Research

Particle Concentration in Engine Exhaust Emissions

The exhaust emissions of diesel vehicles can contain nanoparticles that have a health-damaging effect. In order to develop suitable measures for avoiding particle emissions, precise and reliable processes to determine the number of particles (PN) are necessary. The processes described in the Particle Measurement Programme (PMP) of the European guidelines ECE-R49 and 83 present problems with respect to comparability and repeatability. To resolve these problems, this process was systematically tested on an engine and a model gas test stand as part of an FVV project. The variation among different manufacturer's PMP-conform particle counters reached up to 15 per cent for the same aerosol. To reduce measurement uncertainty, it makes sense to rework calibration regulations and to define more precisely the device parameters. Beyond this single calibration, it is also recommended to calibrate the entire system and in general to validate the systems more frequently.

» In this FVV project, we have identified the weaknesses in the process for determining the particle concentration in engine exhaust emissions and shown possibilities for improvement. These results provide an important impulse for evaluating the particle exhaust emissions of combustion engines. «
Dr. Harald Beck (MAN Truck & Bus AG)

Motivation

Nanoparticles in the diesel exhaust emissions of combustion engines present a health risk. To define and control reduction measures it is important to have precise measurements of particle emissions. The process for doing this is determined by the Particle Measurement Programme (PMP) of the European guidelines ECE R49 and 83. There are still significant problems, however, with these guidelines with respect to comparability and repeatability. The FVV project aims to identify error sources when determining the particle concentration in engine emissions according to PMP.

Methodology

Measurements on an engine and a model gas test stand were used for evaluating PMP. In an aerosol laboratory, the correctness and the repeatability of CPC and VPR based particle concentration measurements (Condensation Particle Counter/Volatile Particle Remover) with varied model aerosols were evaluated. To separate volatile exhaust particles during the VPR process, a newly constructed catalytic stripper and evaporation tube was used. On the engine test stand, a simulated comparison of four entire systems for counter determining occurred.

Result

The variation among different manufacturer's PMP-conform counters reached up to 15 per cent for the same aerosol. Variations of up to 50 per cent in CPC responding behaviour were seen for different volatile particles. Using a catalytic stripper and evaporation tube, a complete separation of isolated volatile exhaust emission components from the aerosol flow was possible. However, it was not possible to compare different types of VPR devices or differences among manufacturers. The tests on the engine test stand not only show differences in the total values from +/- 20 percent, but also that system components are systematically influenced. To reduce measurement uncertainty, it makes sense to rework the CPC calibration requirements and to define more precisely the VPR device parameters. In addition to the individual calibration, a calibration of the entire system and more frequent validation of the systems would be desirable.

Documentation

PN Measurement Process | Investigation and evaluation of different methods for particulate number mesurement | Project No. 1073

Themis

Status
Finalised

Programme
FVV Funding

Budget
241.350,00 EUR EUR

Time Period
2011-07-01 to 2013-06-30

Research Association for Combustion Engines (FVV) eV

Lyoner Strasse 18
60528 Frankfurt am Main
Germany

Industry

Dr. Harald Beck
MAN Truck & Bus AG

Research & Technology Performers

1 | Institute of Internal Combustion Engines (LVK) | Technical University Munich (TUM)

Head of Research:
Prof. Dr.-Ing. Georg Wachtmeister

Research Associate:
Dipl.-Phys. Thomas Maier

2 | Chair of Analytical Chemistry | Institute of Hydrochemistry and Water Chemistry (IWC) | Technical University Munich (TUM)

Head of Research:
Prof. Dr. Reinhard Nießner

Research Associates:
Bettina Kiwull, MSc
Jan-Christoph Wolf, MSc

Technical University of Munich (TUM)

Institute of Internal Combustion Engines (LVK)

Arcisstrasse 21
80333 Garching
Germany

Technical University of Munich (TUM)

Institute of Hydrochemistry and Water Chemistry (IWC)/Chair of Analytical Chemistry

Marchioninistrasse 17
81377 Munich
Germany

Project Management

Ralf Thee

FVV
+49 (0) 69 6603 1349
+49 (0) 69 6603 2349


Research Association for Combustion Engines eV

Lyoner Strasse 18
60528 Frankfurt am Main
Germany
T +49 69 6603 1345