Loose Coal Spontaneous Combustion Numerical Simulation Analysis And Prevention Techniques Concerned In Coal Drift Top-coal Falling Region

Coal spontaneous combustion which threats safety production of coal mine is one of the major disasters. According to statistics, there are dangerous mines with spontaneous combustion accounted for about 47% in national uniform allocation and the key coal mine. Fully mechanized mining is universally applied along with the development of coal mining technology. Its roadway layout characteristic is the intake and return airways lies along coal seam floor.All coal seams are laid around the roadway except the bottom roof. Because of the existence of geologic changes and geologic structure, the coal seam thickens partially and the top-coal falling region formed. The cracked coal in the top-coal falling region is easy to cause spontaneous combustion on the condition of the air leak channel and heat accumulation. So it is an important practical significance to control losing coal spontaneous combustion through researching its law which consisted in top-coal falling region.In this article, the spontaneous combustion characteristics of Coal is researched based on the Coal Oxygen Test and TGA experiment.The shortest period of coal combustion is determined based on the Coal Sample Oxidation of heating experiments.the loose coal spontaneous combustion Mechanism of top-coal falling region is analyzed based on the heat transfer, mass transfer theory and the results show that the loose coal spontaneous combustion in the top-coal falling region is the Interaction between internal heat convection and the external heat transfer and the heat transfer process is accompanied by mass transfer. The mathematical model of flow field and temperature field is established in the top-coal falling region using of percolation theory.taking the 11111 of the 13th mine of Pingdingshan Coal Co. Ltd example and using fluid calculation software FLUENT to partition the top-coal falling region mesh and combined with characteristic parameter of the spontaneous combustion and field observation data to determine its boundary conditions.The seepage field and concentration field and temperature field model is solved and air leakage conditions, the distribution of each component gas concentration and the temperature distribution in the top-coal falling region are got.The self-developed filling material of compound foam is used to control loose coal spontaneous combustion in top-coal falling region and the sign gas of O2 and CO is taken to analysis. It is indicated that the material is effective to prevent the loose coal spontaneous combustion in the top-coal falling region.