The effect of oxygen concentration on CO and soot yields in fires

摘要

In addition to global ventilation effects on fires, vitiation of air can also affect the generation of chemical species in a built environment. Experiments were performed at lab-scale with the Fire Propagation Apparatus (ASTM E2058) in order to study the effect of air vitiation on CO and soot yields. Results regarding the fuel burning rate are also presented. Both carbon dioxide and nitrogen were used as diluents in the inlet air flows. The oxygen concentration was decreased stepwise until the extinction point was reached. A first set of experiments was performed in well-ventilated fire conditions (equivalence ratio between 0.1 and 0.25). A second set of experiments was carried out in under-ventilated fire conditions (equivalence ratio equal to 1.1). A procedure is proposed for experimental data reduction. The results revealed themselves useful for improving combustion sub-model predictions.