深部采空区煤自燃早期预测预报方法研究

Study on early prediction method of coal spontaneous combustion in deep goaf

目的煤矿深部开采中出现的“三高一扰动”特点,导致深部采空区煤自燃危险区域出现判定困难和煤自燃早期预测预报理论依据不足等问题。方法在分析深部高应力条件下,煤氧化气体衍生规律的基础上,计算不同轴向应力下煤体的格雷哈姆系数和链烷比,结果结果表明:不同承压状态下,煤样氧化自燃过程中CO,CO_(2)气体的生成量随温度升高而增加;相同温度条件下,随着轴向应力增加,CO和CO_(2)气体的生成量先增加后减小。相同温度条件下,随着轴向应力增大,格雷哈姆系数先增大后减小,R1在9 MPa时达到极大值,R2在6 MPa时达到极大值,R3在9 MPa时达到极大值;相同轴向应力条件下,随着煤样室内温度升高,格雷哈姆系数基本呈线性变化。相同温度条件下,随着轴向应力增加,煤样的链烷比逐渐增大;不同承压状态下链烷比随着温度升高而升高。结论研究结果可为深部煤自燃早期预测预报提供理论依据。

Objectives The characteristics of“three highs and one disturbance”in the process of deep mining bring problems such as difficulty in determining the risk area of spontaneous combustion in deep mining areas and unclear early prediction and reporting of coal spontaneous combustion.Methods Based on the analysis of coal oxidation gas derivation law under deep high stress conditions,the Graham coefficient and alkane ratio of coal bodies under different stresses are calculated.Results The results showed that the production of CO and CO_(2) gas increased with the increase of temperature during the oxidative spontaneous combustion of coal samples under different pressure conditions;Under the same temperature conditions,the production of CO and CO_(2) gas showed a trend of increasing and then decreasing with the increase of axial stress.At the same temperature,with the increase of axial stress,the Graham coefficient increases first and then decreases.R2 reaches the maximum at 6 MPa,R3 reaches the maximum at 9 MPa and R1 reaches the maximum at 9 MPa;Under the condition of the same axial stress,the Graham coefficient basically changes linearly with the increase of indoor temperature of coal samples.At the same temperature,the alkane ratio of coal samples increases with the increase of axial stress;The alkane ratio under different pressure conditions basically shows an increasing trend with the increase of temperature.Conclusions The research results offer a theoretical foundation for the early prediction of deep coal spontaneous combustion.