基于多商品流理论与成本效益分析的公路危险品运输路径优化研究

风险是危险品运输区别与普通货物运输的基本要素,因此,危险品运输既要实现经济目标,又要满足安全的需要。危险品运输其路径优化问题的关键在于在经济性与安全性间取得平衡。为此,在运输成本与风险值间引入权重参量,并充分考虑到路网容量及个别路段最大期望风险等限制因素,运用多商品流理论建立了基于运输成本和运输风险最小化的双目标路径优化模型。进一步地,运用成本效益分析法,并从全局角度对不同解所对应的路径优化方案进行比较,提出了相应的比选准则。最后,通过算例分析证明了该方法的有效性。     

Optimizing safety-constrained solvent selection for process systems with economic uncertainties

Solvents are very commonly used in industrial facilities for a multitude of reasons. Traditionally, solvent selection has been based on minimizing the process operating cost while satisfying a set of operational requirements. Regrettably, safety considerations have typically been overlooked during the design phase. In this paper, a systematic approach is introduced to integrate safety issues into solvent selection and provides a computationally effective method for establishing tradeoffs between the economic and safety objectives. In order to quantify the risk associated with the solvent, we focus on the potential spillage of the solvent and introduce a risk index that is a function of the amount of solvent used and stored, as well as the Permissible Exposure Limit (PEL) dictated by regulatory directives. An optimization formulation is developed and the associated mathematical program solved to select optimal solvents and blends while incorporating economic, technical, and safety considerations. Tradeoff (Pareto) curves are developed to represent the multi-objective optimization results and tradeoffs. Furthermore, economic-data uncertainty and variability over expected ranges are included in the optimization formulation to conduct an insightful sensitivity analysis. Finally, an illustrative case study is considered via increasing levels of complexity in order to evaluate the proposed optimization method which considers both operating cost and safety risk implications in the presence of economic uncertainties.     

化工过程开发中本质安全化设计策略

本质安全化设计是预防人为失误及设备失效、降低化工过程风险应优先采用的技术。在比较传统设计方法与本质安全化设计方法的基础上,讨论了化工过程开发各阶段实现本质安全的机会,认为在开发初期,实施本质安全化的成本低,难度小;通过分析可行性研究、工艺研究、概念设计、基础设计、工程设计等阶段本质安全化设计的影响因素、设计目标和设计方法,探索化工过程开发中本质安全化设计策略,提出了化工过程本质安全化设计流程。通过工艺过程本质安全设计、工艺流程的简化和优化、不同设计方案的本质安全度评估等措施,可提高化工过程本质安全水平。     

The trade-off between efficiency and equity in road safety policy

This paper discusses the relationship between efficiency and equity as objectives of road safety policy. The term efficiency refers to the efficient use of all road safety measures. Road safety measures are used efficiently if the priority given to them is based on the criterion that marginal social benefits should be at least equal to marginal social costs. To use road safety measures efficiently therefore means that the priority given to each measure is set strictly according to cost–benefit analyses. Thus, the main question discussed in this paper is whether setting priorities for safety measures strictly according to cost–benefit analyses will produce results that are regarded as equitable and fair. The notions of equity and fairness do not have any universally accepted definitions. In the paper, an attempt is made to apply John Rawls’ difference principle as a criterion of fairness with respect to the distribution of risk. The distribution of risk is examined along several dimensions: between groups of road users, between regions, between social groups, and with respect to the relationship between who pays for a road safety measure and who benefits from it. It is concluded that there is a conflict between efficiency and equity as far as the provision of road safety is concerned. Promoting greater equity requires a departure from efficiency, as defined in economic welfare theory, as the only criterion for setting policy priorities.     

