空调工况下地铁站台PM2.5动态变化特性与影响因素分析

Dynamic Variation Characteristics and Influential Factors of PM2.5 in Subway Platforms under Air-conditioning Condition

本文以空调工况下地铁站台区域PM值为研究对象,采用现场动态监测的方法,对上海某地铁车站站台1.5 m高度典型代表点及站台典型送风口和回风口处、屏蔽门附近、楼梯处和新风井区域的PM值和温湿度值进行动态监测,获得站台及其相关因素PM值的动态变化特性。结果表明:送风口平均PM值比站台平均PM值高25μg/m 3,站台屏蔽门附近处平均PM值比站台平均PM值高50μg/m 3。本文还利用CFD软件进行数值模拟,并通过正交试验数学方法分析各因素对站台PM浓度影响的显著性,结果表明:送风口PM和屏蔽门PM对站台PM值影响非常显著,送风口风速和回风口风速对站台PM值影响显著,送风温度、屏蔽门处温度和站台温度对站台PM值影响不显著。

This study investigated some of the major factors influencing subway PM pollutants under air-conditioning conditions through field measurements and CFD simulations on a Shanghai subway station.Based on the principle of the air-conditioning system,the particle concentrations at the air supply outlet,return air outlet and the screen door creates a direct impact on particle concentration of the platform.Dust accumulation at the fresh air shaft is found to be a secondary dusting action when the fresh air is supplied,which leads to a higher particle concentration in the subway station than that in outdoor air.The average PM value of the air outlet is 25μg/m 3 higher than the average PM value of the platform.The average PM value near the platform screen door is 50μg/m 3 higher than the average PM value of the platform.Each factor′s influence on the platform particle concentration was analyzed through the orthogonal test.Results confirmed that the particle concentrations at air outlet and platform screen door,along with the supply air and return air velocity,significantly influenced the particle concentration at platform;while the temperature of supply air,platform screen door and the platform has little impacts on the particle concentration at platform.