基于Fluent的埋地原油管道泄漏事故后果分析

埋地输油管道一旦发生泄漏,一方面会造成土壤污染,另一方面当原油泄漏量过多时会上渗到地面形成油池,进而引发池火灾,对人员、环境、设备均会造成危害。为了研究埋地输油管道泄漏事故的后果,为事故救援及处理提供参考,提出了一种针对此类事故的土壤污染、池火灾后果定量分析方法。方法以Fluent软件为工具模拟原油被点燃前的泄漏扩散情况,分析原油在土壤及地面上的扩散规律及范围,并结合危害模型得到池火灾造成的热辐射危害范围。利用该方法对不同管道压力和泄漏孔径的6种工况下的事故进行了分析,结果表明,原油管道泄漏时的压力及泄漏孔径对原油扩散速度影响较大,进而影响避免事故的难易程度。     

架空天然气管道泄漏事故后果数值模拟研究

针对架空天然气管道泄漏引起的火灾爆炸问题,采用事件树分析泄漏扩散引起的事故后果,并在数值模拟中着重分析了模拟数学模型的选择。在三种不同泄漏孔径、两种不同风速、两种不同运行压力条件下分别应用ALHOA软件对事故后果进行数值模拟,结果表明:泄漏孔径、运行压力与危害影响范围成正比关系;在闪火和蒸气云爆炸中,风速与危害影响范围成反比关系,而风速对射流火灾的热辐射范围基本没有影响。     

埋地输氢管道泄漏爆炸事故后果模拟分析

为了输氢管道的安全建设与运营,基于计算流体力学FLACS软件,模拟了埋地输氢管道在半受限空间内的泄漏爆炸事故后果,探讨了泄漏孔径、泄漏时长、输氢压力和环境风速对爆炸事故后果的影响规律,并得出相应的危险区域。结果表明:泄漏孔径、输氢压力和最大爆炸超压均与危险区域呈正相关关系,泄漏时长对事故后果几乎无影响;随着输氢压力的增大,危险区域受建筑物和风速的影响更为明显,在建筑物附近形成了狭长的危险区域带;最大爆炸超压和危险区域随环境风速的增大均呈现出先增大后减小的趋势。     

基于社会风险曲线的液氯泄漏事故后果分析研究

以某化工企业液氯泄漏为研究对象,针对不同泄漏孔径,采用PHAST软件对气瓶的最远扩散距离、云团扩散最大高度以及氯罐的氯气扩散距离进行了计算,对该企业3种液氯生产配置方案进行了社会风险曲线模拟分析,得出了影响其整体社会风险曲线的关键指标,并指出可以通过控制关键指标来降低其社会整体风险,保障企业安全平稳运行.     

液氨储罐连续泄漏事故后果的影响因素分析

液氨储罐连续泄漏会产生喷射火、闪火、蒸气云爆炸和中毒事故,利用DNV PHAST软件模拟分析了风速、大气稳定度和储存温度对事故后果的影响。结果表明,随着风速不断增大,喷射火、闪火和蒸气云爆炸后果逐渐减小,单纯大气扩散情况下,毒性后果随风速的增大而减小;大气稳定度对喷射火后果没有影响,闪火和蒸气云爆炸后果随大气稳定度增加有增大的趋势,毒性后果随大气稳定度增加而增大;随着储存温度升高,泄漏质量流率增加,喷射火、闪火、蒸气云爆炸和毒性后果逐渐增大。     

化学品泄漏扩散仿真软件--泄漏事故后果评价的得力工具

化学品泄漏扩散仿真软件的用途 危险化学品在生产、储存、经营、运输、使用和废弃物处置等各个环节都存在发生泄漏的危险。化学品意外泄漏是最常见的化学品相关紧急事故。一旦发生毒物泄漏事故,除了可能造成人员伤亡和财产损失外,还牵涉到大批人员的紧急疏散,污染环境,影响人们的正常工作和生活。正因为如此,政府监管部门(如国家和地方的安全监管局)在规划审核化工企业设计布局、安全评价中介机构(如劳动安全预评价中心)在对化学品相关场所进行风险评价、化学品相关场所的安全管理人员在日常管     

重大泄漏事故统计分析及事故模式研究

对建国以来我国化工系统发生的重大及典型泄漏事故进行了统计分析,提取出应优先进行控制和管理的危险性物质,总结分析了造成这些重大及典型泄漏事故的基本原因。结合对重大及典型泄漏事故的剖析,分析了泄漏扩散事故的七大影响因素,提取并建立了泄漏事故模式,并对各种事故模式的泄漏机理和发生条件进行了研究分析。     

重大泄漏事故统计分析及事故模式研究

对建国以来我国化工系统发生的重大及典型泄漏事故进行了统计分析,提取出应优先进行控制和管理的危险性物质,总结分析了造成这些重大及典型泄漏事故的基本原因。结合对重大及典型泄漏事故的剖析,分析了泄漏扩散事故的七大影响因素,提取并建立了泄漏事故模式,并对各种事故模式的泄漏机理和发生条件进行研究分析。     

