SIMULATION OF CRITICAL EVACUATION CONDITIONS FOR FIRE SCENARIOS INVOLVING CABLES AND COMPARISON OF DIFFERENT CABLES

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SIMULATION OF CRITICAL EVACUATION CONDITIONS FOR
FIRE SCENARIOS INVOLVING CABLES AND COMPARISON OF
DIFFERENT CABLES
Patrick van Hees Daniel Nilsson Lund University
Department of Fire Safety Engineering and
Systems Safety
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Outline

• Background and Scope
• Choice of building
• Fire modelling
• Evacuation modelling
• Tenability assessment
• Conclusions
• Future research

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Background

• Is a cable fire dangerous in a realistic building
  environment?
• Is cable A better then cable B?
• Suitable methods for assessment?

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Background

• Performance based rules
• Example
• Everyone must be able to evacuate before
  conditions become critical

• Prescriptive rules
• Example
• Exit must be 1 m wide

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Background

• Prescriptive rules
• Example
• Only cables of class X are allowed in evacuation
  routes

• Performance based rules
• Example
• A specific cable is allowed in evacuation paths
  if safety can be demonstrated

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Background

• Fire Safety Engineering (FSE) methods

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Scope

• Develop feasible technique using FSE
• Compare 2 cables with the technique

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Layout of the procedure
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Choice of the building

• Requirements
• a public building
• a realistic building - FSE possible
• existence of fire risk related to cables
• data available evacuation or fire
• possible exposure to gases

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Choice of the building
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Choice of the building
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Fire scenario

• Possible locations
• Cable cabinet under balcony
• Cables in appliances - kitchen
• Vertical cable tray in atrium

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Fire scenario

• Possible locations

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Fire scenario

• Choice fire position
• Vertical cable tray in atrium
• from pre-simulations

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Fire scenario

• Design fire
• Data from cable tests prEN 50399
• 2 cables - Euroclass D
• Cable I
• Cable M
• FIGRA value gt growth rate up to 0.5 MW

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Fire scenario

• Design fire
• Product yields from fire tests
• Cable I carbon monoxide, carbon dioxide, soot
• Cable M carbon monoxide, carbon dioxide, soot,
  acrolein, formic aldehyde, hydrogen chloride

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Fire scenario

• Design fire

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Fire modelling

• Computational Fluid Dynamics (CFD)

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Fire modelling

• FDS 5 software
• parallel version on cluster

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Fire modelling
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Evacuation scenario

• Evacuation experiment input data
• Time to start (pre-movement)
• Exit choice
• Flow on stairs

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Evacuation scenario

• Evacuation experiment input data

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Evacuation scenario

• Evacuation scenarios 6 scenarios
• Number and location of occupants
• Exit choice
• One scenario selected for tenability assessment
  (based on 450 occupants)

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Evacuation modelling

• Simulex software

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Tenability assessment

• FED and FEC ISO TS 13571
• FED accumulated dose
• FEC momentary concentration
• Combination of results
• FDS Fire simulations
• Simulex Evacuation simulations
• Matlab FED and FEC calculations

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Tenability assessment
Property Cable I Cable M
FED gt 0.3 0 0
FEC gt 0.3 0 41
Based on 450 occupants
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Conclusions

• Feasibility of the method was demonstrated in
  this case study
• Cable M worse than Cable I
• for this case study

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Future Research

• Develop method further
• Compare cables with other characteristics
• Test method for other buildings and cases
• Sensitivity of input data from fire tests
• Extend to other materials/products

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Acknowledgments

• Report available at www.brand.lth.se/publikationer
  
• Video available at http//safety-during-fire.com/l
  ibrary.html

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www.brand.lth.se/english