Integration of accident scenario generation and multiobjective optimization for safety-cost decision making in chemical processes

Investment in Chemical Process Industries for improving their safety requires considering risk level, environmental effect, cost and many other aspects simultaneously. This paper focuses on a new systematic method of finding the most cost–risk–effective investment scenario set. The method uses the automatic accident scenario generation technique first to find a set of the most dangerous scenarios. Then it uses the multiobjective optimization method to decide the priority of the investment. These computations includes considering many constraints such as limited budget, environmental requirements and social demands. The Styrene Monomer plant case study proves the practical use of this integration method of accident scenario generation and multiobjective optimization.     

Optimization of facility location and reallocation in an industrial plant through a multi-annual framework accounting for economic and safety issues

The industrial layout traditionally has been addressed accounting for the facilities distribution and installation since the first day of operation of the plant; this is, without considering future expansions that involve additional facilities in the future operation years. This way, this paper proposes a mathematical programming formulation for the optimal facility sitting and reallocation in an industry accounting for future expansions and involving simultaneously economic and safety objectives. The proposed formulation is based on a multi-annual framework and this corresponds to a multi-objective mixed integer linear programming problem. The proposed optimization approach was applied to a case study for the facility sitting (office buildings and control rooms) in an ethylene oxide plant. The economic objective function involves the minimization of the total annual cost accounting for the value of the money through the time and the safety objective function involves the minimization for the accumulated risk over the operation time. Results show the applicability of the proposed approach.     

危险品道路运输多目标路径优化方法研究

道路危险品运输路径优化是提高危险品运输安全的一项重要措施。通过对国内外文献的分析研究，本文提出了危险品道路运输路径优化的数学模型，该模型首先求出单项目标的最优解，然后找出每项目标的实际值尽可能接近各自单项的最优值。本文也建立了包括路线长度、时间、费用、路线风险、敏感目标人数在内的危险品道路运输目标体系，并给出危险品运输路线选择决策的程序，为政府相关部门进行路线选择提供决策依据。     

安全投资经济分析与效益评价

安全投资分析的目的是实现必要的安全功能,减少损失,保障企业的生产安全,以便集中投资,获取最大的安全效益。笔者给出了安全效益的新定义,以安全价值和边际效益分析为基础,结合企业安全生产实际,采用FTA法,分析安全所具有的功能与所耗成本的关系。揭示安全投入在生产经营活动中的作用,发现和消除不必要的安全投入,提高安全资金的利用率,以便优选安全措施方案和确定安全投资的方向,选择最优经济投入方案。运用数学方法,分析在多种生产要素限制条件下,安全投资对社会和其他方面影响的最优化问题。采用技术经济方法,评价净现值、内部收益率和投资回收期各指标是否符合设定值,确保安全投资项目的可行性,以利于人们对安全投入的认识,强化企业安全投入工作。     

Safety investment optimization in process industry: A risk-based approach

Process plant safety is a critical indicator of organizational performance. Adequate investment into safety practices to avoid future accident cost is therefore a beneficial strategy. The current approach to such investments in the process industry is driven largely by simple risk-based heuristics, insurance market premiums, organizational culture and management judgment. There is, however, an absence of an overarching methodology to assist such an effort. Therefore, there is a need for developing a robust decision-making framework for enabling systematic and optimal allocation of financial resources across all significant risk elements within a process plant.The present work proposes a safety investment optimization (SIO) framework for a typical process plant. Such an optimization approach targets maximal reduction of risk values across all potential hazards within the constraint of a given safety investment budget at the incipient stage of establishing a plant such that it saves future cost to company by reducing the risk from accidents. At the same time the framework takes into account the need to comply with the regulatory requirements imposed by the government. Additionally, access to insurance market as a strategy to transfer risk is also integrated. Finally, the residual risks are managed through investments in selective safeguards while ensuring that the benefits over-weigh the cost of such an exercise. For illustrating the application of the framework, a representative process plant with a select number of risk scenarios is chosen and all steps suggested by the framework are demonstrated quantitatively. It is anticipated that the proposed SIO framework will help optimal resource allocation for managing the risks implicit in a typical process plant.     