天然气管道泄漏火球事故后果模拟评价

天然气管道发生泄漏时,大约90%的气体产生燃烧并形成火球,遇火源即发生危害性非常大的火球爆炸事故。本文针对城市天然气管道泄漏事故,综合考虑天然气泄漏后可能发生的火球燃烧和爆炸,利用爆炸冲击波和火球热辐射模型对天然气管道(完全破裂)在发生泄漏时发生火球爆炸进行计算,结果表明:2分钟内泄漏天然气云团超压爆炸的死亡半径和热辐射的火球半径分别高达39.44m和92.93m。因此,通过计算天然气泄漏火球事故爆炸和热辐射范围,对天然气火球爆炸事故预防与应急救援具有一定的意义。     

FLUENT在公路隧道有毒气体事故泄漏扩散研究中的应用

针对公路隧道内氯气扩散问题,以计算流体力学(CFD)为理论基础,应用GAMBTT软件进行几何模型构建和网格划分.用FLUENT对所建模型中的风场和氯气泄漏扩散结果进行了模拟分析.通过不同位置氯气质量分数的比较,分析了稳定纵向通风条件下.隧道内障碍物和氯气重力效应对扩散的影响.从模拟结果可以看出,隧道内的障碍物(主要是汽车)对氯气扩散有明显阻拦作用.造成氯气在下部空间的扩散比上部空间要慢,而且距泄漏源相同距离处.下部空间的氯气质量分数远小于上部空间.同时讨论了泄漏源位置对氯气扩散范围的影响,结果表明即使在泄漏源较高的情况下,经过一段距离的扩散,氯气也会由于重力作用逐渐到达地面.最后,论证了FLUENT软件对处理隧道内毒气扩散问题的适用性,为研究工作的进一步开展提供了依据.     

毒气泄漏事故避难场所避难效果分析

有毒气体泄漏时,疏散和就地避难都是保护人员安全的有效行动。当疏散行动无效时,此时可考虑进行就地避难,应急决策者必须准确认识就地避难的可靠性。文中模拟分析了渗透吸附作用、换气次数、避难室空间体积、有效吸附面积对避难室内浓度的影响。结果表明,渗透吸附作用的存在明显降低了室内浓度,且强度越大浓度越低;换气次数越小,浓度越低;避难室空间越大,浓度越低,但影响不明显;吸附面积与空间体积之比越大,浓度下降越明显;毒负荷指数越大,规定暴露时间内避难室内毒负荷上升越缓慢。最后确定了特定场景下避难室最佳换气次数。     

The Bhopal gas leak: Analyses of causes and consequences by three different models

The Bhopal Gas Leak, India 1984 is the largest chemical industrial accident ever. Haddon's and Berger's models for injury analysis have been tested, together with the project planning tool Logical Framework Approach (LFA).

The three models provide the same main message: That irrespectively of the direct cause to the leakage, it is only two parties that are responsible for the magnitude of the disaster: Union Carbide Corporation and the Governments of India and Madhya Pradesh. The models give somewhat different images of the process of the accident.

Models developed for analysis of injuries can be used for analysing a complicated mega accident like the Bhopal gas leak, although different models might stress different aspects.     

Model off-site emergency plan. Case study: toxic gas release from a fertilizer unit

An emergency plan is a formal written plan which, on the basis of identified potential accidents together with their consequences, describes how such accidents and their consequences should be handled either on-site or off-site. The primary objective of the off-site emergency plan for a hazardous installation is the prevention of accidents resulting in harm to human health, the environment or property. The prevention of accidents involving hazardous substances is the concern of many interested parties, including public authorities (district emergency authority, police, fire and medical services etc.) at all levels, industry and the community. This paper provides an overview of the release scenarios and affected areas, rescue and evacuation plans, communication and public information systems, roles and responsibilities of the district emergency authority, police, fire and medical authorities and their training, testing the plan/mock drill performance, review/observations, and finalization.     

工业企业事故性泄漏扩散模型

对工业企业的泄漏扩散模型的国内外研究情况进行了调查研究,在对各模型优缺点分析的基础上,针对目前工业企业的事故后果模拟评价中所采用泄漏扩散模型存在的问题和不足,提出应用PG扩散模型研究物质泄漏的扩散模式,结合某企业的物质扩散算例说明该模型的实际应用,为工业企业的事故后果模拟评价以及重大事故应急预案的编制提供了一定的参考.     

