Search Results

In the current diesel vehicle exhaust emissions legislation Particle Number (PN) limits for solid particles >23 nm are prescribed. The legislation was extended to include Gasoline Direct Injection (G-DI) vehicles since September 2014. Target of this paper was to investigate whether smaller than 23 nm solid particles are emitted from engines in considerable concentration focusing on G-DI engines. The literature survey and the experimental investigation of >15 vehicles showed that engines emit solid sub-23 nm particles. The average percentage over a test cycle for G-DIs (30-40%) is similar to diesel engines. These percentages are relatively low considering the emission limit levels (6×1011 p/km) and the repeatability (10-20%) of the particle number method. These percentages are slightly higher compared to the percentages expected theoretically not to be counted due to the 23 nm cut-off size (5-15%).

The regulation of particle number (PN) has been introduced in the Euro 5/6 light-duty vehicle legislation, as a result of the light duty inter-laboratory exercise of the Particle Measurement Program (PMP). The heavy-duty inter-laboratory exercise investigates whether the same or a similar procedure can be applied to the heavy-duty regulation. In the heavy-duty exercise two "golden" PN systems sample simultaneously; the first from the full dilution tunnel and the second from the partial flow system. One of the targets of the exercise is to compare the PN results from the two systems. In this study we follow a different approach: We use a PMP compliant system at different positions (full flow, partial flow and tailpipe) and we compare its emissions with a "reference" system always sampling from the full flow dilution tunnel.

Limited and nonlimited emissions of scooters were analysed during several annual research programs of the Swiss Agency of Environment Forests and Landscape (SAEFL, BUWAL)*). Small scooters, which are very much used in the congested centers of several cities are a remarkable source of air pollution. Therefore every effort to reduce the emissions is an important contribution to improve the air quality in urban centers. In the present work detailed investigations of particle emissions of different 2-stroke scooters with direct injection and with carburetor were performed. The nanoparticulate emissions with different lube oils and fuels were measured by means of SMPS, (CPC) and NanoMet *). Also the particle mass emission (PM) was measured with the same method as for Diesel engines. Extensive analyses of PM-residuum for PAH & SOF/INSOF, as well as for VOC were carried out in an international project network.

Gas-operated vehicles powered by natural gas (NG) or other gaseous fuels such as liquefied petroleum gas (LPG), are seen as a possible option for curbing CO₂ emissions, fuel consumption and operating costs of goods and passenger transport. Initiatives have been adopted by various public organizations in Europe and abroad in order to introduce gas-fueled vehicles in their fleets or use retrofit fueling systems in existing ones. In this study a retrofit dual fuel (diesel-gas) fuelling system was investigated as a potential candidate technology for city bus fleets. The system is marketed under the commercial name d-gid. It is a platform developed by the company Ecomotive Solutions for the control and management of a diesel engine fuelled with a mixture of gaseous fuels. In order to assess its environmental and cost effectiveness the system was tested on a Volvo city bus. The tests were performed on an HDV chassis dyno under various driving conditions.

A proposal for sub-23 nm Solid Particle Number (SPN) measurement method was developed by the Particle Measurement Programme (PMP) group, based on the current SPN measurement method. In the proposal, a Particle Number Counter (PNC) having (65 ± 15)% counting efficiency at 10 nm and >90% at 15 nm (PNC10) replaces the current regulation PNC efficiency of 50±12% at 23 nm and >90% at 41 nm. Additionally, a catalytically active evaporation tube (CS) is required for sub-23 nm measurement method instead of the non-reactive evaporation tube (ET) of the current regulation. Here experimental work carried out at the JRC to address the issues of sub-23 nm SPN-measurement method is presented. The PNC10 was shown to be less dependent on the particle material than the PNC23, thus soot-like particles are still allowed for PNC-calibration. The high charging probability of soot-like particles was shown to have a low effect on PNC calibration uncertainties.