【摘要】 随着中国山区输气管道规模的不断增加，天然气泄漏导致的环境破坏和人员伤亡等事故日益频繁。为了研究高压埋地天然气管道泄漏后在山区环境中的扩散行为及垂向危害距离，基于计算流体力学建立了管道-土体-空气的三维模型，分别研究了不同泄漏方向、泄漏孔形状、土壤类型、土壤埋深、障碍物类型对天然气管道泄漏扩散及危害距离的影响。结果表明：随着泄漏方向与浮力方向夹角的变大，气体泄漏后扩散到地面的速率及垂向危害距离相应变小；三角形和正方形的泄漏孔扩散和危害范围均大于圆形；泄漏气体在土壤中的扩散速度随着土壤颗粒度和孔隙度的增加而不断增加；不同的土壤埋深将影响泄漏气体到达地面的时间，同一时间的垂向危害距离随土壤埋深的增大而缩小；障碍物将改变泄漏气体的扩散路径并加快垂向危害距离的增长，而暗沟将使天然气在沟内积聚形成高浓度区。更多还原

【Abstract】 As China’s mountainous regions host more and more gas pipelines, incidents involving natural gas leaks that cause harm to the environment or injure people are growing increasingly common. To investigate the diffusion behavior and vertical hazard distance of leakage gas in mountainous regions, a three-dimensional model of pipeline-soil-air was created with CFD software. The impacts of various obstructions, soil types, burial depths, leak hole shapes, and leak directions on the propagation of natural gas pipeline leaks and hazard distances were studied separately. The results show that in proportion to the direction angle between the buoyant force and the leakage hole, the vertical hazard distance and the rate of gas diffusion to the ground decrease. Diffusion rates and hazard ranges are larger for square and triangle leaking holes compared to circular ones. As soil porosity and granularity increase, the rate at which escaping gases diffuse into the soil increases steadily. The time it takes for the gas leak to release will vary depending on the burial depth, and as soil burial depth increases, so will the vertical hazard distance. Obstructions will alter the diffusion path of the leaking gas and accelerate the vertical hazard distance. Culverts will allow the gas to accumulate in the ditch to form an area of high concentration.更多还原