Research On Risk Assessment Of Ship To Ship LNG Bunkering And Prevention

Liquefied Natural Gas(LNG),as the most commonly used alternative clean energy,is an important option for energy conservation and emission reduction in ships.In recent years,it has received great attention from the shipping industry,and LNG powered ships have developed rapidly.LNG ship to ship bunkering is an important way to meet the fuel bunkering needs of LNG powered ships and an important link in promoting the utilization of clean fuel in ships.As a new type of ship,LNG bunkering ships frequently shuttle through densely trafficked waters for LNG cargo operations.In order to ensure operational safety,reasonable safety measures need to be developed based on risk analysis.However,t here is currently a lack of practical experience,cases,and data to support risk analysis in LNG ship to ship bunkering operations,which has become an important issue faced by risk analysis.The main work of this article is as follows:(1)Based on the HAZID method,hazards are identified throughout the entire process of LNG ship to ship bunkering operations.A questionnaire survey method is used to determine the frequency and severity of each risk occurrence.Based on the above two indicators,a risk matrix is established for qualitative risk assessment.(2)In view of the lack of experience,cases and data related to LNG ship to ship bunkering operation,the bayesian network method based on fuzzy confidence rule base is selected to conduct risk modeling and assessment combined with evidential reasoning.Taking the synchronous loading and unloading operation during a LNG ship to ship bunkering operation at Yangshan Port Phase II Wharf as a case study,a quantitative assessment was conducted on the risk of fire during the synchronous loading and unloading operation of LNG ship to ship bunkering.The risk factors at each level of the two factors that cause fire,na mely "LNG leakage" and "introduction of fire sources",were ranked.(3)On the basis of risk assessment,the main risks and prevention and control directions of LNG ship to ship bunkering were summarized,and more comprehensive safety suggestions were proposed based on existing safety measures.Finally,combined with the Internet of Things and other related technologies,the idea of designing a LNG water injection risk monitoring system and strengthening the intelligent prevention and control of LNG water injection risk was put forward.The main functions,characteristics and key technologies involved in the system were discussed.The existing detection technologies and realizability of risk factors such as monitoring system failure and collision of foreign objects that have a greater impact on quantitative risk assessment were analyzed,proved the feasibility of the proposed concept.The research results of this article have practical application value for enriching the risk assessment methods of LNG ship to ship bunkering operations and improving the risk prevention and control level of LNG ship to ship bunkering.