Smolanov S. Development of scientific foundations for the elimination of complex underground fires in coal mines by methods of ventilation influence

The object of researches - the processes of eliminating complex underground fires in coal mines by ventilation methods. The purpose of the work is to establish the regularities of thermal and aerogasdynamic processes occurring in the isolated fire area of the mine during extinguishing fires and developing methods of ventilation for improving the efficiency of the elimination of complex underground fires. Research methods: analysis of existing literary sources and generalization of scientific and technical achievements in the area of he elimination of complex underground accidents in coal mines - when choosing and substantiating the research direction; mathematical modeling, using the basic laws of thermodynamics, heat and mass transfer and mine aerology; simulation of the processes of distribution of gas-air masses and heat at the areas of mines ventilation, isolated from the common-type ventilation network; experimental research of the factors determining the ventilation and thermal regime of emergency areas - during research on thermal depression and aerodynamic and gas-dynamic processes in isolated ventilation areeas (IVA); methods of numerical simulation - when substantiating the parameters of the proposed ventilation regimes; methods of economic analysis - in assessing the proposed solutions and prospects of application of the developed fire extinguishing technology using methods of ventilation. For the first time a mathematical model of the heat balance in the volume of the fire center of an IVA was developed, which allows to predict the dynamics of the average air temperature in the fireplace and the surrounding array of rocks taking into account the dependence of the air density on temperature for a long period of time (up to several months) from the moment of fire. For the first time, the analytical dependences of the air temperature in the fire center and the adjoining zones are obtained from the aerodynamic parameters of IVA, which allows to simulate the results of the influence of the ventilation regime on the thermal mode of the IVA. For the first time, regularities of changes in air leaks during sodirectional and antidirectional action of thermal depression of a fire and the main ventilation fan were established. For the first time, regularities of interaction between different sources of traction (thermal depression, natural traction, depression of main ventilation fan) were established at the emergency unit during the extinguishing of fires by the method of recycling of combustion products. For the first time the regularities of the transition of gas-dynamic and aerodynamic processes occurring at the emergency area during multiple reversal of the jet and the addition of inert gases are established. For the first time, the condition for changing the direction of movement of the ventilation jet in the section at the general-phase reversal, depending on the depression of the mine in normal and reverse regimes and the volume of the critical depression of the area in the normal mode and the volume of the natural traction, was determined. The method of extinguishing complex fires, based on the recirculation of combustion products, and typical schemes of recirculation of combustion products were developed. The method of extinguishing complex fires by means of multiple reversal of an air jet and a scheme of repeated reversal of combustion products were developed. The "Methodic of calculating the parameters of the compensation method for reducing leakage of air through isolated fire areas" was developed. The "Methodic for determining the amount of methane involved in the explosion" was developed. An express method for determining the temperature at the hearth of an isolated fire was developed. The "Methodic for determining the thermal parameters of the fire" was developed. The "Methodic of choosing an optimal fire extinguishing method" was developed. Software was developed for performing heat depression calculations, aerodynamic and gas-dynamic processes in isolated ventilation areas, dynamics of fire development, technological circuit parameters and ventilation regimes on a PC. The methods and means of preventing and eliminating underground fires in mines and improving the safety of mining operations are developed. The results of the dissertation work were introduced at the elimination of complex underground accidents at the mines. The actual economic effect obtained from the application of developed methods only at the expense of a reduction of the fire extinguishing period amounted to 209,21 thousand UAH for SE "Coal company "Krasnolymanska" and 171,36 thousand UAH for the SE "Mine by G.G. Kapustin" PJSC "Lisichanskvugillya".