Research On Calculation Methods And Leakage Accidents Consequence Of Natural Gas Pipeline

Pipeline is a transport carrier for large quantities,long-distance transport for natural gas.The surrounding environment of natural gas long-distance pipeline is quite complex,pipeline is often subject to varying degrees of projects overlapping,corrosion and man-made damage.Due to the high risk of natural gas and high pressure of the pipeline and large diameter,it is easy to cause a large number of leakage and lead to fire and explosion accidents,resulting in a large number of casualties and property loss.Therefore,it is very important for pipeline safety management to strengthen the risk assessment and accident analysis of natural gas pipeline,and to analyze the consequence of pipeline accidents.This thesis mainly focuses on the leakage of natural gas pipeline,and makes qualitative and quantitative analysis on the development and influence of natural gas leakage.The main work of this thesis is divided into four parts:(1)Based on the relevant literatures of natural gas pipeline leakage,the application scope of three kinds of leakage calculation methods,such as the hole model,the large hole model and the pipeline model,has been analyzed.(2)FLUENT software is used to simulate the diffusion of natural gas under different leak conditions,and the influences of leakage aperture,wind speed and obstacle on diffusion are analyzed.(3)Gauss model is chosen to calculate the influence scope of gas leakage and diffusion after pipeline leakage,by comparing various mathematical models of gas diffusion.Gauss Plume Model and Puff Model are used to simulate the diffusion range under continuous and instantaneous leakage.(4)The event tree is used to analyze the types of natural gas pipeline leakage accident,the basic parameters and influence range of jet fire,fireball and vapor cloud explosion are calculated respectively,and the calculation result suggests that the effect of fireball accident should be considered while risk analyzing.