Hot-Spot Ignition of a Reactive Gas in an Inert Porous Medium

The main stages of development of hot-spot ignition of a reactive gas in a high-porous medium with high values of the Peclet number under conditions of natural gas filtration and limited internal heat transfer between the phases are determined. Gas ignition in a U-shaped hot spot is considered within the framework of an asymptotic analysis with high values of the temperature difference and Frank-Kamenetskii parameter. The critical relation of parameters separating the regimes of gas ignition and gradual cooling of the hot spot is determined. The dependence of the ignition time on parameters of the process is found and analyzed. A strong effect of interphase heat transfer on the ignition limit and time is demonstrated. An example of calculating the critical parameters of hot-spot ignition of methane in processed rocks is given. __________ Translated from Fizika Goreniya i Vzryva, Vol. 41, No. 5, pp. 41–48, September–October, 2005.