Simulation of critical evacuation conditions for a fire scenario involving cables and comparison of two different cables

Författare

Patrick Van Hees
Daniel Nilsson
Emil Berggren

Summary, in English

Previous studies on the evaluation of irritant species from burning cables in a

modified prEN 50399 fire test produced FEC/FED values based on ISO TS 13571.

However, the ISO standard mentions in its scope that these indices can only be used

within e.g. modelling. For this reason Europacable (ECBL) initiated a preliminary

case-study to asses the possibility of using modern fire safety engineering techniques.

The scope of the project was the evaluation of the evacuation conditions for a

realistic fire scenario involving two types of cable fires that produce different levels

of heat, smoke and gases. Both CFD (Computational Fluid Dynamics) modelling by

means of the software package FDS (Fire dynamics simulator) and evacuation

modelling by means of the software package Simulex were performed. The results

were used to calculate FED (fractional effective doses) and FEC (fractional effective

concentration). The results showed that the developed methodology allows

evaluation of critical evacuation conditions based on not only temperature and

visibility, but also on gas composition. One of the selected cables created critical

conditions for some of the occupants during evacuation for the chosen design fire

when the production of irritant gases (HCl, acreolein, Formaldehydes) is considered.

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