基于Fluent的地下综合管廊天然气泄漏模拟及分析

基于Fluent的地下综合管廊天然气泄漏模拟及分析摘要我国天然气运输管道建设取得了显著进展，但仍面临一些安全问题。例如，部分管道运行时间较长，存在老化问题：管道腐蚀、外力损伤或操作失误等原因可能导致天然气泄漏，引发安全事故。利用计算流体力学的数值模拟软件，可以在较短的时间内对此类事故进行合理的模拟，不仅经济高效而且数据可靠。地下综合管廊，作为城市地下基础设施的重要组成部分，用于集中容纳和管理多种公共设施管线，其安全性不容忽视。本文采用Fluent软件进行模拟地下综合管廊天然气管道发生小孔泄漏。通过对仿真结果进行分析，可以得出其发生泄漏后的气流由泄漏口高速喷射而出，并且互相粘连不会在低空扩散的太广而是积聚在管廊顶部。速度在泄漏口垂直中心线上的变化是自下而上，从大到小，并且距离泄漏点越远，速度越小。具体模拟仿真包括以下步骤：模型建立、网格划分、求解设置、初始化及模拟。仿真模拟可以为地下综合管廊天然气管道的设计运行以及发生类似泄漏事故后分析提供参考，从而提高管道的安全可靠性，带来巨大的经济效益和社会效益。在模拟分析结果中发现，天然气管道自身的参数中，运输压力对泄漏的影响较大，且运输温度的变化也会对泄漏产生影响。通过综合的比对发现要想减小泄漏事故危害把对损失降到最小，可以尽可能选择低温低压的条件进行天然气的输运。关键词综合管廊：天然气：泄漏扩散：数值模拟-I-Simulation and Analysis of Natural Gas Leakagein Underground Comprehensive Pipe TunnelBased on FluentAbstractAlthough significant progress has been made in the construction of naturalgas transportation pipelines in China,there are still some safety issues.Forexample,some pipelines have been in operation for a long time and may haveaging problems;pipeline corrosion,external damage or operational errors canlead to natural gas leaks and cause safety accidents.The use of computationalfluid dynamics numerical simulation software can provide a reasonablesimulation of such accidents in a short period of time,which is not only cost-effective but also reliable.Underground comprehensive pipe tunnels as an important part of urbanunderground infrastructure,is used to centrally accommodate and manage avariety of public facilities pipelines,and its safety cannot be ignored.In thispaper,Fluent software is used to simulate small hole leakage in undergroundcomprehensive pipe tunnels.By analyzing the simulation results,it can beconcluded that the airflow will be ejected from the leakage point at high speedafter the leakage occurs,and it will stick together without spreading too widelyin the low altitude area but accumulate at the top of the utility tunnel.Thechange in speed along the vertical center line of the leakage point is a trend ofdecreasing from top to bottom,and the farther away from the leakage point,thesmaller the speed.Specific simulation steps include model establishment,griddivision,solution settings,initialization and simulation.This simulation canprovide reference for the design and operation of natural gas pipelines in-Ⅱ-underground comprehensive pipe tunnels as well as analysis after similarleakage accidents occur to improve the safety reliability of pipelines and bringabout significant economic and social benefits.In analyzing the simulatedresults it was found that among the parameters related to natural gas pipelinesthemselves,transport pressure has a greater impact on leaks while changes intransport temperature also affect leaks.Through comprehensive comparison itwas discovered that to minimize hazards from leakage incidents and reducelosses to a minimum possible extent one should choose low-temperature low-pressure conditions for transporting natural gas.Keywords utility tunnel,natural gas,leakage diffusion,numerical simulation-川-目录摘要Abstract.…Ⅱ第1章绪论1.1课题背景11.2研究意义21.3