Gas Drainage Technology Research On The81505Fully Mechanized Working Face Of Baode Coal Mine

Firstly,this paper describes the fact of coal mine safety production,which is caused by gas overrun, gas drainage status quo at home and abroad are reviewed. It is concluded that the domestic and foreign gas drainage efficiency generally is not high. Then,the paper show the purpose and significance of research: the gas extraction rate of Baode coal mine is low, the five panel of Baode coal mine has the fully mechanized coal face mining coal mine of the deep zone, working face of coal seam gas pressure and gas content is higher and higher, the number of gas emission is more and more bigger.In order to guarantee the safety of coal mine production, the original gas extraction parameters need to be reset.So, the author establishes the subject.The81505fully mechanized coal face is selected as the test surface, then author compare the roadway drainage with the drainage drilling.It is concluded that the rationality of the drainage drilling working face gas. Along through the holes and put holes in the comparison between the two methods of drainage gas, the final selection of drilling this bedding method.This paper introduces the state of gas in coal and the gas flow field classification, elaborated the three about gas flow theory in detail. The basis for the back of the gas parameter determination and the selection of gas drainage method provides a theoretical support.In order to comprehensive and to understand the basic characteristics of the coal seam, the comprehensive test of working face of coal seam gas parameters were measured. With the specific parameters of coal seam gas，we can forecast the gas emission of the test surface more easily,and can make the forecast data more real and effective.The source prediction method is adopted to predict the gas emission of experiment work face. The paper eventually poured out of the working face is obtained by extraction layer supplemented, adjacent layer.From the state’s relevant laws and regulations and coal oneself circumstance,the paper demonstrates the necessity of the gas extraction.According to the determination of the permeability coefficient of coal seam and its drilling before gas flow attenuation coefficient to validate the feasibility of gas extraction.FLUNET software is adopted to carry on the numerical simulation, to analog variety drainage, suction under negative pressure conditions and different drill diameters around the drilling of gas pressure variations.Finally,the paper draw the conclusion: drill drainage with negative pressure drainage radius of little impact,drained time and drill hole greatly influenced coal-bed methane drilling gas drainage rate. To the design of the gas drainage parameters,the conclusion provides the scope or the choice of parameters of more clear direction, to ensure the accuracy of extraction parameters selection.Through the simulation results, the aid of these results combined with the design theory of gas drainage parameters, the paper ensure the concrete drainage borehole parameters for the design.FLUENT software is adopted to simulate the drainage effect of the parameter optimization and from the aspects of the gas extraction rate to show the rationality and validity of the design.