Study On Fire Propagation Law And Control Technology Of Main Inclined Shaft Belt In Songzao Mine

Aiming at the problem of mine external fire,based on the theory of mine belt fire,taking the major fire accident of Songzao mine in Chongqing on september 27,2020 as the background,the research methods of literature review,field investigation,theoretical analysis and numerical simulation were used to analyze the smoke migration and diffusion law of different belt fire influencing factors,reproduce the development process of the accident,divide the dangerous area,and then compare and analyze the prevention and control effect of the combination of reverse wind and reverse wind water spraying.The main research results are as follows :Through literature research and numerical simulation,it is concluded that the influencing factors of common mine belt fire include fire source power,roadway wind speed and roadway dip angle.The variation law of flue gas thermal physical characteristic parameters of fire source power and roadway wind speed is consistent,that is,with the increase of fire source power and roadway wind speed,the flue gas propagation speed increases,the temperature increases,the visibility decreases and the CO concentration increases,but the low wind speed will cause the flue gas to retreat.The variation law of roadway dip angle is more complicated.With the increase of roadway dip angle,the smoke propagation speed increases,the temperature decreases,the visibility decreases and the CO concentration decreases.Through field investigation and simulation analysis,it is concluded that the flue gas propagation paths of Songzao mine are 2# large dip angle belt roadway(the temperature is up to600℃,causing 1 person to die from high temperature)→head 2# coal bunker→+175 Maokou roadway→working face(the CO concentration is up to 23060 ppm,causing 13 people to die from CO concentration overrun)→return air roadway→ground and 2# large dip angle belt roadway→head 2# coal bunker→coal transfer roadway→+100 Maokou roadway→3# coal uphill(the CO concentration is up to 18390 ppm,causing 2 people to die from CO concentration overrun)→ground;the simulation results are consistent with the results of the accident investigation report,so as to achieve the purpose of accident reconstruction,so as to provide preventive measures for the mine under production.Through numerical simulation and comparative analysis,it is concluded that the underground danger A,B and C areas are divided according to the distribution of casualties.After adopting the anti-wind measures,the temperature in the roadway is effectively reduced,the visibility is improved,and the CO concentration is reduced,but the flue gas after the anti-wind will threaten the upstream roadway of the original fire source;under the condition that the jet diameter of the nozzle in the spray water system is the same as the size of the roadway,the combined measure of the anti-wind spray water is the best control measure to reduce the fire risk of the roadway.Thus according to the actual situation of the mine to develop targeted preventive measures to enhance the level of mine emergency.The paper has 63 figures,7 tables and 73 references.