Particle Size and Number Emissions from Modern Light-Duty Diesel Vehicles 2011-01-0632
This paper focuses on measuring particle emissions of a representative light-duty diesel vehicle equipped with different engine exhaust aftertreatment in close-coupled position, including one designed to meet the upcoming Euro 6 emission standards. The latter combines a lean NOx trap (LNT) and a diesel particulate filter (DPF) in series to simultaneously reduce NOx and PM.
Particle Matter (PM) and particle number emissions are measured throughout testing procedure and instrumentation which are compliant with the UN-ECE Regulation 83 proposals. Specifically measuring devices for particle number emissions, provided by two different suppliers, are alternatively used. No significant differences are observed due to the different system employed. On the other hand particle size distributions are measured by means of a specific experimental set-up including a two stage dilution system and an electrical low pressure impactor (ELPI).
Particle emissions are evaluated over New European Driving Cycles (NEDCs) in cold start conditions with different amount of soot loaded into the DPF. Additionally, effect of different aftertreatment used are also registered and the impact of rich phase during DeNOx events is also evaluated with respect to this type of emissions.
Traditional particle mass gravimetric measurements and particle counting emissions are compared to highlight differences and effectiveness of both measurement methods.