摘要
在实际生活中,气体泄漏扩散情况会受到风向、风速及建筑物等影响,常见的气体扩散研究主要是在无降雨情况下对其他环境因素进行分析。以氨气为例,利用氨气极易溶于水的性质,以原有的高斯烟羽模型为基础,通过数值模拟进行分析,研究在雨季情况下,有害气体泄漏受降雨影响时的扩散情况。首先根据实际情况对高斯烟羽模型的有效源强进行改进,然后引入沉降系数表征降雨量对扩散的影响,在相同条件下进行模拟,将前两者的模拟结果与传统的高斯烟羽模型进行对比分析。试验结果表明,降雨量和有效源强对气体泄漏扩散有明显影响,与传统高斯烟羽模型相比,改进后的高斯烟羽模型更符合实际情况。
To provide a more accurate description of the changes in concentration mass fraction during gas diffusion under rainy conditions,this article uses ammonia as a case study,given its high solubility in water.By conducting numerical simulations of gas diffusion resulting from ammonia cylinder leaks at a chemical plant on rainy days,the impact of rainfall on gas dispersion is assessed.This study examines the Gaussian plume model as it pertains to rainy conditions,focusing on trends in gas diffusion mass concentration,peak mass concentration,and the size of hazardous areas.Initially,the analysis investigates the impact of both real and virtual leakage sources on the accuracy of the Gaussian plume model based on actual gas diffusion scenarios.To address this influence,a reflection coefficient is introduced for correction.Next,the traditional Gaussian plume model is enhanced by selecting suitable ground roughness based on the simulated environment.A comparison of the performance between the traditional and improved models at a wind speed of 1.5 m/s over diffusion durations of 30 seconds and 100 seconds reveals that the peak concentrations for the traditional model are 2762 mg/m^(3) and 5657 mg/m^(3),respectively,while the improved model yields peak concentrations of 2834 mg/m^(3) and 6859 mg/m^(3).The improved Gaussian plume model outperforms the traditional model regarding the downwind distance to the peak gas mass concentration and the peak concentration values,demonstrating a closer alignment with actual gas leakage scenarios.Based on concentration contour maps,the sizes of hazardous areas are determined,revealing that the improved Gaussian plume model indicates slightly larger areas in various hazardous zones compared to the traditional model.Finally,to examine the attenuation effect of rainfall on gas diffusion intensity,a wet deposition coefficient is employed to characterize wet deposition in relation to rainfall intensity.Trends in gas diffusion mass concentration and hazardous area sizes are compared under varying rainfall intensities.At a consistent wind speed and a diffusion duration of 30 seconds,an increase in rainfall intensity leads to a reduction in the area of the lightly injured zone by up to 66.63%,the severely injured zone by up to 76.46%,and the half-lethal dose zone by up to 87.86%.With a diffusion duration of 100 seconds,an increase in rainfall intensity results in a decrease in the area of the lightly injured zone by up to 65.59%,the severely injured zone by up to 72.02%,the half-lethal dose zone by up to 64.60%,and the immediately lethal zone by up to 79.28%.This indicates that as rainfall increases,its attenuation effect on gas diffusion becomes more pronounced.The improved Gaussian plume model,which incorporates a deposition coefficient,effectively captures the actual dynamics of gas leakage and diffusion during rainy conditions.
作者
徐凯宏
杨悦
徐梓敬
谷志新
XU Kaihong;YANG Yue;XU Zijing;GU Zhixin(College of Information and Computer Engineering,Northeast Forestry University,Harbin 150040,China;College of Home and Art Design,Northeast Forestry University,Harbin 150040,China)
出处
《安全与环境学报》
北大核心
2025年第2期656-664,共9页
Journal of Safety and Environment
关键词
公共安全
气体泄漏
高斯烟羽模型
危险区域划分
降雨环境
public safety
gas diffusion
Gaussian plume model
hazardous area classification
rainfall environment
