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A Method for Detection of Fire Source Positions in High-Temperature Areas

Spontaneous combustion of coal is an important disaster that needs to be addressed in the coal mine production process. Since its ignition position is often unknown and concealed, determining the ignition position in the goaf is of great significance to the work safety of the mining area. This study measured the thermal conductivity of coal samples using the spherical thermal conductivity model, and obtains the fitting relationship between the thermal conductivity, the heating voltage U and the inner sphere outer wall temperature t1 by inputting different voltages, and the correlation coefficient R2 was all greater than 0.99. Through analysis of the spherical geometric model, it was determined that the ignition point was at the vertical depth of 16.542m from the highest temperature point in the goaf, and that the distance from the ignition position to the ignition source ranged between 13.49m to 1.03m when the temperature in the goaf was 60℃ to 1700℃. Through comparison with the actual data, the error was found to be 4.7%, indicating that the proposed model was more accurate. Finally, it was found that the thermal conductivity of coal is closely related to the porosity, degree of metamorphism and inhomogeneity of the medium.