| In recent years,accidents of coal spontaneous combustion detonating gas occur frequently,which indicates that the compound disaster of gas and coal spontaneous combustion has become the source of serious and serious accidents in coal mines and a new challenge to ensure the safety of coal mine production,so it has attracted the attention of experts and scholars at home and abroad.the study found that there is a certain relationship between coal spontaneous combustion disasters and gas disasters in goaf,in mines with serious gas and coal spontaneous combustion disasters.It is not advisable to study gas and coal spontaneous combustion independently.In this paper,the 21219 working face of Dongpang coal mine is the research background.In view of the characteristics of high gas and spontaneous combustion of coal seam coal,and based on the disaster mechanism of gas and coal spontaneous combustion,this paper focuses on the influence of technical parameters such as ventilation,extraction and nitrogen injection on the compound disaster of gas and coal spontaneous combustion in goaf under the condition of three-dimensional extraction.It includes the relationship between gas control system and fire prevention and extinguishing technology system,as well as experimental research and on-site investigation on the determination of optimal parameters of gas control and fire prevention and extinguishing technology.the comprehensive prevention and control technology system of goaf gas and coal spontaneous combustion disaster suitable for three-dimensional extraction face is constructed to ensure efficient and safe mining in the production process of 21219 working face.The main research results are as follows:?1?The 2#coal seam belongs to the second type of self-combustion coal seam.In the process of low temperature oxidation,CO begins to appear from 30?and increases rapidly from 130?.C2H4 begins to appear between 120?and 130?,and C3H8 appears between 140?and 150?.The concentration of free radicals in coal is greatly affected by oxidation temperature.As a whole,the concentration of free radicals in coal increases with the increase of oxidation temperature.When the temperature is higher than 80?,the concentration of free radicals increases rapidly.?2?By simulating and studying the influence of face air volume,extraction parameters and nitrogen injection parameters on the dangerous area distribution of gas,oxygen and compound disaster in goaf,it is determined that the design air volume of21219 face is 1200 m3/min,the extraction effect is the best when the depth of corner buried pipe is 10 m,the drainage flow of corner buried pipe should be between 2436 m3/min,and the horizontal distance of high borehole end hole is 1030 m.The pumping flow of high boreholes should be no more than 54 m3/min,and the best depth of nitrogen injection should be set to 30 m and 50 m,and the flow rate of nitrogen injection should be set to 600 m3/h.?3?The comprehensive prevention and control system of gas and coal spontaneous combustion compound disaster in goaf of 21219 working face is constructed,and the application effect is investigated.It is found that the gas concentration in the upper corner is less than 0.69%,the average mixed flow rate of drainage in high boreholes is 39.4 m3/min,the average extraction concentration is14.2%,the average pure amount of extraction is 5.6 m3/min,the concentration of CO in the rear part of the support decreases gradually,and the maximum concentration of CO in the working face is 2ppm.The comprehensive prevention and control of the compound disaster of gas and coal spontaneous combustion in 21219 working face is realized.The paper has 60 pictures,27 tables,and 63 references. |
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