| In this dissertation,combined with the practical problems of spontaneous combustion control in the mined-out area of the-850 fully mechanized coal caving face in Jiudao Mine,CFD software is used to simulate the CO2 injection in the goaf and determine the location and injection flow of CO2 in the mined-out area.The determination of oxygen consumption rate of coal samples is an important problem in the study of spontaneous combustion and the numerical simulation analysis.In order to determine the oxygen consumption rate of coal samples at different oxygen concentrations in Jiadaoling-850 working face,the volume oxygen consumption rate and quality were obtained by the coal-like closed oxidation experiment(closed oxygen consumption experiment)and regression analysis method.Oxygen consumption rate constant,CO production rate and CO production rate and oxygen consumption rate ratio and other key indicators.According to the specific situation of mined-out area of-850 face in Jiudaoling Mine,Gambit is used to model and divide the grid.Considering the inclination angle of 9.59° coal,the gravity factor is added.The distribution of porosity in goaf is uniform,Using the "O-ring" distribution coefficient of broken coefficient.Based on the actual fire protection arrangement of-850 face in Jiudaoling Mine,the wind pressure and air leakage in the goaf area before and after CO2 injection are compared with the specific model,and the effectiveness of CO2 injection in inhibiting the air leakage in the working area is verified.In order to ensure the reasonable value of CO2 fire control parameters in the mined-out area,the optimal CO2 location of the-850 face is obtained by changing the CO2 injection position and the CO2 concentration in the mined-out area.And the relationship between the CO2 flow rate and the oxidation zone width is obtained by MATLAB.The maximum oxidation zone width of the non-spontaneous combustion of the coal and the CO2 concentration of the working face return air are not exceeded,and the minimum CO2 is determined. |
