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A New Miniaturized Sensor for Ultra-Fast On-Board Soot Concentration Measurements

SAE International Journal of Engines

Aristotle University of Thessaloniki-Zissis C. Samaras
Finnish Meteorological Institute-Risto Hillamo
  • Journal Article
  • 2017-01-1008
Published 2017-03-28 by SAE International in United States
In this article we present a design of a new miniaturized sensor with the capacity to measure exhaust particle concentrations on board vehicles and engines. The sensor is characterized by ultra-fast response time, high sensitivity, and a wide dynamic range. In addition, the physical dimensions of the sensor enable its placement along the exhaust line. The concentration response and temporal performance of a prototype sensor are discussed and characterized with aerosol laboratory test measurements. The sensor performance was also tested with actual engine exhaust in both chassis and engine dynamometer measurements. These measurements demonstrate that the sensor has the potential to meet and even exceed any requirements around the world in terms of on-board diagnostic (OBD) sensitivity and frequency of monitoring. Further to potential OBD applications, this has the capacity to be used as an engine and combustion diagnostics sensor, for example to detect misfiring, cylinder combustion variability, exhaust gas recirculation flowrate, etc.
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Effect of Injection Parameters on Exhaust Gaseous and Nucleation Mode Particle Emissions of a Tier 4i Nonroad Diesel Engine

Metropolia Univ of Applied Sciences-Liisa Pirjola
Tampere Univ of Technology-Topi Rönkkö, Panu Karjalainen, Jorma Keskinen, Heino Kuuluvainen
Published 2013-10-14 by SAE International in United States
During the past few decades the exhaust emissions of diesel engines have significantly decreased due to efficient emissions regulation. Compared to the situation in the 1990s, the nitrogen oxide (NOx) and particulate matter (PM) emissions, the main challenges for diesel engines, are now reduced 80-95 % in many industrialized countries. To meet the demanding requirements, engine technologies have been updated and improved step by step. These improvements have also kept Specific Fuel Consumption (SFC) figures at a low level or they have even improved. The latter issue is of great significance for consumers (cost) and also for the environment (CO2).Nowadays many diesel engine fuel injection strategies rely on the use of exhaust after-treatment systems. Efficient and clean combustion is obtained by utilizing high injection pressure and advanced injection timing. The resulting high engine-out NOx is reduced to the target level by using an efficient NOx after-treatment system, possibly supported by an EGR system. In several applications no particulate filter is necessarily yet required for a nonroad engine to meet its emission limits. However, according to…
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The Effect of a Particle Oxidation Catalyst (POC®) on Particle Emissions of a GDI Car during Transient Engine Operation

Aristotle University of Thessaloniki-Theodoros Tzamkiozis
Ecocat Oy-Matti Happonen, Pekka Matilainen, Kauko Kanniainen, Toni Kinnunen
Published 2013-04-08 by SAE International in United States
Particle emissions have been generally associated to diesel engines. However, spark-ignition direct injection (SI-DI) engines have been observed to produce notable amounts of particulate matter as well. The upcoming Euro 6 legislation for passenger cars (effective in 2014, stricter limit in 2017) will further limit the particulate emissions from SI engines by introducing a particle number emission (PN) limit, and it is not probable that the SI-DI engines are able to meet this limit without resorting to additional aftertreatment systems.In this study, the solid particle emissions of a SI-DI passenger car with and without an installed Particle Oxidation Catalyst (POC®) were studied over the New European Driving Cycle (NEDC) on a chassis dynamometer and over real transient acceleration situations on road. It was observed that a considerable portion of particle number emissions occurred during the transient acceleration phases of the cycle. The application of the POC resulted in a reduction of those emission peaks and, as a conclusion, the car was able to meet the 2017 Euro 6 particle number emission limit with the POC.The…
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Reduction of Heavy-Duty Diesel Exhaust Particle Number and Mass at Low Exhaust Temperature Driving by the DOC and the SCR

