Research On Gas Extraction Technology In High Lane Of Changcun Coal Mine

In the treatment of gas in coal mine goaf,gas drainage in high-level roadway is a way to effectively control gas in goaf.In actual production,the different layout of high-levelroadway of the working face will have different effects on the treatment of gas in the goaf and the distribution of oxygen concentration and temperature in the goaf.Therefore,this paper takes the high-level roadway of S5-13 working face in Changcun Coal Mine as an example,and studies and determines the layout of its reasonable horizon.Firstly,by analyzing the failure law of overlying rock in the goaf of S5-13 working face,the range of the falling zone of the working face is calculated to be 10.25~14.65 m,and the range of the crack zone is 39.2~50.4m.According to the theory of mining “O” ring and the theory of high-level roadway,the theoretical horizon of the high-level roadway of the working face is roughly estimated.Secondly,using the FLUENT numerical simulation method and loading the custom UDF,combined with the gas migration law in the goaf and the oxidation temperature rise theory of the coal,the numerical simulation of the gas,oxygen concentration and temperature distributionin the goafon different level of high-levelroadwayof S5-13 working face is carried out.Through the analysis of the simulation results,combined with the gas distribution,oxygen concentration and temperature distribution in the goaf,the optimal horizon of the high-level roadway layout of the working face is obtained,and the drainage flow range of the high-level roadway under the horizon is determined.Then,based on the numerical simulation results,the actual application of the layout of the high-level roadwayof S5-13 working face is applied.The comparison between the measured data and the simulation results shows that the high-level roadway of the working face is arranged at a distance of 23 m from the coal floor and 20 m from the inner side of the return airway.At the time,the concentration of the gas at the corner of the working surface can be well controlled,the gas concentration of the upper corner is maintained at about 0.49%,and the concentration of the high-level roadway is at a high level,and the concentration of the extraction is maintained at about 7.0%.At the same time,it has little effect on the oxygen concentration distribution in the goaf,and will not pose a threat to the spontaneous combustion of the coal in the goaf.The research results of this paper can provide relevant parameters and technical guidance of the selection of high-level roadway of the working facein Changcun Coal Mine and adjacent mines with similar conditions.There are 54 figures,8 tables and 73 references in this paper.