Monitoring And Intering Protection For Spontaneous Combustion In Sealed Spherical Coal Yard

The relatively closed coal storage condition makes the coal body oxidize spontaneously in the bunker,causing economic loss and safety hazard,To analyze the process of oxidation of coal spontaneous combustion is oxidation and spontaneous combustion of coal is closely related for wind condition and heat condition,on the basis of establishing the coal spontaneous combustion process of leakage of wind field,the oxygen concentration field and temperature field mathematical model.According to coal spontaneous combustion experiment platform for heat production rate of coal and oxygen consumption rate is proportional to the actual oxygen concentration coal body relations,and analyzing the inside and outside warehouse for wind is the main source for the ball within the warehouse temperature difference caused by the "chimney effect",in accordance with the established goals within the warehouse the three field coupling mathematical model of spontaneous combustion coal oxidation,coal ball storehouse for the next step temperature field numerical simulation to establish the theoretical foundation.Based on FLUENT software,the oxidation of coal spontaneous combustion inside the ball storehouse reasonable assumptions,by writing user-defined functions into heating rate and oxygen consumption rate of boundary conditions,implement the ball storehouse oxidized spontaneous combustion of coal is three field coupled temperature field numerical simulation,Through the analysis of simulation results acquired by the characteristics of temperature field distribution of coal and high temperature will be to the law of coal mouth mobile storage,affecting factors after the analyses of coal porosity and the height of the coal ball storage compaction coal storage strategy of coal can be taken to slow the spontaneous combustion period of coal.The temperature monitoring and measurement points of the ball warehouse are large,and the traditional method of using the traditional temperature value directly for the warning will produce a large number of false positives.By studying the data fusion technology,USES the LMBP neural network to data fusion processing temperature,build three input three output of three-layer LMBP neural networks,with the temperature data of three characteristics: the average temperature,temperature rising rate,temperature rising trend as input,the cumulative value with no coal in the ball storehouse,smoldering fire,fire probability as output.On the MATLAB simulation experiment platform,the actual data of fire in mine goaf is simulated,and the simulation results show that the accuracy of the method can reach more than 90%,which is feasible.The closed silo adopts the inertial protection system as the fire prevention measure,but the current flow characteristics of the inert gas in the enclosed bunker are not studied,Using FLUENT software,this paper analyzes the dispersion characteristics of carbon dioxide inert gas inside the coal pile,the concentration of carbon dioxide,inert gas flow rate,the ball in the "chimney effect",carbon dioxide,cooling effect and gas mouth,the influence of different arrangement of inerting.Results show that the concentration of carbon dioxide for inerting effect is not big,as long as it can reach the lowest inerting concentration,increasing the flow of inerting can effectively reduce the time of the inerting,at the same time,the coal mouth closed will be effective measures to improve the effect of inerting.Finally,the simulation of the different arrangement schemes of the inflatable port is provided to provide the basis for the layout of the inertial protection system.