考虑温度变化的采空区瓦斯抽采数值模拟  

Numerical simulation of gas drainage in gob considering temperature change

作　　者：汪腾蛟 聂朝刚[3] 杨小彬 王朋浩[3] WANG Tengjiao;NIE Chaogang;YANG Xiaobin;WANG Penghao(School of Mining,Liaoning Technical University,Fuxin 123000,China;Bulianta Coal Mine,Shenhua Shendong Coal Group Co.,Ltd.,Ordos 017209,China;School of Emergency Management and Safety Engineering,China University of Mining and Technology-Beijing,Beijing 100083,China)

机构地区：[1]辽宁工程技术大学矿业学院,辽宁阜新123000 [2]神华神东煤炭集团有限责任公司补连塔煤矿,内蒙古鄂尔多斯017209 [3]中国矿业大学(北京)应急管理与安全工程学院,北京100083

出　　处：《煤炭科学技术》2021年第7期85-94,共10页Coal Science and Technology

基　　金：国家自然科学基金资助项目(51274207);国家自然科学基金青年基金资助项目(50904071)。

摘　　要：考虑采空区瓦斯抽采工作面漏风引起采空区遗煤氧化升温问题,基于Darcy渗流定律、Fick扩散定律和Fourier导热定律,利用质量守恒方程和能量守恒方程建立了考虑温度变化的采空区流场、瓦斯浓度场、氧浓度场、固体温度场和气体温度场的瓦斯抽采多场耦合数学模型;应用有限体积法分别离散了考虑温度变化下的采空区瓦斯抽采多场耦合二维数学模型,基于Microsoft Visual Basic编制了计算机解算程序,利用Tecplot软件对求解结果进行可视化,研究了瓦斯抽采前后的采空区瓦斯压力、瓦斯浓度、氧浓度、固体温度和气体温度分布情况及前后变化趋势。结果表明:瓦斯抽采前,采空区下隅角附近存在明显的气体高压区并且向四周逐渐降低,上隅角附近存在明显的气体低压区并且向四周逐渐升高;瓦斯浓度从下隅角向上隅角逐渐降低,采空区深处的瓦斯体积分数高于近工作面处,高达16.0%;采空区下隅角附近的氧气体积分数较高,达到7.0%,且氧气浓度由下隅角向上隅角逐渐降低;在采空区漏入风侧存在明显的固体和气体高温区,并且温度由此处向四周逐渐降低。瓦斯抽采后,在抽采点处形成气体低压区,气体压力在采空区深度方向变化趋势缓慢;采空区上隅角的瓦斯浓度大幅降低,而采空区深处的瓦斯受抽采的影响较小;采空区浅部(0-100 m)氧气浓度升高,采空区深部(100-300 m)氧气浓度基本保持不变;高温区依旧形成于采空区漏入风侧,但高温区的范围有所扩大,采空区内固体和气体温度最大值要比抽采前高2℃。Considering the air leakage of the gas drainage face in the gob,which causes the oxidation and heating of the remaining coal in the gob,based on Darcy's law of seepage,Fick's law of diffusion and Fourier's law of heat conduction,combined with the mass conser⁃vation equation and the energy conservation equation,a multi-field coupled two-dimensional mathematical model of gas extraction in the gob was put forward.This model includes gas concentration field,oxygen concentration field,solid temperature field and gas temperature field and the interaction of these fields considering temperature changing.The finite volume method and Microsoft Visual Basic platform were used to discretize the multi-field coupling of gas drainage in the gob considering temperature changes.A three-dimensional mathe⁃matical model,a computer solution program based on Microsoft Visual Basic,and Tecplot software were used to visualize the solution re⁃sults.The pressure,gas concentration,oxygen concentration,solid temperature and gas temperature distribution in the gob before and after gas drainage were studied.The results show that:before gas drainage,there is an obvious gas high pressure area near the lower corner of the gob and gradually decreases to the surroundings,and an obvious gas low pressure area near the upper corner and gradually increases to the surroundings;the gas concentration gradually decreases from the lower corner to the upper corner,and the gas concentration in the depths of the gob is higher than that near the working face,up to 16.0%;the oxygen concentration near the lower corner of the gob is higher,reaching 7.0%,and the oxygen concentration gradually decreases from the lower corner to the upper corner;there is an obvious solid and gas high temperature area on the side of the gob that leaks into the wind,and the temperature gradually decreasesfrom here to the surroundings.After the gas is drained,a gas low-pressure area is formed at the drainage point,and the gas pressure changes slowly in the depth direction of the

关 键 词：遗煤 采空区 瓦斯抽采 多场耦合 

分 类 号：TD712[矿业工程—矿井通风与安全]