化工储罐间距和体积对爆炸碎片多米诺效应概率的影响

化工储罐爆炸后将产生大量碎片,这些抛射碎片一旦击中相邻罐体容易引发多米诺效应。碎片的抛射方位和抛射距离具有很大的随机性,已有研究多采用概率模型来描述碎片抛射的各分过程。通过总结和发展已有的分过程模型,建立了求取多米诺效应的综合概率模型,并基于蒙特卡罗算法编制了模拟软件,可对化工储罐多米诺效应的发生概率进行预测计算。选取若干常用化工球罐为相邻目标储罐进行实例分析,计算结果表明储罐间距和体积是影响多米诺效应发生概率的两个重要影响因素：随着距离的增大,多米诺效应发生概率不断减小;目标储罐体积越大,多米诺效应发生概率将越大。其中,爆炸碎片对目标储罐的击中概率受上述因素的影响程度更大。该文工作对化工储罐区的安全评价具有一定的参考价值。     

基于蒙特卡洛法的储罐爆炸碎片冲击失效模型研究

为定量研究相邻储罐间爆炸碎片冲击的多米诺效应,基于蒙特卡洛方法建立爆炸碎片冲击失效模型。该模型共包括爆炸能量与碎片初始速度、考虑风速及碎片初始位置的碎片三维抛射轨迹、空气阻力、碎片冲击穿透等4个分步模型。基于上述模型,研究储罐爆炸后碎片的初始状态、抛射轨迹以及对相邻储罐的冲击效应。在数值模拟结果的基础上,用储罐最高允许工作压力代替泄放装置的泄压压力来计算爆炸压力,绘制碎片质量及初始速度的直方图,定量分析储罐间距对击中概率的影响。结果表明,热辐射、超压和碎片冲击3种能量作用方式均可能导致储罐间火灾爆炸事故多米诺现象发生,但爆炸碎片冲击导致相邻罐失效的概率较低。     

Estimation of the impact probability in domino effects due to the projection of fragments

Despite the remarkable severity of domino effects in activities at major hazard, a complete methodology analysing such events has not been developed and integrated within Quantitative Risk Analysis (QRA). Such a deficiency appears to be particularly remarkable for domino effects triggered by the projection of fragments. The aim of the present work is therefore to propose a systematic procedure for the quantification of domino effects due to fragments projection within QRA. To achieve this objective, the deterministic approach for the estimation of the realistic trajectory of fragments is entirely reviewed. In order to incorporate such a reviewed approach within the standard QRA, a probabilistic model for the impact probability of the fragments is developed by applying a Monte-Carlo method to the trajectory equations. The validation of the proposed framework is carried out by using the data related to an accident occurred in 1993 in the oil refinery of Milazzo (Italy).     

Assessment of the hazard due to fragment projection: A case study

Fragment projection following vessel burst is a possible cause of domino effects in industrial accidents. The projection of fragments from stationary equipment usually follows the catastrophic rupture of process equipment due to internal pressure exceeding design values. In recent years, a detailed model was developed to assess fragment impact probability. The model, based on the use of fragmentation patterns and of a simplified analysis of fragment trajectory, allows the calculation of impact probabilities considering different scenarios leading to vessel burst and fragment projection. In the present study a case-study was analyzed to assess model performance and to test the credibility of the model predictions for fragment number, shape and impact probability. The cumulative probability of fragment impact was found to be in good agreement with the actual distribution of the landing points experienced for the fragments formed in the accident. The maximum projection distance predicted by the model resulted comparable to the maximum landing distance experienced in the accident. The model tested thus seems to yield significant results, well in the range of those experienced in the case-study analyzed.     

Influence of the source size on domino effect risk caused by fragments

We developed the movement equations for fragments with the size of the bursting vessel. The ground distributions of fragments, the probability of impact between the fragments and the target, the rupture probability of the impacted target, and the domino effect risk caused by fragments were investigated for different source types and sizes using Monte-Carlo simulations. The distribution of fragments from the lower half of the source vessels onto the ground was non-zero, that is, it is probable that the fragments would hit the target vessel close to the source. The relative difference of impact probability is larger than 10% when the target vessel is within eight times the source diameter for the three types of sources considered. The proportion of impacts of fragments from the lower part of the source to total impact decreased with distance, while that for fragments from the upper part increased. The proportion of upper and lower parts is equal for distance approximately five times the source diameter. The source size needs to be considered along with the distance from the source to the target when less than approximately 14 times the source diameter. Its effect on impact probability and domino effect risk was significant. The rupture probability of the target depended very little on the source size.     

基于多米诺效应的定量风险评价研究

多米诺效应是引发化工重大事故的主要原因之一.本文综合国内外的研究成果,对火灾热辐射、冲击波超压等造成的多米诺效应进行了深入分析,建立基于多米诺效应的定量风险评价模型,其中包括了评价流程、传播概率、阈值距离计算、多米诺效应对事故频率的影响及后果分析的内容.最后利用Matlab7.1计算平台,以汽油储罐进行实例分析,结果表明该方法是一种适用于多米诺效应定量评价的良好方法,能够比较科学、有效的对危险单元进行风险评价,使重大事故风险评价更切合实际,为政府监管部门和化工企业进行事故的控制和预防提供决策技术.     

