环氧树脂在玻璃钢设备及管道修补方面的改进应用

本文对玻璃钢设备存在的质量隐患原因进行了分析,指明运用玻璃钢（FRP）修补与加固相结合的措施,使修补后的玻璃钢与复合衬里的抗渗透性增强,防止强腐蚀性介质对金属的腐蚀作用;对脱硫系统的玻璃钢管道,添加了一些耐磨填料进行耐磨加固,使修补后的管道既能耐酸碱又能耐石灰浆液的冲击,修补后的效果明显。     

煤气管道带压开孔作业的安全技术保障

鞍山钢铁集团公司(以下简称鞍钢)拥有高炉、转炉、焦炉几十座,煤气管路千余条,总长度可达300 km,遍布鞍钢每个角落,最大直径是西区新2#高炉煤气管道,直径3 500 mm.最长煤气管道是由厂区新1#高炉到灵山厚板厂输送,全长7 km. 如此众多的管道,不可避免要进行管道的维护和保养,特别是要进行煤气管道的改造,即开孔作业.常规的作业方法是:首先在开孔作业管道下方搭设检修作业平台,作业平台须满足相关安全技术要求,其次停煤气,将要进行改造即开孔作业的煤气管道压力为零.     

带煤气堵盲板作业的安全要求

带煤气堵盲板作业应严格遵循以下要求 :作业前应对作业区域进行封闭 ,禁止行人通行 ,下风侧40ｍ内无火源。在工业炉窑前进行堵盲板作业 ,管道内应通入蒸汽。凡距火源较近或在室内作业 ,不准带煤气作业 ,并且在管道内必须通入蒸汽。所有参加堵盲板作业人员必须佩戴防毒面具。在作业点附近 (上风侧 5ｍ ,下风侧 10ｍ)的所有裸体高温蒸汽管道 ,必须在作业前做绝热处理。作业法兰距支架较远 ,应设临时支架 ,以防反口。雷雨天禁止进行带煤气堵盲板作业。在组织进行大型带煤气作业时 ,应有医务人员到场 ,做好中毒救护工作 ,为防止发生意外火灾事故…     

煤气安全知识 第四讲 冶金工厂煤气管道附属装置(续)

三、煤气隔断装置煤气隔断装置用于停止输送煤气,以及需要动火或进入管道、设备、炉窑机组内作业时可靠地隔断煤气。它与煤气作业安全有着十分密切的关系。煤气隔断装置的类型很多,按其性能可分为一般隔断装置和可靠隔断装置。前者只     

在煤气设备上动火应做哪些准备工作？

答：在煤气设备或管道上动火时，首先应确保作业环境安全，工作方便，要挪走5米以内的易燃物品，否则应采取防燃措施。如有高处作业，则要搭好脚手架。如动火处已漏煤气，则要在点火之前进行处理。动火前要在动火设备或管道的附近安装压力表，以测量设备或管道内的煤气压力，安装好史焊用的零线，在动火现场要根据情况准备必要的灭火工具。     

安全管理虚拟团队在冶金安全风险防范中的应用

通过组建高温熔融金属作业安全管理、煤气作业安全管理、工程检修作业安全管理、危险化学品安全管理和协力安全管理五大虚拟团队,发挥团队力量,实施专业支撑,推动相关单位安全风险管理责任的落实,推进高温熔融金属、煤气等重点工艺、领域安全风险源头治理,预防和控制事故的发生。     

煤气安全知识——第四讲 冶金工厂煤气管道附属装置(续)

四、置换介质引入装置该装置用于置换管道或设备内的煤气以及在管道或设备送煤气之前置换其内部的空气。置换介质可以从人孔引入,也可以从管道始末端或设备下部引入,至管段各终端放散管排出,从而实现置换。一般来说,应在介质一侧和煤气一侧各设一个阀门和连结短管,并用软管连接,置换作业完毕应立即拆除软管;如果用钢管连接,则中间应设活接     

马钢煤焦化公司自力更生消除隐患

马钢煤焦化公司依靠自身力量,采用防腐技术,成功地给危及安全生产的一段通洞严重的煤气管道罩上了“防护套”,消除了一处隐患,为企业节省一大笔外委费用。马钢煤焦化公司回收车间风机房承担着向外输送煤气的重任,连接这个“心脏”的一段长４４米、直径６３０毫米的煤气大循环管道,因连续数年使用,受腐蚀严重,管壁出现多处剥落通洞。由于是负压运行作业,不能动火和停产检修,这个隐患成为危及焦化生产的“心病”。煤焦化公司有关部门经多方论证,确认采用防腐处理技术能解决这个难题,但外委费用高达十多万元。为节省开支,马钢煤焦化公司决定依…     

煤气设施检修前的安全措施

由于煤气生产系统具有易燃、易爆、易中毒的危险,加之检修时常常需要动用明火,有时为了保证生产不中断,还要带煤气进行作业,这样就极易导致作业人员煤气中毒,以及发生火灾和爆炸事故.在总结安全生产经验和教训的基础上,从构建专门的组织领导机构、制定检修施工方案、安全教育、实行作业证制度、检修前的安全检查、安全处理事项等六个方面,介绍煤气设施在检修作业前的安全保障措施.     

