差分红外型甲烷浓度光纤网络传感系统的研究

基于甲烷气体在其特征吸收波长下光的吸收程度随浓度变化的机理和差分吸收测量方法,结合空分复用技术和长光程吸收池技术,并考虑煤矿矿井中环境的特点,复用多个气体吸收型光纤传感器.介绍了利用差分红外光谱方法测量矿井中甲烷浓度的光纤网络传感系统的工作原理,给出了系统的结构框图.实验表明,吸收气室光程长为20 cm时,该传感器的检测限为4.278 mg/m3,精确度和稳定性可以满足实际要求,可在不同场合进行多点在线测量.     

Vacuum chamber suppression of gas-explosion propagation in a tunnel

To control and reduce the harm of a gas explosion, a new method is proposed for suppressing gas-explosion propagation in a tunnel by using a vacuum chamber. We studied the suppression effect on gas explosions by placing a vacuum chamber at dif-ferent positions along the tunnel. The results indicate that: 1) the vacuum chamber can absorb the explosion wave and explosion energy as much as possible at the beginning of the gas explosion, and; 2) when the vacuum chamber is used the closer it is to the ignition source the more significant the suppression effect. In addition, by using the vacuum chamber: 1) the flame propagation velocity decreases from ultrasonic to subsonic; 2) the flame propagation distance is remarkably shortened; 3) the maximum peak value of overpressure (Pro) decreases from 0.34 to 0.17 MPa or less, and; 4) the impulse of the blast wave (/) decreases from 20 to 8 kPa-s or less.     

激波诱导瓦斯气体爆燃的三维数值模拟

基于激波诱导瓦斯爆炸的19步化学反应模型，建立了三维非定常守恒方程，采用迎风的TVD格式对方程进行数值离散，数值模拟了氢氧燃烧驱动点燃甲烷和空气混合气体的爆炸过程，根据爆炸产物以及流场中压力和温度变化的结果，说明了激波诱导瓦斯爆炸的物理机制，同时验证了程序在模拟化学反应起主导作用的瓦斯预混爆炸现象中的可靠性和精确性，为研究煤矿瓦斯爆炸过程的特性，制定有效的防爆、抑爆技术措施提供了技术和理论支持。     

煤矿巷道瓦斯爆轰理论分析和参数计算

应用Ｃ－Ｊ爆轰理论和质量、动量、能量守恒原理,针对煤矿巷道瓦斯变绝热指娄建立了雨贡纽方程和瑞利方程,在此基石上分析了煤矿巷道瓦斯爆炸的条件和可能过程,建立了煤矿巷道瓦斯Ｃ－Ｊ爆轰参数计算公式,提出了激波点燃瓦斯混合气的条件的最小理论马赫数Ｍｍｉｎ的表达式。计算了煤矿恭和种瓦斯浓度情况下爆压、爆温、煤速等爆轰参数玫相应的点燃瓦斯混合气的量小理论马赫九Ｍｍｉｎ。     

综放开采顶板冒落撞击摩擦火花引爆瓦斯研究

针对康家滩煤矿8^#煤层综放开采条件，采用专门设计的实验装置对其顶板冒落撞击摩擦火花引爆瓦斯的可能性进行了实验研究．结果表明：冒落岩石的质量、冒落岩石撞击高度与角度、岩石性质及砂岩中的石英含量、岩石的潮湿度等是影响岩石撞击摩擦火花温度及其能否引爆瓦斯的重要因素．当石英砂岩间在接触压力迭171．2N以上、以10m／s的速度摩擦，在2～30s内可引起瓦斯爆炸．康家滩煤矿8^#煤层局部区域的石英砂岩冒落撞击高度最大达6．76m，撞击速度可达11．51m／s，具有引爆瓦斯的可能性．     

Review of preventive and constructive measures for coal mine explosions: An Indian perspective

Firedamp and coal dust explosion constitute a lion’s share in mine accidents in a global mining scenario. This paper reports a list of mine explosion disasters since last two decades, a critical review of the different prevention and constructive measures, and its recent development to avoid firedamp and coal dust explosion. Preventive legislation in core coal-producing countries, viz. China, USA, Australia, South Africa, and India related to firedamp and coal dust explosion are critically analysed. Accidents occurred due to explosion after Nationalisation of Coal Mines (1973) in India are listed. Prevention and constructive measures adopted in India are critically analysed with respect to the global mining scenario. Measures like methane credit concept, classification of mines/seams with respect to explosion risk zone, deflagration index; installation of automatic fire warning devices, canopy air curtain technology, explosion-prevention measures, such as fire-retardant materials, inhibitors, extinguishing agent, dust suppressor, and active explosion barrier are discussed in detail to avoid explosion and thereby adhering to zero accident policy due to coal mine explosion.     

