高速公路收费站区空气污染特征分析与数值模拟  

Analysis and Simulation of Air Pollution in Expressway Toll Station Area

作　　者：王占宇[1] 关强[1] 

机构地区：[1]东北林业大学交通学院,黑龙江哈尔滨150040

出　　处：《公路交通科技》2009年第4期154-158,共5页Journal of Highway and Transportation Research and Development

基　　金：交通部西部交通建设科技项目(200631800083)

摘　　要：根据高速公路收费站区实际环境,考察来流风向与风速、车流量、建筑物等因素对机动车排放污染物扩散的影响,建立高速公路收费站区污染物扩散的CFD仿真模型,进行三维流场的数值模拟,运用风向频率加权模型,比较模拟结果与实地采样分析数据,预测探讨高速公路收费站区空气流场和污染物迁移扩散特征。结果表明,数值模拟结果和实测数据符合较好,显示两者具有良好相关性;受收费站布局和大气边界层的影响,在建筑物背风面形成气流漩涡,污染物难以扩散形成局部高浓度污染,在环境温度25℃,风速1.9 m.s-1,小时车流量为465 veh.h-1,NOx的浓度达到0.232 mg.m-3;污染物扩散特征主要受环境建筑、气象条件及车流量的影响,在1.5~2 m高度范围污染物呈现较高的浓度。The effect of various factors of the real environment of the toll station area such as wind speed and direction,vehicle flow and buildings on the diffusion of vehicular emission pollutants were explored.The CFD simulation model was set up to simulate the 3D airflow.By using the wind direction frequency weighted method and comparing the simulation result and collected data on the spot,the airflow and the dispersion characteristics of vehicular emission under real atmospheric conditions were predicted.The results show that(1) numerical result agrees well with the measured concentration;(2)airflow whirlpools come into being in the leeward of the buildings and the pollutants assembled around the leeward are difficult to disperse due to the influence of atmospheric boundary layer and layout of the buildings,thus it may be easy to result in locally air pollution;(3) under the condition of the 25 ℃environmental temperature,1.9 m·s-1 wind velocity,465 veh·h-1 peak hour volume and 0.232 mg·m-3 NOx concentration,the characteristic of vehicle emission dispersion is affected by the buildings,meteorological condition and vehicle volume,in the altitude range of 1.5～2 m,the pollutant presents higher concentration.

关 键 词：环境工程 污染物扩散 数值模拟 高速公路 

分 类 号：X51[环境科学与工程—环境工程]