特厚易自燃煤层综放工作面采空区氧化自燃带分布规律模拟研究

特厚煤层(厚度8m)放顶煤开采过程中,采空区遗煤多,煤自燃火源隐蔽,位置和程度难以判定,加大了矿井火灾防治的难度。本文通过ANSYS FLUENT软件对山西峁底矿13204易自燃煤层综放面(煤层平均厚度12.06m)采空区的空间自燃"三带"分布规律进行了研究。模拟结果表明:沿采空区走向,在底板进风侧附近,氧化自燃带离工作面最小距离为20m,宽度68m;沿工作面倾向,氧化自燃带沿垂直于工作面的中心线呈非对称分布,进风侧氧化自燃带最宽,回风侧次之,采空区中部最窄;沿垂直高度方向,进风侧氧化自燃带距离底板最高可达30m,其宽度为12m。本文研究结果有望为特厚易自燃煤层综放面采空区防灭火提供理论借鉴作用。     

应用反演变换确定齿轮传动中主动轮的位置及节圆大小

应用反演变换中直线和圆的反演特点,以及反演变换中图形相切性质保持不变这一特性,在图解法解决机构设计中构件的定位问题及确定构件尺寸,使作图大大简化。     

防治煤炭自燃的三相泡沫理论与技术研究

针对目前我国煤矿防灭火技术和手段存在不足,特别是针对大范围采空区或巷道高冒火灾、采空区隐蔽火源及高位火源、综放及俯采工作面煤炭自燃防治的难题,提出了由粉煤灰（黄泥）、氮气和水组成的三相泡沫防灭火新技术,该技术可以利用煤矿已有的注浆系统将三相泡沫注入采空区并形成覆盖面广、可向高冒区堆积的泡沫体,能较好地充填采空区或高冒区,有效扑灭火灾．针对固体不燃物（粉煤灰、黄泥）、水和氮气三相介质的特性,成功研制出了使浆液具有较高发泡倍数和较长稳定时间的三相泡沫发泡剂．应用浮选动力学、表面化学、物理化学、热力学和流体机械等理论,较系统地提出了三相泡沫的形成机理．根据三相泡沫的特点,发明了三相泡沫发泡器。应用流体力学理论,建立了发泡器喉部至扩散段区域负压大小和浆液流量的方程关系式,并通过CFD流体力学软件模拟了三相泡沫发泡器内不同扩散角度下管内静压和浆液流速的分布状况,得出了扩散角为60°时的压力分布和流速是形成三相泡沫的最佳条件．开展了三相泡沫发泡剂溶液阻止煤自燃的试验研究,结果表明：三相泡沫发泡剂溶液对煤自燃的阻化效果显著,能有效地减缓煤的氧化放热速率,抑制煤温度的升高,同时也有效地抑制CO的释放量,是很好的防止煤炭自燃的阻化剂;三相泡沫的灭火性能试验表明,三相泡沫可在较致密的多孔介质中不同方向流动,渗透性强,流动范围广,可扑灭较大范围区域内的高位火源和隐蔽地点的火源．三相泡沫流变特性研究表明,含黄泥或粉煤灰颗粒的三相泡沫属于屈服假塑性非牛顿流体;试验考察了发泡倍数、浆液浓度、外界温度及气体介质对三相泡沫黏度的影响;建立了三相泡沫在水平管道中流动的数学模型,确定了三相泡沫发泡器在井巷中合理的安装位置;建立了三相泡沫在大空间中堆积高度的数学模型． 在矿井灌浆系统中加入氮气,使泥浆发泡,体积增大,大流量的三相泡沫能在采空区中形成面与三维的流动方式,较之一般的水浆流动,覆盖面广,并可向上部堆积,能将更多的水、固体不燃物（黄泥、粉煤灰）带入防灭火区域,防灭火效果显著．建立了一套适合煤矿自然火灾防治的注三相泡沫的工艺系统,该系统安全可靠,操作方便,可连续大流量灌注．提出了沿顺槽采空区埋管、综采（综放）支架插管、地面打钻和与其它防灭火技术手段相互配合使用的多种注三相泡沫新工艺,并在现场得到了广泛应用．     

露天煤矿煤炭自燃进程的数学模型

探讨了露天煤矿煤炭自燃进程的数学关系，所得结果对分析露天煤矿煤炭自燃机理和预测其自燃进程与自燃点位置具有重要的指导意义。     

关于热传导方程源项系数的确定方法

考虑了一类利用终端观测值反演热传导方程中源项系数的反问题,此类问题无论是在理论讨论还是在实际应用中都有极其重要的研究意义。基于最优控制框架下讨论了控制泛函极小元的存在性及其满足的必要条件,最后证明了最优解的唯一性及稳定性。     

