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
Lund University / Faculty of Engineering / Department of Fire Safety Engineering and Systems Safety
Outline
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Background and Scope
Choice of building
Fire modelling
Evacuation modelling
Tenability assessment
Conclusions
Future research
Lund University / Faculty of Engineering / Department of Fire Safety Engineering and Systems Safety
Background
• Is a cable fire dangerous in a realistic
building environment?
• Is cable A better then cable B?
• Suitable methods for assessment?
Lund University / Faculty of Engineering / Department of Fire Safety Engineering and Systems Safety
Background
• Prescriptive rules
• Performance based
rules
• Example:
• Example:
Exit must be 1 m wide
Everyone must be
able to evacuate
before conditions
become critical
Lund University / Faculty of Engineering / Department of Fire Safety Engineering and Systems Safety
Background
• Prescriptive rules
• Performance based
rules
• Example:
• Example:
Only cables of class X
are allowed in
evacuation routes
A specific cable is
allowed in evacuation
paths if safety can be
demonstrated
Lund University / Faculty of Engineering / Department of Fire Safety Engineering and Systems Safety
Background
• Fire Safety Engineering
(FSE) methods
Lund University / Faculty of Engineering / Department of Fire Safety Engineering and Systems Safety
Scope
• Develop feasible technique using FSE
• Compare 2 cables with the technique
Lund University / Faculty of Engineering / Department of Fire Safety Engineering and Systems Safety
Layout of the procedure
Lund University / Faculty of Engineering / Department of Fire Safety Engineering and Systems Safety
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
Lund University / Faculty of Engineering / Department of Fire Safety Engineering and Systems Safety
Choice of the building
Lund University / Faculty of Engineering / Department of Fire Safety Engineering and Systems Safety
Choice of the building
Lund University / Faculty of Engineering / Department of Fire Safety Engineering and Systems Safety
Fire scenario
• Possible locations
• Cable cabinet – under balcony
• Cables in appliances - kitchen
• Vertical cable tray – in atrium
Lund University / Faculty of Engineering / Department of Fire Safety Engineering and Systems Safety
Fire scenario
• Possible locations:
Lund University / Faculty of Engineering / Department of Fire Safety Engineering and Systems Safety
Fire scenario
•Choice fire position:
Vertical cable tray – in atrium
from pre-simulations
Lund University / Faculty of Engineering / Department of Fire Safety Engineering and Systems Safety
Fire scenario
• Design fire
• Data from cable tests – prEN 50399
• 2 cables - Euroclass D
• Cable I
• Cable M
• FIGRA value => growth rate up to 0.5 MW
Lund University / Faculty of Engineering / Department of Fire Safety Engineering and Systems Safety
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
Lund University / Faculty of Engineering / Department of Fire Safety Engineering and Systems Safety
Fire scenario
• Design fire
Lund University / Faculty of Engineering / Department of Fire Safety Engineering and Systems Safety
Fire modelling
• Computational Fluid Dynamics (CFD)
Lund University / Faculty of Engineering / Department of Fire Safety Engineering and Systems Safety
Fire modelling
• FDS 5 software –
parallel version on cluster
Lund University / Faculty of Engineering / Department of Fire Safety Engineering and Systems Safety
Fire modelling
Lund University / Faculty of Engineering / Department of Fire Safety Engineering and Systems Safety
Evacuation scenario
• Evacuation experiment – input data
• Time to start (pre-movement)
• Exit choice
• Flow on stairs
Lund University / Faculty of Engineering / Department of Fire Safety Engineering and Systems Safety
Evacuation scenario
• Evacuation experiment – input data
Lund University / Faculty of Engineering / Department of Fire Safety Engineering and Systems Safety
Evacuation scenario
• Evacuation scenarios – 6 scenarios
• Number and location of occupants
• Exit choice
• One scenario selected for tenability
assessment (based on 450 occupants)
Lund University / Faculty of Engineering / Department of Fire Safety Engineering and Systems Safety
Evacuation modelling
• Simulex software
Lund University / Faculty of Engineering / Department of Fire Safety Engineering and Systems Safety
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
Lund University / Faculty of Engineering / Department of Fire Safety Engineering and Systems Safety
Tenability assessment
Property
FED >
0.3
FEC >
0.3
Cable I
0
Cable M
0
0
41
Based on 450 occupants
Lund University / Faculty of Engineering / Department of Fire Safety Engineering and Systems Safety
Lund University / Faculty of Engineering / Department of Fire Safety Engineering and Systems Safety
Conclusions
• Feasibility of the method was demonstrated in
this case study
• Cable M worse than Cable I
for this case study
Lund University / Faculty of Engineering / Department of Fire Safety Engineering and Systems Safety
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
Lund University / Faculty of Engineering / Department of Fire Safety Engineering and Systems Safety
Acknowledgments
• Report available at www.brand.lth.se/publikationer
• Video available at http://safety-during-fire.com/library.html
Lund University / Faculty of Engineering / Department of Fire Safety Engineering and Systems Safety
www.brand.lth.se/english
Lund University / Faculty of Engineering / Department of Fire Safety Engineering and Systems Safety