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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. Outline. Background and Scope Choice of building Fire modelling
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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
Outline • Background and Scope • Choice of building • Fire modelling • Evacuation modelling • Tenability assessment • Conclusions • Future research
Background • Is a cable fire dangerous in a realistic building environment? • Is cable A better then cable B? • Suitable methods for assessment?
Prescriptive rules Example: Exit must be 1 m wide Performance based rules Example: Everyone must be able to evacuate before conditions become critical 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 Background
Background • Fire Safety Engineering (FSE) methods
Scope • Develop feasible technique using FSE • Compare 2 cables with the technique
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
Fire scenario • Possible locations • Cable cabinet – under balcony • Cables in appliances - kitchen • Vertical cable tray – in atrium
Fire scenario • Possible locations:
Fire scenario • Choice fire position: • Vertical cable tray – in atrium • from pre-simulations
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
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
Fire scenario • Design fire
Fire modelling • Computational Fluid Dynamics (CFD)
Fire modelling • FDS 5 software – • parallel version on cluster
Evacuation scenario • Evacuation experiment – input data • Time to start (pre-movement) • Exit choice • Flow on stairs
Evacuation scenario • Evacuation experiment – input data
Evacuation scenario • Evacuation scenarios – 6 scenarios • Number and location of occupants • Exit choice • One scenario selected for tenability assessment (based on 450 occupants)
Evacuation modelling • Simulex software
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
Tenability assessment Based on 450 occupants
Conclusions • Feasibility of the method was demonstrated in this case study • Cable M worse than Cable I • for this case study
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
Acknowledgments • Report available at www.brand.lth.se/publikationer • Video available at http://safety-during-fire.com/library.html