Study On Experimental And Numerical Simulation Of Coal Self-ignition Process

Coal self-ignition seriously affects the development of coal industry, and brings about extremely safety trouble for coalmine. Because it is difficult to clearly describe the process of coal self-ignition at actual condition, development of the technique for forecasting and predicting coal seam spontaneous combustion is seriously restricted.According to actual condition, grasping mostly contradiction both heat liberation of coal oxidation and heat elimination of environment, based on mechanics of fluids in porous media and theory of heat and mass transfer, the mathematical model is set up. According to the model, oxygen consumption rate and heat liberation intensity of coal, diffusion coefficient and osmotic coefficient of oxygen is confirmed for key parameter to numerical simulation of coal self-ignition process, and these parameters are researched and test by experiment. The calculation method of oxygen consumption rate and heat liberation intensity is put forward on actual condition, and influence function of particle size is gained by experiment.The greatest experiment unit (loading coal for 15t) of coal spontaneous combustion is designed and built in china. The experimental simulation is firstly realized to whole process of coal spontaneous combustion on laboratory. The process is mastered, which highest temperature point initiates, develops and changes during coal spontaneous combustion, and the rule is mastered, which highest temperature point cools after stopping oxygen supply. According to condition of experimental unit, the mathematical model is set up, and the question is solved, which condition is single by experimental unit to simulate coal spontaneous combustion.Put forward the method measuring air-leakage intensity and the criterion determining dangerous area of coal self-ignition on actual condition, and develop the theory forecasting coal spontaneous combustion of gob and tunnel in fully mechanized top-coal caving face. Adopting the key parameters measured by experiment and the parameters practically measured, and thinking their change rule on actual condition, applied the method combining theory with practice, coal self-ignition process is recurred by numerical simulation in gob and tunnel in fully mechanized top-coal caving face. It is firstly solved to determine position and condition and forecast period of coal spontaneous combustion on actual condition. The achievement is examined by many examples forecasting and controlling coal seam self-ignition on actual condition, many fires is successfully prevent and extinguished under the direction of the achievement hi coal mine.