Study On Numerical Simulation Of Spontaneous Combustion Coal Around A Roadway Based On The Rapid Oxidation Experiment

A coal mine roadway, as the excavate tunnel which meets the need of elevation, transportation, ventilation, drainage and power supply during mining operations, is one of the locations which is prone to spontaneous combustion under mine sites. So prevention and monitoring the development condition of fire origin spot is a vital task. With the development of coal industry, the issue of coal spontaneous combustion in tunnels has become more conspicuous. Origin spot of tunnel fire has high level of concealment. To quickly determine the fire origin spot will greatly raise the efficiency of disaster relief when facing coal spontaneous combustion in tunnels. However, due to the complexity of the exogenous factors, related mechanism remains to be further research.Due to the concealment of the coal spontaneous combustion in tunnels, especially in caving zones which sight and workers are hard to get, it is difficult to predict tunnel coal spontaneous combustion by routine detection method. Adopting numerical simulation technique to predict coal spontaneous combustion in tunnels can be an effective solution.This article did a research on one section of fully mechanized coal tunnel of Zaoquan coal mine,Ningxia Coal Industry Group.By using coal and oxygen compound theory, this article applys experimental tests and computer simulation method to study the process of coal spontaneous combustion in tunnels. Analyse experimental furnace construction and coal rapid oxidation experiment, using computational fluid dynamics as an auxiliary way to simulate the process of coal spontaneous combustion in tunnels. First of all, by means of constructing a coal spontaneous combustion experiment apparatus under heating by auxiliary heat source, conducted programmed temperature rise experiment on coal samples from Zaoquan, oxidation kinetics parameters as the rate of oxygen consumption and oxidation heat liberation intensity of coal sample can be measured through experiment, limit parameters of coal, when it occurs,of spontaneous combustion are also derived. Secondly, according to the actual condition of experiment apparatus, a three-dimensional physical models of loose coal spontaneous combustion in tunnels was established and grids were divided. According to the spontaneous combustion parameters concluded from rapid oxidation experiment to divide dangerous zone of coal spontaneous combustion in tunnels, determined caving zone as the research key point. Finally, a mathematical model of coal spontaneous combustion process in tunnels was created and boundary conditions of three-dimensional models were determined, in addition to simulated process of coal spontaneous combustion in tunnels by FLUENT software. Comparison between numerical simulation results and data from reference [44] shows that numerical simulation consists with the actual condition, verifies the applicability of the three-dimensional models of coal spontaneous combustion in tunnels. And the propensity of spontaneous combustion in caving zones,can be divided into three zones. The simulation results have guidance for the accurate monitoring distribution and development of high temperature spots of coal in tunnels.