【摘要】 针对城市埋地燃气管道泄漏扩散至邻近并行电缆沟引发的重大安全风险，选取合肥某段输电网线路与市政燃气管道并行的场景，采用CFD建立三维数值模型，研究泄漏燃气在土壤中向电缆沟扩散的规律，分析不同土壤类型(沙土、壤土、黏土)、泄漏压力(0.1～0.3 MPa)和泄漏孔径(10～20 mm)对燃气扩散过程的影响，探讨电缆沟作为障碍物时，其两侧侧壁处的燃气浓度分布情况，以及渗入孔对周围泄漏燃气扩散的影响。研究结果表明:泄漏形成的流线分布与压力场在100 s内迅速达到稳定状态，电缆沟泄漏孔附近存在显著的速度与压力梯度;土壤特性是影响扩散速度与危险性的关键因素，危险性排序为沙土>壤土>黏土;增大泄漏压力与孔径显著提升了泄漏速率、初始动能及扩散范围;电缆沟实体结构对扩散产生严重阻碍并导致流场变化，靠近泄漏侧呈点源泄漏，远离泄漏点侧呈现类似线源泄漏趋势，其渗入孔对附近燃气具有持续吸附作用，并导致远距离扩散滞后。本研究为评估燃气-电力耦合场景下的泄漏风险及制定防控措施提供了理论依据。更多还原

【Abstract】 In response to the significant safety risks caused by the leakage of urban buried gas pipelines spreading to adjacent parallel cable trenches,this paper selected the scenario where a section of the power grid line in Hefei runs parallel to the gas pipeline,and adopted the CFD method to establish a three-dimensional numerical model and studied the law of the leakage of gas spreading from the soil to the cable trench. The influences of different soil types( sandy soil,loam,clay),leakage pressure( 0. 1 ～ 0. 3 MPa) and leakage aperture( 10 ～ 20 mm) on the gas diffusion process were analyzed,the distribution of gas concentration on both sides of the cable trench as an obstacle and the influence of infiltration holes on the diffusion of surrounding leaked gas were studied. The results showed that:(1)The streamline distribution and pressure field formed by the leakage rapidly reach a stable state within 100 seconds,and there are significant velocity and pressure gradients near the leakage holes in the cable trench;(2)Soil properties are the key factors influencing the diffusion rate and hazard. The hazard ranking is: sandy soil > loam >clay．(3)Increasing the leakage pressure and pore size significantly enhances the leakage rate,initial kinetic energy and diffusion range．(4)The solid structure of the cable trench seriously hinders diffusion and causes changes in the flow field. The side close to the leakage point shows point source leakage,while the side far from the leakage point shows a trend similar to line source leakage. The infiltration holes have a continuous adsorption effect on the nearby gas and cause a lag in long-distance diffusion. This study will provide a theoretical basis for assessing the leakage risk in the gas-electric coupling scenario and formulating prevention and control measures.更多还原