CO Generation Mechanism And Control Method Of High Output And High Efficiency Mine

Spontaneous combustion of coal is one of the main disasters in coal mines,which causes the waste of coal resources and the safety of production.It may also lead to coal mine gas and coal dust explosion accidents,and produce toxic gas.Spontaneous combustion of coal mine is one of the most serious countries in the world,which brings about billions of economic losses to China's coal mines every year.Especially in high yield and high efficiency mine,the economic loss caused by coal spontaneous combustion can not be estimated.The key to the spontaneous combustion of coal is the prediction of temperature rise.CO gas is the most commonly used index for prediction of coal spontaneous combustion gas,has obvious correspondence with the process of coal oxidation;on the other hand,exposed to different concentrations of CO in atmosphere for a period of time will cause damage to the human body,therefore,the research of CO gas in coal mine underground roadway in the migration and accumulation of the one hand can improve the index prediction method gas precision,on the other hand can ensure the personal safety of the staff.Through the study of literature,this paper summarizes the theoretical basis of prediction method of index gases,is a heating experiment research,large scale experimental research and field test research on a large number of procedures,and Analysis on Shun magnetic resonance analysis means by infrared spectrum.The primary stage of research can be proved that the coal natural temperature to produce CO gas,produced dramatic rise after rising slowly,and the regularity of a CO gas can be used as indicators of gas,but different concentration of the corresponding early warning easy to spontaneous combustion of coal is different,according to the actual conditions to determine.Other CO gas sources in coal mines cause misleading results in the prediction of index gases.In the process of coal mine production,there are CO source,CO source,CO source,CO source,CO source and coal spontaneous combustion,which are produced by blasting.Based on the study of the origin and migration of different CO sources,the migration and accumulation characteristics of different CO sources are summarized in order to provide reference for improving the accuracy of prediction methods.Under the condition of mining coal in front of working face along the depth is divided into relief zone,stress concentration zone and the original rock stress zone,firstly through from the angle of rock mechanics,the pressure relief zone width is calculated in the pressure relief zone,fractured coal fully developed,the formation of a new fracture,old fracture continued development,caused by coal permeability increases,the air in the tunnel under the action of the wind into the broken coal wall,at the same time,the original equilibrium state of the extended coal wall hole,fissure and transfixion will destroy the original occurrence of gas desorption,gas escape caused by primary occurrence CO.Therefore,under the condition of coal mining,the coal wall of the working face is broken,and the escape of the primary CO gas and the filling of the O2 in the fresh air.Through the FLAC simulation method in Dananhu mine as the calculation model is simulated under the condition of mining working face of coal body in front of the damaged area,simulation results show that the stress of coal body in front of failure zone in 0~13m,the development of fissures of coal in this range,O2 and native CO gas migration.The design of working face coal wall sampling,desorption and calculation method is used to verify the existence of the rapid oxidation of CO in the coal seam wall under the mining condition.Continuous sampling method,no oxygen through the depth of the working face,the coal wall depth of 1.5,3,4.5,6,7.5,9,10.5m a total of7 groups of coal,coal mining,within 30 s in nitrogen sampling tank,and sealing.After returning to the laboratory,in the 100 rad/min ball mill speed of continuous crushing of2 h,constant temperature of 25 degrees,through the introduction of the nitrogen gas desorption temperature of 10mL/min,the desorption gas into the gas chromatograph analysis of gas species and concentration analysis.Through the analysis of the desorption curve,it can be found that there is a large amount of CO gas in the coal seam from the coal face of the working face at 3~4m,and the CO value of the coal wall is 7.5m and above.The sampling,desorption and calculation methods of the original coal samples are designed to verify the existence of CO gas.Nowadays,there is not yet conclusive whether exist in many coal seam gas and native CO Fu made the original stock,not affected by coal mining method through layer 30 m drilling,nitrogen sealed crushing,desorption,at 100 rad/min under 2h continuous grinding ball speed,constant temperature of 25 ?,into the 10 m L/min nitrogen thermostatic desorption,after calculation,Dananhu coal mine in a 1.19 L per ton of coal in primary CO gas.In order to exclude the possible link of oxidation in the process of sampling and experiment,according to the experimental results of isothermal oxidation,the consumption of O2 based on the results,the specimen may exclude the maximum CO oxidation producedby calculation,CO