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为了掌握埋地穿越段天然气管道泄漏扩散特性、防止因管道泄漏引起的火灾爆炸等事故发生,研究了埋地穿越段天然气管道泄漏扩散的机理。针对埋地穿越段天然气管道泄漏扩散问题,运用多孔介质模型,结合三大守恒方程,构建了基于计算流体力学的数值模型,探讨了大小孔隙率特性下,对非线性对流项和压力梯度项分别采用4种不同离散格式组合方式时的天然气体积分数分布,并与试验进行对比分析。以泰州至戴南的埋地穿越段天然气管道泄漏进行实例研究。结果表明:大孔隙率特性下,一阶standard格式在精度和计算速度上要优于其他离散格式,与试验结果更加接近;小孔隙率特性下,二阶presto!格式相比其他几种压力离散方式具有更高的求解精度。
In order to grasp the characteristics of leakage and diffusion of buried natural gas pipeline and prevent fire and explosion accidents caused by pipeline leakage, the mechanism of leakage and diffusion of buried natural gas pipeline crossing section was studied. Aiming at the problem of diffusion and diffusion of natural gas pipeline passing through buried sections, a numerical model based on Computational Fluid Dynamics (CFD) was constructed by using porous media model and three conservation equations. The effects of size and porosity on nonlinear convection and pressure gradient The distribution of natural gas volume fraction when using four different combinations of discrete formats was compared with the experimental data. A case study was conducted on the leakage of buried natural gas from Taizhou to Dainan. The results show that the first-order standard format is superior to the other discrete formats in accuracy and computational speed under the condition of large porosity, which is closer to the experimental results. In the second-order presto! The method has a higher solution accuracy.