焦炉地下室煤气安全防护

焦化企业焦炉地下室一般都存在高炉、焦炉煤气管道及各类煤气附件,涉及到的煤气事故主要有火灾、爆炸、中毒等.通过对焦炉地下室涉及到的煤气危险特性的分析.依据相关标准提出焦炉地下室煤气安全要点,为焦化企业焦炉地下室煤气安全防护提供参考.     

Consequence analysis of premixed flammable gas explosion occurring in pipe using a coupled fluid-structure-fracture approach

A coupled fluid-structure-fracture approach incorporating a high-efficiency detonation modeling algorithm was proposed to study the consequences of premixed flammable gas explosion occurring in pipe. A strain-rate-dependent failure criterion which is the vital prerequisite for accurate consequences prediction was derived based on the failure mechanism of materials at high strain rates and it was applied to account for the fracture of pipe. The simulated pressure time history and fracture patterns were validated against experimental results and good agreements were acquired. The interaction between detonation wave and pipe during crack extension, dynamic fracture processes of pipes with different initial flaws, venting features of detonation products and pressure profiles out of pipe were obtained and discussed in detail. The comparison with existing semi-empirical and CFD methods was performed and it is revealed that the deformation and fracture of pipe have obvious negative influences on the peak overpressure and the rate of pressure increase out of pipe. Because the energy absorption and dissipation due to structural deformation and fracture are well taken into account, the coupled fluid-structure-fracture method is expected to provide more rational consequences prediction and analysis results.     

某钢厂工业输水管路系统可靠性分析

用事件树分析法对工业输水管道进行了系统可靠性分析和定量计算,得出了不同维修策略模型下系统的概率,有效地估计了维修策略对系统的影响,给出了提高管道系统安全性的建议.     

球接管容器气体爆炸尺寸效应的试验研究与数值分析

为了解尺寸对球形容器连接管道甲烷-空气混合物爆炸的影响规律,利用Fluent软件,采用κ-ε湍流模型、涡耗散模型(简称EDC模型)、壁面热耗散、热辐射模型及SIMPLE算法,建立了球形容器连接管道内甲烷-空气混合物爆炸的数值模型,对容器与管道内甲烷-空气预混气体爆炸的尺寸效应进行了数值模拟。结果表明:随管道内径增大,球形容器内最大爆炸压力逐渐增大,管道末端最大爆炸压力变化无明显规律;而随管道长度增加,球形容器内最大爆炸压力逐渐减小;改变管道内径,较大体积球形容器内最大爆炸压力均大于较小体积球形容器内最大爆炸压力,最大爆炸压力上升速率的规律则相反,容器体积对管道末端最大爆炸压力的影响无明显规律。     

T型管道不同封闭状态瓦斯爆燃火焰传播特征

为了研究分岔管道不同封闭状态下瓦斯爆燃火焰阵面传播规律,在自制的T型透明分岔管道内,设置支管端口完全封闭、直管左端口弱封闭,采用光电传感器和压力传感器测试了直管右端弱封闭、完全封闭2种情况下,预混甲烷-空气可燃气体爆燃火焰传播过程中速度、超压参数的变化情况。结果表明:由于分岔的存在,2种封闭状态在支管端点火后瓦斯爆燃火焰阵面在支管中的传播速度均先增大后减小;直管右端弱封闭时,经过分岔后火焰加速向直管两端传播速度基本一致,分别达到86.29 m/s和88.07 m/s;直管右端完全封闭时,火焰向弱封闭端传播速度增大至166.67 m/s,火焰向完全封闭端传播时并不断压缩未燃气体产生高压振荡反馈导致火焰振荡传播现象,火焰速度不断减小至4.84 m/s;管道内瓦斯爆燃超压均迅速上升到达峰值,之后受压缩气体的膨胀和冲击后爆燃产物的振荡作用迅速下降。     

初始压力对连通容器甲烷-空气混合物泄爆压力的影响

建立球形容器与管道、2个球形容器与管道组成的2种形式的连通容器试验装置,研究初始压力对连通容器甲烷-空气混合物泄爆压力的影响。结果表明:连通容器内泄爆超压随初始压力增加而增大,并与初始压力近似成线性关系;对于2个球形容器与管道组成的连通容器,起爆容器的泄爆超压始终小于传爆容器;泄爆方式和点火方式对连通容器泄爆超压有较大影响,大容器点火时,2个容器的泄爆压力差随初始压力增加而增大,但小容器点火时,2个容器的泄爆压力差随初始压力的增加变化较小;初始压力对不同结构和尺寸的连通容器的泄爆压力的影响不同,当令初始压力对大容器点火时,小容器内泄爆压力受影响最大,而当对单球形容器与管道组成的连通容器的小容器点火时,小容器内泄爆压力受影响最小。     

