Theoretical prediction model for minimum ignition energy of combustible gas mixtures

Abstract

Minimum ignition energy (MIE) is a crucial parameter for identifying the hazards of combustible gases. To rapidly obtain accurate MIE values for various gases, the shape of the ignition source was simplified to cylindrical. Based on theories of heat conduction and chemical reaction kinetics, a physical model of the ignition process was established. The spatial and temporal evolution of temperature was used as a basis for judging the success of ignition. A numerical algorithm was developed and maximum flame temperatures and MIE were calculated for several combustible gases (H2, CH4, C2H6, C3H8, C4H10, C2H4, C2H2). This model accurately predicted the U-shaped trend of MIE values with concentration for CH4/air and H2/air mixtures. It found that the MIE was minimal at the stoichiometric concentration, at 0.37 mJ and 0.017 mJ, closely aligning with experimental data. This numerical model has been validated for its accuracy and promises to make relatively precise theoretical predictions for the MIE values of uncommon combustible gases or mixtures of various gases.