Research On Y Type Ventilation And Gas Relief Drainage Technology In Protective Layer

Pingdingshan ten coal mine has mined depth of more than 1000 m,it belongs to coal and gas outburst mine.For the government of the gas,the floor roadway and other management methods are usually used to control the gas.Long time and small range of gas control,failed to effectively solve the gas problem.Aiming at this problem,a new method of gas drainage in Ji15-16 outburst coal seam has been put forward,the pressure relief gas drainage is carried out in Ji15-16 outburst coal seam by using protective layer mining,next,pressure relief gas extraction.At the same time,combined with ventilation of Y type to ensure the safe mining of protective layer.Therefore,it is of great practical significance for the safe and efficient production of Pingdingshan ten coal mine carry out the gas migration law and the gas drainage in goaf under the condition of ventilation of Y type along the goaf.The paper according to the existing conditions of high gas and low permeability of Ji15-16 coal seam in Pingdingshan ten coal mine,using the migration law of overlying strata and the distribution of three belts after the protective layer mining are analyzed and the laws of mining pressure relief gas migration.Based on the theory of gas flow state equation and gas flow equation,the mechanics model of gas flow is established.Through the numerical simulation software Fluent to simulate the goaf gas migration law and the Y type ventilation air volume ratio.The paper designed for the Ji18-24130 protective layer working face and gas drainage scheme for mining Ji 15-16 coal seam in protected layer,the gas drainage is also investigated.Through the numerical simulation of Fluent,the three-dimensional gas migration law of goaf with Y type ventilation in gob side entry retaining wall is obtained;When the total air volume is certain,through the simulation and the field verification,the best air ratio of the working face of the Ji18-24130 rock protection layer is Y,which is 2:1;The protective layer mining protective seam gas drainage system:intake borehole and pre drainage roadway horizontal drilling.After the investigation and analysis of a certain period of time that the gas drainage system drainage amount is 3.3764 million m3 and the remaining gas volume is 5.9982 million m3.The overall gas extraction effect is good.