gas containing at least 0.983 2L per ton of coal in the.The original CO gas measured quantity and the working face along the depth of the CO coal sample gas contained in the amount of comparison,the two content of the same point is defined as the mining depth of oxidation,rapid oxidation in front of the working face under the conditions by comparison,oxidation of different working depth,different,about 6~9m.Using the method of fluid dynamics,using the CFD simulation software,deduces the work broken surface control equation of coal wall gas escaping CO migration,including continuity equation,mass conservation equation and momentum conservation equation,simulation of the working face of broken coal wall from 0.9,0.7 and 0.5L CO in the gas migration and accumulation law of 2m/s and 3m/s ventilation conditions.The simulation results show that in the 0.9L/t CO content and the inlet air condition of 2m/s,the CO concentration in the air return side of the tunnel reaches the highest value of 10 ppm,and does not reach the maximum allowable concentration,so it does not pose a threat to human health.The simulation results show that the greater the inlet air flow rate,the smaller the amount of primary CO gas,the smaller the concentration of CO gas in the air.The concentration analysis found that through the establishment of monitoring points in the model,Jinfeng high wind speed conditions,the return air side CO concentration is low,and diluted faster.In order to study the mining,determine the broken coal CO emission from natural temperature influence the oxidation of CO concentration field of coal mined out area,using CFD simulation software,developed the mined-out area heating energy conservation equation and mass conservation equation,the control equation of goaf and the working face of fluid migration.And discusses the method of coupling control equation between the combination of low temperature oxidation of coal temperature programmed experimental results fit the segmentation of CO generation rate and oxygen consumption rate,into the control equation to simulate.The simulation process of 2m/s into the wind conditions,the coal face 2.5L/t CO emission per ton of coal gas under goaf dynamic heating process,the simulation results show that the goaf of loose coal heating in 2 stages,in the slow heating stage release a small amount of CO gas,CO gas at the working face of emission on the return side accumulated up to 16 ppm,although not reach the maximum value,but in the early stage of oxidation spontaneous combustion in goaf determine the extent of misleading,resulting in coal mined out area to determine the time of spontaneous combustion risk in advance.By 2.8,2,CO concentration and temperature transient 1.2m/s intake air velocity under the conditionof simulation results showed that the wind speed is higher,the degree of accumulation of CO source by the release of the return side of coal wall is low,the error of the degree of oxidation of coal spontaneous combustion in early judgment caused by the smaller;according to the analysis of simulation results CO concentration and temperature on the transient oxidation of coal mined out area of 200,300,400kJ/mol heat release conditions,coal oxidation heat is high,coal spontaneous combustion in the primary stage of the release of CO and the higher the concentration of effect of coal wall broken caused by the concentration of CO CO emission source in the tunnel is relatively small,the judgment error is smaller at the early stage of coal spontaneous combustion.This paper summarizes the world of underground coal mine the maximum value of CO concentration effect and exposed to different concentration of CO under the condition of different time on the human body caused by the concentration of CO in China,pointed out that the provisions of the maximum allowed value is established to ensure the personal health,the value is not entered for the coal spontaneous combustion risk has no practical significance.CO coal mine is mainly composed of the following sources: coal seam occurrence and mining of native rapid oxidation of working face,explosion-proof vehicle operation,underground blasting and goaf spontaneous combustion;the rapid oxidation of primary storage and working face of CO gas because they are in the process of mining work,in the actual production is difficult to distinguish the the source,therefore is classified as a class discussion.CO gas explosion-proof vehicle running number less,with the wind to dissipate quickly;blasting produces high concentration of CO,has increased dramatically after the concentration sharply decreased with increasing mining;CO gas dynamic escape continues to exist in the process of mining.According to the characteristics of different CO sources,this paper puts forward the identification method of different sources of CO,and puts forward the corresponding management methods,in order to ensure the personal safety of underground workers and the efficient production of coal mine.This paper analyzes the Dananhu mine CO monitoring data,using the identification method to analyse the change of CO concentration,proposed a method to control its concentration,in order to improve the index gas prediction method,to ensure personal safety and provide the basis for the production of funny.