Fe(III)盐溶液吸收法处理H2S气体的研究

对一种新的用可溶性盐吸收硫化氢的方法进行了研究。采用填料塔对Fe3+盐溶液吸收H2 S的过程进行了初步的考察 ,通过正交实验选出了最佳的操作条件 ,实验证明 ,在最佳的条件下H2 S的去除率接近 1 0 0 %。反应中生成的硫磺可以通过过滤的方法除去。在对Fe3+再生时 ,采用了单极压滤机式电解槽 ,电解过程中阳极的电流效率初步达到 60 % ,基本满足要求 ,而且阴极析出氢气 ,减少了电解的费用。实验结果表明 ,这种H2 S气体处理方法是可行的     

微胶囊化红磷阻燃剂的制备和应用的研究

该微胶囊化红磷阻燃剂是一种高效、新型阻燃剂，主要用于橡胶、塑料行业，如用于煤矿上的阻燃橡胶输送带，防止或减少瓦斯爆炸事故．另外还可用于聚氨酯泡沫、聚酰胺、聚丙烯、不饱和聚酯玻璃钢等制品和材料中．     

含添加剂细水雾熄灭油池火的机理及实验

为了提高普通细水雾灭火的有效性,采用小尺度实验方法,通过在普通细水雾中加入添加剂,研究了在受限空间内含添加剂细水雾扑灭油池火的有效性.实验研究发现:当火源位于细水雾的作用范围内时,灭火时间较短,灭火性能较高;当火源位于细水雾的防护区域外时,灭火有效性显著降低.而在相同流量和压力下向细水雾中加入添加剂,能显著地影响它的灭火性能,使火焰容易熄灭,灭火时间大大缩短,从而提高了细水雾的灭火能力,因此细水雾对受限空间内油池火的灭火有效性大大增强.通过细水雾对O2、CO、CO2的体积分数以及对火焰温度、烟气温度影响分析,为筛选和制备细水雾灭火添加剂提供了实验数据.     

Analysis of vacuum chamber suppressing gas explosion

In order to suppress the harm of gas explosion, the current study researched on the body of vacuum chamber. The previous studies verified that it could obviously lower the explosion overpressure by reasonably arranging vacuum chamber on pipe. That is to say, the vacuum chamber has the effect of absorbing wave and energy. To further deeply analyze the vacuum chamber suppressing gas explosion, this research designed the L-type pipe of gas explosion, and compared the experimental results of gas explosion with vacuum chamber and without vacuum chamber. Besides, using the gas chromatograph, this study also investigated the gas compositions in the pipe before and after explosion. The results show that: (1) without vacuum chamber, the maximum value of explosion overpressure is 0.22 MPa, with 60 ms duration, and after explosion, the concentration of oxygen drops to 12.07%, but the concentration of carbon monoxide increases to 4392.3 × 10^?6, and the concentration of carbon dioxide goes up to 7.848%, which can make the persons in danger suffocate and die; (2) with vacuum chamber, explosion overpressure drops to 0.18 MPa, with 20 ms duration or less, and after explosion, the concentration of oxygen still remains 12.07%, but the concentration of methane is 7.83%, however the concentration of carbon monoxide is only 727.24 × 10^?6, and the concentration of carbon dioxide is only 1.219%, at the this moment the concentration ratio of toxic gas drops by more than 83% in comparison to be that without vacuum chamber. Consequently, the vacuum chamber can guarantee that most methane does not take part in chemical reaction, and timely quenches the deflagration reaction of gas and oxygen. Because of the two points mentioned above, it reduces the explosion energy, and lowers that the overpressure of blast wave impacts and damages on the persons and facilities, and also decreases the consumption of oxygen and the production of the toxic gas. Therefore, it is safe to conclude that the vacuum chamber not only absorbs wave and energy, but also prevents and suppresses explosion.     

