Study On Gas Control Technology In Working Face Of Yangliu Coal Mine

With the increase of coal mining depth,the existing gas drainage methods in Yangliu Coal Mine have not been able to fully meet the requirements of underground safety production.In this paper,taking the 1075 working face of Yangliu Coal Mine as the research object,through the methods of theoretical analysis,numerical simulation and field test,the pressure relief gas drainage technology of this coal seam and its adjacent layers is studied during the mining of 1075 working face.The details are as follows:First of all,through the prediction of the gas emission of coal seam 10,it shows that the gas emission of the working face is large,and the gas content of coal seam 82in the adjacent layer is high.Therefore,it is necessary to carry out gas drainage,and in addition to pre drainage before mining,it is also necessary to adopt the comprehensive gas control method during the mining period to prevent the gas in the working face from exceeding the limit.In addition to the common high-level drilling and surface drilling technology in Huaibei mining area,the paper puts forward the technical scheme of adopting roof strata directional long drilling instead of high-level drilling during the mining of 1075 working face.Through these comprehensive gas drainage measures,the gas drainage efficiency can be improved and the upper corner buried pipe drainage can be eliminated.For this reason,this article focuses on research from two aspects.One is to determine the layout of the directional long drilling in the roof rock layer to ensure that gas can be effectively extracted.The second is to drill the gas in the goaf and the upper part of the mining layer at the same time.In the adjacent layer,there is a shortcoming of gas extraction.Existing methods for the calculation of drained-sources have the disadvantages of complex procedures,long test cycles,and inconveniences.This paper establishes a new calculation model with accurate research results based on the specific situation of the Yangliu Mine.According to the lithology of the 10th coal seam roof of Yangliu Mine,the method of theoretical calculation and UDEC numerical simulation were used to determine the height of the falling three zones of the overlying strata on the working face and the pressure relief range of the working face,so as to arrange the drainage boreholes.Provide theoretical references.The results show that the height of overburden caving zone is 0¹4m,the height of fracture zone is 14⁴0m,and 8₂ coal in the upper adjacent layer is in the range of pressure relief.Based on this,the normal distance of the high hole in the high drilling field is controlled between 15³0m above the 10 coal seam,and the horizontal distance is 4⁶0m from the return air lane.19²5m of siltstone;the bottom of the hole on the ground is located 20⁶0m away from the return air lane,which is the best range for gas drainage.After the new gas drainage plan for the 1075 working face was implemented on site,the rationality and reliability of the drilling drainage design parameters were verified from the aspects of drilling drainage concentration,drainage volume,and drainage volume;working in 1075 The volume of gas extracted through high-level drilling sites is 1.301 million m³,the volume of gas extracted through directional long drilling sites is 565,600 m³,and the volume of gas extracted through surface drilling is2.279 million m³.The drainage effect of 1075 working face is comprehensively analyzed from the aspects of drainage volume and gas concentration in the return air lane of Shangqijiao.The research shows that after the new gas drainage scheme is adopted,the average gas concentration in the return air lane is 0.14%.The average angle gas is 0.18%,which eliminates the gas overrun,which indicates that the current gas drainage method adopted in the design is feasible.A comprehensive analysis of the construction volume,economic benefits,gas drainage effects,and safety status of the working surface of the drilling field and boreholes shows that it is obviously advantageous to replace 6 high-level drilling fields with 1 directional drilling field.Drilling in some suitable locations instead of high-level drilling drainage provides a feasible reference.According to the specific situation of Yangliu mine,a new model is established to calculate the proportion of gas in the pressure relief coal seam and goaf in the surface drilling and drainage,which provides a basis for the evaluation of the extraction effect of the protected layer.The research shows that from the total amount of extracted gas in the boreholes on the ground,the proportion of gas released from the pressure of 8₂ coal is 65%-88%,with an average of 81%.From this,the pre-gas extraction of 8₂ coal from the protected layer is calculated.The rate reaches 76.01%,the residual gas content in the pressure relief area is 2.62 m³/t,and the 8₂ coal pressure relief gas drainage has achieved good results.Through the above research,the comprehensive gas drainage during the 1075working face proposed in this paper achieved the expected drainage effect,which verified that it is feasible to cancel the upper corner buried pipe drainage.The directional drilling of the roof rock layer can replace the drilling performance of the high-level drilling site.Achieve the same or even better drainage effect.And the ground borehole drainage gas diversion source calculation model provides an accurate and simple calculation method for calculating the gas drainage volume in the upper adjacent layer.The thesis has 38 figures,15 tables,and 94 references.