The criteria of criticality and transition conditions of gas explosion

The characteristics of a gas explosion are investigated. The investigation assumed the Arrhenius form for a reaction's rate constant as well as the Frank-Kamenetskii approximation for it. The critical and transitional conditions of a gas explosion at constant pressure and varying pressures are investigated. Analytical solutions are desired for zero and first-order reactions in the pressure-time, temperature-time, and pressure-temperature planes. The analysis showed that the critical parameters for a constant pressure explosion are lower than that for constant volume where theta{*}(tr) is lowered from 0.5 to 0.29 and theta(atr) is also lowered from 0.25 to 0.17. The sensitivity of the critical pressure to the ambient temperature and the boundary between ignition and non-ignition regions are also determined. It was found that the critical parameters in the temperature-pressure plane were different from those obtained in the temperature-time plane or the pressure-time plane.