Optimal Assignments of Allocating and Scheduling Emergency Resources to Accidents in Chemical Industrial Parks

Accidents in chemical industrial parks can result in mass casualties and the risk usually escalates due to domino effects. However, most of the existing models of emergency logistics do not account for domino effect and may be unsuitable for emergency response to accidents in chemical industrial parks. This paper presents a mathematical model proposed for optimal assignments of allocating and scheduling emergency resources for rescuing victims and preventing accident spreading simultaneously. The detailed characteristics of accident scenarios and emergency resources are taken into account. Based on this, the efficiency of emergency response is evaluated by the total number of fatalities and the amount of losses caused by domino effects which are the optimal objectives of the model. A numerical case study was conducted by solving the model using a designed heuristic algorithm. The results showed the applicability and reliability of the proposed model for making optimal assignments for emergency response to accidents in chemical industrial parks.     

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.     

Hierarchical pre-positioning of emergency resources for a chemical industrial parks concentrated area

Accidents in chemical industrial parks always cause fateful damage which can be reduced greatly by providing emergency resources sufficiently and timely. One effective way to enhance the emergency response capacity and agility is by pre-positioning of emergency resources for the potential accidents. The Yangtze River Delta of China is a large region where a large number of chemical industrial parks are concentrated. According to the distributing characteristics of demand points in this region, a mathematical model of hierarchical pre-positioning of emergency resources is proposed to ensure that accidents in all chemical industrial parks in this region can be responded timely and effectively. Considering accident domino effect and minimizing the total cost, the model gives optimal decisions of pre-positioning emergency resources, including the location and inventory of depots. The innovative hierarchical pre-positioning method greatly reduces the total cost in the premise of sufficient preparation for supplying emergency resources. Finally, in a visual graph of the Yangtze River Delta, the model is applied and the result shows its applicability.     

Mechanism analysis and risk assessment of escalation scenario in chemical industry zones

Many major hazard installations (MHIs) are located in chemical industry zones and escalation effect may be triggered when the fire or explosion occurs on a MHI. To investigate the mechanism of the accident escalation, a systematic quantitative assessment methodology is proposed by the considering the feature and uncertainty of the escalation scenario. The main accident energy carriers of the escalation are heat radiation, overpressure of blast and fragments. The escalation probability, joint influence of the three energy carriers and risk characterization of the accident scenarios are carried out. By the new methodology, the escalation scenario in chemical industry zones can be analyzed and the risk escalation morphology is demonstrated by the simulation software. The visualized risk cloud figure gives a supplementary way to prevent the escalation scenario in chemical industry zones planning.     

基于DEA对抗交叉评价模型的化工园区脆弱性评价

化工园区的脆弱性是评估园区安全现状的重要指标,采用DEA对抗交叉评价方法对某省5个化工园区的脆弱性进行了评价研究。首先从园区固有危险性、园区承灾体脆弱性以及事故后果损失程度3个方面构建了化工园区脆弱性评估指标体系,通过DEA对抗交叉评价模型得出的效率值对园区事故成灾效率进行了评估,成灾效率越大说明脆弱性越大,反之,脆弱性越小;最后,探讨了5个化工园区脆弱性等级,对其进行了优劣排序,分析了园区脆弱性的影响因素;可为化工园区的管理者提供理论支持。     

博弈论在预防化工园区事故多米诺效应中的应用

针对化工园区内各单元不愿意为预防相邻单元事故多米诺效应进行安全投入的问题,提出采用博弈论分析化工园区内各单元预防事故多米诺效应的投入意愿,将化工园区内2个相邻单元预防事故多米诺效应的关系定义为2人博弈的过程,构建2人博弈的支付函数与支付矩阵,讨论不同参数情形下的纳什均衡点,将实际均衡点与理想均衡点进行比较,判断园区管理者或政府机构是否应当采取相关措施。结果表明:实际化工园区所处的博弈情形与各单元均选择为预防园区事故多米诺效应的投入值有关,不同取值范围的纳什均衡点不同,园区管理者根据均衡点的不同选择相应措施。     

DomPrevPlanning: User-friendly software for planning domino effects prevention

Chains of accidents, in literature generally referred to as domino effects, knock-on effects, cascade effects or escalation effects occur very infrequently but with disastrous consequences. There exist very few software packages to study such domino accidents in complex industrial areas and to forecast potential catastrophes caused by secondary order (involving a sequence of three installations submitted to two consecutive accidents), tertiary order or even higher order accidents. Moreover, available domino software focuses on risk assessment and on consequence assessment. None of these toolkits specifically addresses the prioritization of installation sequences in an industrial area in order to facilitate objective prevention decisions about domino effects. This paper describes the application of a new computer-automated tool designed to support decision-making on preventive and protective measures to alleviate domino effects in a complex surrounding of chemical installations. Using a holistic approach and thus looking at the entire industrial area as a whole, all sequences of three installations in the area are ranked according to their danger contribution to domino effects. An example of a cluster of chemical plants demonstrates the level of qualitative and quantitative input data required. The example is also used to explain the toolkit results, as well as the surplus value and the benefits for company safety managers and regulators.     

