非均质采空区气-固耦合温度场迎风有限元求解

重点讨论了用迎风有限元方法结合图形显示技术计算回采采空区温度场温度分布问题．先建立采空区煤耗氧和自燃升温的定解数学模型，联立求解了漏风渗流方程、氧浓度消耗——弥散方程和传热方程．详细描述了在漏风流作用下采空区遗煤氧化自燃过程，给出了采空区温度分布的稳定的动态数值解．通过计算对比，该方法有效地控制了数值解的振荡，避免了人工干预对计算结果影响，又便于可视化处理．     

多邻近采空区瓦斯抽采下工作面漏风规律研究

为了掌握邻近多采空区及本煤层采空区瓦斯抽采背景条件下的采空区漏风规律,以沙曲矿15202工作面为例对邻近多采空区的开采环境及其采空区瓦斯抽采所导致的漏风问题开展研究。通过对采空区的空间环境分布及瓦斯抽采对15202工作面漏风影响的分析,辅助工作面沿程漏风量实测,采空区及瓦斯抽采系统中气体体积分数的测定,结果表明:(1)多邻近采空区及在瓦斯抽采条件下,工作面采空区漏风严重;(2)采空区漏风风量中的55.7%经采空区漏入工作面,18.5%经上覆裂隙进入14202采空区抽采系统,14.7%进入邻近采空区,11.1%进入上隅角瓦斯抽采系统。此结果为采空区煤自燃防治提供了决策依据,并对类似工作面的漏风识别具有指导意义。     

瓦斯抽采对采空区浮煤自燃影响及防治措施

针对立体瓦斯抽采对采空区自燃带分布及浮煤自燃的影响,以采空区风流速度的变化为切入点,以义马集团U+Ⅰ型通风系统为背景,研究在立体瓦斯抽采系统中由于漏风而造成采空区"三带"分布变化及对浮煤自燃的影响.结果表明,瓦斯抽采及采空区浮煤自热产生的"内生火风压"加剧了采空区的漏风,使自燃带的划分范围更复杂,增加了采空区发火的危险性,最后提出了增阻漏风及同步注氮、注水、注浆的综合防灭火措施.     

前进式预埋管法抽放采空区瓦斯的试验研究

以采空区瓦斯涌出规律为基础，探讨了采空区瓦斯的治理原则；并以平煤（集团）公司十矿２０１３０综采面为试验点，进行了前进式预埋管法抽放采空区瓦斯的试验研究．研究结果表明：该技术不仅对解决采空区上隅角瓦斯积聚问题具有重要作用，而且还为采空区瓦斯资源的开发利用提供了实用技术．     

采空区自燃"三带"微循环理论及漏风流场数值模拟

为掌握采空区自燃"三带"分布及其自然发火规律,通过唐口煤矿2307工作面采空区自燃"三带"现场温度和气样观测,利用FLUENT软件对采空区漏风流场数值模拟.结果表明:采空区自燃是一个氧热微循环过程,当漏风供氧大于氧化耗氧、氧化生热大于漏风散热时,氧热微循环可持续进行,直至自燃;得出工作面不同风量下采空区自燃"三带"的区域.进风巷侧采空区可能自燃带范围在48.2～98.6 m,而回风巷侧采空区可能自燃带范围在24.3～98.6 m.经对比分析,得出最有利于采空区防灭火的最佳供风量为1 200～1 440 m~3/min,可满足防灭火的需要.     

近距离保护层开采采场下行通风瓦斯涌出及分布规律

平煤集团四矿在开采过程中工作面φ（CH4）频繁超限,影响了工作面正常安全生产．通过;理论分析,阐述了采空区内风流流动状况和采用不同通风方式时采空区的瓦斯涌出规律．结合现场实验,探讨了工作面采用下行风时采空区的瓦斯涌出和分布规律．在此基础上,提出了用下行风解决工作面瓦斯超限问题．结果表明,在采用下行通风后,采空区绝对瓦斯涌出量为上行风时的80％,工作面φ（CH4）下降了75％,瓦斯不再超限．     

综放面采空区矿压特征与漏风形态

分析了综采放顶煤工作面采空区岩体碎胀特征，着重讨论了采空区内各分区漏风形态和范围以及由此引起的遗煤自燃特性和上隅角瓦斯超限问题。     

前进式预埋管法抽放采区瓦斯的试验研究

以采空区瓦斯涌出规律为基础，探讨了采空区瓦斯的治理原则；并以平煤（集团）公司十矿２０１３０综采面为试验点，进行了前进式预埋管法抽放采空区瓦斯的试验研究。研究结果表明：该技术不仅对解决采空区上隅角瓦斯积累问题具有重要作用，而且还为采空区瓦斯资源的开发利用提供了实用技术。     

