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Technical Paper

Considerations of Periodical Technical Inspection of Vehicles with deNOx Systems

2019-04-02
2019-01-0744
An independent periodical technical inspection (PTI)*) of vehicles is proposed in the last time as a better prevention against increased emissions of the fleet. Several projects focused on the Diesel vehicles (HD & LD) and on the functionality of the exhaust aftertreatment systems as a key element for lowering emissions of a vehicle or machine. The present paper summarizes the results obtained on 3 modern passenger cars Euro 6b (with EGR, DOC, DPF & SCR) during load jumps, representing the heat-up or cool-down behaviour of the exhaust system. The portable devices for PTI were tested together with the stationary measuring systems of the engine laboratory. In the second part of the report, the present knowledge and proposals of supplementary test procedures (like IUC or PTI) were shortly described.
Technical Paper

Influences of Butanol Blends on Combustion and Emissions of a Small SI Engine

2018-10-30
2018-32-0058
In the general efforts to replace the fossil fuels in transportation by renewable fuels the bioalcohols are an important alternative. The global share of Bioethanol used for transportation is continuously increasing. Butanol, a four-carbon alcohol, is considered in the last years as an interesting alternative fuel, both for Diesel and for Gasoline application. Its advantages for engine operation are: good miscibility with gasoline and diesel fuels, higher calorific value than Ethanol, lower hygroscopicity, lower corrosivity and possibility of replacing aviation fuels. In the present work research with different nButanol portions in gasoline (BuXX)* was performed on the 2-cylinder SI engine with variations of several parameters on engine dynamometer. At different steady state operating points were varied: spark timing (αz), air excess factor (λ) and EGR-rate. Furthermore, the conversion rates and light-off of a 3-way-catalyst were investigated.
Technical Paper

PN-Emissions of Gasoline Cars MPI and Potentials of GPF

2018-04-03
2018-01-0363
Further efforts to reduce the air pollution from traffic are undertaken worldwide and the filtration of exhaust gas will also be increasingly applied on gasoline cars (GPF1 … gasoline particle filter). In the present paper, some results of investigations of nanoparticles from four MPI gasoline cars are represented. The measurements were performed at vehicle tailpipe and in CVS-tunnel. Moreover, two variants of GPF were investigated on a high-emitting modern vehicle, including analytics of PAH and attempts of soot loading in road application. The modern MPI vehicles can emit a considerable amount of PN, which in some cases attains the level of Diesel exhaust gas without DPF and can pass over the actual European limit value for GDI (6.0 x 1011 #/km). The GPF-technology offers in this respect further poten-tials to reduce the PN-emissions of traffic.
Technical Paper

Experimental Investigation of Fuel Injection and Spark Timing for the Combustion of n-Butanol and iso-Butanol and Their Blends with Gasoline in a Two-Cylinder SI Engine

2017-09-04
2017-24-0115
In this study, the combustion of butanol, neat and mixed with gasoline, was investigated on a 0.6 liter two-cylinder spark ignition engine with fully adjustable fuel injection and spark timing, coupled with an eddy current dynamometer. Two isomers of butanol, n-butanol and iso-butanol, were examined. This basic parameter study gives information about potential requirements of engine control systems for butanol FFV. Compared to the traditionally used ethanol, butanol does not exhibit hygroscopic behaviour, is chemically less aggressive and has higher energy density. On other hand, different laminar burning velocity and higher boiling temperature of butanol, compared to gasoline, requires some countermeasures to keep the engine operation reliable and efficient.
Technical Paper

Nanoparticle Emissions of DI Gasoline Cars with/without GPF

2017-03-28
2017-01-1004
In the present paper some results of investigations of nanoparticles from five DI gasoline cars are represented. The measurements were performed at vehicle tailpipe and in CVS-tunnel. Moreover, five variants of “vehicle - GPF” were investigated. These results originate from the project GasOMeP (Gasoline Organic & Metal Particulates), which focused on metal-nanoparticles (including sub 20nm) from gasoline cars with different engine technologies. The PN-emission level of the investigated GDI cars in WLTC without GPF is in the same range of magnitude very near to the actual limit value of 6.0 × 1012 #/km. With the GPF’s with better filtration quality, it is possible to lower the emissions below the future limit value of 6.0 × 1011 #/km. There is no visible nuclei mode and the ultrafine particle concentrations below 10mm are insignificant. Some of the vehicles show at constant speed operation a periodical fluctuation of the NP-emissions, as an effect of the electronic control.
Technical Paper