三相泡沫防治采空区煤炭自燃研究

针对目前煤矿防灭火技术与材料存在的一些不足，研制了一种用于防治采空区煤炭自燃的三相泡沫材料．简要介绍了三相泡沫的制备流程和主要技术参数；建立了采空区煤炭自燃过程的化学动力学方程，根据对方程中C，O2反应的物质的量浓度，煤体温度T，采空区的孔隙率γ等参数的控制，研究了三相泡沫防治采空区煤炭自燃的机理．结合三相泡沫在大兴煤矿N2703综放工作面采空区防治高温火源点的实际应用情况，对比了注三相泡沫前后取样气体中CO，O2体积浓度以及采空区温度丁的变化结果，有效地防治了煤炭自燃．应用结果表明三相泡沫防治采空区煤炭自燃的效果显著，是一种具有广阔应用前景的新型防灭火材料．     

基于主被动源频散曲线拼接策略的面波频散曲线反演研究

面波勘探是浅地表勘查的主要方法之一,传统的主动源面波方法探测深度通常在30 m以浅,且在噪声干扰复杂的城市环境中作用严重受限;被动源面波正是利用背景噪声为信号源,探测深度大,但对浅层介质分辨能力较差。为此,提出一种主动源、被动源面波数据处理方法,兼顾勘探深度和浅层分辨率。首先对主动源和被动源数据的频散曲线进行拼接,从而获得更宽频带的多阶频散曲线。然后采用数值模拟并反演处理,验证主被动面波频散曲线拼接策略的有效性。通过实测数据处理,对比分析了主动源方法和拼接策略的反演效果,证明了主被动源频散曲线拼接策略能有效提高反演结果精确度。该策略解决了单一震源能量频带有限对反演结果造成的影响,为面波勘探提供了新的手段。     

高硫自燃煤层低温氧化气体衍生规律研究

煤炭氧化后,随着氧化进程的不同将依次释放出各种气体,这些气体的出现及释放量能准确反映煤炭氧化自燃程度.利用煤氧化升温实验装置,研究了王台矿15号煤层煤自燃氧化特性,以及自燃升温过程中产生氧化气体和碳氢类气体随温度的变化规律.确定了15号煤自燃指标气体,并进行了详细分析,所得结果能够指导煤自燃的早期预测预报与防治工作.     

矿井火灾火源燃烧特性的实验研究

首先介绍了用锥形量热计测定矿用可燃物燃烧特性的测试方法 ,并对几种不同类型的矿用输送机胶带及木材进行了对比实验 .实验结果表明 :非阻燃的输送机胶带释热速率最高 ,阻燃输送机胶带产生的毒气危害性最大 .针对井巷网络火灾的特点 ,还对通风巷道中的火源燃烧特性进行了研究 ,介绍了在中国矿业大学矿井火灾综合模拟实验系统中进行的网络火灾线火源的火焰蔓延速率、温度分布及火源燃烧带对节流作用的影响的实验结果     

瑞雷波勘探的f-k域能量最大模方法

瑞雷波的频散特性已在地震勘探及工程勘察等领域得到了大量应用,但目前存在一些问题亟待解决,例如当层状介质中存在低速层时,提取的频散曲线会发生"之"字形回折,利用传统的基阶模反演不能得到正确的结果.本文主要针对"之"字形频散曲线问题,提出f-k域能量最大模的概念,并成功地将最大模应用于频散曲线的f-k域提取及对地层结构的反演分析.通过反演模拟以及实测数据发现,最大模方法可以较好地解决基阶模反演所不能解决的"之"字形频散曲线反演问题.     

Locating method of fire source for spontaneous combustion of sulfide ores

In order to achieve a more efficient way to accurately detect the position of the fire source of spontaneous combustion underground mine,a simple fire source locating method,based on infrared scanning system which can determine the point where the highest temperature on the surface of igniting ores occurs,was proposed.First,the differential equations that describe heat flow in ore body were presented and the relationship between the surface temperature distribution and the depth and intensity of inner fire ...     

