Модели, системы, сети в экономике, технике, природе и обществе (Jun 2024)
ANALYTICAL EVALUATION OF THE EFFECTIVENESS OF EXTINGUISHING FIRES OF SOLID COMBUSTIBLE SUBSTANCES AND MATERIALS WITH SPECIAL GAS EXTINGUISHING AGENTS
Abstract
Background. The work is devoted to the problem of evaluating the effectiveness of extinguishing open fires of solid combustible substances and materials, as well as internal (closed) fires (if it is impossible to ensure the sealing of the protected volume) by gas fire extinguishing installations when using gas extinguishing agents with special physicochemical properties. The aim of the work is to develop an analytical model for evaluating the effectiveness of extinguishing fires of solid combustible substances and materials with gas extinguishing agents having special physico-chemical properties, taking into account the dynamics of internal (closed) and external (open) fires and the intrinsic electrophysical properties of the flame. Materials and methods. Mathematical models of polarization of electron displacement, as well as ionization by electron impact of gas dielectrics are used in the work to determine the values of the velocity and cross-section of dissociative recombination, and as a consequence, estimation of the time of extinguishing the fire. Results. The physical mechanism of the extinguishing effect of gas extinguishing agents and their mixtures is substantiated, comparative quantitative estimates of the values of the time of the flame flare from the surface of the combustible substance are given, the values of the fire extinguishing time based on the comparison of the values of concentrations and energies of the electronic component during the process of dissociative recombination, accompanied by the decay of the intermediate complex, in the flow of extinguishing agent and flame torch in a stationary combustion mode. Conclusions. A necessary and sufficient condition for extinguishing fires of solid combustible substances and materials with gas extinguishing agents having special physico-chemical properties is the intensification of the rate of dissociative recombination occurring in the structure of flame flare zones when an electronic component of a gas extinguishing agent, polarized and ionized in an external static electric field, is introduced into the fire source. Also, the work shows a relatively higher efficiency of applying an external longitudinal static electric field to the flow of the extinguishing agent, which is due to higher concentrations of the electronic component in the electrode gap.
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