深圳市机动车PM_(2.5)排放因子隧道测试研究

为深入了解深圳市机动车排放PM2.5化学特性,选取深圳具有代表性的城市隧道进行机动车排放因子测试。通过连续8 d的监测,获得隧道内PM2.5质量、EC、OC的浓度、交通参数、气象参数等实测数据。利用单程隧道活塞效应计算出隧道内机动车排放PM2.5质量、EC、OC的平均排放因子,分别为64.0,9.68,20.2 mg(/km.辆)。隧道内OC/EC的值在0.32~0.74之间,平均为0.52,表明深圳市机动车对PM2.5的排放,柴油车起主要作用。对塘朗山隧道与国内外其他隧道实验的测定结果进行比较,结果显示PM2.5质量的平均排放因子高低与机动车组中重型车所占比例大小规律一致,说明机动车组中重型车比例是城市控制机动车PM2.5排放的主要因素。利用线性回归分别计算重型车、轻型车对PM2.5质量、EC、OC的排放因子,经分析重型车为深圳市机动车尾气排放控制的重点,尤其是重型柴油车。

A Tunnel Test for PM2.5 Emission Factors of Motor Vehicles in Shenzhen

To find out chemical characteristics of PM2.5 emitted by motor vehicles,a tunnel test was conducted in a tunnel of Shenzhen.Through eight-day continuous monitoring,quantified data of PM2.5 factors,i.e.PM2.5 mass,EC and OC,were obtained based on the piston effect of traffic in one-way tunnel.The ratio of OC/EC,which ranged from 0.32 to 0.74,indicated that diesel-engine vehicles contributed most to PM2.5 emissions.Method of regression analysis was used to estimate PM2.5 mass,EC and OC,the PM2.5 factors of heavy-duty vehicles and light-duty vehicles respectively.The findings of the test suggested that being the main emission source,heavy-duty vehicles,especially heavy-duty diesel cars,should be taken into full consideration in exhaust emission control.