复杂地形下有害气体泄漏的模拟预测与输运规律

Numerical prediction and transportation study of poisonous gas transport on complex terrain

从近几年国内外发生的几起重大气体泄漏事故的情况来看,由于缺乏对有害气体迁移和输运规律的把握,频频发生人员疏散延误和盲目疏散等现象,因此对有毒有害气体迁移和输运规律的研究显得尤为重要。现有研究方法大多使用经验模型预测气体泄漏过程,但是这些模型无法模拟在存在建筑物、山体等复杂地形条件下的气体泄漏输运时产生的低洼积聚、地形导向等重要现象。该文利用计算流体力学方法求解Navier-Stokes方程,对泄漏发生后的流场内的有害气体组分流动进行了研究。在对开县天然气井喷过程的数值模拟中,成功模拟了有害气体输运的积聚、导向等现象,模拟结果和事故现场的定性和部分定量结果进行比较,得到较为一致的结论。

Severe gas leakage accidents in recent years have shown that poor understanding and estimates of the poisonous gas movement could lead to dangerous evacuation delays. Therefore, this study analyzed the mechanisms for poisonous gas transportation across complex terrain. Traditional empiried models are not valid where the terrain is not smooth and especially in low-lying areas where the gas accumulates, which often occurs in complex terrain with dense gas leaks. Therefore, a computational fluid dynamics method was used to solve the Navier-Stokes equations to model the movement of the poisonous gas species. The natural gas leak in Kaixian city was taken as an example with simulations of spreading of the gas in the mountainous area, The results agree well with qualitative observations and quantitative data from the field.