Risk Assessment Of LNG-lithium Battery Hybrid Inland River Cargo Ship

Nowadays,under the development of green energy and energy saving and emission reduction,although pure electric ships have become the frontier of current ship technology research;however,pure electric ships have poor power and endurance,making them unable to sail long distances.Marine hybrid technology can make the best compromise between emissions and economy,and gradually ease the contradiction between immature technological development and more stringent regulations,so hybrid ships are now the most suitable type for the development of the marine industry.Then it also involves new risks.The ship studied in this paper is a LNG-lithium battery hybrid inland cargo ship(hereinafter referred to as hybrid ship),which belongs to a new type of power ship.The research object is an 1830 t hybrid ship.According to the FSA,the risk of key conditions of its berthing(LNG bunkering,lithium battery charging)and navigation are identified and analyzed;the coupling risk of LNG and lithium batteries is mainly carried out The analysis also briefly analyzed other risks during the voyage,and finally analyzed and discussed the fire protection solutions.The main research works are listed as follows:(1)Analyze various methods in safety evaluation theory,among which the characteristics of FSA can conduct targeted risk analysis on own ship,so finally select FSA(comprehensive safety assessment method)as the risk assessment of LNG-lithium battery hybrid ship Method of analysis.It gives a certain introduction to the definition,status and characteristics,application fields and processes of FSA.The LNG model theory is mainly analyzed from three aspects: leakage and diffusion,fire and explosion.Introduce and analyze the working principle,thermal runaway and heat generation mechanism of lithium iron phosphate battery.(2)Select a method of LNG bunkering,and then use the fault tree to identify risks and perform a qualitative analysis of LNG bunkering.Using the leakage data statistics and calculation formulas,combined with the actual situation of the 1830 t hybrid ship,quantitative analysis of small holes,middle holes and full aperture leaks,calculate their leakage probability,and summarize the calculation results.According to the calculationresults,different scenarios are used to study the impact of natural gas filling and leakage on the battery.They are divided into three types of scenarios: prone scenarios,possible scenarios,and the most dangerous scenarios;Phast is used to diffuse natural gas leakage,fire heat radiation,and explosion overpressure Simulate the consequences of the shock wave to obtain their impact strength and range to analyze the impact on the cabin battery.(3)In the scenario where the battery is charging and the BOG is being discharged when the hybrid ship is at berth,the overheating of the battery causes thermal runaway,which leads to combustion and explosion.The coupling risk of the LNG system is analyzed.First introduce the ship's battery system,control system and charging system,and then analyze the thermal runaway and propagation of the battery,respectively analyze the risk of BOG discharge and battery overcharge,mainly through software simulation of BOG explosion,through electricity The core overcharge experiment analyzes the risk of battery overcharge,and finally analyzes the coupling risk of the battery to natural gas,and proposes protective measures for LNG and lithium batteries.(4)Calculate the cause of the fire of the lithium-ion battery during navigation based on the expert opinions of the burning triangle,establish the fault tree and analyze it,and give safety countermeasures and suggestions.Analyze and discuss the fire protection plan of the engine room fire,and finally briefly analyze other risks when the ship is sailing and give measures.