Abstract: This paper proposes a risk assessment method combining event tree analysis and numerical simulation, to assess the risks of truck-to-ship bunkering operations for methanol-fueled ships and enhance the safety level of methanol bunkering. Risk factors for methanol bunkering operations were identified based on ship layout, bunkering system, and operational procedures. An event tree model for methanol leakage was established considering influencing factors such as ignition conditions, leakage source location, and fire protection system response. The occurrence probabilities of different scenarios were calculated using typical failure data. On this basis, the three-dimensional computational fluid dynamics (CFD) tool FLACS was used to simulate the distribution of flammable hazard zones and toxic hazard zones following methanol leakage. Individual risk values were calculated according to the acceptable individual risk criterion. The results show that the individual risk of truck-to-ship bunkering operations for methanol-fueled ships is at an unacceptable level. It is recommended that based on quantitative calculation results, the restricted area for bunkering operations be delineated along the vessel's length and breadth directions according to the flammability limits, and a warning zone be established with the methanol tanker as the center and the toxic concentration limit as the radius. The research findings can provide input for the development of bunkering operation manuals for methanol-fueled ships.

Key words: methanol fuel, truck-to-ship bunkering, quantitative risk assessment, event tree model

摘要： 为评估甲醇燃料动力船槽罐车加注作业的风险,提高甲醇加注作业安全水平,该文提出了一种结合事件树分析和数值模拟的风险评估方法。根据船舶布置、加注系统和作业操作,识别了甲醇燃料加注作业的风险因素;基于点火条件、泄漏源位置和消防安全系统响应等影响因素,建立了甲醇泄漏事件树模型,并利用典型故障数据计算得到不同场景发生概率;在此基础上,采用三维计算流体力学软件（FLACS）计算甲醇泄漏后的火灾危险区域和毒性危险区域的分布;最后,根据个人可接受风险准则对风险值进行计算,结果表明：甲醇燃料船槽罐车加注作业的个人风险值处于不可接受水平。建议依据定量计算结果,沿船长和船宽方向,以可燃浓度界限包络线设置加注作业限制区域;以甲醇槽罐车为圆心、以毒性浓度界限为半径设置警戒区域。研究成果可为甲醇燃料船加注作业手册的制定提供输入。

关键词: 甲醇燃料, 槽罐车加注, 定量风险评估, 事件树模型