基于COMSOL的采空区埋管抽采参数优化数值研究

针对回采工作面上隅角瓦斯浓度超限问题,提出了回采工作面采空区埋管抽采的方法。以保德煤矿81307工作面为研究对象,运用数值模拟软件COMSOL模拟采空区无抽采和不同抽采参数条件下工作面内瓦斯分布规律,研究埋管抽采参数对上隅角瓦斯浓度的影响规律,确定最佳的采空区埋管抽采参数。同时进行现场抽采参数优化试验,对瓦斯浓度进行监测,研究结果表明:合适的布置间距、抽采负压和抽采流量能够有效解决上隅角瓦斯超限问题,试验期间内,上隅角瓦斯体积分数最大为0.74%,进风流中瓦斯体积分数最大为0.2%,工作面风流中瓦斯体积分数最大为0.45%,回风流中瓦斯体积分数最大为0.5%,均没有超过安全标准。     

Internal corrosion hazard assessment of oil & gas pipelines using Bayesian belief network model

A substantial amount of oil & gas products are transported and distributed via pipelines, which can stretch for thousands of kilometers. In British Columbia (BC), Canada, alone there are over 40,000 km of pipelines currently being operated. Because of the adverse environmental impact, public outrage and significant financial losses, the integrity of the pipelines is essential. More than 37 pipe failures per year occur in BC causing liquid spills and gas releases, damaging both property and environment. BC oil & gas commission (BCOGS) has indicated metal loss due to internal corrosion as one of the primary causes of these failures. Therefore, it is of a paramount importance to timely identify pipelines subjected to severe internal corrosion in order to improve corrosion mitigation and pipeline maintenance strategies, thus minimizing the likelihood of failure. To accomplish this task, this paper presents a Bayesian belief network (BBN)-based probabilistic internal corrosion hazard assessment approach for oil & gas pipelines. A cause-effect BBN model has been developed by considering various information, such as analytical corrosion models, expert knowledge and published literature. Multiple corrosion models and failure pressure models have been incorporated into a single flexible network to estimate corrosion defects and associated probability of failure (PoF). This paper also explores the influence of fluid composition and operating conditions on the corrosion rate and PoF. To demonstrate the application of the BBN model, a case study of the Northeastern BC oil & gas pipeline infrastructure is presented. Based on the pipeline's mechanical characteristics and operating conditions, spatial and probabilistic distributions of corrosion defect and PoF have been obtained and visualized with the aid of the Geographic Information System (GIS). The developed BBN model can identify vulnerable pipeline sections and rank them accordingly to enhance the informed decision-making process.     

Application and effect of negative pressure chambers on pipeline explosion venting

Explosion venting is a frequently-used way to lower explosion pressure and accident loss. Recently, studies of vessel explosion venting have received much attention, while little attention has been paid to pipe explosion venting. This study researched the characteristics of explosion venting for Coal Bed Methane (CBM) transfer pipe, and proposed the way of explosion venting to chamber in order to avoid the influence of explosion venting on external environment, and investigated the effects of explosion venting to atmosphere and chamber. When explosion venting to atmosphere, the average explosion impulse 4.89 kPa s; when explosion venting to 0 MPa (atmospheric pressure) chamber, average explosion impulse is 7.52 kPa s; when explosion venting to −0.01 MPa chamber, explosion flame and pressure obviously drop, and average explosion impulse decreases to 4.08 kPa s; when explosion venting to −0.09 MPa chamber, explosion flame goes out and average explosion impulse is 1.45 kPa s. Thus, the effect of explosion venting to negative chamber is far better than that to atmospheric chamber. Negative chamber can absorb more explosion gas and energy, increase stretch of explosion flame, and eliminate free radical of gas explosion. All these can promote the effect of explosion venting to negative chamber.     

The influence of gas storage parameters on gas emission rate from borehole

Gas emission rate from borehole is one of the most important indexes for the coal and gas outburst prediction. The mathematical model of gas flow in the coal seam, gas flow into the measuring chamber, gas pressure change in the measuring chamber, and gas flow out of the chamber through the pipe is established. Gas migration in the coal seam, gas pressure in borehole chamber and gas flow in pipe is simulated using the finite difference method. Gas emission rate is obtained under dynamic boundary conditions. The influence of gas storage parameters on gas emission rate from borehole is analyzed. Results show that: the gas pressure and the permeability coefficient have great impacts on the value of gas flow quantity in borehole. The larger the original gas pressure of coal seam and the permeability coefficient of coal seam are, the greater the maximum value of gas emission rate form borehole and the later the maximum appears.     

Experimental and computational fluid dynamic (CFD) simulation of leak shapes and sizes for gas pipeline

In this paper, a parametric study has been carried out to predict the exit velocity of air through the leakage in the pipe with the help of CFD software ANSYS Fluent. The effect of air pressure in the pipe and the shape of leakage have been studied. Further experiments were also carried out to determine the exit velocity for the defined shape of leakage by varying the air pressure in the pipe. Experimentally, the velocity at a distance of 8 cm from the location of a leak in the horizontal plane was obtained with the help of differential pressure transducers. Using the experimental results, the computational results were validated. The results of the parametric simulation study showed that even for a pressure of 2 bars the velocity profile at the leak location indicates the supersonic state where the Mach number is greater than 1. The study is useful because it may be used as a foundation for risk assessment and safety management in the case of flammable gas leaks through gas pipes.