BLEVE事故后果分析软件化实现

对BLEVE的三种主要灾害模式,火球辐射、超压以及碎片抛射进行了研究,研究总结了各自的灾害计算模型及相关的伤害准则,采用STATLSTICA6．0对火球直径、持续时间进行了重新拟合,给出了爆炸能量计算模型中不确定性参数的选取方法,对碎片抛射的各个不确定性参数的分布进行了总结。根据总结得出的模型,采用VB6．0编制了BLEVE事故后果分析软件,并分别以球罐、丙烷的热BLEVE算例及卧罐、二氧化碳的冷BLEVE算例对软件的计算功能进行演示。     

重大毒气泄漏事故应急预警通知接收端优化与实现

从毒气泄漏事故预防和应急处置的国内外现状分析出发,指出了目前我国预警通知方法的不足及发展趋势。论述了毒气泄漏事故中安全疏散的时间构成以及预警通知接收端低功耗模式的种类,从提高预警通知系统响应时间的角度分析了不同的低功耗方案的优劣,并给出了实现方法和适用的条件,不仅实现了不同使用条件下的最佳低功耗模式,还保证了系统有较好的实时响应速度。响应时间的优化有利于提高系统报警通知的效能,在保证较好响应时间的前提下应用低功耗模式则有利于降低成本,同时提高受灾群众安装该预警系统的积极性性,对于报警器在不同地区的推广具有指导意义,从而为对系统的优化与改进提供依据。     

电气短路事故的分析

出了事故,如何分析研究,如何总结经验教训,站在不同角度,追溯不同深度,得出的结论就会相去甚远,付出了“学费” 而获得的“效益”也就相差悬殊。这里分析两起事故并略作评价。1 带地线合闸 保护线成烧人线1.1 事故经过 1994年4月6日下午3时许,某厂671变电站。运行值班员接班后,312油开关大修负责人提出申请要结束检修工作票,赶上4点的下班车离厂;而值班班长临时提出要试合一下312油开关上方的母线侧3121刀闸,看看该刀闸贴合情况。于是,值班班长在没有拆开312油开关与3121刀闸     

液氯的安全使用及氯气泄漏的防治

氯做为一种消毒剂,因其消毒效果好、价格低的特点广泛使用于生活饮水用消毒、污水处理等方面,同时氯气又是一种毒性很强的气体,在第一次世界大战中作为毒气曾被德国采用。氯气常温下是一种呈淡黄绿色气体,在加压至0.101 MPa、-34.6℃即可被液化,利用这一特点,通常使用的都是充入钢瓶中的液氯,常见的氯瓶规格有50kg、500kg、1000kg。     

An approach for risk reduction (methodology) based on optimizing the facility layout and siting in toxic gas release scenarios

In this work, a new approach to optimize facility layout for toxic release is presented. By integrating a risk analysis in the optimization formulation, we propose a safer assignment for facility layout and siting. Accompanying with the economical concepts used in a plant layout, the new model considers the cost of willing to avoid a fatality, i.e. the potential injury cost due to accidents associated with toxic release near residential areas. The proposed formulation incorporates a real meteorological data to calculate the injury risk through the probit model and Monte Carlo simulation using dense gas dispersion modeling (DEGADIS). The overall problem was initially modeled as a disjunctive program where the coordinates of each facility and cost-related variables are the main unknowns. Then, the convex hull approach was used to reformulate the problem as a Mixed Integer Non-Linear Program (MINLP) that identifies potential layouts by minimizing overall costs. This approach gives the coordinates of each facility, and estimates for the total length of pipes, the land area, and the selection of safety devices. Finally, the 3D-computational fluid dynamics (CFD) was used to compare between the initial layout and the final layout. Moreover, analyses of separation distances fr2om hazard facilities and hindrance effects will be discussed based on the approach used in this work.     

Methodology for global sensitivity analysis of consequence models

A methodology is presented for global sensitivity analysis of consequence models used in process safety applications. It involves running a consequence model around a hundred times and using the results to construct a statistical emulator, which is essentially a sophisticated curve fit to the data. The emulator is then used to undertake the sensitivity analysis and identify which input parameters (e.g. operating temperature and pressure, wind speed) have a significant effect on the chosen output (e.g. vapour cloud size). Performing the sensitivity analysis using the emulator rather than the consequence model itself leads to significant savings in computing time.To demonstrate the methodology, a global sensitivity analysis is performed on the Phast consequence model for discharge and dispersion. The scenarios studied consist of above-ground, horizontal, steady-state discharges of dense-phase carbon dioxide (CO₂), with orifices ranging in diameter from ½ to 2 inch and the liquid CO₂ stagnation conditions maintained at between 100 and 150 bar. These scenarios are relevant in scale to leaks from large diameter above-ground pipes or vessels.Seven model input parameters are varied: the vessel temperature and pressure, orifice size, wind speed, humidity, ground surface roughness and height of the release. The input parameters that have a dominant effect on the dispersion distance of the CO₂ cloud are identified, both in terms of their direct effect on the dispersion distance and their indirect effect, through interactions with other varying input parameters.The analysis, including the Phast simulations, runs on a standard office laptop computer in less than 30 min. Tests are performed to confirm that a hundred Phast runs are sufficient to produce an emulator with an acceptable degree of accuracy. Increasing the number of Phast runs is shown to have no effect on the conclusions of the sensitivity analysis.The study demonstrates that Bayesian analysis of model sensitivity can be conducted rapidly and easily on consequence models such as Phast. There is the potential for this to become a routine part of consequence modelling.