Leakage Diffusion Simulation And Development Of Visualization Software Of Submarine Gas Pipeline

The safety problems of submarine pipelines has been brought into sharp focus,once the submarine gas pipeline leak will seriously affect the production safety,resulting in huge economic losses and cause a very bad social impact.However,at present,there are some limitations in the study of gas pipeline.There are few studies on the leakage and diffusion problems of submarine gas pipeline in China.Therefore,it is necessary to study the leakage and diffusion law of the submarine gas pipeline,and provide the basis for the risk assessment and emergency treatment of the marine oil and gas leakage accident.In this paper,the leakage and diffusion of the submarine gas pipeline is studied,the numerical simulation of the leakage and diffusion of the submarine gas pipeline is carried out.On the basis of this,a visual simulation software for the leakage and diffusion of the submarine gas pipeline is developed.Firstly,the leakage and diffusion model of the submarine gas pipeline is established according to the computational fluid mechanics and production practice.Taking the leakage rate,the size of leaking hole and the speed of ocean current as the factors,the simulation test scheme was designed by orthogonal test method,and the simulation was carried out by using Fluent software.The simulation results show that:The law of diffusion motion of the leakage gas is consistent with the theory of bubble plume.In the initial stage of gas leakage,the leaking gas accumulated into a gas mass above the leaking hole.As gas leakage increases,the gas mass moves upwards and breaks into a bubble plume mixed with sea water,the gas distribution in water shows a clear characteristic of bubble plume.The leaking hole size and the leakage velocity shows a positive correlation with the initial gas mass size,shows a negatively correlated with the mixing degree of the bubble plume and the sea water,and the influence of leaking hole size is obvious.The velocity of the ocean current has no obvious effect on the size of the initial gas mass and the mixing degree of the bubble plume.The results of variance analysis show that the leakage rate and the size of leaking hole are significant factors affect the time of leaking gas arrive to the sea surface;the velocity of the ocean current and the size of leaking hole affect the leaking gas diffusion,but they are all nonsignificant factors;for the comprehensive experiment index,the size of leaking hole and the velocity of the ocean current are the significant factors,and the leaking rate is the nonsignificant factor.Secondly,according to the simulation results of Fluent,the leakage and diffusion model library is built,and the Matlab program is written to process the simulation data of the leakage and diffusion,the ASCII code files output from Fluent are simplified and the data point matrix of the area that leakage gas diffusion influence are created.Meanwhile,in order to describe the influence scope of the leakage gas more accurately,the edge curve correction coefficient is introduced,and the boundary curve of the leakage influence area is corrected.The edge curve fitting program is written,and the detection of whether a query area is affected by the leakage is realized.Finally,the visual simulation software is divided into several functional modules,and the corresponding dynamic link library files are generated by using Matlab software.The software development environment is set up,and the visualization simulation software for the leakage diffusion of the submarine gas pipeline is developed through the Matlab/C++ mixed programming method.