高架覆盖的街谷内可吸入颗粒物的浓度分布  

Concentration diffusion of particulate matter in street canyon covered with elevated road

作　　者：冯寒立 赵敬德[1] 翟静[1] 

机构地区：[1]东华大学环境科学与工程学院,上海201620

出　　处：《环境工程学报》2017年第8期4669-4676,共8页Chinese Journal of Environmental Engineering

基　　金：上海市自然科学基金资助项目(13ZR1401500)

摘　　要：可吸入颗粒物影响及危害不断增大,微气候环境也越来越引起学者们的关注。对覆盖高架路的街道峡谷颗粒物浓度分布进行了研究;实地测量在风温、有无高架、建筑物附近植被覆盖程度、高度四种情况影响下颗粒物在街谷内分布情况,引入相关性分析,同时进行了CFD数值模拟研究。实测结果表明,早高峰时段街谷内达到5级重度污染;有高架路覆盖的街谷,内部颗粒物浓度高于无高架路覆盖的街谷;颗粒物浓度随高度增加逐渐降低,但是在刚高过高架路时,浓度会突增;街道植被覆盖程度越大,颗粒物浓度越低。相关性分析表明,颗粒物浓度与高度呈负相关,颗粒物浓度与温度呈负相关。模拟结果表明,有高架路覆盖的街谷,在高架路周围会形成涡流,导致颗粒物不容易离开街谷。With the impacts of particulate matter becoming more and more harmful,environmental microclimates are increasingly receiving more attention. In this study,the concentration dependent diffusion of particles in a street canyon under an elevated road was investigated. Field surveys were conducted in relation to four conditions,atmospheric temperature,with or without elevated road,vegetation coverage,and vegetation height,to reveal the distribution of particulate matter in the street canyon. Correlation analysis was performed along with Computational Fluid Dynamics numerical simulation. The results show that five levels of heavy pollution can be reached during the early peak period of the street. The concentration of particulate matter in the street canyon under an elevated road was higher than that not under an elevated road. The concentration of particulate matter decreased with increase of height,but sharply increased just above the elevated road. The more the vegetation cover,the lower the concentration of particulate matter was. Correlation analysis showed that the particle concentration was negatively correlated with height and with temperature. Simulation results show that in a street canyon under an elevated road,eddies form around the elevated road,making it difficult for particulate matter to leave street canyons.

关 键 词：高架路 街道峡谷 微气候环境 可吸入颗粒物 数值模拟 

分 类 号：X513[环境科学与工程—环境工程]