A calculation method of chamberless thermal determination of intrinsic safety for electrical circuits

A mathematical model of electric ignition for methane-air mixture from a source of sustained power is applied to develop a reliable calculation method for determination of the intrinsic safety of electrical circuits of explosion-proof electrical equipment. A method for rapid calculating of the intrinsic safety for explosion-proof electrical equipment is developed that is suitable for evaluation of a wide class of circuits, including systems with reduced discharge time, based on regression relationships obtained by the preliminary pattern of thermal explosion field. The possibility of using the proposed method is shown by the example of determination of the intrinsic safety of electrical circuits of a dc power supply with high load capacity, which responds to the excess of the modulus for the rate of change of load current strength. © 2013 Allerton Press, Inc.