Hot-spot thermal ignition in a porous medium under conditions of natural gas filtration

The development of a hot spot in a porous reactive medium with chemical rea ctions occurring at the inner surface of the pores between a solid skeleton and a gaseous oxidizer is studied by asymptotic methods at large values of the Peclet number, the Frank-Kamenetskii parameter, and the temperature he ad. It is shown that upon natural gas filtration, the process develops in t wo stages. In the first stage, the pressure, density, and temperature of th e gas are equalized over the entire porous medium, and a hot spot develops on the skeleton in the second stage. The limit of hot-spot ignition and the ignition time for a hot spot are determined. An example of calculation of the critical parameters of the system is given.