Conditions of occurrence of fire in the room with a gas explosion. Experimental data

Introduction. Fires that occur when gas explosions occur in residential areas exacerbate an already dangerous ¬situation, but they do not always happen. This allows us to hope for the possibility of reducing fire risks in gas explosions by conducting research and developing measures for this. The task of the research is defined as the study of the conditions under which fires occur in the case of gas explo¬sions in the room. The process of interaction of gases and combustible materials is characterized by short-term ¬explosion and heating of combustible materials with a lack of oxygen. Presumably, the conditions for the ignition of combustible materials are their low heat capacity, the location of the position in the volume and the flow of ex¬ternal air into the chamber. Methods and means of research. The research was carried out experimentally on a 10 m3 cubic chamber filled with propane-air mixture. The explosion pressure was recorded and video was recorded outside and inside the chamber. To assess the level of flame impact on the combustible material, the developed indicators of heat flows with a sensitive element in the form of paper were used. There were 24 indicators inside the chamber. Research result and discussion. It was found that less fire-dangerous places, where the thermal impulse was no more than 500 kJ/m2, were the corners of the chamber and its wall areas, excluding the upper wall, and more ¬fire-dangerous was the volume from the center up to the window opening along its entire width, where the thermal impulse was 600 kJ/m2 or more. There were no visible traces of coking in the places where the paper and wire were glued together. The paper, which was in a fire-hazardous area, ignited when the outside air came in after the explosion. Assumptions about the conditions of fire in a gas explosion in the room were confirmed: the risk of fire depends on the heat capacity of the combustible materials, their position in the volume and the flow of external air into the chamber after the explosion.