SAE International Journal of Fuels and Lubricants

Finnish Meteorological Institute-Sanna Saarikoski, Minna Aurela, Risto Hillamo
Metropolia Univ of Applied Sciences-Aleksi Malinen, Liisa Pirjola
  • Journal Article
  • 2012-01-1664
Published 2012-09-10 by SAE International in United States
The effect of SCR on nanoparticle emissions has been a subject for some recent diesel particle emission related studies. In this study, the effect of after-treatment (DOC and SCR) on particle emissions was studied with a heavy-duty off-road diesel engine (emission level stage 3b with an SCR). A special “transient cold test cycle” (TCTC) was designed to describe the SCR system operation at low exhaust gas temperatures. The particle instrumentation made it possible to measure on-line the particle number concentration, particle size distribution and chemical composition of particles. The largest particle number concentrations were measured after the exhaust manifold. The exhaust after-treatment was observed to reduce the total particle number concentration by 82.5% with the DOC and 95.7% with the DOC+SCR. Also the mean particle composition was affected by the after-treatment; while the organics formed the main fraction of the particulate mass without exhaust after-treatment, after the DOC and especially after the DOC+SCR the organic particulate matter was reduced so that most significant particle fraction was soot. The effect of after-treatment was similar both on…
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Performance of Particle Oxidation Catalyst and Particle Formation Studies with Sulphur Containing Fuels

SAE International Journal of Fuels and Lubricants

BOSMAL Automotive R&D Institute-Piotr Bielaczyc, Jakub Dzida, Rafal Sala
Ecocat Oy-Toni Kinnunen, Pekka Matilainen
  • Journal Article
  • 2012-01-0366
Published 2012-04-16 by SAE International in United States
The aim of this paper is to analyze the quantitative impact of fuel sulfur content on particulate oxidation catalyst (POC) functionality, focusing on soot emission reduction and the ability to regenerate. Studies were conducted on fuels containing three different levels of sulfur, covering the range of 6 to 340 parts per million, for a light-duty application. The data presented in this paper provide further insights into the specific issues associated with usage of a POC with fuels of higher sulfur content. A 48-hour loading phase was performed for each fuel, during which filter smoke number, temperature and back-pressure were all observed to vary depending on the fuel sulfur level. The Fuel Sulfur Content (FSC) affected also soot particle size distributions (particle number and size) so that with FSC 6 ppm the soot particle concentration was lower than with FSC 65 and 340, both upstream and downstream of the POC. Conversely, FSC did not have major effects on the soot particle number reduction efficiency of the POC. Soot and other exhaust compounds accumulated within the POC…
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Effect of Exhaust Flow Conditions and External Cooling on the Performance of the Particle Oxidation Catalyst (POC)

Ecocat Oy-Kati Lehtoranta, Pekka Matilainen, Toni Kinnunen
Tampere Univ of Technology-Panu Karjalainen, Juha Heikkila, Topi Ronkko, Jorma Keskinen
Published 2010-10-25 by SAE International in United States
Under on-road driving conditions, the engine load and speed and the cooling effect of ambient air may affect the functioning of exhaust aftertreatment devices. In this paper, we studied the effects of these parameters on the functioning of the combination of a Diesel Oxidation Catalyst and a Particle Oxidation Catalyst (DOC+POC). In the engine tests, the engine load and speed were observed to affect the nonvolatile particle reduction efficiency curve of the DOC+POC; while the nonvolatile core particle (Dp ≺ 15 nm) reduction was high (97-99%) in all the engine test modes, the reduction of soot varied from 57% at low load to 70% at high load. Because the change in engine load and speed affected both the exhaust temperature and flow velocity, the effects of these parameters were measured separately in an aerosol laboratory. Results indicated that compared to the exhaust temperature, the exhaust flow velocity had a more significant role from the viewpoint of the nonvolatile particle reduction efficiency of the DOC+POC system. At three engine test modes, the external cooling did not…
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Particle oxidation catalyst in light duty and heavy duty diesel applications

