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Combustion of high-energy chemical fuels containing dioxins in their elemental composition can lead to the formation of super eco toxicants on smoke particles-polychlorinated dioxins and furans. The choice of the method of solving the equations of chemical kinetics is basic in numerical experiment. Calculation and theoretical studies were carried out to solve the problem of determining the parameters of combustion products of chemical fuels taking into account the formation of traces of polychlorinated dioxins. Basic information on the adopted method of determining non-equilibrium composition of combustion products of chlorine-containing chemical fuels is presented. Based on the literary analysis on the mechanisms and rates of chemical reactions of conversion of chlorine-containing compounds, a kinetic model of formation of traces of dioxins was built. Numerical calculations on the assumption of chemical equilibrium have shown that the dioxins formation process is substantially non-equilibrium. The results of kinetic studies on the emission of dioxins precursors showed the nature of the change in time of various components of combustion products of chemical fuels depending on temperature.

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Main gas pipelines are classified as energetically stressed objects. With an increase in their service life, there appears a need to model emergency breaks and analyze the distribution of the damaging factors of the accident. The main gas pipelines often run near residential areas and cross various communications, therefore possible accidents with gas emissions and damaging factors can negatively affect both the environment and the population. An emergency rupture of a gas pipeline section is numerically modeled in this article. The calculations of intensity of accidental gas emissions outflow and distribution of the accident damaging (the length of the methane jet in unlimited airspace, the range and height of the scattering of the soil and pipe fragments were found). The parameters of free jets of exhaust gas were determined. Such calculation is required during investigation of accidents and development of documents related to the environmentally safe operation of pipeline transport. In case of gas non-ignition, it disperses in the atmosphere with the formation of gas zones. The study of the influence of velocity, density and pressure on the emergency gas emission allows us to determine possible gas contamination zones. Graphs of distribution of static and total pressure over the ejection height, distribution of velocities along the axis of the ejected jet and along the axis of the pipeline were obtained. The ability to evaluate the parameters of free jet flow of natural gas (methane) from a damaged pipeline: the total flow rate, total pressure and flow rate at the rupture point is relevant in solving applied environmental safety problems of gas transportation facilities.

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