障碍物形状对含硫天然气管道泄漏扩散影响的数值模拟

对含硫天然气管道泄漏扩散进行模拟研究，在不同风速下对比分析了计算区域内障碍物形状、障碍物坡度对泄漏气体扩散过程的影响规律，并模拟了不同条件下H₂S组分的安全区域。结果表明，障碍物的存在使泄漏气体在风力作用下堆积在障碍物的迎风面，障碍物的形状改变泄漏气体的运动路径。当障碍物为无坡度障碍物（建筑物）时，泄漏气体的扩散高度增大，且在水平方向的传输被阻碍；当障碍物为有坡度障碍物（山体）时，泄漏气体在水平方向的扩散距离增大，且在外界风力达到一定速度之后，泄漏气体绕过障碍物在背风区扩散时开始向下沉降，导致地面附近的安全区域范围减小。减小障碍物坡度，风速较小时对泄漏气体的扩散无影响，风速较大时泄漏气体将障碍物包围并在近地面处扩散；增大障碍物坡度，泄漏气体的扩散规律与无坡度障碍物（建筑物）存在时相似。模拟结果可为含硫天然气泄漏事故的处理提供参考。

Numerical Simulation of Obstacles Shape Influence on Leakage and Diffusion of Sulfurous Gas

The numerical simulation study was performed on the sulfurous gas leakage diffusion. The effects of obstacles shape, slope size of obstacles and the distance between leakage hole and obstacles in the calculation region and different wind speeds on leakage diffusion process were analyzed. The hydrogen sulfide component and methane component safety area were simulated in the different conditions. The results showed that under the action of wind, the presence of obstacles changed the motion path of the gas leakage and led the leakage gas to store in front of its surface. The height of leakage gas diffusion was increased and its transmission in horizontal direction was prevented if the obstacle was no slope obstructions(buildings). The horizontal distance of leakage gas diffusion was increased if the obstacle was gradient obstacles(mountain), and the leakage gas started setting down in the protected area after it bypass obstacles when the wind speed was more than a certain speed, causing the safety area reduced.Reducing obstacles slope, light wind could not influence the diffusion of gas, the leakage of gas was surrounded by obstacles and diffused near the ground when the heavy wind came. Increasing obstacles slope, leakage gas diffusion regularity of slope was similar with no obstructions. The suggestion for emergency rescue and safety management of sulfurous gas leakage accident was provided.