Ecocat Oy-Kati Lehtoranta, Pekka Matilainen, Juha-Matti Åsenbrygg, Ari Lievonen, Toni-JJ Kinnunen
Tampere University of Technology, Aerosol Physics Laboratory-Jorma Keskinen
Published 2007-09-16 by Consiglio Nazionale delle Ricerche in Italy
The effect of a novel particle oxidation catalyst (POC®) on diesel particle emissions is studied in heavy duty and light duty applications. Regulated particulate matter (PM) emission measurement is followed by analyzing either soluble organic fraction (SOF) or volatile organic (VOF) fraction. In addition, in heavy duty diesel application, size distributions are measured. Results show that PM reductions as high as 48-79% can be achieved when using POC in combination with a conventional diesel oxidation catalyst (DOC). As expected, the volatile fraction of the PM was very effectively reduced, but also the non-volatile fraction (i.e. soot) was reduced. In tested steady state driving modes soot reduction was found to be 31-55%.
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Performance Evaluation of a Novel Sampling and Measurement System for Exhaust Particle Characterization

Dekati Ltd.-Pirita Mikkanen
Ford Forschungszentrum Aachen-Roberto Casati, Volker Scheer, Rainer Vogt
Published 2004-03-08 by SAE International in United States
This paper presents a novel partial flow sampling system for the characterization of airborne exhaust particle emissions. The sampled aerosol is first conditioned in a porous dilutor and then subsequent ejector dilutors are used to decrease its concentration to the range of the instrumentation used. First we examine the sensitivity of aerosol properties to boundary sampling conditions. This information is then used to select suitable sampling parameters to distinguish both the nucleation and the accumulation mode. Selecting appropriate sampling parameters, it is demonstrated that a distinct nucleation mode can be formed and measured with different instruments. Using these parameters we examine the performance of the system over transient vehicle operation. Additionally, we performed calculations of particle losses in the various components of the system which are then used to correct signals from the instruments. Several quality characteristics are then discussed, such as the repeatability and reproducibility of the measurements and the potential to derive total emission rate with a partial flow sampling system. Comparisons in different laboratories show that repeatability (intra-laboratory variability) is in the…
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Effective Density of Diesel Exhaust Particles as a Function of Size

Tampere Univeristy of Technology, Institute of Physics-Annele Virtanen, Jyrki Ristimäki, Marko Marjamäki, Kati Vaaraslahti, Jorma Keskinen
VTT Energy-Maija Lappi
Published 2002-03-04 by SAE International in United States
New method to define the particle effective density as a function of particle size has been applied to diesel vehicle exhaust particles. The results show that, the effective density of agglomerated diesel particles decreases as a function of particle size. The density of primary particles varies from 1.1 to 1.2 g/cm3. Also the effect of used dilution method and fuel type on particle density was studied. The dilution effect seems to have stronger effect on particle effective density and structure than the fuel type.
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Electrical Filter Stage for the ELPI

Dekati Ltd.-Mikko Moisio, Marko Palonen
Tampere University of Technology. Institute of Physics-Marko Marjamäki, Leonidas Ntziachristos, Annele Virtanen, Jyrki Ristimäki, Jorma Keskinen
Published 2002-03-04 by SAE International in United States
Electrical low pressure impactor ELPI was modified to measure particles below 30 nanometers in aerodynamic diameter. This was accomplished by adding a filter stage to collect and measure nanoparticles. The charging unit of the instrument was modified to increase the charging efficiency of the smallest, nanometer sized, particles. The modified charging unit was calibrated and the new construction of the ELPI was tested in laboratory and in vehicle dynamometer test cell. Measurements performed in the engine test cell showed that modifications improve the size range and measurement capability of the ELPI for engine emissions.
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