【作者】 刘志军；

【导师】 纪卓尚； 林焰；

【作者基本信息】 大连理工大学 ， 船舶与海洋结构物设计制造， 2011， 博士

【摘要】 为了满足海运市场和能源市场的需求,船舶不断向大型化、高速化和专业化发展,海洋平台也逐步由浅海向深海发展。因此船舶与海洋工程领域的风险研究引起越来越多的重视。本文在分析当前全生命周期风险研究领域的基础上,讨论船舶与海洋平台的全生命周期风险分析,主要研究内容包括船舶与海洋平台全生命周期风险评估和风险控制的模型方法,并对机舱火灾进行分析。(1)船舶与海洋平台风险评估是一个复杂的系统工程,目前各项研究都是针对船舶与海洋平台生命周期中的某一阶段特定的风险进行评估,本文从系统工程的角度,把船舶与海洋平台工程项目全生命周期看作一个整体,以时间为主线,研究其全生命周期的机舱火灾风险评估方法。首先根据船舶与海洋平台全生命周期的特点进行阶段划分,具体分为规划阶段、设计阶段、建造阶段、运营阶段和退役阶段,把风险分为环境风险、技术风险、经济风险、管理风险和行为风险5类,并对风险损失进行分级,然后对各阶段进行风险识别,可建立船舶与海洋平台全生命周期风险评估指标体系。根据客观问题的复杂性和可获取信息量的多少,可分别采用确定型或不确定型的风险评估方法。在风险估计时需要专家进行判断,由于客观问题的复杂性和风险的不确定性,专家并不一定总能做出一个确定性的判断。如果问题相对简单,或者有一定数量的信息,专家可以采用确切的数值来表示判断,这种情况下可以采用灰色层次分析法进行全生命周期的风险评估；如果问题相对复杂,并且信息量不够充分,专家就难以采用确切的数值来表达自己的判断,相对而言,对于风险的上下界进行估计比较容易,因此采用区间数来表示专家的判断,并提出了采用区间数灰色层次分析法进行全生命周期风险评估,对于该方法,讨论了区间数判断矩阵的满意一致性问题及区间权重求解问题,在进行权重求解时尽可能地包含全部的一致性信息,以使求得的权重具有较高的可信性,从而使风险评估的结果更加可靠。(2)在船舶与海洋平台风险控制领域,现有的研究大多是针对特定风险在全生命周期某一阶段的控制方法,尚未有从全生命周期的角度进行综合研究。本文建立了基于全生命周期的船舶与海洋平台风险控制模型,根据不同风险的特点,分析在生命周期各个阶段进行风险控制的可能性,为最终作出风险控制决策,研究在不同阶段风险控制的理论与方法。根据船舶机舱火灾的特点,对其在设计阶段和运营阶段的风险控制进行研究。在设计阶段的机舱火灾风险控制,目前的研究没有考虑船体结构对火灾烟气运动的影响,本文基于风险的设计理论,采用大涡模拟方法(LES)研究了船舶结构对火灾的烟气扩散运动和温度分布的影响,得出船舶舱室内火灾烟气的扩散规律,在此基础上提出了烟池效应的概念,并分析了烟池效应的特点,然后对一艘26000DWT油船机舱在三种不同的通风条件下进行火灾模拟,根据模拟的结果,对船舶设计提出了建议。在运营阶段的机舱火灾风险控制,建立了机舱火灾贝叶斯网络模型。机舱火灾发生后,为了确定火情,往往采用人工探火的方式,而人工探火不但具有危险性,而且耗时,往往由于人工探火而失去灭火的最佳时机。针对该问题,可以采用该模型对机舱火灾的火情进行推理分析,从而为消防决策提供参考。更多还原

【Abstract】 With the development of marine transportation and exploitation of resources in response to the market requirment of ocean shipping and energy, the development of ships is towards large-scale, high-speed and specialization in order to expand the volume of sea cargo, and offshore platforms step gradually from shallow water to deep sea. Therefore, the field of risk in shipping and marine engineering has been given rise to more and more attention. Based on the research of the current life cycle risk analysis, ship and offshore platform life cycle risk analysis is discussed, and the contents include life cycle risk assessment and risk control models on engine room fire of ship and offshore platform.(1) Risk assessment of ship and offshore platform is a complicated system. The current studies mainly focus on a specific risk in ship and offshore platform life cycle. In this paper, life cycle risk assessment methods of ship and offshore platform are studied from the system engineering point of view.First of all, according to the characteristics, the life cycle of ships and offshore platforms can be divided into five phases, that is, planning, design, construction, operation and decommissioning. All the risks consist of five categories, that is, environmental risk, technical risk, economic risk, management risk and behavioral risk. Risk loss is graded according to the consequence. Then after risk identification for each phase, life cycle risk assessment index system of ships or offshore platforms can be established.In terms of the complexity and uncertainty involved in real world decision problems and how much information can be obtained, the expression of certainty or uncertainty are introduced into risk assessment methods, In the course of risk estimatement, judgments are given by experts. Because of the complexity of the practical problems and uncertainty of risks, experts are not always able to elicit exact judgments. If the problem is relatively simple, or has a certain amount of available information, experts can make judgment with crisp numbers, in which case the Grey-AHP method can be conducted for the life cycle risk assessment. If the problem is relatively complex, and the necessary information is not sufficient, it is unrealistic and infeasible to acquire exact judgments. Relatively it is easier for experts to use the upper and lower bounds for risk estimation, so interval number is taken to express experts’ judgments. Interval number Grey-AHP method is proposed for life cycle risk assessment and satisfactory consistency and priority generation methods are studied. (2) In the field of ship and offshore platform risk control, most of current studies focus on the control methods at specific phase of life cycle. However, it is essential to study life cycle based risk control of ship and offshore platform.Life cycle risk control model of ship and offshore platform is established. Depending on the characteristics of various risks, possibility of risk control in each phase of life cycle is analyzed. In order to make decision for risk mitigation, risk control methods at different phases of life cycle are investigated. The analysis of the engine room fire demonstrates that the risk reduction plan can be taken at design and operation phases and the risk control methods of engine room fire is analyzed according to various incentives.In order to control the risk in engine room at design phase, large eddy simulation(LES) is adopted to analyze the effect of smoke diffusion and temperature distribution caused by ship structure, and diffusion law of fire smoke under deck is obtained. On this basis, smoke pool effect is proposed and its characteristics are analyzed. As an example, fire scenario in engine room of a 26000DWT tanker is simulated in conditions of three different ventilations. According to the simulation results, suggestion is given with regard to ship design.In order to control the risk in engine room at operation phase, Bayesian network model of engine room fire is built. For the purpose of finding out the situation after the engine room fire occured, manual fire detection is often implemented. It is not only dangerous, but also time-consuming, so the best time of extinguishing is often lost. To solve the problem, Bayesian network model of engine room fire can be used for reasoning and providing reference for firefighting decision.更多还原