Effects of Ethanol Blend Fuels E10 and E85 on the Non-Legislated Emissions of a Flex Fuel Passenger Car

2016-04-05
2016-01-0977
A well-balanced use of alternative fuels worldwide is an important objective for a sustainable development of individual transportation. Several countries have objectives to substitute a part of the energy of traffic by ethanol as the renewable energy source. The global share of Bioethanol used for transportation is continuously increasing. Investigations of limited and unregulated emissions of a flex fuel vehicle with gasoline-ethanol blend fuel have been performed in the present work on the chassis dynamometer according to the measuring procedures, which were established in the previous research in the Swiss Network to adequately consider the transient (WLTC) and the stationary operation (SSC). The investigated fuel contained ethanol (E), in the portions of 10% & 85% by volume. The investigated vehicle represented a newer state of technology and an emission level of Euro 5. The engine works with homogenous GDI concept and with 3-W-catalyst (3WC).
Technical Paper

Investigations of NO2 in Legal Test Procedure for Diesel Passenger Cars

2015-09-06
2015-24-2510
As a result of increased use of catalytic exhaust aftertreatment systems of vehicles and the low-sulfur Diesel fuels there is an increasing share of nitrogen dioxide NO2 in the ambient air of several cities. This is in spite of lowering the summary nitric oxides NOx emissions from vehicles. NO2 is much more toxic than nitrogen monoxide NO and it will be specially considered in the next legal testing procedures. There are doubts about the accuracy of analyzing the reactive substances from diluted gas and this project has the objective to show how NO2 is changing as it travels down through the exhaust- and the CVS systems. For legal measurements of NO2 a WLTP-DTP subgroup (Worldwide Light Duty Test Procedures - Diesel Test Procedures) proposed different combinations of NOx-analyzers and analysis of NO and NOx. Some of these set-ups were tested in this work.
Technical Paper

Experiences from Nanoparticle Research on Four Gasoline Cars

2015-04-14
2015-01-1079
The invisible nanoparticles (NP)*) from combustion processes penetrate easily into the human body through the respiratory and olfactory pathways and carry numerous harmful health effects potentials. NP count concentrations are limited in EU for Diesel passenger cars since 2013 and for gasoline cars with direct injection (GDI) since 2014. The limit for GDI was temporary extended to 6 × 1012 #/km, (regulation No. 459/2012/EU). Nuclei of metals as well as organics are suspected to significantly contribute especially to the ultrafine particle size fractions, and thus to the particle number concentration. In the project GasOMeP (Gasoline Organic & Metal Particulates) metal-nanoparticles (including sub 20nm) from gasoline cars are investigated for different engine technologies. In the present paper some results of investigations of nanoparticles from four gasoline cars - an older one with MPI and three newer with DI - are represented.
Technical Paper

Investigations of SDPF -Diesel Particle Filter with SCR Coating for HD-Applications

2015-04-14
2015-01-1023
Diesel exhaust gas aftertreatment systems, which include the selective catalytic reduction (SCR)*) for reduction of NOx are necessary to fulfil the latest legal requirements and are extensively used in the heavy duty (HD) sector. The present paper informs about some results obtained with SCR and with SDPF (a DPF with SCR-coating) on a medium duty research engine Iveco F1C. Beside the limited gaseous emission components NH3, NO2 and N2O were measured. The analysis of nanoparticle emissions was performed with SMPS and 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.
Technical Paper

