Liquid fuel ignition features during its spilling on the metallic substrate heated up to high temperatures

Abstract

Forecasting heat and mass transfer model for the numerical investigation of fuel ignition features during its spilling on the metallic heated up to high temperatures was developed. The dependences of fuel (by the example of kerosene) ignition delay times on the velocity of its spilling, the liquidfilm (which is formed) thickness and the metallic temperature were found. The least values of these parameters (whereby the ignition is possible under the heat and mass transfer conditions considered) were determined. The analysis of historical data shows that the number of fires and explosions at the places of production associated with the usage of flammable and combustible matters is steadily increased over the last years. The broad-scale research carrying out of macroscopic regularities of ignition and combustion of liquids in its coordination with different, primarily, typical heating sources with the purpose of the determination of the safe conditions for production, storage, transportation, transshipment and allocation of matters is necessary under such conditions (not to mention the requirement strengthening on the part of fire protection agency, routine and discipline strengthening at the places of production). It should be pointed out that the uncontrollable processes of fuel pouring and the matters unappropriated for combustion represent the maximal fire and explosion hazard, as a rule. According to such conditions the ignition can occur in coordination with a heated body, spark, exposed conductors, direct flame and other energy sources. Probably, the interacting processes of spilling liquids with the working areas (heated up to high temperatures) of equipment and metal constructions are the most typical ignition conditions. The liquid film - substrate systems are used as often as not in the numerical analysis of such processes. At that, the emphasis, as a rule, is on the stationary-state combustion. The analysis of ignition conditions for the spilling fuel on the surface heated up to high temperatures is of interest. The purpose of the article is the numerical investigation of macroscopic regularities of typical fuel ignition under its spilling on the metal heated up to high temperatures.