METHOD FOR CALCULATED ASSESSMENT OF SPARK SAFETY OF ELECTRIC CIRCUITS OF MINE EQUIPMENT

摘要

Method for calculated assessment of spark safety of electric circuits of mine equipment includes mathematical modeling of parameters of arc discharge of interruption and thermal burst and evaluation of ignition ability of methane-air mixture. One calculates value of thermal constant of arc time and power that is taken off from it, depending on current and voltage of transition process, with account of those changes at determination of energy of electric discharge and time of its existence, with quantitative evaluation of development of temperature field of thermal burst. Determination of temperature of explosion-dangerous methane-air mixture is carried out by means of solving equations of its heat conductivity, diffusion and exothermal chemical reaction of oxidation, and at values of temperature front of flame equal to temperature of burning of methane-air gas mixture 2000 K one makes conclusion on fact of danger of sparking in electric circuit.