化学工业重大事故的多米诺效应分析

针对化学工业重大事故多米诺效应的严重后果,进行重大事故多米诺效应发生规律的研究。在指出触发重大事故多米诺效应发生条件和发生模式的基础上,设计重大事故多米诺效应的研究程序。借助生成重大火灾爆炸事故场景和其后果分析方法,建立多米诺效应概率分析的数学模型,利用VB开发了多米诺效应计算软件DOMISOFWARE,解决较为复杂的重大事故多米诺效应概率的计算问题。研究表明,爆炸事故总是较火灾事故具有更高触发多米诺效应的可能性,并且火灾和爆炸触发加压设备发生多米诺效应的概率与常压设备相比随间距增大几乎呈线性下降;确定了爆炸和火灾触发多米诺效应的概率和临界距离。研究结果对于化工装置的安全设计和重大事故的预防控制具有重要的指导意义。     

Investigation of multiple domino scenarios caused by fragments

A model of multiple domino scenarios and the risk of the domino effect, which is a sequential chain escalating from the primary unit to the last unit, is presented in this paper. The trajectories of fragments from all units, the ground distribution of projectiles, and the risk of the sequential chain of the domino effect were calculated using Monte Carlo simulations. The results showed that the range affected by the fragments from each tank included the other tanks, meaning that fragments from one tank could hit the other tanks and cause multiple accidents, and that the sequential chain of the domino effect could indeed happen. The distributions of ground impacts showed that tank fragments were projected over long distances, up to 1200 m from the source. The spatial distribution of the kinetic energy at ground impact for tank fragments was also obtained. Moreover, the magnitudes of the probabilities of the primary, secondary, third, and fourth accidents in the domino chain were respectively about 10⁻⁷, 10⁻¹¹, 10⁻¹⁵, and 10⁻¹⁹. These results showed that for neighboring domino effect units in the same accident chain, the risk of the most recent domino effect was 10⁴ times that of the following domino effect.     

某储罐区火灾多米诺效应场景推演

化工园区中危险源众多,一旦发生事故很容易在整个园区内蔓延和发展.针对化工园区内储罐密集,容易引发连锁反应导致事故扩大的特点,利用FDS软件对储罐火灾场景进行数值模拟,根据储罐所受热辐射确定化工园区内储罐火灾最可能的事故发生序列,并引入基于设备失效前时间的机械设备故障概率模型对罐区内单个储罐的火灾风险进行研究,得到储罐区...     

An approach for domino effect reduction based on optimal layouts

An approach to reduce the probability of producing a domino effect in process industry is developed in this work. It is assumed that optimal layouts should include appropriate analysis to reduce risk during the process design stage. The model developed for this approach combines the estimation of probability of damage due to overpressure, proposed by Mingguang and Juncheng (2008), and escalation threshold values defined by Cozzani, Gubinelli, and Salzano (2006). These equations are combined with other typical layout constraints as well as bounding the probability constraint, which has resulted in a highly non-linear MINLP problem. Solving a case study used by other authors provides evidence for reliability of the developed approach. In this way, layouts are designed to reduce the escalation probability yielding safe distributions.     

飞行事故概率模型与风险评估方法

以事故统计为基础,建立了飞行事故概率模型与随机过程模型,对飞行安全可靠性指标进行定量评估。根据独立性假设,推导了飞行风险的概率分布,并给出飞行安全重要指标间的关系。假设飞行事故发生是Poisson过程,导出了飞行安全可靠性概率指标的区间估计计算方法。实例计算表明,通过统计量可以对飞行安全进行风险评估,根据飞行事故风险概率等级要求得到评定等级。     

大型原油储罐火灾多米诺效应概率计算模型及应用

随着油品储罐区规模的不断扩大,近年来多储罐火灾事故呈上升趋势。现有的储罐防火间距是在以往事故经验的基础上设定的,通过罐组内的火灾多米诺效应概率计算,可从风险的角度为罐组内储罐防火间距的设定提供理论依据。通过综合考虑火灾环境下受辐射储罐失效时间和着火储罐火灾得到控制时间,确定了罐组内火灾多米诺效应的判定原则,并在火灾得到控制时间模型和储罐失效时间模型的基础上建立了火灾多米诺效应概率计算模型。以2万立外浮顶原油储罐为例进行模拟计算,得出在现行标准给出的防火间距下,发生罐组火灾多米诺效应的概率为3.94×10-8/a-1,属于可接受风险,为罐组内储罐的合理布局提供了理论依据。     

危险化学品事故多米诺效应历史数据研究评述

系统整理分析近十五年来国内外利用历史数据进行危险化学品事故多米诺效应研究的相关文献,介绍该领域研究的主要数据来源、主要研究方法,对主要研究内容进行交叉比对,整理挖掘包括危险化学品多米诺事故场景下的易发物质、高发区域/过程、主要事故致因、高频事故序列、致死概率5项事故内在规律并对规律的运用进行初步探讨。提出在后续研究中可以从改进采样时间区间设计和进行细分事故场景研究作为该领域的完善方向。     

