中压天然气管道泄漏扩散模拟研究

建立了埋地中压天然气管道发生泄漏时时的数学模型，将土壤视为各向同性的多孔介质，采用FLUENT对天然气在土壤中的扩散规律及浓度分布进行模拟，分析不同时刻地表的危险区域范围，并对比了不同管道压力、泄漏孔径大小、泄漏位置等工况下危险半径随时间的变化。结果表明:管道压力越大，泄漏的体积流量越大，同一时间危险范围越大；相同的泄漏压力下，泄漏孔径对危险半径没有很大影响；不同泄漏孔位置，泄漏初期向上开口时危险半径最大，一段时间后向下开口危险半径最大。

Simulations on diffusion of natural gas in the soil for medium-pressure gas pipeline leak

A 2-D CFD model of a buried medium-pressure pipeline was set up and simulated by FLUENT to re-search the diffusion law and gas concentration for the natural gas leaking into the soil .The soil was taken as homo-geneous porous medium in this model .The radius of dangerous area on the surface at different time was described , and different factors such as pipe pressure , leak size , leak location were analyzed .The results showed that higher inlet pressure causes larger volume flow and wider dangerous area at the same time .Leak hole diameter effects slightly on the dangerous area radiuses for the same inlet pressure .The radius of dangerous area for the upward leak direction is largest initially while the radius of downward direction exceeds to be the largest after a certain time .