动载下高密度全尾砂胶结充填体稳定性试验研究

为研究动载下高密度全尾砂胶结充填体(HTB)的稳定性,制备直径为50 mm×25 mm的HTB试件,进行静态单轴压缩试验。首次采用分离式霍普金森杆(SHPB)装置研究HTB的动态力学性质,通过观察冲击试验后试件的破坏程度,来评判高应变率下试件的稳定性。结果表明:HTB试件波阻抗较小,对弹性应力波传播有较强的阻尼作用;在冲击载荷下,试件最大应变率可达305 s-1,动态抗压强度随着应变率的增加而增大,最大动态抗压强度为17 MPa;HTB试件的稳定性与应变率密切相关,当应变率低于10 s-1时,试件稳定性较好;当应变率为10~39 s-1时,试件产生一定的损伤裂纹,但尚有一定的残余强度;当应变率大于39 s-1时,试件完全失稳。     

瓦斯在石门揭构造软煤诱发煤与瓦斯突出中的作用

为了更好地认识和防治煤与瓦斯突出,利用扫描电子显微镜和静态液氮吸附仪研究一种构造软煤的微孔结构特征,同时利用自主搭建的大型石门揭煤相似模拟试验系统,研究石门揭露构造软煤过程中瓦斯压力的变化规律。在试验研究的基础上,分析构造软煤的微孔特性对瓦斯赋存的影响,以及瓦斯在石门揭露构造软煤诱发煤与瓦斯突出中的作用。通过试验得出:构造软煤的结构破坏严重,微孔发育并且为特殊瓶颈的不透气孔,为瓦斯的赋存提供了极为有利的条件;瓦斯在突出的启动和发展过程中起重要作用,即在瓦斯压力突然降低、释放膨胀潜能时,瓦斯压力作为动力来源,加速了煤体向采掘空间抛出的过程。     

基于气压监测的外浮顶储罐火灾报警系统研究

目前,外浮顶储罐的火灾报警系统是采用光纤光栅火灾报警系统。但是,考虑到光纤光栅火灾报警运行费用高和存在报警盲目的缺点,研制了基于气压监测的外浮顶储罐火灾报警系统。针对不同型号的感温探头,开展了火灾报警系统火灾报警响应时间和报警温度实验,分析了火焰距离、热熔管管径以及管壁厚度与对火灾报警响应时间和报警温度的影响。实验结果表明:随着火焰距离的增大,报警响应时间增长;相同火焰距离条件下,随着感温热熔管直径的增大,报警响应时间增长,报警温度升高。Φ6热熔管的火灾报警温度为116.8℃,Φ8热熔管的火灾报警温度为129.1℃,Φ10热熔管的火灾报警温度为156.7℃。     

某铅锌矿采空区处理与卸压开采方案研究

900m水平似上采空区回收矿柱及900 m水平以下的巷道掘进或矿房开采时经常发生岩爆.为了安全、经济地回收矿柱并实施深部开采,在数值分析的基础上,提出了一种急倾斜矿体的采空区处理与卸压开采方法,并用ANSYS数值模拟确定了采空区处理及卸压开采的施工参数.结果表明,在下盘脉外巷道离采空区边缘的水平距离为10 m时,上盘脉外巷道离采空区边缘的水平距离取20m;在巷道底板隔断开采的深度不超过20m;必须从上、下盘脉外巷道同时向采空区围岩实施V型松动爆破;可只在上盘巷道底板进行隔断开采.该采空区处理与卸压开采方法技术可行、经济合理、简便适用.当地表允许岩体移动时这种新方法适合急倾斜、厚度大矿体的采空区处理与卸压开采;如果地表不许可岩体移动,使用这种新方法是不合适的.该采空区处理与卸压开采方法是一种采空区处理的联合法.它能够用工程爆破这一种手段实现采空区处理、应力向有利于安全生产的方向转移等多种目的.     

中国省域环境压力综合评价

以中国30个省、自治区和直辖市为研究对象,以1997-2010年为研究区间,选取各省工业SO2排放量、烟尘排放量、粉尘排放量、废水排放量、固体废弃物产生量和碳排放量6类环境污染基础指标,运用“纵横向”拉开档次法构建环境压力综合指标,从环境压力平均水平、变化趋势和变动程度3个角度深入分析各省、自治区和直辖市在1997-2010年的环境压力.结果表明,根据环境压力平均水平,我国各省、自治区和直辖市可分别划入高、中、低3个环境压力区域,各省环境压力也分别呈现上升、下降、U型和倒U型4种变化趋势.此外,内蒙古环境压力不断上升,四川和辽宁环境压力不断下降,三者变动系数较大,分别达到0.08、0.06和0.05.研究表明,内蒙古的环境现状不乐观,亟须改善;而四川和辽宁二省环保工作实施效果较好,大幅度降低了环境压力,可作为其他省、自治区和直辖市降低环境压力的学习对象.     

