Research On Numerical Simulation Of Air Leakage In Fully Mechanized Gob Under The Condition Of Gas Drainage

Huainan panyi coal mine seam, whose shortest period of self-ignition is 15 days, is high gas-containing mined by fully machanized mining technology. In recent years, the application of fully-machanized technology in this mine has greatly improved its output. However, the low efficiency of mining upper coal has caused "two lines", "two laneways" become the hazard zone in gob. The key to prevent coal mine fire and exterminate it is to ascertain the location of high temperature site. But this technology has not well been solved home and abroad, and related research is not thorough.The article, from characteristics of fully machcnized gob under the condition of gas dranage, which based on the cause and research level of coal self-ignition at present, and the forecast model of coal spontaneous combustion and status quo of numerical simulation, directs the numerical simulation of air leakage zone in gob. First, by making use of the self-ignition experiment oven, three important parameters of oxygen consumption, intensity of heat transmission and the shortest coal igniton period which can provide basic data for setting-up of forcast model of fully mechanized gob, can be attained. Second, by using the knowledge of hydrodynamics and thermodynamics etc, equation of gas distribution of loose coal with ventilation leakage in the gob, equation of osmosis coefficient of different depth, influence function of oxygen consumption with depth, equation of airflow on both sides of the working face, and mathematical model of diffusion of air leakage in the gob and forecast model of fully mechanized gob can be set up. Third, ventilation leakage condition in the 2322(3) fully mechanized gob can be numerically simulated by using fluid calculation software FLUENT, thus the hazard zone can be compartmentalized. The result, which is identical with that of fatual observation, validates the reliability of the numerical mode.