Research On Comprehensive Treatment Technology For Compound Disasters Of Gas And Coal Spontaneous Combustion In Y-Type Fully Mechanized Caving Face Of Zhangcun Coal Mine

The single thick coal seam high gas mine,gas drainage and coal spontaneous combustion in the goaf interact and restrict each other.In recent years,the"Y+high-drainage roadway"ventilation method has been widely used due to its excellent gas control effect.Y-shaped ventilation can not only effectively eliminate the problem of over-limit gas in the upper corner caused by U-shaped ventilation,but also significantly reduce the gas concentration in the return air flow.The effectiveness of gas drainage in high-drainage roadways has been fully verified in reducing the amount of gas emitted from the goaf to the working face and eliminating gas overruns.However,the“Y+high extraction lane”type ventilation makes the air leakage law in the goaf more complicated.At the same time,caving coal mining leaves a large amount of coal in the goaf.For the mining of high gas coal seams,spontaneous combustion and detonation of the left coal may occur.Gas and other secondary disasters.Therefore,it is of great significance to carry out research on the gas concentration distribution law in the goaf of the working face of the"Y+high drainage roadway"ventilation method,as well as the simulation and optimization of the air supply and extraction parameters that affect the gas distribution law.In this paper,combined with the current situation of ventilation and gas control in the fully mechanized caving face of Zhangcun Coal Mine 2603"Y+High Drainage Roadway",through theoretical analysis,on-site measurement and numerical simulation,the study on the flow field of air leakage and the distribution of gas and oxygen concentration in the goaf is carried out.Divide the spontaneous combustion and compound disaster risk areas,simulate and optimize the optimal and reasonable air supply range of the fully mechanized caving face of"Y+high extraction roadway",the best layout of high extraction roadway,and the best gas drainage parameters.The main research results are as follows:(1)Through the low-temperature oxidation temperature-programming experiment and free radical characteristic experiment of 3#coal,the oxidation characteristic parameters and its iconic gases during the oxidation and heating process of 3#coal are determined;it is found that the concentration of free radicals increases with the increase of temperature.In addition,it is also related to the degree of coal metamorphism.130°C is the inflection point of the 3#radical concentration change,which can be used as the key temperature for monitoring the oxidation of coal in the goaf.(2)Through numerical simulation methods,carry out the influence of different main and auxiliary air intake lanes,different locations of high-extraction lanes,and different negative pressures on the distribution of CH₄ and O₂ concentrations in the goaf,as well as the compound disaster risk area of gas and coal spontaneous combustion The impact of distribution.It is optimized to determine that the total air supply volume of2603 working face is 4000m³/min,the horizontal staggered distance L=15m and the vertical distance H=21m of the high-drainage roadway are better,and the reasonable suction pressure Pex=15KPa for the high-drainage roadway.(3)Through the beam tube monitoring system in the goaf of the 2603 working face,which further verifies the most effective ventilation method under the"Y+high drainage roadway"ventilation method.The scientificity and safety reliability of the optimal air supply,the best high drainage location and the gas extraction parameter range effectively prevent the occurrence of spontaneous coal combustion and compound disasters in the goaf area of 2603 working face,and realize the spontaneous combustion and compound disaster of the left coal.Coordinated prevention and control of disasters.This article includes a total of 51 figures,18 tables,and 85 references.