Study On The Organization Scheme Of Liquefied Natural Gas Carrier Traffic In The Yangtze Estuary Deep Water Channel

As a clean and efficient low-carbon energy,natural gas is of strategic significance to the adjustment of China’s energy structure and the promotion of energy conservation and emission reduction.Driven by the carbon peak and carbon neutrality policy in China’s "14th Five-Year Plan",the demand for natural gas is bound to further increase.In the context of the gasification of the Yangtze River,water transportation will also become an essential mode of LNG transportation.Considering that the Yangtze River is not navigable for LNG ships,and the regulations and regulations related to the navigable safety of LNG carriers have not been established,and the deep channel of the north channel,as the passage section of the Yangtze River mouth,is the only way for LNG ships to sail into the river.Therefore,the traffic organization of LNG vessels in the Estuary section of the Yangtze River is the primary problem to be solved for the development of inland RIVER LNG carrier business.This study can provide theoretical basis for relevant departments to formulate the traffic organization plan of LNG vessels entering the river in the future.Based on the related literature at home and abroad to consult,learned about the vessel traffic organization and the research status and achievements of LNG ship navigation,determines the research content and methods of the thesis,summarizes the purposes and principles of LNG vessel traffic organization.Navigation factors of traffic organization should consider two aspects of risk and loss of navigation flow reasoning was calculated,and the focus of comprehensive consideration of both towards the navigable flow losses under the influence of the LNG ship navigation research,establish a decision-making model of traffic organization scheme based on dual index factors,on the basis of decision-making for schemes are simulated and adaptability analysis.Firstly,in order to evaluate the navigation risk of LNG ships in the Yangtze Estuary,this paper analyzes the navigation risk factors of LNG ships in the Yangtze Estuary deepwater channel from four levels of "man-ship-environment-management",and constructs the fuzzy Bayesian network structure with 18 risk indicators as the parent node to determine the risk assessment index system.Combined with expert experience method and fuzzy mathematics theory,the prior probability and posterior probability of Bayesian network are determined.Based on Ge NIe software,the navigation risk probability of two LNG ship navigation modes is deduced,and the inference results can reflect the difference of navigation risk between the two navigation modes to a certain extent.Secondly,in order to analyze the ship flow loss under the influence of LNG vessels,a channel traffic flow aggregation and dispersion model under the influence of LNG vessels was established based on the traffic wave theory,and the channel traffic flow aggregation and dispersion process under the two navigable modes was simulated.Combined with the difference between LNG vessels and common vessels,the calculation model of navigable loss flow is built.Third,combining the theory of water traffic engineering,two-way navigable and can follow to the LNG carrier state of one-way navigation two navigation mode loss of navigable flow are calculated respectively,and traffic organization scheme for the effect evaluation model is established,considering navigation risk probability and loss of navigation flow,realize the quantitative evaluation of the traffic organization scheme,The results show that the influence degree of LNG vessels passing through the Yangtze Estuary deepwater channel in two-way navigation mode is less than that in one-way navigation mode under shadowable state,that is,the comprehensive adverse impact of the two-way navigation mode is less.On this basis,the specific scheduling arrangement of traffic organization scheme is set up.Finally,the traffic organization scheme is simulated and channel scale adaptability is analyzed.On the basis of the decision scheme,combined with the traffic flow status of the Yangtze Estuary deepwater channel,a simulation environment was built with the help of Matlab tools,and the simulation process and related parameters were set up to simulate and analyze the navigable flow loss of the decision scheme.The simulation results were basically consistent with the data calculated by the theoretical model under certain conditions.It verifies the feasibility of the theoretical model in this paper to calculate the ship flow loss under the influence of LNG ship navigation,and also indicates that the ship flow loss in the channel can be reduced to a certain extent with multiple LNG ships sailing in the form of LNG fleet.Combined with relevant specifications,the adaptability of navigation schemes and channel scales for LNG ships under different specifications is obtained.In the case that the transverse safety distance of LNG ships is set to 100 m at the left and right sides of the first and last lines,the transverse safety zone should occupy at least 40 m of slope water to meet the bidirectional navigation requirements of LNG ships.This paper provides a reference for the study of LNG ship traffic organization scheme,provides a new idea for the analysis of the impact of LNG ship navigation,and provides a scientific basis for the formulation of regulations and regulations for LNG ship navigation in the Yangtze Estuary deepwater channel in the future.