Phenomenological description of actual electrical cabinet fires in a free atmosphere
Titre du congrès :Interflam 2007 - 11th International Conference on Fire Science and Engineering
Ville du congrès :Londres
Date du congrès :03/09/2007
The IRSN is carrying out research programs on the consequences of fire at nuclear facilities. This paper presents an experimental study, carried out in collaboration with AREVA, on fires in electrical cabinets with open or closed doors.
The study concerns temporal variation of the heat release rate of the fire, temporal and spatial variation of the incident radiant heat fluxes in front of the burning cabinet, and the quantity of soot produced during the fire. A phenomenological description of the fire is proposed based on the variation of the heat release rate. Flashover of electrical components leading to a fully developped fire appears for a heat release rate of about 100kW. Based on measurements and a simplified approach to heat transfer, an isoflux map has been drawn up for the fully developed fire phase. This allows us to determine, as an initial approach, the thermal stresses imposed on equipment located in the vicinity of the electrical cabinet on fire. Soot production is more intense in the case of closed-door cabinets than open-door cabinets but the quantity of soot produced during the fire is greater in the case of open-door cabinets. Finally, based on comparison of measured heat release rates and radiant heat fluxes, open-door cabinet fires are not reproducible in terms of instantaneous values but are reproducible in terms of average values.