瓦斯抽采下沿空留巷采空区自燃危险区域判定

由于沿空留巷工作面采空区漏风严重且对具有自然发火的煤层影响较大,所以研究沿空留巷采空区自燃危险区域具有重要意义。针对沿空留巷侧采空区瓦斯抽采及充填墙裂隙演化诱导漏风及自燃问题,以沙曲矿沿空留巷综放面为研究对象,通过SF6漏风实测及束管观测研究,研究了工作面及沿空留巷侧采空区漏风规律及氧气体积分数分布特征,并对采空区不同倾向范围内自燃氧化"三带"的分布区间进行了识别及划分,进而在理论及实测分析的基础上,结合工作面推进速度及煤层自然发火期发现在沿空留巷侧采空区倾向方向5~30 m存在自燃危险区,若改变工作面开采条件,其他非自燃区域可能转变为自燃危险区。     

自燃采空区注氮过程标志性气体分布特征研究

在高瓦斯自燃煤层采空区采取高抽加尾巷排放瓦斯的立体抽放方式时,为避免采空区发生自燃,对采空区进行注N2防火．以华晋焦煤有限责任公司沙曲矿15201工作面为例,在确定采空区自燃三带划分标准的基础上,通过埋管测试方法,研究采空区注N2前后采空区N2和O2分布状态,以及采空区N2运移规律．结果表明,注N2后,注入N2与采空区原有气体混合,气体在采空区漏风压与注N2压力共同作用下运移．N2影响区内O2体积分数下降,氧化带范围缩小,降低了工作面自燃的危险程度．为工作面优化注N2参数和提高注N2防灭火效果提供了参考．     

CFD simulation of spontaneous coal combustion in irregular patterns of goaf with multiple points of leaking air

Based on the non-linear air leakage seepage equation for an anisotropic porous medium, on the seepage diffusion equation of multicomponent gas and on the seepage synthetic heat transfer equation of a porous medium, the numerical model for field flow problems of irregular patterns of a goaf with multiple points of leaking air is established and simultaneously solved by the upwind mode finite element method (G3 computer program). According to the complexity of irregular patterns of a goaf with multiple points of leaking air, the flow pattern in a large area of such a goaf and the variation in gases of methane, oxygen and CO and in temperature are theoretically described. In the calculation, the goaf is regarded as a caving anisotropic medium and the coupling effect of methane effusion on spontaneous combustion is considered. The simulation results agree well with practical experience. In addition, the spontaneous combustion process is also simulated, indicating that 1) the spontaneous combustion often takes place near the area where fresh air leaks in and 2) the fire sources can be classified into static and dynamic zones. Therefore, in practical fire preventing and extinguishing, we should clearly distinguish the upstream air leaking points from the downstream ones in order to take proper measures for leakage stopping.     

简放工作面供风量与采空区遗煤自燃危险性研究

针对地方煤矿易自燃厚煤层简易放顶煤开采推进速度低的现实条件,本文在分析不同氧浓度条件下煤的耗氧速度、采空区煤氧化自燃三带及其与采空区漏风量关系基础上,研究了工作面供风量与漏风量及其采空区氧化带宽度的关系,研究结果为厚煤层简放开采工作面的合理供风量及防治煤炭自燃措施应用提供了技术依据.     

Risk assessment of gas control and spontaneous combustion of coal under gas drainage of an upper tunnel

The adjustment of the gas drainage rate has an immediate impact on air leakage in gob, thus resulting in the change of self-heating of coal. While regulating the gas drainage parameters, the risk of spontaneous combustion of coal should be considered. The risk assessment of gas control and spontaneous combustion of coal under gas drainage in a tunnel was investigated at different gas drainage rates. The distributions of the air volume along the working face, the gas management effects and the width of the oxidation zone were subjected to risk analysis. As the simulation results showed, with increasing gas drainage rate,although the safety of gas dilution by ventilation was assured, the intensifying air leakage caused the oxidation zone to move into the deeper gob and led to an increase in the width of the oxidation zone.A risk assessment method was proposed to determine a suitable gas drainage rate for the upper tunnel.The correctness of the risk assessment and the validity of the numerical modelling were confirmed by the field measurements.     

