Numerical Simulation On Spontaneous Combustion Of No.4 Seam Outcrop In Da Baoding And Its Application

The spontaneous combustion of seam outcrop is very serious in China, it not only burns a large number of coal, destroys the coal seam and endangers the safety production of coal mine around the seam outcrop, but also emits lots of poisonous gas, pollutes atmospheric environment and causes bad effect. It is one of the major natural disasters that human is facing, so it is important to study the law of the spontaneous combustion of seam outcrop.The law of the spontaneous combustion of seam outcrop was studied by the method of numerical simulation in the article, which was based on the spontaneous combustion of No.4 seam outcrop in Da Baoding, Pan Zhihua City and applied to instruct the control work of the spontaneous combustion. First, according to the features and the geological materials of the combustion area, the physical model of No.4 seam outcrop was established by way of reasonable simplification, after that the two-dimensional mathematical model of the spontaneous combustion of seam outcrop was established by the percolation theory with porous medium, heat transfer theory and mass transfer theory. Then the key parameters of the mathematical model, such as the air leakage intensity, the oxygen consumption rate, the heat emit intensity and the granularity influence function, were determined by theoretically analyzing the drive of air leakage and applying programmed heating experiment to study the exothermic and oxidation features of the coal sample that was sampled from No.4 coal seam. Second, the airflow field, the oxygen concentration field and the temperature field of seam outcrop were simulated by Fluent under different position and intensity of air leakage, then obtained the law of the spontaneous combustion of seam outcrop. Finally, according to the results of numerical simulation, proposed the idea of controlling the spontaneous combustion of seam outcrop and applied the idea to guide the control work, after that the spontaneous combustion of No.4 seam outcrop in Da Baoding was extinguished successfully. The results of study have instructional significance to study the combustion mechanism and the control of the spontaneous combustion of seam outcrop.