工程项目施工安全保证的投入效率分析

利用ALARP原则构建工程项目施工风险可容忍区域,对处于不可容忍区域的安全事故,采取安全投入措施使之进入可容忍区域;对处于可容忍区域的安全事故,进行安全投入效益分析,以确定最佳安全投入额。采用事故树分析法探究事故与事故发生原因之间的内在逻辑关系,并探讨安全投入与事故发生概率的函数关系。在此基础上,构建安全投入优化分配模型,结合历史统计数据,利用Lingo软件对模型进行计算求解。     

煤炭安全成本及其变动趋势分析

煤炭安全成本是煤炭生产的一种"附加性成本",它是煤炭企业安全工作质量的综合反映,是安全决策和安全工作评价的重要指标.对于煤炭企业来讲,安全生产的特殊性决定了安全成本在煤炭生产成本中占有很高的比例.研究煤炭安全成本及其变化趋势,对于促进安全与生产的协调发展,合理控制安全投入和优化安全成本结构,都具有重要的理论价值和现实意义.本文结合煤炭生产实际,理论与实践相结合地提出了安全成本分析指标,并在现场调研的基础上,利用调研资料,采用回归分析方法,对安全成本进行了变动趋势分析,建立了煤炭安全成本分析模型.通过模型分析得出了安全成本随安全保证程度而变化的规律.安全成本趋势分析及相关分析模型的建立,为煤炭企业进行安全管理与决策提供了有效的分析手段.     

A quantitative risk management framework for dust and hybrid mixture explosions

Dust and hybrid-mixture explosions continue to occur in industrial processes that handle fine powders and flammable gases. Considerable research is therefore conducted throughout the world with the objective of both preventing the occurrence and mitigating the consequences of such events. In the current work, research has been undertaken to help move the field of dust explosion prevention and mitigation from its current emphasis on hazards (with an accompanying reliance on primarily engineered safety features) to a focus on risk (with an accompanying reliance on hierarchical, risk-based, decision-making tools). Employing the principles of quantitative risk assessment (QRA) of dust and hybrid-mixture explosions, a methodological framework for the management of these risks has been developed.The QRA framework is based on hazard identification via credible accident scenarios for dust explosions, followed by probabilistic fault-tree analysis (using Relex – Reliability Excellence – software) and consequence severity analysis (using DESC – Dust Explosion Simulation Code – software). Identification of risk reduction measures in the framework is accomplished in a hierarchical manner by considering inherent safety measures, passive and active engineered devices, and procedural measures (in that order). An industrial case study is presented to show how inherent safety measures such as dust minimization and dust/process moderation can be helpful in reducing dust and hybrid-mixture explosion consequences in a 400-m³ polyethylene storage silo.     

安全投入与事故直接经济损失的问题研究

通过对安全投入及事故直接经济损失的分析研究,利用最小二乘法对安全投入比例(安全投入占GDP的比例)与事故直接经济损失之间的关系进行了回归分析,确定了其对应的函数关系.结果表明,安全投入比例与事故直接经济损失之间呈较明显的负指数关系.探讨了安全投入存在的主要问题,提出了几点关于加强安全投入的建议及措施.     

不确定性条件下危险废物物流LRP建模与求解

在危险废物产量不确定的条件下,为解决加工中心建设点、加工技术和危险废物车辆运输路径的选择问题,考虑危险废物与加工技术的多样性、危险废物与加工技术的相容性,设定风险公平性的度量方法,以风险和成本最小化,风险公平性最大化为优化目标,建立危险废物产量为三角模糊数的多目标模型。根据三角模糊数的特征转化模糊约束条件,将原模糊模型转化为多目标0～1混合整数线性规划模型,并基于模糊优化技术设计多目标线性规划模型的求解方法。最后,算例结果表明,相对于既有模型,新模型所得的优化方案能降低风险和成本。     

Risk management in operations of petrochemical plants: Can better planning prevent major accidents and save money at the same time?

