Study On Numerical Simulation Of The "Three Zone" Of Spontaneous Combustion In Gob And Synthetical Technique Preventing And Extinguishing Fire

The spontaneous combustion of coal, one of the serious disasters in coal mine, it leads to the sere sources unable to exploitation and coal resources devaluation, with destroyed underground coal seams, production materials and equipment. The spontaneous combustion consumes a lot of oxygen in the air with producing high energy absorption rates, virulent noxious gas and harmful dust. Threatens people personal safety and property seriously, affects the social stability and has been hindering the sustainable development of coal in dusty. The coal resource in the underground fire zone was striking.In this paper, it not only discusses the synthetically technique preventing and extinguishing fire with easy self-ignition of coal seams at a slower mining speed, but also analysises of spontaneous combustion "three zone" in goaf based on CFD, and summaries the experience of managing fire area, as follow:(1) We study the mechanism, process and of spontaneous combustion of coal, and the significance and principle of division of the "three zone" area. The primary influence factors on the "three zone" area contains thickness and porosity of loose coal, oxygen concentration, temperature, air leak intensity, particle size of loose coal and moisture content in original coal. Meanwhile, using the programmed heating experiments, we analysis the signal gases from different coal sample and the properties of fire extinguishing materials;(2) According to the mine’s realistic conditions, find spontaneous ignition "three zone" in goaf by the local beam tube monitoring systems and the CFD software, discuss the feature of coal spontaneous combustion zone.(3) This paper introduces and analyses the fire extinguishing comprehensive technology: air leakage control, pressure balancing, preventive grouting, inhibited aerosol, inert gas, gel and three-phase foam. In the first instance, PeiCheng7377work face is easy self-ignition, steeply dipping seam and mining slow. The second one, YongGu3434work face faces with the coal spontaneous ignition in high gas coal face. LongGu7321mechanized top-caving mining face is difficult to improve the mining and support removing speed in the third case.According to local beam tube monitoring and numerical simulation, adopt the reasonable method such as air supply reasonable and leakage control, inhibited aerosol, glue injection, lock wind removing support. An effective fire-fighting technology eventually formed by using optimal combination of fire-prevention technology.