| China's rich mineral resources play an indispensable role in energy supply for the rapid development of national economy,so safe and efficient exploitation is an important guarantee for the sustainable and effective supply of national energy.According to statistics,every year there are hundreds of millions of tons of coal due to its oxidation and spontaneous combustion loss,at the same time to human life and property safety,ecological environment pollution damage caused a huge impact.Therefore,it is of great significance to study the spontaneous combustion characteristics of coal in 9102 working face of Chang-heng coal mine and to determine the distribution area of oxidized spontaneous combustion zone in mined-out area to formulate comprehensive fire prevention measures.First of all,In the engineering background of Chang-heng 9102 fully mechanized coal face,the further study of the present situation of the application of mine fire tube monitoring system,reveals the current tube acquisition system exist in the practical application,for example,when collecting tube sampler is according to the coal wall fall off naturally goaf coal and rock damage,prone to water,dust and air inlet of slurry plugging gas sampler.Through the literature and combining with actual,the key to improve the process principle of gas collecting device,puts forward a kind of both can protect the goaf collection tube road was damaged,and can guarantee the gas sampling device smoothly-gas cases,the meaning of innovation lies in the tube line on dual protection,the iron net and vent at the top of the case to ensure the flow of gas gathering,to accurate collection and analysis of the gas composition of mined-out area designated location,identification basis to determine spontaneous combustion "three zones".Secondly,In the process of underground field experiment and laboratory experiment measurement regularly during the stopping of 9102 working face,the variation law of gas composition with the advance distance of working space was recorded and analyzed,and the "three zones" distribution area of spontaneous combustion in goaf was preliminarily obtained.Then the mine 9102 working face and goaf with inlet and return air roadway as a blueprint,using Tec-plot software Gambit and Fluent,after creating the model,boundary conditions,mesh,solver to solve,postprocessing,and a series of numerical simulation,schematic drawing the working face gas concentration distribution,to verify the rationality of the measured data and the accuracy of the actual conditions,and combined with field test and laboratory experiment of determination results,ultimately determine the scope of the 9102 working face of goaf spontaneous combustion "three zones".Respectively,the areas within 9m from the working space are The Scattered Zone,the areas between 9 and 71 m from the working space are The Oxidative Spontaneous Combustion Zone,and the areas above 71 m from the working space are The Asphyxia Zone.According to the measured maximum width of the oxidation spontaneous combustion belt in the goaf and the shortest spontaneous combustion period of the coal seam,the minimum critical advance speed of the working face is 45m/month,that is,the daily advance speed should not be less than 1.5m to ensure that the goaf's natural hidden dangers are under control.Finally,the paper puts forward the comprehensive fire prevention and extinguishing measures,which are mainly to pour mud through the slurry pipeline before stopping,to spray inhibitor between hydraulic supports during stopping and nitrogen injection after stopping.The mud material is loess,fly ash,and the water-solid ratio of slurry is 4:1.Industrial calcium chloride was selected as the retarding agent and the concentration was 20%.Nitrogen injection and fire prevention technologies include intermittent nitrogen injection in normal production conditions and continuous nitrogen injection in slow advance.It greatly reduces the hidden danger of spontaneous combustion of waste coal in goaf,which has certain reference significance.The paper has 24 figures,10 tables and 84 references. |
PDF Full Text Request