Electrical discharges caused by opening contacts in an ignitable atmosphere – Part I: Analysis of electrical parameters at ignition limits

Ignition by Low-Voltage Electric Discharges of Diluted and Undiluted C3H8–Air Mixtures

“…The minimum ignition currents measured for break sparks and the critical ignition energies for hydrogen–, alkane–, and alkene–air mixtures using the standard test cell and the standard method recommended by IEC were previously reported, − ,,− mostly at ambient initial conditions. Experimental studies on critical conditions of ignition by low-voltage electric sparks, conducted on n -butane–air, , liquefied petroleum gas (LPG)–air, ethylene–air, and propene–air mixtures delivered MICs over an extended range of initial pressures, down to 0.25 bar and outlined the MIC variation with pressure.…”

“…The standard method for studying the ignition hazards of fuels is the determination of minimum ignition energy (MIE) using high-voltage capacitive discharges as ignition sources. , Lewis and von Elbe were the first authors who reported minimum ignition energies for a large number of fuels in various initial conditions (composition, pressure, and temperature). They defined the minimum ignition energy as the energy that a capacitor can accumulate at a known voltage and then transfer to a flammable mixture, using capacitive discharges for ignition. , Still, recent reports have outlined the fact that electric spark ignition is a statistical process, difficult to characterize by a single threshold value, as suggested by classic MIE studies. , Many authors studied the characteristics of electric discharges able to produce ignition, such as the types of discharge, the duration of the spark, the characteristics of the spark gap, and the energy of the spark. − Other studies have been focused on the characteristics of the flammable mixtures that can be ignited by electric sparks, such as the critical ignition values of initial pressure, temperature, and composition of flammable mixtures able to be ignited by some defined transferred energy. − …”

“…Experimental studies on critical conditions of ignition by low-voltage electric sparks, conducted on n -butane–air, , liquefied petroleum gas (LPG)–air, ethylene–air, and propene–air mixtures delivered MICs over an extended range of initial pressures, down to 0.25 bar and outlined the MIC variation with pressure. The ignition of hydrogen–air and methane/hydrogen–air by break sparks was experimentally studied by monitoring the transient flame kernel using high-resolution interferometry, and numerically, assuming a three-dimensional (3-D) reactive flow along with detailed chemical kinetics. − ,, To validate the computational model, which uses the discharge at the contact arc as a heat source, the ignition delay and critical currents were measured. Then, the temporal and spatial distributions of the energy were correlated by an empirical model using the measured current, the intensity of radiation, and the voltage of the produced arc.…”

Optimal Design Method for Inner-Intrinsically Safe Buck-Boost Converters Based on Ignition Capability

“…(1) According to the above parameters and equation (8), the inductance L must be greater than L E min , which is given by the following:…”

“…e inner-intrinsically safe buck-boost converter (IISBBC) must not ignite explosive gases when an inductordisconnected discharge (IDD) occurs [3][4][5]. Intrinsic safety is achieved by limiting the ignition capability of components in the IISBBC [6][7][8][9][10]. erefore, research on the design and optimization of the IISBBC is needed.…”