亚甲蓝分光光度法测定氧化降解瓦斯的羟基自由基

建立一种亚甲蓝作显色剂分光光度法测定Fenton试剂氧化降解瓦斯反应体系中·OH含量的方法,所产生的羟基自由基与亚甲蓝作用后使其吸光度降低,利用吸光度值的变化可间接测定·OH表观生成率,系统研究了H2O2浓度c(H2O2),Fe2+浓度c(Fe2+),初始pH值、反应温度等因素对·OH表观生成率的影响;同时,研究了异丙醇对·OH表观生成率和甲烷降解率的影响规律.结果不仅找出Fenton试剂氧化降解瓦斯反应体系中的·OH表观生成规律,而且为矿井瓦斯的绿色治理技术提供了重要的基础数据.     

Numerical simulation to determine the gas explosion risk in longwall goaf areas: A case study of Xutuan Colliery

Underground gassy longwall mining goafs may suffer potential gas explosions during the mining process because of the irregularity of gas emissions in the goaf and poor ventilation of the working face, which are risks difficult to control. In this work, the 3235 working face of the Xutuan Colliery in Suzhou City, China, was researched as a case study. The effects of air quantity and gas emission on the three-dimensional distribution of oxygen and methane concentration in the longwall goaf were studied. Based on the revised Coward’s triangle and linear coupling region formula, the coupled methane-oxygen explosive hazard zones (CEHZs) were drawn. Furthermore, a simple practical index was proposed to quantitatively determine the gas explosion risk in the longwall goaf. The results showed that the CEHZs mainly focus on the intake side where the risk of gas explosion is greatest. The CEHZ is reduced with increasing air quantity. Moreover, the higher the gas emission, the larger the CEHZ, which moves towards the intake side at low goaf heights and shifts to the deeper parts of the goaf at high heights. In addition, the risk of gas explosion is reduced as air quantities increase, but when gas emissions increase to a higher level (greater than 50 m³/min), the volume of the CEHZ does not decrease with the increase of air quantity, and the risk of gas explosion no longer shows a linear downward trend. This study is of significance as it seeks to reduce gas explosion accidents and improve mine production safety.     

基于光谱吸收和谐波检测的瓦斯浓度测量技术

提出了一种基于瓦斯特征光谱吸收特性和二次谐波检测原理的煤矿瓦斯监测方法,从理论上论证了该方法的可行性,并进行了实验验证.以分布反馈(DFB)激光器做光源,使用正弦信号对激光器输出的激光频率进行调制,激光通过瓦斯密闭气室后,由光电探测器探测,对所得到的信号使用二次谐波技术处理后,得到密闭气室中的瓦斯浓度,结果与实际浓度吻合.最后对影响实验检测分辨率的因素进行了分析.结果表明:该技术实现了完全非接触在线自动检测,能够满足煤矿瓦斯安全检测的要求.     

半封闭受限空间煤尘与瓦斯耦合爆炸研究

煤尘参与的瓦斯爆炸事故具有很强的破坏性和伤害性,是煤矿的重大事故之一.用一端开口的半封闭管道爆炸实验装置,通过改变瓦斯与煤尘耦合爆炸浓度及点火条件,揭示受限空间瓦斯与煤尘耦合爆炸的规律.实验结果表明,封闭下的耦合体爆炸火焰传播速度较开口状态达到极值快,但极值点距点火位置较近,开口爆炸火焰传播距离是积聚耦合体长度的2倍左右;瓦斯参与的煤尘爆炸,爆炸相对强度随瓦斯浓度的增加而增加,传播距离更远;理论推导瓦斯与煤尘耦合爆炸超压传播距离与爆炸能量的平方根成正比,与巷道断面积的平方根成反比,研究结果为防治瓦斯爆炸、事故勘验以及阻隔爆装置的研制提供了可靠的实验数据.     

烷烃气体对甲烷爆炸下限影响的实验研究

为确定烷烃类混合气体中甲烷的爆炸极限,设计了混合气体爆炸实验系统.在实验系统中,采用高精度计算机配气系统配气,其所得到的混合气体含量误差小于1%,从而使气体爆炸下限更加精确.运用该实验系统研究了丙烷、异丁烷混合气体对甲烷爆炸下限的影响.实验结果表明：当混有丙烷的体积分数达到0.60%时,甲烷的爆炸下限可以降到1.35%;当异丁烷的体积分数约为0.30%时,甲烷的爆炸下限可降到1.80%.研究结果对煤矿瓦斯监测的可靠预警具有重要意义.     

