Fire Safety Science Digital Archive

This paper presents an experimental study of the behaviour of the mass loss rate (MLR) of pool fires in mechanically ventilated compartments within the framework of fire research activities conducted at the French Institute for Radiological Protection and Nuclear Safety (IRSN). Two typical scenarios are investigated: the 1-room configuration and the 2-rooms configuration with an open doorway between the two rooms. This study is based on full scale tests carried out as part of the international OECD PRISME project (OECD: Organisation for Economic Co-operation and Development; PRISME: French acronym for “Fire Propagation in Elementary Multi-room Scenarios”). First the behaviours of the MLR for the two scenarios are presented independently. A comparison is then proposed that highlights the effect of the air change rate on the MLR. The analysis shows that the MLR depends on two effects: the oxygen concentration and a blowing effect towards the pool. For most tests, the effect of oxygen concentration is predominant and the MLR varies linearly with the change of oxygen concentration. For one test with the 2- rooms scenario, the air flow at the door seems to induce higher oxygen level adjacent to the pool and the MLR is identical to that in the open air, albeit with an oxygen concentration below 21%vol; In this configuration, the air flow at the door may induce not only a locally higher oxygen level, but also a blowing effect that stokes the fire. This large-scale test campaign shows that the air flow around the pool is also an important parameter to predict the MLR.