CFD Simulation And Effects Analysis Of Urban Gas Pipeline Leakage And Diffusion

In the development of natural gas, urban natural gas pipeline become more andmore complex. Gas pipelines are often located in population and building concentratedarea, which makes the town gas become the most serious consequences combustiblegas. Grasp the urban gas pipeline leakage and diffusion can accurately predict, evaluateand control the accident, thereby reducing natural gas pipeline accidents.To master the law of natural gas leakage and diffusion Call be useful to accuratelypredicted, evaluation and control it, reducing gas pipe-conveying accidents.In this paper, a model of natural gas continuous leakage and diffusion of outdoorpipeline is established. Theoretical analysis, numerical simulation and experimentaldemonstration are used in this paper.First, analyze the flow of the gas pipeline leakage diffusion process using thebasic theory of fluid mechanics to establish the basic control gas flow equation;analyze gas turbulent jet theory and set up the gas leakage diffusion turbulence model;Using the basic formula of fluid mechanics and engineering thermodynamics derivedthree leakage model, pipe, pipe-holes integrated model and pore model and thecorresponding calculation formula; calculate leakage of the own high pressure gaspipeline leakage accidents using mathematical Mat lab software and Providingtheoretical basis for later study;Second, due to the turbulent flow is a highly nonlinear flow and complicated flowstate theory research method obviously cannot meet the requirements, so numericalsimulation method was adopted. Through theoretical analysis and combined withpractical engineering situation, establish the natural gas pipeline leakage diffusion ofgeometric model under the mode of urban streets. Using CFD numerical simulationsoftware simulation calculation and analysis of simulation results, come to town thegeneral rule of high pressure gas pipeline leakage diffusion. Using CFD to simulate theleakage of natural gas diffusion under different time, line pressure, leakage apertureand conditions of obstacles, analysis the influence of different factors on natural gasleakage diffusion;Finally, although the CFD simulation has advantages of short cycle, highprecision and low cost, the simulation result is carried out by many assumptions andcontradicted with the reality of the complexity and variability. Measurement is impossible under various working conditions, but by concrete experiments can bebetter to guide the simulation and provides the fact basis for the analysis of urbanmedium pressure gas pipeline leakage. To test the rationality of the numericalsimulation, using similarity principle and combining with actual situation the gaslaboratory, we set up the model and take measurement. Comparing with the simulationresults with the result of the experiment, we found experimental results and simulationresults within the allowed error range. This result proves the right of CFD numericalsimulation and account for using k-ε turbulence model for gas pipeline leakagediffusion simulation is feasible.