Future Particulate Emission Measurement

Abstract:

Particle emissions in modern IC engines are coming to a range where they are just detectable with high sensitive instruments. The actual mass-based methods for the detection of emissions from modern EURO 5 engines are coming to their limit of detection especially during measurements after a Diesel Particle Filter (DPF).

According to a proposal by the “PMP” group, a technical forum set up by the Economic Council for Europe and supported by several federal environmental agencies, counting of non-volatile particles would be required in future regulations starting with Euro 5+ (Light Duty) and proposed for Euro VI (Heavy Duty) in addition to Particulate mass measurement, which will be still required with some modifications similar to the US 2007 procedure.

Volatile particles must be eliminated by an elaborate sampling procedure defined by the PMP group, therefore only solid particles, i.e. mainly black soot, will be counted. The background for this requirement is twofold. First, solid particles are suspected to be more relevant to the human health than liquid aerosols. Second, it has been found to be extremely difficulty to obtain reproducible emissions of volatile particles.

This paper shows a detailed set-up of a Particle Number Concentration (PNC) counting system according to PMP with experimental results from evaluation programs. Also the functional principle of the sampling system and the CPC from AVL will be shown in detail.

In addition also alternative measurement technologies for detecting lowest particulate mass emissions like the photo acoustic soot sensor are shown.

Keywords: Particle emissions, Particle Couning, Diesel Particle Filter, PMP, Euro 5