米诺效应中的多事故点协同作用后果研究

为了研究多米诺效应中多事故点协同作用的后果,将并联系统概率模型运用到贝叶斯概率计算过程中,体现出多事故点协同作用对多米 诺效应传播的概率影响;后果分析部分从人、物、环境3个方面出发,对事故的后果影响以及事故预防提出建议措施。最后运用模型对实例进行 了应用分析,结果表明:多事故点协同作用下储罐的多米诺失效概率增大,罐区危险性增强,可以通过对储罐设置安全屏障等措施,有效的切 断导致事故最大概率的链条。     

质子交换膜燃料电池电站多米诺事故概率和风险研究

为探究氢能电站火灾爆炸事故发展规律,采用多米诺效应对电站进行事故概率和风险研究,建立氢能电站多米诺效应定量风险分析模型。基于设备受损概率模型与多米诺理论基础,提出氢能电站多米诺效应概率计算方法,并将方法运用到实际案例,结合SAFETI软件对具体多米诺事故场景进行定量计算。研究结果表明：氢能电站易发生多米诺事故,考虑一级多米诺效应后人员潜在死亡概率增加56%。研究结果可为制定氢能电站安全防控措施以及降低火灾爆炸事故对人员和设备的危害提供依据。     

储罐爆炸碎片最可能抛射距离的Monte-Carlo(蒙特卡罗)数值模拟

在总结前人工作的基础上,推导了储罐爆炸碎片抛射距离的理论计算公式,并给出具体的计算方法;分析了计算参数的不确定性,同时介绍用Monte-Carlo方法模拟高压储罐爆炸时碎片抛射距离的算法;在数值模拟结果的基础上,计算了碎片抛射距离的分布函数和概率密度函数,引入最可能抛射距离的概念,并指出可以用此来确定碎片抛射的危害范围。该方法对于定量评价储罐爆炸碎片危害性,减缓和控制碎片产生的风险,具有重要的意义。     

基于多米诺效应的油品储罐区个人风险研究

介绍了多米诺效应的基本原理和多米诺事故发生的概率分析方法。提出在一定条件下进行储罐区风险评价时,多米诺效应对个人风险值的影响不容忽视,并给出了考虑多米诺效应的个人风险计算方法。最后利用开发的个人风险计算软件通过分析计算,给出了某储罐区的个人风险等值线分布图。结果表明,该罐区正北方向相邻的一劳动密集型工厂需搬迁,或采取相应安全保护措施降低风险。该方法考虑了多米诺效应对装置事故发生概率的影响,能提高个人风险计算结果的真实性与准确性。     

化工储罐区池火灾多米诺效应风险评估

化工储罐区储罐数量较多且集中,一旦发生事故很可能诱发多米诺效应造成灾难性的后果。在分析池火灾多米诺效应作用模式的基础上,建立了池火灾多米诺效应风险评估模型,并对某化工储罐区进行了实例计算,分析了单一储罐池火灾事故引发其他储罐池火灾的风险。分析结果表明,池火灾是诱发化工储罐多米诺事故的重要因素,且会造成风险的显著增加,但并非所有的池火灾事故都会诱发多米诺效应。此外,将多米诺效应评价方法应用于化工储罐池火灾事故风险评估中可有效地预测次生事故的发生概率和后果,从而提出针对性措施。     

FREEDOM II: An improved methodology to assess domino effect frequency using simulation techniques

The uncertainty and the complexity associated with the domino effect is a barrier to assessing the frequency of such accidents analytically. The use of simulation techniques, such as Monte Carlo, to examine the domino effect instead of analytical techniques has shown great promise. In this paper, a new method to assess the frequency of domino accidents is proposed—FREEDOM II—which is an improvement on the recent algorithm proposed by the authors (FREEDOM). The modifications on FREEDOM were carried out to overcome a limitation of the method and to extend its capabilities. A key shortcoming of the earlier method was its inability to handle multiple failure scenarios. This shortcoming has been overcome in FREEDOM II. A new and improved algorithm has been developed that carries out the simulation in a significantly shorter run time. The applicability of the new model is shown by performing a multi-scenario case study.     

Modeling and algorithm of domino effect in chemical industrial parks using discrete isolated island method

Studies on domino effect in chemical industrial parks are crucial for avoiding accident escalation. Domino effect network (DEN) may be formed as a consequence of widely distribution of major hazard installations (MHIs) in chemical industrial parks. To decrease accident scale and prevent catastrophic consequence, it is essential to cut off the relations between entities in a DEN during accident periods. Focusing on this aspect, based on the conceptual model of discrete isolated island (DII) discussed, an objective function was brought out to evaluate the linking level of the whole park; while to help determine the dominant MHI (namely Domino hub in a DEN), equations for calculating accident escalation factor (AEF) was advanced. Further, an algorithm was developed for the proposed model. Application showed that the proposed model, which is capable of providing possible ways to determine the dominant MHI contributing to domino effect, was quite useful and effective for choosing technical prevention measures to enhance the safety level of chemical industrial parks.