The photo is sourced from mediakuzbass.ru
Pit coal mining is accompanied with emission of methane, a flammable gas that poses hazard for coal pit production. To prevent the risk of fire, it is critical to control methane concentration and remove methane with the help of large volumes of air supplied by the ventilation system. In this respect, coal pit owners should determine optimal parameters of coal pit systems so that sufficient air flow can reach a required place of the underground system.
With this end in view, scientists of the Tomsk Polytechnical University suggested to use a 3-D calculation model that takes due account of the front view (elevation) of ventilation system sections, thus simplifying the design of ventilation systems. In addition, it also helps to optimally place sensors measuring methane concentration of air flows. The new method has been developed on the basis of coal pit parameters of Sadkinsk coal deposit, including the length of coal mining districts and location of control units.
“As part of the study, it was identified that continuity of air supply and gas explosion safety is to a large extent affected by diagonal connections. They have their own features and in different ways affect distribution of air flows and methane emissions in coal pits, affecting fire safety as a whole. Therefore, constructing a spherical scheme of the ventilation system with the use of response surface projection allows to improve scientific beliefs on controlling aero gas conditions in the working area”, says one of the study authors, Nikita Martushev, an Assistant Professor of the Metal Science Department, as quoted by the Tomsk Polytechnical University.
According to the Fuel and Energy Complex Central Dispatch Office, the share of underground mining has been decreasing over the last decades. While in 1995 coal mines accounted for 42.1% of all coal production in the Russian Federation, in 2020 their number was 25.6%, while the number of coal quarries grew from 57.9% to 74.4%, respectively (any later data are unavailable). At the same time the total amount of coal produced over the same period increased by slightly over 50% (from 262.8 million tons to 401.6 million tons).