • Simulex (I.E.S. International) • License 2500€/yr • Exodus 3D Greenwich University (Fire Safety Group) • License 5000 €/yr CERN - European Organization for Nuclear Research

  14. What we have to assess on fires: (continued)‘…The construction works must be designed and built in such a way that in the event of an outbreak of fire:.. • …(d) occupants can leave the construction works or be rescued • …(e) the safety of rescue teams is taken into consideration Will occupants leave the structure before the smoke/fire produces untenable conditions? Ship muster point video CERN - European Organization for Nuclear Research

  15. Exodus Validation References • The Validation of Evacuation Models. Authors: E Galea. CMS Press, Paper No. 97/IM/22, ISBN 1 899991 22 0, 1997 • The EXODUS Evacuation Model Applied to Building Evacuation Scenarios. Authors: M Owen, E Galea, P Lawrence. Journal of Fire Protection Engineering 1996, Vol.8(2), pp 65-86 • The Collection and Analysis of Pre-Evacuation Times from Evacuation Trials and their Application to Evacuation Modelling”. Gwynne S, Galea E.R., Parke J, Hickson J. Fire Technology, Kluwer Associates, US, pp173-195, vol 39, number 2, 2003. CERN - European Organization for Nuclear Research

  16. APPLICATIONS AT CERN CERN - European Organization for Nuclear Research

  17. The fire • Parabolic ramping fire power 0 -> 5MW then steady • Two different growth rates ( 5 MW in 700s , 1500s) • Located in 3 different position (bottom, top, side) • 6 different runs per each experimental cavern CERN - European Organization for Nuclear Research

  18. ATLAS CERN - European Organization for Nuclear Research

  19. Atlas Fires Locations In front of one exit Under Detector Top of Detector CERN - European Organization for Nuclear Research

  20. ATLAS Videos • ATLAS THE CONSTRUCTION OF THE MODEL2.avi • ATLASLARGE.avi CERN - European Organization for Nuclear Research

  21. ATLAS Slices (Fire under det. 5Mw 300s) t=150 s Smoke fills upper level t=100 s t=200 s Smoke starts to descend on upper gangways t=250-300s Smoke at level of upper exits CERN - European Organization for Nuclear Research

  22. CMS CERN - European Organization for Nuclear Research

  23. Smoke development and transport within the cavern CMS model showcase CMS Fire Under Detector 5 MW CERN - European Organization for Nuclear Research

  24. Smoke layer position on the xz plane of the cavern 3rd level gangway flooded by smoke t=3’ t=5’ 1st level gangway flooded by smoke 2rd level gangway flooded by smoke t=7’ t=6’ CERN - European Organization for Nuclear Research

  25. Evacuation modelling • 130 people in ATLAS 100 people in CMS Snapshots of the CMS Model Snapshot of the Atlas Evacuation Simulation CERN - European Organization for Nuclear Research

  26. Results Overview ATLAS • ATLAS: • Smoke propagation to exit level gangways: • 300s (medium propagation) to 480s (moderate propagation) • Evacuation Time: [120s for discovery] + 90to160s= • 210s to 280s • Evacuation Validated CERN - European Organization for Nuclear Research

  27. Results Overview CMS • ATLAS: • Smoke propagation to exit level gangways: • 250s (medium propagation) to 360s (moderate propagation) • Evacuation Time: [120s for discovery] +85 to 110s= 205 to 230s • Evacuation Validated CERN - European Organization for Nuclear Research

  28. Conclusions • CFD and evacuation simulation tools allowed simulation and reasoned validation of complex and non standard geometries • The findings show that the gap between evacuation and smoke propagation is not high • Several measures have to be in place in order to minimize delays and difficulties in case of emergency • …(but this is by itself a different and huge subject) CERN - European Organization for Nuclear Research

More Related