Comparison of Particle Mass and Solid Particle Number (SPN) Emissions from a Heavy-Duty Diesel Vehicle under On-Road Driving Conditions and a Standard Testing Cycle

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• 作者：Zhongqing Zheng ; Thomas D. Durbin ; Jian Xue ; Kent C. Johnson ; Yang Li ; Shaohua Hu ; Tao Huai ; Alberto Ayala ; David B. Kittelson ; Heejung S. Jung
• 刊名：Environmental Science & Technology
• 出版年：2014
• 出版时间：February 4, 2014
• 年：2014
• 卷：48
• 期：3
• 页码：1779-1786
• 全文大小：430K
• ISSN：1520-5851

文摘

It is important to understand the differences between emissions from standard laboratory testing cycles and those from actual on-road driving conditions, especially for solid particle number (SPN) emissions now being regulated in Europe. This study compared particle mass and SPN emissions from a heavy-duty diesel vehicle operating over the urban dynamometer driving schedule (UDDS) and actual on-road driving conditions. Particle mass emissions were calculated using the integrated particle size distribution (IPSD) method and called M_IPSD. The M_IPSD emissions for the UDDS and on-road tests were more than 6 times lower than the U.S. 2007 heavy-duty particulate matter (PM) mass standard. The M_IPSD emissions for the UDDS fell between those for the on-road uphill and downhill driving. SPN and M_IPSD measurements were dominated by nucleation particles for the UDDS and uphill driving and by accumulation mode particles for cruise and downhill driving. The SPN emissions were 3 times lower than the Euro 6 heavy-duty SPN limit for the UDDS and downhill driving and 4鈥? times higher than the Euro 6 SPN limit for the more aggressive uphill driving; however, it is likely that most of the 鈥渟olid鈥?particles measured under these conditions were associated with a combination release of stored sulfates and enhanced sulfate formation associated with high exhaust temperatures, leading to growth of volatile particles into the solid particle counting range above 23 nm. Except for these conditions, a linear relationship was found between SPN and accumulation mode M_IPSD. The coefficient of variation (COV) of SPN emissions of particles >23 nm ranged from 8 to 26% for the UDDS and on-road tests.