CFD方法对突发性化学事故中危险物质泄漏范围的确定

简要分析了目前国内主要用于预测易燃易爆(有毒)物质发生泄漏事故后浓度扩散范围的计算方法。并介绍了国际上比较成熟的计算流体力学相关软件的数学模型及特点和边界条件的设置。针对液氨发生泄漏后氨气在一定大气环境条件下扩散的过程和特征,建立了相应的数学模型并设置了边界条件,通过数值计算得到氨气在水平方向风速环境下在三维空间内浓度分布规律。通过分析氨气扩散后爆炸浓度下限范围,探讨了如何设置警戒区的方法。最后分析了将计算流体力学方法应用于确定易燃易爆(有毒)物质泄漏后浓度范围的前景与不足。

Leaking Coverage Definition for Dangerous Materials during Emergent Chemical Accidents Based on CFD Method

This paper analyzed the major forecasting methods currently applied in china for calculating the diffusing range caused by the leakage of inflammable, explosive or toxic materials, and then introduced a comparatively matured mathematical model used by related software for Computing Fluid Dynamics (CFD), its characteristics and the setup of boundary conditions of this model. Based on the process and characteristics of ammonia diffusing under certain atmospheric condition after leakage, a mathematic model was established and its boundary condition was set up, the distribution rule of ammonia concentration along the velocity to horizontal direction in three-dimensional space was obtained by numerical calculation. According to the range of lower explosive concentration limit, methods for how to set up warning region were research. Finally, the prospect and shortage of CFD being used in determining the concentration distribution of flammable, explosive or toxic materials after leakage was discussed.