This paper presents an argument that improvement in operational safety can be achieved concurrently with increased operational efficiency. This is a fundamentally different viewpoint on the investment in safety. Traditionally, the cost of providing safety barriers is offset by the expected benefits of reducing the occurrence and severity of accidents. Our approach departs from this method of accounting for safety improvements and focuses on planning as a means of managing systems' response uncertainty and consequently reducing both major accident risk and the cost of operations. The scope of the paper is limited to interventions such as maintenance and repairs and defined in the context of major accident prevention e.g. hydrocarbon leaks. However, the developed methodology is general enough to be applied across the spectrum of process industry facilities and operations.     

基于风险管理方法的危险源评价分级研究

以化工企业内涉及危险物质的装置、设施而构成的危险源为研究对象,在简要分析重大危险源评价分级的作用与方法的基础上,针对中小型化工企业,提出基于风险管理方法的危险源评价分级概念。通过计算危险源引发事故的概率和事故后果来确定危险源的风险值,并将其分为4个等级,指导企业制定合适的安全管理制度、使用恰当的安全技术措施,以最小化的代价确保危险源安全运行,从而提高中小型化工企业的危险源管理水平。     

施工承包企业安全成本及其核算的研究

依据施工承包企业安全管理的目标、特点和程序,提出安全成本的概念和构成以及保证性安全成本对损失性安全成本的直接影响.同时,借助施工安全成本与安全度的关系、提高安全技术工作的经济合理性、加速构建施工承包企业安全成本核算制度,优化施工承包企业的安全管理工作,并为提高企业经济效益及社会经济运行的安全度奠定基础.     

Safe handling of combustible powders during transportation,charging, discharging and storage

The knowledge of the ignition behavior of dust–air mixtures due to electrical sparks (MIE, Minimum Ignition Energy) and hot surfaces (MIT, Minimum Ignition Temperature) is important for risk assessments in chemical production plants. The ignition behavior determines the extent and hence the cost of preventive protection measures.This paper describes the use of the minimum ignition energy and minimum ignition temperature as very important safety indexes in practice.     

Application of inherent safety principles to dust explosion prevention and mitigation

The aim of the current work is to explicitly link the inherent safety principles of minimization, substitution, moderation and simplification with strategies for dust explosion prevention and mitigation. A brief review of inherent safety and its basic principles is first given. This is followed by a discussion of various ways in which the dust explosion hazard can be minimized, substituted, moderated and simplified. Particular attention is paid to the relationship between each inherent safety principle and (i) various dust explosibility parameters, (ii) alternate methods of processing, (iii) selection of process equipment, and (iv) development and implementation of safe-work procedures. Original research results are presented, along with industrial case studies and previously published results that have been reinterpreted in terms of inherent safety and its basic principles. It is anticipated that this research will be of value to industry as a complement to the relatively well-established suite of engineered and procedural dust explosion risk reduction measures.     

Optimizing the design of storage facilities through the application of ISD and QRA

Four strategies can be used to achieve safety in chemical processes: inherent, passive, active and procedural. However, the strategy that offers the best results is the inherent safety approach, especially if it is applied during the initial stages of a project. Inherently Safer Design (ISD) permanently eliminates or reduces hazards, and thus avoids or diminishes the consequences of incidents. ISD can be applied using four strategies: substitution, minimization, moderation and simplification. In this paper, we propose a methodology that combines ISD strategies with Quantitative Risk Assessment (QRA) to optimize the design of storage installations. As 17% of major accidents in the chemical industry occur during the storage process and cause significant losses, it is essential to improve safety in such installations. The proposed method applies QRA to estimate the risk associated with a specific design. The design can then be compared to others to determine which is inherently safer. The risk analysis may incorporate complex phenomena such as the domino effect and possible impacts on vulnerable material and human elements. The methodology was applied to the San Juanico tragedy that occurred in Mexico in 1984.