Quantitative assessment of domino scenarios by a GIS-based software tool

A software procedure was developed for the quantitative assessment of domino effect. The procedure was based on a systematic methodology for the identification of domino scenarios and for the assessment of consequences and expected frequencies of the escalation events. A geographical information system (GIS) platform was interfaced to the domino assessment software. The implementation of plant lay-out data to the GIS allowed the automatic identification of the possible targets of escalation effects by the software procedure, and a straightforward calculation of the contribution to individual and societal risk indexes caused by the possible domino scenarios. The procedure was applied to the analysis of several case-studies based on actual plant lay-outs. The results evidenced that the approach allows the quantitative assessment of risk caused by escalation events with a limited additional effort with respect to that required by a conventional QRA. The use of a GIS-based software was a key element in the limitation of the effort required for the quantitative assessment of domino scenarios. Moreover, the results of the case-studies pointed out that the estimation of risk increase due to domino events is an important tool for an effective assessment and control of industrial risk in chemical and process plants.     

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。     

多米诺效应的风险分析方法

介绍与分析多米诺效应的相关研究,并针对多米诺效应的定量风险分析,建立了从多米诺场景辨识到后果分析的多米诺效应定量分析方法.通过分析初始事故带来的物理效应对邻近设备的影响,计算了二次设备的损坏概率;分析了多米诺场景,计算了多米诺事故频率,并根据多米诺事故的后果得到个人风险和社会风险曲线.多米诺效应的风险是工业区一个潜在的严重风险,加强多米诺效应的研究对工厂和工业区的安全管理与规划都有重要意义.     

油库火灾爆炸事故多米诺效应定量评价

引入多米诺效应定义,介绍多米诺效应定量评价的方法。结合具体实例对油库进行火灾爆炸事故的风险分析,给出事故多米诺效应定量评价的具体程序。通过油库火灾爆炸事故多米诺效应评价,得出油库事故的升级因素和导致事故扩大的途径,并指出相应的多米诺效应控制措施。与传统的评价方法相比,多米诺效应评价方法可预测次生事故发生情况和发生概率及后果,从而可以有针对性地采取相应的预防措施,预防事故多米诺效应,降低次生灾害的发生率,提高油库的本质安全程度。     

Bayesian estimation and consequence modelling of deliberately induced domino effects in process facilities

Process facilities handling hazardous chemicals in large quantities and elevated operating conditions of temperature/pressure are attractive targets to external attacks. The possibility of an external attack on a critical installation, performed with an intention of triggering escalation of primary incidents into secondary and tertiary incidents, thereby increasing the severity of consequences needs to be effectively analysed. A prominent Petrochemical Industry located in Kerala, India was identified for studying the possibility of a deliberately induced domino effect. In this study, a dedicated Bayesian network is developed to model the domino propagation sequence in the chemical storage area of the industry, and to estimate the domino probabilities at different levels. This method has the advantage of accurately quantifying domino occurrence probabilities and identifying possible higher levels of escalations. Moreover, the combined effect from multiple units can be modelled easily and new information can be added into the model as evidences to update the probabilities. Phast (Process hazard analysis) software is used for consequence modelling to determine the impact zones of the identified primary and secondary incidents. The results of the case study show that such analyses can greatly benefit green field and brown field projects in determining the appropriate safety and security measures to be implemented or strengthened so as to reduce its attractiveness to external threat agents.     

Resilience-based optimal firefighting to prevent domino effects in process plants

Domino effects triggered by fire can cause extremely severe damages to the chemical and process plants. In the need of a more effective prevention of fire domino effects, the present study focuses on firefighting which has received less attention compared to passive and active fire protection systems. Considering both the vulnerability and recoverability phases during fire domino effects, we have introduced a methodology for optimal identification of firefighting strategies so as to increase the resiliency of process plants in dealing with fire escalation scenarios. The area above the resilience curve (AARC), which is equal to the accumulation of loss of resilience over time, was considered as the metric to identify the optimal firefighting strategies. In other words, the strategy leading to the lowest AARC can be selected as the optimal strategy from a resiliency perspective.     

