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The paper discusses the problem of the underground mining safety control. The long-term air intake to coal accumulations is reviewed as one of the reasons of endogenous fires during mining. The methods of combating air leaks (inflows) in order to prevent endogenous fires are analyzed. The calculations showing the discrepancy between the design calculations for the mine ventilation, disregarding a number of mining-andgeological and mining-engineering factors, and the actual conditions of mining are given. It is proved that the conversion of operating mines to combined (pressure and exhaust) ventilation system in order to reduce the endogenous fire hazard of underground mining is unreasonable due to impossibility of providing an optimal distribution of aerodynamic pressure in mines. The conversion does not exclude the entry of air into potentially hazardous zones of endogenous fires. The essence of the combined application of positive and negative control methods for the distribution of air pressure is revealed. It consists of air doors installation in easily ventilated airways and installation of pressure equalization chambers equipped with auxiliary fans near the stoppings, working sections and in parallel airways.The effectiveness of the combined application of negative and positive control methods for the air pressure distribution in order to reduce endogenous fire hazard of mining operations is proved.

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Научного центра по безопасности работ в угольной промышленности Научно-технический журнал Кемерово 4-2018 © ООО «ВостЭКО», 2018 www.ind-saf.ru ВЕСТНИК Научного центра по безопасности работ в угольной промышленности

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Ventilation is presently primary among the existing gas and fire safety methods in coal mines; therefore, solution of key problems in this area at a qualitatively new level is of great theoretical and practical importance.In relation to the exploitation of upper levels and the further development of mining work, the working space plays a special role in the ventilation systems of modern mines. The large area and voltune of the workings and their numerous aerodynamic connections with the areas previously worked and the surface have a significant influence on the ventilation conditions of the shaft and the air distribution between the volumes being ventilated. Air flow between the working spaces forms a considerable proportion of the overall shaft output, and any deficiency leads to significant negative consequences. The working space is also a basic gas collector in the active underground systems; sources of self-ignition of the coal appear there principally. In this connection, establishing paths of air motion in the aerodynamically active zones of the working spaces is a very urgent problem. Its solution offers the possibility of developing complex gas and fire safety measures in the development of highgas-bearing beds of self-igniting coal, improving ventilation calculation methods, and maintaining rational conditions of shaft ventilation.There have been numerous investigations of the aerodynamic properties of the working space. Extensive experimental observations on models under full-scale conditions have led to the formulation of empirical dependences for air filtration through fallen rocks certrain conditions, the elucidation of the distribution laws of the ventilational pressures, and the establishment of the specific aerodynamic drag. However, in all preceding studies, significant simplifications have been made in the physical representation of the working space, and practically no consideration has been given to data on the deformation and destruction of rock masses and the formation of aerodynamically active zones of clearing excavation. The air permeability of broken rock is assumed to vary with increasing distance from the face, and to be practically constant within the cross sections parallel to its plane, i.e., the flow is distributed uniformly over the thickness of the destruction zone. Moreover, the working space is characterized, in aerodynamic terms, by anisotropy over both the area and width of the working, as shown by experimental observations conduced by the Eastern Scientific-Research Institute on mineshafts of the Kuznetsk basin. The basic air flows are confined to the edges of the excavation columns, the exhausted workings, and, over the thickness, to the upper layers of the broken rock.Experimental data on the flow distribution over the thickness of the destruction zone are in good agreement with analytical calculations if the model of the working space is based on recent results regarding the geomechanics of rock.On the basis of numerous full-scale investigations [I-3] into the shift of ...

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