液化天然气动力船航行过程风险动态仿真

Dynamic simulation of process risk for the navigation of liquefied-natural-gas-fueled vessels

为研究复杂装备系统液化天然气(LNG)动力船的营运风险演变规律,受限水域船舶航行的过程风险,本文采用系统理论过程分析方法,通过构建船舶系统、LNG燃料系统及燃料使用过程的系统理论事故建模与过程模型,从组件失效、外部环境干扰及组件交互3个维度分析LNG动力船航行系统的安全性。基于马尔可夫过程假设,采用马尔可夫链与云模型并构的方法,提出LNG动力船受限水域船舶航行的过程风险性态仿真模型。以LNG动力船从长江某锚地航行至指定泊位为例,结合复杂水域船舶航行的场景,对LNG动力船受限水域船舶航行的过程风险进行性态仿真。通过单一环境和真实环境下仿真结果对比分析,验证模型的有效性和灵敏性。仿真结果表明:LNG动力船舶航行过程风险演化呈“浴盆曲线”规律,船舶航行初始和终末时段风险较高,且人因素和外部环境干扰是LNG动力船系统营运过程中风险形成的首要原因。

To expound on the evolution law of the operational risk of liquefied-natural-gas-(LNG)fueled vessels in complex equipment systems,the process risk status of ships in restricted waters needs to be investigated.The system theoretic process analysis method is used to analyze LNG-fueled vessels in three dimensions,namely,component failure,external environmental interference,and component interaction,by constructing the system theoretic accident modeling and process model between ship system,LNG fuel system,and fuel operational process.Based on the Markov process hypothesis,and along with the Markov chain and cloud model,a process risk simulation model is proposed for LNG-fueled ships in restricted waters.Considering the LNG-fueled vessels from an anchorage of the Yangtze River to a designated berth as an example,combined with the navigation conditions of complex waters,the behavioral risk of ship navigation of LNG-fueled vessels in restricted waters is simulated.The validity and sensitivity of the model are verified by comparing and analyzing the simulation results in a single environment and a real environment.The simulation results show that the risk evolution of the navigation process of LNG-fueled ships presents a“bathtub curve”law.The risk of ship navigation is higher during the start and end periods,and the human and environmental elements are the primary causes of risk formation during the operation of LNG-fueled vessels.