Experimental and Numerical Study on the Gas Explosion in Urban Regulator Station

Regulator station is an important part in the urban gas transmission and distribution system. Once gas explosion occurs, the real explosion process and consequences of methane gas explosion in the regulator station were not revealed systematically. In this study, a full-scale experiment was carried out to simulate the regulator station explosion process, and some numerical simulations with a commercial CFD software called FLACS were conducted to analyze the effect of ignition and vent conditions on the blast overpressure and flame propagation. The experimental results demonstrated that the peak overpressure increased as the distance from the vent increased within a certain distance. And the maximum overpressure appeared 3 m away from the door, which was about 36.6 kPa. It was found that the pressure-time rising curves obtained from the simulation are basically the same as the ones from the experiment, however, the time of reaching the peak pressure was much shorter. The numerical simulation results show that the peak overpressures show an increase trend as the ignition height decreased and the vent relief pressure increased. It indicates that the damage and peak overpressure of gas explosion could be well predicted by FLACS in different styles of regulator station. In addition, the results help us to understand the internal mechanism and development process of gas explosion better. It also offers technical support for the safety protection of the urban regulator station.     

ABC 干粉对爆燃火焰传播抑制的实验

为了研究ABC干粉的抑爆效能,利用自行研制的抑爆实验装置对ABC超细干粉和磷酸二氢铵质量分数分别为90％、75％、50％的ABC干粉进行抑爆实验,通过对火焰传播速度抑制效果的比对,研究不同类型ABC干粉和磷酸二氢铵质量分数对粉剂抑爆效能的影响。结果表明：ABC干粉作为抑制爆燃火焰传播的介质,能够对火焰起到持续的消焰作用,减缓火焰传播速度,有效控制爆燃向爆轰的发展;ABC干粉的粒径和磷酸二氢铵质量分数不同,对爆燃火焰传播速度的抑制能力存在差别;同等磷酸二氢铵质量分数的ABC干粉,粒径越小、均匀程度越好,抑制火焰速度的效果越好;同等粒度的ABC干粉,磷酸二氢铵质量分数越高,抑制火焰速度的效果越好;减小ABC干粉的粒径和增加磷酸二氢铵的质量分数都可以提升抑爆效能,通过增加ABC干粉的磷酸二氢铵质量分数可以在一定程度上弥补粉剂粒径和均匀度上的不足。     

Computational fluid dynamics simulation on the longwall gob breathing

In longwall mines, atmospheric pressure fluctuations can disturb the pressure balance between the gob and the ventilated working area, resulting in a phenomenon known as ‘‘gob breathing". Gob breathing triggers gas flows across the gob and the working areas and may result in a condition where an oxygen deficient mixture or a methane accumulation in the gob flows into the face area. Computational Fluid Dynamics(CFDs) modeling was carried out to analyze this phenomenon and its impact on the development of an explosive mixture in a bleeder-ventilated panel scheme. Simulation results indicate that the outgassing and ingassing across the gob and the formation of Explosive Gas Zones(EGZs) are directly affected by atmospheric pressure changes. In the location where methane zones interface with mine air, EGZ fringes may form along the face and in the bleeder entries. These findings help assess the methane ignition and explosion risks associated with fluctuating atmospheric pressures.     

人工神经网络在瓦斯涌出量预测中的应用

当采掘工作面遇有岩浆岩破坏煤系和煤层时,地质条件尤为复杂,采用常规的矿山统计法和瓦斯含量法预测瓦斯涌出量难以取得理想的结果.作者从矿井地质综合分析入手,采用BP神经网络的方法建立了适用于矿井未采区瓦斯涌出量的预测模型,分别用48个4-2煤层、40个7-2煤层钻孔点的煤层瓦斯质量体积、煤层埋藏深度、煤质、火成岩分布、顶底板砂泥岩比值等数据作为输入层,预测地质条件相对复杂矿井的瓦斯涌出量.经已采区实测值与预测值比较分析认为,预测结果可信.     

人工神经网络在瓦斯涌出量预测中的应用

当采掘工作面遇有岩浆岩破坏煤系和煤层时，地质条件尤为复杂，采用常规的矿山统计法和瓦斯含量法预测瓦斯涌出量难以取得理想的结果．作者从矿井地质综合分析入手，采用BP神经网络的方法建立了适用于矿井未采区瓦斯涌出量的预测模型，分别用48个4-2煤层、40个7-2煤层钻孔点的煤层瓦斯质量体积、煤层埋藏深度、煤质、火成岩分布、顶底板砂泥岩比值等数据作为输入层。预测地质条件相对复杂矿井的瓦斯涌出量．经已采区实测值与预测值比较分析认为．预测结果可信．