Study On Typical Accident Scenario Construction And Emergency Strategy Of Urban Gas Pipeline

As the lifeline of modern city,urban gas pipeline plays an indispensable role in the development of social economy.On the other hand,urban gas pipeline accidents emerge one after another,causing heavy casualties and bad social impact,which also highlights the necessity of gas pipeline emergency strategy research.In view of the problems such as incomplete understanding of evolution law,immature simulation of accident consequences and inaccurate emergency decision-making in the process of urban gas pipeline accidents,the emergency decision-making method of urban gas pipeline that integrates scenario construction,scenario deduction,accident simulation and emergency knowledge atlas is established.The main research contents and results are as follows:(1)The accident scenario of gas pipeline leakage and explosion in densely populated area is constructed.Through the analysis of a large number of urban gas pipeline accident cases,the accident scenario is screened.According to the three elements of scenario construction--scenario,consequence and task,based on a gas pipeline accident,the gas pipeline leakage and explosion accident scenario in densely populated area is constructed,covering the whole process of occurrence and development of accident scenario.(2)The scenario inference model of urban gas pipeline accident is constructed.Typical of constructed town gas pipeline accident scene,a dynamic bayesian network scenarios deduction model to analyze the evolution of urban gas pipeline accident scenarios typical path,evolution law,through calculating the probability of all kinds of scenario,eventually forming urban gas pipeline accident scenario development comprehensive situation maps,provide support for emergency decision making work.The results show that even under the intervention of positive measures,the probability of indoor gas gathering,indoor gas explosion causing fire and further spread of fire is more than 30%,so it can be seen that the most fundamental focus of reducing casualties and losses of urban gas pipeline accidents is to prevent urban gas pipeline leakage.(3)Establish a three-dimensional numerical model of gas pipeline leakage and explosion accident in densely populated areas.FLACS software is used to model typical scenes of urban gas pipelines,simulate and analyze the whole process of gas leakage and explosion in typical scenes,accurately calculate the law of gas leakage and diffusion in a confined space and the overpressure value generated by gas explosion,and establish the scope of influence of the accident according to the damage criterion.The results show that: in the process of gas diffusion,it reaches a stable state after leakage diffusion for500 s,and the concentration above the building is stable at about 12%.Once ignited,the overpressure value generated by explosion will reach 1.016 mpa,which will destroy the building and cause heavy casualties.(4)Establish an emergency decision-making method for gas pipeline accidents based on knowledge graph.Integration scenarios inference results and the influence of leakage,explosion,from accident incident,state scenes,emergency task,event data,model calculation,the five core elements build town gas pipeline emergency domain knowledge map,by 343 gas pipeline accident investigation report for entities and relationship extraction,has created 4034 nodes and 5384,Combined with retrieval and matching method,the emergency decision scheme of urban gas pipeline can be generated quickly.The research results show that the method based on knowledge graph can grasp the key points of emergency treatment in the process of emergency response,quickly generate emergency decision scheme,and has good operability.