Investigations of nanoparticle emissions of two gasoline cars MPI & DI at stationary part load operation
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Publication date: 2014-07-01
Combustion Engines 2014,158(3), 3–11
Starting from Euro 6 not only for diesel but also for gasoline vehicles, with direct injection technology (GDI) a solid particle number emissions limit of 6 × 1011 #/km becomes effective. The limit was temporary extended for GDI to 6 x 1012 #/km. Nuclei of metals as well as organics are suspected to significantly contribute especially to the ultrafine particle size fractions, and thus to the particle number concentration. In the project GasOMeP (Gasoline Organic & Metal Particulates) metal-nanoparticles (including sub 20 nm) from gasoline cars are investigated for different engine technologies. In the present paper some results of basic investigations of nanoparticles from two gasoline cars – an older one with MPI and a never one with DI – are represented. The measurements were performed at vehicle tailpipe, with varying sampling conditions and with different SMPS-systems, which enabled the mobility scanning in different size ranges. The results show that the older vehicle with MPI emits high particle count concentrations. The size distributions are decisively bimodal with high numbers in nuclei mode. In this case, the particle counting below 10 nm yields important information. The emissions of the newer vehicle with DI show no typical uniform shape of particle size distributions and are at lower level, than for the older vehicle. There is no visible nuclei mode and the ultrafine particle concentrations below 10 nm are insignificant. A sampling with a strongly increased primary dilution has a clear influence on the indicated (higher) particle concentrations.