Application of domino effect quantitative risk assessment to an extended industrial area

Escalation of primary accidental scenarios triggering a “domino effect” have caused extremely severe accidental events in the chemical and process industry. The identification of possible escalation events is required in the safety assessment of sites where relevant quantities of hazardous substances are stored or handled. In the European Union, “Seveso-II” Directive requires the assessment of on-site and off-site possible escalation scenarios in sites falling under the obligations of the Directive. In the present study, a methodology developed for the quantitative assessment of risk due to domino effect was applied to the analysis of an extended industrial area. Recently developed equipment damage probability models were applied for the identification of the final scenarios and for escalation probability assessment. The domino package of the Aripar-GIS software was used for risk recomposition. The results evidence that quantitative risk assessment of escalation hazard is of fundamental importance in order to identify critical equipment and to address prevention and protection actions.     

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。     

Improved models of failure time for atmospheric tanks under the coupling effect of multiple pool fires

Fire accidents of chemical installations may cause domino effects in atmospheric tank farms, where a large amount of hazardous substances are stored or processed. Pool fire is a major form of fire accidents, and the thermal radiation from pool fire is the primary hazard of domino accidents. The coupling of multiple pool fires is a realistic and important accident phenomenon that enhances the propagation of domino accidents. However, previous research has mostly focused on the escalation of domino accidents induced by a single pool fire. To overcome the drawback, in this study, the failure of a storage tank under the coupling effect of multiple pool fires was studied in view of spatial and temporal synergistic process. The historical accident statistics indicated that the accident scenario of two-pool fires accounted for 30.6% in pool fires. The domino accident scenario involving three tanks is analyzed, and the typical layout of tanks is isosceles right triangle based on Chinese standard “GB50341-2014”. The thermal response and damage of a target tank heated by pool fires were numerically investigated. The volume of 500 m³, 3000 m³, 5000 m³ and 10000 m³ were selected. Flame temperature was obtained by FDS, and then was input onto the finite element model. The temperature field and stress field of target tanks were simulated by ABAQUS. The results showed that the temperature rise rate of the target tanks under multiple pool fires was higher than that under a single pool fire. The failure time of the tank under the coupling effect of multiple fires was lower than that under the superposition of multiple fires without the first stage. The stress and yield strength were compared to judge the failure of the target tank. The model of failure time for the tank under the coupling effect of pool fires was established. Through the verification, the deviation of this model is 4.02%, which is better than the deviation of 15.76% with Cozzani's model.     

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。     

基于层次分析-模糊综合评判的化工园区安全评价研究

应用模糊数学理论,把模糊综合评价方法具体应用到化学工业园区安全综合评价研究中,结合化工园区的实际情况,建立了化工园区的安全现状综合评价指标体系,采用定性与定量相结合的层次分析法计算评价因素的权重,运用模糊综合评判理论,提出安全现状二级模糊综合评价方法,实现对化工园区安全等级的综合评判。应用该方法对某化工园区的安全现状进行了综合评价,得出其安全等级为"一般"。实例表明:模糊综合评价方法可操作性强、效果较好,可在化工园区的安全综合评价中广泛应用。     

Preparing for major terrorist attacks against chemical clusters: Intelligently planning protection measures w.r.t. domino effects

Chemical industrial areas or so-called chemical clusters consist of hundreds, and sometimes thousands, of chemical installations situated next to each other. Such areas can thus be seen as the summation of a large number of structures exhibiting danger to a certain degree for initiating or continuing accident domino effects or knock-on effects. In this article, an approach to investigate in a systemic way the vulnerability of each installation within the larger chemical cluster context, is developed. Our suggested method results in a prioritization of chemical installations with respect to their vulnerability for domino effects. The method can be used for intelligently designed protection of chemical industrial areas against terrorist attacks.     

Method for quantitative assessment of the domino effect in industrial sites

Accidents caused by the domino effect are the most destructive accidents related to industrial sites. The most typical primary incidents for a domino effect sequence are explosions (57%), followed by fires (43%) (Abdolhamidzadeh et al., 2010). These former can generate three escalation vectors (heat load, overpressure, and fragments), and may affect the surrounding equipments and/or facilities. If the affected targets are damaged, they may also explode and generate other threats to other surrounding facilities and so on. These chains of accidents may lead to catastrophic consequences and may affect not only the industrial sites, but also people, environment and economy. This paper presents a methodology for quantitative assessment of domino effects caused by fire and explosion on storage areas. The individual and societal risks are also estimated.