Research On Risk Of Coal Spontaneous Combustion In The Goaf Of Fully Mechanized Caving Face Of Close Distance Coal Seams

In fully mechanized caving face of Close Distance Coal Seams, there are many characteristics of too much residual coal、 large falling height、 serious break of Coal and Rock Mass、large air leak intensity、 slow advance speed、 height space exist in a double of coal and so on, which increases risk of coal spontaneous combustion in the goaf. Accurate division of risk region in fully mechanized caving face of close distance coal seams plays a important role in working out the reasonable fire extinguishing measures. In this paper, a study approach of theoretical analysis、 laboratory experiment、field test is adopted to systematically research coal spontaneous combustion in the goaf of fully mechanized caving face of close distance coal seams. Starting with law and characteristic to comprehensively analyze the influencing facters of coal spontaneous combustion in the goaf of fully mechanized caving face of close distance coal seams. Collecting the15、14coal, it makes use of the temperature programmed experiment to find gas production rules in the process of low temperature oxidation, CO and C2H4were selected as the index gases forecasting coal spontaneous combustion in the goaf. At the same time, by virtue of carve fitting of the CO density during different temperature period to analyze the changing rule of CO density, at last, achieve the early prediction of coal spontaneous combustion in the goaf. Research on the characteristic of porous media in the goaf, we can conduct the distribution of the Porosity and calculate the resistance of air leakage in the goaf.3-D physical model and mathematical model are established for fully mechanized caving face of close distance coal seams in the goaf, using the Fluent software to simulate the distribution of the "three zone" and temperature field in the goaf. Through bury six groups strap tube and temperature probe in advance to actually measure the changing rule of gas and temperature in the goaf.According to the working face of air leakage, we partition the"three zone" of1504full-mechanized caving mining face in the goaf.According to actual ignition time of1504goaf, the minimum of safe fitting speed is calculated.finally, combining with the advance speed of fully mechanized caving face, the risk region of coal spontaneous combustion is conducted.