基于力学分析的深井煤与瓦斯突出临界值研究

为研究应力对深井煤与瓦斯突出工作面的影响,采用力学模型分析了平行六面微元体各个面的受力情况,结合煤体强度理论和矿山压力理论,从煤体所受瓦斯压力、地应力和煤体破坏条件等方面入手,研究了三轴应力态下煤体力平衡问题.探讨了瓦斯压力、地应力、煤壁支撑力等参数和煤与瓦斯突出之间的关系.结果表明,煤与瓦斯突出的瓦斯压力临界值由采场内的应力、煤壁支撑力和煤的力学参数等确定,综合考虑上述因素后,对煤与瓦斯突出预测时瓦斯压力临界值进行了理论推导和关键参数修正,建立了包含应力、采场条件和煤的力学参数的推算瓦斯压力临界值的理论模型,并对理论模型的可靠性进行了分析.突出实例的反演表明在深部开采时,如果不考虑应力对煤与瓦斯突出的影响,会出现预测结果偏差而影响安全生产.建立的理论模型可对这种偏差进行分析和校正.     

Risk analysis of deepwater drilling operations using Bayesian network

Deepwater drilling is one of the high-risk operations in the oil and gas sector due to large uncertainties and extreme operating conditions. In the last few decades Managed Pressure Drilling Operations (MPD) and Underbalanced Drilling (UBD) have become increasingly used as alternatives to conventional drilling operations such as Overbalanced Drilling (OVD) technology. These newer techniques provide several advantages however the blowout risk during these operations is still not fully understood. Blowout is regarded as one of the most catastrophic events in offshore drilling operations; therefore implementation and maintenance of safety measures is essential to maintain risk below the acceptance criteria. This study is aimed at applying the Bayesian Network (BN) to conduct a dynamic safety analysis of deepwater MPD and UBD operations. It investigates different risk factors associated with MPD and UBD technologies, which could lead to a blowout accident. Blowout accident scenarios are investigated and the BNs are developed for MPD and UBD technologies in order to predict the probability of blowout occurrence. The main objective of this paper is to understand MPD and UBD technologies, to identify hazardous events during MPD and UBD operations, to perform failure analysis (modelling) of blowout events and to evaluate plus compare risk. Importance factor analysis in drilling operations is performed to assess contribution of each root cause to the potential accident; the results show that UBD has a higher occurrence probability of kick and blowout compared to MPD technology. The Rotating Control Devices (RCD) failure in MPD technology and increase in flow-through annulus in UBD technology are the most critical situations for kick and blowout.     

On the explosion and flammability behavior of mixtures of combustible dusts

In the work presented in this paper, the explosion and flammability behavior of combustible dust mixtures was studied. Lycopodium, Nicotinic acid and Ascorbic acid were used as sample dusts.In the case of mixtures of two dusts, the minimum explosive concentration is reproduced well by a Le Chatelier's rule-like formula, whereas the minimum ignition energy is a linear combination of the ignition energies of the pure dusts.An unexpected behavior has been found in relation to the explosion behavior and the reactivity. When mixing Lycopodium and Nicotinic acid or Ascorbic acid, the rate of pressure rise of the mixture is much higher than the rate of pressure rise obtained by linearly averaging the values of the pure dusts (according to their weight proportions), thus suggesting that strong synergistic effects arise; but it is comparable to that of the most reactive dust in the mixture.The observed behavior seems to be linked to the presence of minerals in the Lycopodium particles which catalyze oxidation reactions of Nicotinic acid and Ascorbic acid, as suggested by TG analysis.In the case of mixtures of three dusts, a similar behavior is observed when the concentration of Lycopodium is twice that of the other two dusts.     

涟钢烧结厂成品仓除尘系统的改造

涟钢烧结厂成品仓扩建,老除尘器处理能力有限,无法达到除尘效果,必须改造.长袋低压脉冲袋式除尘器具有清灰能力强,喷吹压力低,过滤风速大,运行能耗低,换袋方便,维修简单等特点,运用于此除尘系统中,取得了良好的除尘效果.     

变频恒压供水控制技术在泵站供水系统中的应用

初步讨论变频恒压供水的基本原理及其在泵站中的应用.通过介绍泵站供水工艺系统的组成、自动化及仪表系统的配置、变频恒压供水的控制原理及监控系统的构成等的泵站供水自动化控制工程实例说明变频恒压供水在泵站中的应用.