注氮防灭火技术在煤矿中的应用

为了有效预防、控制和扑灭井下火灾,通过煤矿对注氮防灭火的实践应用,认为以注氮为主的防灭火是井下预防火灾和减少火灾损失的一种非常有价值和实用的技术,它可用于煤矿自燃发火的预防（稳定和控制发热）、火势控制、窒息火区、可控制的缩封和启封火区。当氮气注入工作面采空区或火区,使氧含量降低到5％～10％时,可抑制煤的氧化自燃以及瓦斯爆炸,而氧含量降低到3％以下时,则可以使煤炭燃烧熄灭并阻止其复燃。该技术在宁夏煤矿火灾的防治中得到多次应用,其技术处在国内先进水平之列,对于开采自燃煤层煤矿火灾预防与防治具有积极的推广价值。     

Method for prevention and control of spontaneous combustion of coal seam and its application in mining field

Spontaneous combustion of coal seam has been and continues to be a big problem in coal mines. It could pose great threat to the safety of the whole mine and all miners, especially when it occurs in or nearby coal mines. Besides, environment of area surrounded mines during combustion can be threatened where large amount of toxic gases including CO_2, CO, SO_2 and H_2S can be leased by fire in mine. Hence, it is important and significant for scholars to study the controlling and preventing of the coal seam fire. In this paper, the complicated reasons for the occurrence and development of spontaneous combustion in coal seam are analysed and different models under various air leakage situations are built as well. Based on the model and approximately calculation, the difficulty of fire extinguishment in coal seam is pointed out as the difficulty and poor effect to remove the large amount of heat released. Detailed measurements about backfilling and case analyses are also provided on the basis of the recent ten years' practice of controlling spontaneous combustion in coal seams in China. A technical fire prevention and control method has been concluded as five steps including detection, prevention, sealing, injection and pressure adjustment. However, various backfill materials require different application and environmental factors, so in this paper, analyses and discussion about the effect and engineering application of prevention of spontaneous combustion are provided according to different backfilling technologies and methods. Once the aforementioned fire prevention can be widely applied and regulated in mines, green mining will be achievable concerning mine fire prevention and control.     

A review of research on spontaneous combustion of coal

Coal oxidation at low temperatures is the heat source liable for the self-heating and spontaneous combustion of coal. This phenomenon has imposed severe problems in coal related industries. Attempts to understand this phenomenon by previous researchers have provided significant progress. It is wellknown that coal oxidation at low temperatures involves oxygen consumption and formation of gaseous and solid oxidation products. This process is majorly influenced by temperature, oxidation history of coal,coal properties, particle size distribution of the coal, etc. The current understanding of the phenomenon of self-heating and spontaneous combustion of coal is discussed along with the different experimental and numerical models established to predict self-heating characteristics of coal. This paper focuses on the global position of the study carried out by academics, research institutes and industries on spontaneous combustion of coal and coal mine fires. Within this framework, the generally used spontaneous combustion techniques to predict the spontaneous combustion liability of coal were evaluated. These techniques are well-known in their usage, but no specific method has become a standard to predict the spontaneous combustion liability. Further study is still needed to indicate a number of impending issues and to obtain a more complete understanding on the phenomenon.     

The shortest period of coal spontaneous combustion on the basis of oxidative heat release intensity

It’s necessary to forecast the shortest spontaneous combustion period for preventing and controlling the coal spontaneous combustion. During the experimental process, a calculating model of the SSCP is established on the basis of the oxidative heat release intensity and thermal capacity at different temperatures. According to the basic parameters of spontaneous combustion, heat of water evaporation and gas desorption, the SSCPs of different coals are further predicted. Finally, this study analyzed the relationships of the SSCP and the judging indexes of the self-ignite tendency. The result shows that the SSCP non-linearly increases with the decrease of dynamic oxygen adsorption and increase of activation energy. Compared with the practical fire situation of mine, this reliable method can meet the actual requirement of mine production.     

综放开采回采巷道喷射砼防火技术研究

根据煤层巷道自然发火的特点 ,研究了喷射砼在易自燃发火煤层综放开采回采巷道防火原理 ,并在现场进行了工业性试验 .实践证明 :喷射砼可以有效地预防巷道自燃火灾 ,这一技术在义马矿区得到了推广应用     

煤矿内因火灾防治方法及其有效性分析

介绍了煤矿中煤自然发火的一般规律,并分析了技术方法防(灭)火、均压防(灭)火、黄泥灌浆防(灭)火、氮气防(灭)火、凝胶防(灭)火等几种常用的预防内因火灾的防(灭)火方法;同时,对这些方法的防(灭)火有效性进行了分析,提出了实施这些方法的注意事项,以期能更好地预防煤自燃,从而更好地为矿井安全生产服务.     

基于L-R模糊数的综放工作面瓦斯爆燃火灾事故树分析

瓦斯爆燃是矿井火灾的诱发因素之一,由于瓦斯特殊的物理化学性质和赋存条件导致其爆燃形式与煤自燃有许多不同之处.从瓦斯爆燃的三要素入手,结合综放面瓦斯爆燃事故的特点,建立了基于瓦斯爆燃的火灾事故树,在基本事件概率不清楚的情况下,应用模糊数学理论将基本事件概率看作L-R模糊数,对事故树分析得出各个事件的概率值,为矿井防火提供更加科学的参考依据.     

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.     

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.