煤巷高冒区松散煤体自然发火的数值模拟研究

巷道高冒区自燃火灾，不仅严重影响到采掘工作面的安全生产，而且威胁到矿工们的生命安全．通过对煤巷高冒区特点和影响煤炭自燃因素的分析，根据多孔介质流体动力学、传热和传质理论，建立了高冒区松散煤体自然发火过程三维数学模型．以旗山煤矿高冒区为例，用有限元法进行了数值求解，得到高冒区渗流速度场、温度场和氧浓度场的分布，在此基础上划分出最易自然发火的区域，分析了高冒区自然发火的机理．结果表明：高冒区松散煤体漏风强度随孔隙率的增大而增加；高冒区松散煤体的中部区域存在最易自然发火区，是现场防治高冒区自然发火的重点区域．现场试验数据验证了数值模拟结果的合理性．     

Bulking factor of the strata overlying the gob and a three-dimensional numerical simulation of the air leakage flow field

The present study examines the results of the researches related to the gob bulking factor carried out at home and abroad. A mathematical function of a three-dimensional gob bulking factor is described based on a three-dimensional gob model. The method of taking value for interstice and permeability ratios is also proposed. The law of air leakage of fully mechanized top coal is researched in this study. The results show that the speed of air flow near the upper and lower crossheadings is higher than that in the central section of the gob at the same distance from the working face. When the amount of air at the working face exceeds a critical amount, the width of the spontaneous combustion zone in the upper and lower crossheadings is also larger than that in the central section. In this situation, the key is preventing the coal left in the upper and lower crossheadings from self-igniting. Reducing the amount of air at the working face can decrease the width of the spontaneous combustion zone, especially the width near the upper and lower crossheadings. This also moves the spontaneous combustion zone in the direction of the working face. It can prevent the coal in the gob from self-igniting by making the coal left in the crossheadings to be inert and by effectively controlling the amount of air at the working face.     

易自燃煤层放顶煤开采工作面合理长度分析

以采空区自然发火危险为约束条件,用采空区场流方法(数值模拟)和自燃三带理论,结合实例,研究放顶煤开采工作面合理长度问题.得到工作面长度安全临界值与煤的最短自然发火期成正比关系.通过现场测定风量和采空区气体浓度分布,得到在当前工作面特定采空区流场环境下的自燃氧化带宽度和模型基础参数,数值模拟出不同工作面长度的采空区自燃氧化区宽度的变化关系;回归得到,在理论上,工作面长度与自燃氧化带宽度近似服从二次曲线关系.分析中给出了自燃安全判别量和自燃安全区间.     

易自燃煤层特殊条件下综放开采工作面防火技术研究

分析了耿村矿１３０１工作面易自燃煤层特殊条件下综放开采工作面自然发火的危险性;探讨了因采空区漏风而引起的工作面自然发火的防治措施．经现场实施研究表明,均压通风、低风量供风、加快工作面推进速度的综合防火技术,成功地防止了自然发火,保证了综放开采工作面的安全生产．     

高瓦斯工作面带尾巷的“U”型通风系统最佳横川间距的研究

针对沿工作面向尾巷横川连续漏风的特点，运用计算机程序（Ｃ—语言），给出限定条件下常微分方程的数值解，找到沿工作面漏风的分布规律及漏风中瓦斯浓度的变化规律，得到横川距工作面垂距与横川中瓦斯浓度的变化规律，给出了寻找最佳横川间距的途径。     

Theoretical analysis and applications of Y-Inversion Ventilation System in a mine fire zone

Based on mine fire fighting practices at the 1110 working face of the Brapukuria Coal Mine,Bangladesh,we introduce and discuss the Y-Inversion Ventilation System,the latest technology used both in mine fire zone management and the unsealing process.This ventilation system can ensure that all miners breathed fresh air,providing protection for them during fire fighting and unsealing the fire zone.On the other hand,adjusting the amount of air at the working face and forming a CO leakage path controlled the state of the fire and as well ensured that the different fire extinguishing measures could be applied successfully.These are all fundamental techniques which ensured successful fire extinguishing and unsealing of the fire zone.We also analyzed the main reasons for the spontaneous coal combustion that occurred at the 1110 working face.Successful application of advanced composite polymer colloidal perfusion techniques,polymer foam MEA perfusion and fire-prevention technology by infusing nitrogen,used in mine fire zone management and unsealing,are presented.We value the experience with these techniques very highly and are of the opinion that these techniques could be widely used in mine fire fighting practices under similar spontaneous coal combustion conditions elsewhere.