Abstract:In order to study the law of oxygen concentration distribution in the goaf of the coal mine working face, identify the risk of spontaneous combustion in the goaf and the risk area of spontaneous combustion, the buried thermocouple sensor and sampling bundle tube are used to summarize and analyze the monitoring temperature changes and gas content changes caused by the increase of the buried depth of the goaf, and the relationship between the CH4 and C2H6 gas originally stored in the goaf coal of the working face is studied by establishing a mathematical equation, and it is concluded that the exponential function has the highest fitting degree, 0.9527. The change rule of O2 concentration at different positions in the goaf is obtained by using the sampling bundle tube, and the physical model is established with Fluent according to the actual situation. The boundary conditions of the model are analyzed and set, and it is concluded that the oxygen concentration gradually decreases and the degree of decline gradually decreases with the increase of burial depth. Through the field test and laboratory data simulation of the oxygen concentration zone in the goaf of the coal mine working face, the fan-shaped areas of the “three zones” (heat dissipation zone, oxidation zone and suffocation zone) at different positions in the goaf are obtained, which provides guidance for the fire prevention work.
