Andreas Mayer

Reliability of DPF-Systems: Experience with 6000 Applications of the Swiss Retrofit Fleet

The Swiss 1998 Ordinance on Air Pollution Control (OAPC) mandates curtailment of carcinogenic Diesel particle emissions at construction sites [4]. In addition particle traps are compulsory at underground workplaces [3]. In compliance, more than 6,000 Diesel engines were retrofitted with different particle trap systems. Many traps surpassed 99% filtration efficiency, from the beginning, and secondary emissions were mostly prevented. However, trap failure due to mechanical and thermal damage was initially rather high at about 10%. By Y-2000 the failure rate was halved to about 6%. Thanks to focussed improvements, the Y2003 statistics show yearly failures of “only” about 2%. The Swiss target is to retrofit 15,000 construction machines with traps, fully compliant with environmental directives, having 5,000 operating hours durability and failure rates below 1% . Fig1: Contribution of on-road and off-road Diesel engines to particle emissions in Switzerland. Note the relatively high impact of construction site machines [19], despite much fewer engines than in trucks and agriculture tractors. Construction machines have much higher PM-emission factors than trucks, and are operated more intensely than tractors. Traps must pass the VERT suitability test before deployment. The type certification for a representative example of a trap family comprises very detailed measurements of the filtration characteristics and the tendency to secondary emissions. The trap system is also verified in typical field deployment during more than 2,000 operating hours. Moreover, all construction machines are periodically inspected for emissions and functionality. Trap certification is cancelled when more than 5% failure is detected annually. This paper reports on the filtration quality of VERT-Test compliant traps, both in the new state and after prolonged deployment of at least 2,000 operating hours. The paper examines trap failures, their causes and prevention based on information from manufacturers, retrofitters and independent inspections. The work was performed in close collaboration with the regulatory authorities and the trade association AKPF of the trap manufacturers and retrofitters. The experience with this large retrofitted fleet shows the applicability of traps for Diesel engines of various design, power range and age for all construction machines – the directive includes no exceptions. The particle trap technology is demonstrated as technically, operationally and economically feasible. However there are several important prerequisites: comprehensive suitability testing, careful function monitoring and regular field inspection. Thus the targeted effectiveness and dependability are ensured.

(Nano) Particles from 2-S Scooters: SOF / INSOF; Improvements of Aftertreatment; Toxicity

Two wheels powered motor vehicles are an important pollutant source especially in urban areas. ENEA, in cooperation with Municipality of Rome, carried out an experimental activity aimed at evaluate particulate matter (PM) and polycyclic aromatic hydrocarbons (PAHs) emissions from two-wheel motor vehicles. In this paper, cold and hot PM and particulate PAHs emissions from eight 2-stroke 50 cc in-use mopeds, (3 pre-Euro I, 3 Euro I and 2 Euro II) and four 4stroke 150 cc in-use scooters (2 pre-Euro I and 2 Euro I), are presented. Mopeds and scooters were tested according to ECE-47 and ECE-40 driving cycles, respectively. CONCLUSIONS The tests performed indicate that particulate matter emission from non-catalyzed mopeds is related to lubricant consumption. In the case of Euro I mopeds, lubricant in the exhaust gases is oxidized by the catalyzer. In ECE-47 driving cycle oxy-cat reduced particulate emissions by about 80%. The two tested models of Euro II mopeds showed very different hot emissions factors so, at the moment, we cannot attribute a unique figure to this moped category. Further investigation is necessary. In any case PM moped emissions cannot be neglected in urban emission inventories. For instance, in Italian urban areas moped PM emissions can be of the same magnitude of those from diesel passenger cars, according to the fleet composition. Scooter PM emissions are, as expected, quite low and their contribution to the PM emission inventory could be disregarded as a first approximation. Two-wheel motor vehicles seem to be an important source of atmospheric PAHs releases. Due to their prevailing use in an urban environment, especially mopeds, further investigation is necessary for estimating the contribution of this vehicle category to the amount of this group of unregulated pollutants in an urban atmosphere and for the development of strategies to mitigate their adverse health effects. IEA AMF Annex XXXIII / 06 A 6 Visualization and simulation of a stratified scavenge process for a 50cc two-stroke engine Dipl.-Ing. Franz Winkler, Oliver Schögl, Dipl.-Ing. Roland Oswald, Dipl.-Ing. Dr. Roland Kirchberger Institut für Verbrennungskraftmaschinen und Thermodynamik, Technische Universität Graz Tools for development of modern low emission concepts

Emission Reduction with Diesel Particle Filter with SCR Coating (SDPF)

AbstractThe present paper informs about some results obtained with selective catalytic reduction (SCR) and with SDPF (a diesel particle filter (DPF) with SCR coating) on a medium duty research engine Iveco F1C. This work is a first attempt at evaluating the effects of a SDPF on non-legislated gaseous emissions and on secondary nanoparticles. Beside the limited gaseous emission components, NH3, NO2, and N2O were measured with FTIR, and the analysis of nanoparticle emissions was performed with Scanning Mobility Particle Sizer (SMPS) and condensation particle counter (CPC). The integration of functions of filtration and NOx reduction in one element of exhaust aftertreatment system offers several advantages and is widely investigated and considered as a market solution. The most important technical statements of the research are as follows:The emission behavior of SDPF after urea switch-on (SWON) concerning NOx reduction speed and NH3 peak is always fluctuating even in identical test procedures and with careful conducted conditionings.The loaded SDPF, compared with empty one, shows slower NOx reduction and higher NH3 after SWON because of use of part of NO2 for soot oxidation and consequently less NO2 availability for the deNOx reactions; the secondary nanoparticle (NP) penetration after SWON is clearly lower with the loaded trap.Both investigated systems, SDPF and 2× SCR, attain nearly the same deNOx efficiency.In worldwide heavy duty transient cycle (WHTC) with a lower level of exhaust gas temperature, SDPF causes lower deNOx values (40–45 against 75xa0% in European transient cycle (ETC)), but also lower NH3 emissions.n Further developments of those aftertreatment systems, concerning substrates, coatings, and reduction agent control, open further potentials of improvements.

Qualitätsstandards und Prüfverfahren für Partikelfilter zur Nachrüstung von Nutzfahrzeugen

Zur Prufung von Partikelfiltern fur die Nachrustung von Dieselmotoren mussen neue Wege beschritten werden. Unter Berucksichtigung der gesundheitlichen Wirkungen der Partikel sowie der physikalischen und chemischen Eigenschaften von Partikelfiltern ergibt sich als optimale Losung die Prufung der Komponente selbst, getrennt von der Anwendung. Das gewahrleistet hochste Effizienz bei geringstem Aufwand und gestattet, Worst-case-Situationen und die Bildung von Sekundaremissionen mit zu berucksichtigen. Mit der Schweizerischen Norm SNR 277 205, die das VERT-Prufprotokoll festschreibt, wurde ein erster Schritt in dieser Richtung unternommen, wie der gemeinschaftliche Beitrag von TTM, AFHB, Matter Engineering, AirConsult, EMPA und Tecmot zeigt.