Department of Chemistry and Biochemistry, University of Denver , Denver, Colorado 80208, United States.
Environ Sci Technol. 2017 Apr 4;51(7):4100-4107. doi: 10.1021/acs.est.6b06172. Epub 2017 Mar 14.
The University of Denver repeated its 2013 fuel specific gaseous and particle emission measurements on two California heavy-duty vehicle fleets. In 2015 1456 measurements at the Port of Los Angeles and 694 measurements at the Cottonwood weigh station in northern California were collected. The Port fleet changed little since 2013, increasing the average age (+1.8 years), accompanied by an increase in particle mass (PM) by +266% (0.03 ± 0.01 to 0.11 ± 0.01 gPM/kg of fuel) and black carbon (BC) by +300% (0.02 ± 0.003 to 0.08 ± 0.01 gBC/kg of fuel). Particle number (PN) also increased (1.5 × 10 ± 2.5 × 10 to 2.8 × 10 ± 2.8 × 10 PN/kg of fuel) by a smaller percentage (+87%). Chassis model year 2008 and 2009 vehicles currently dominate the fleet, accounting for the majority of these increases. The long-haul Cottonwood fleet decreased in fleet age (-0.6 model years), where half the decreases in fuel specific PM (-66%), BC (-65%), and PN (-19%) emissions are due to the newer fleet; an increased fraction of pre-2008 chassis model year vehicles with retrofit diesel particulate filters (DPFs) account for the remaining reductions. These opposing emissions trends emphasize the importance of fully functional DPFs.
丹佛大学对加利福尼亚州的两个重型车辆车队进行了 2013 年燃料特定气体和颗粒排放测量的重复测量。2015 年在洛杉矶港收集了 1456 次测量数据，在加利福尼亚州北部的考顿威称重站收集了 694 次测量数据。自 2013 年以来，港口车队的平均年龄增长了 1.8 岁，车辆数量略有增加，颗粒质量（PM）增加了 266%（0.03 ± 0.01 至 0.11 ± 0.01 gPM/公斤燃料），黑碳（BC）增加了 300%（0.02 ± 0.003 至 0.08 ± 0.01 gBC/公斤燃料）。颗粒数（PN）也增加了（1.5×10 ± 2.5×10 至 2.8×10 ± 2.8×10 PN/公斤燃料），增加幅度较小（+87%）。2008 年和 2009 年的底盘车型目前占车队的大部分，这些增加的车型数量占了车队的大多数。长途运输的考顿威车队的车队年龄减少了（减少了 0.6 个模型年），其中燃料特定 PM（-66%）、BC（-65%）和 PN（-19%）排放量减少的一半是由于较新的车队；具有翻新的柴油颗粒过滤器（DPF）的 2008 年前底盘车型的比例增加，占剩余排放量的减少。这些相反的排放趋势强调了功能齐全的 DPF 的重要性。