Particle Emissions of Modern Handheld Machines

2014-11-11
2014-32-0036
The progressing exhaust gas legislation for on- and off-road vehicles includes gradually the nanoparticle count limits. The invisible nanoparticles from different emission sources penetrate like a gas into the living organisms and may cause several health hazards. The present paper shows some results of a modern chain saw with & without oxidation catalyst, with Alkylate fuel and with different lube oils. The measurements focused specially on particulate emissions. Particulates were analysed by means of gravimetry (PM) and granulometry SMPS (PN). In this way the reduction potentials with application of the best materials (fuel, lube oil, ox-cat.) were indicated. It has been shown that the particle mass (PM) and the particle numbers (PN), which both consisting almost exclusively of unburned lube-oil, can attain quite high values, but can be influenced by the lube oil quality and can be considerably reduced with an oxidation catalyst.
Technical Paper

VERTdePN Quality Test Procedures of DPF+SCR Systems

2014-04-01
2014-01-1579
The combined exhaust gas aftertreatment systems (DPF+SCR) are the most efficient way and the best available technology (BAT) to radically reduce the critical Diesel emission components particles (PM&NP) and nitric oxides (NOx). SCR (selective catalytic reduction) is regarded as the most efficient deNOx-system, diesel particle filters are most efficient for soot abatement. Today, several suppliers offer combined systems for retrofitting of HD vehicles. Quality standards for those quite complex systems and especially for retrofit systems are needed to enable decisions of several authorities and to estimate the potentials of improvements of the air quality in highly populated agglomerations. The present paper informs about the VERTdePN *) quality test procedures, which were developed in an international network project with the same name 2007-2011 (VERT … Verification of Emission Reduction Technologies; dePN … decontamination, disposal of PM / NP and of NOx).
Technical Paper

Testing of SCR-Systems on HD-Vehicles-TeVeNOx

2014-04-01
2014-01-1569
The selective catalytic reduction SCR is extensively used for NOx reduction of recent HD-vehicles. There are some manufacturers and some applications of SCR as retrofit systems (mostly for the low emission zones LEZ and in combination with a DPF). In charge of Swiss authorities AFHB investigated several SCR-systems, or (DPF+SCR)-systems on HD-vehicles and proposed a simplified quality test procedure of those systems. This procedure can especially be useful for the admission of retrofit systems but it can also be helpful for the quality check of OEM-systems. The project name was TeVeNOx - Testing of Vehicles with NOx reduction systems. In the present paper the test procedures will be described and some specific results will be discussed.
Technical Paper

Investigations of Changes of the 2-Stroke Scooters Nanoparticles in the Exhaust- and CVS-System

2013-09-08
2013-24-0178
Nanoparticle emissions of two 2-stroke scooters were investigated along the exhaust and the CVS (Constant Volume Sampling) systems. Two configurations were tested: regular full-flow dilution configuration (denoted as “closed”) and also a modified sampling configuration (denoted as “open”). The scooters represent two distinct modern technologies. One scooter had direct injection TSDI*) (Two-Stroke Direct Injection). The other had a carburettor. Depending on the technology, the scooters produce different kind of aerosols (state-of-oxidation and SOF content). Moreover, the scooters were operated with and without oxidation catalyst. The tests were performed at two constant vehicular speeds (20 km/h and 40 km/h). The measuring procedures are those established during the previous research of the Swiss Scooter Network. The nanoparticulate emissions were measured using SMPS (Scanning Mobility Particle Sizer) and DC (Diffusion Charging) sensors.
Technical Paper

Diesel Emissions with DPF & SCR and Toxic Potentials with BioDiesel (RME) Blend Fuels

2013-04-08
2013-01-0523
The use of alternative fuels and among them the biofuels of 1st generation - fatty acid methyl esters FAME's and pure plants oils - for propulsion of IC engines is an important objective in several countries in order to save the fossil fuels and to limit the CO₂ production. The properties of bio-fuels and bio-blend-fuels can vary and this has an impact on the operation and emissions of diesel engines and on the modern exhaust aftertreatment systems. The present paper represents the most important results obtained with RME at AFHB, EMPA and EC-JRC. Most of the activities were performed in the network project BioExDi (Biofuels, Exhaust Systems Diesel) in collaboration between industry and research institutes.
Technical Paper

NO2-Formation in Diesel Particle Filter Systems

2013-04-08
2013-01-0526
NO₂ is much more toxic than NO. The average proportion of NO₂ in exhaust gases of vehicles increases significantly due to the use of oxidation catalysts and catalytic coatings in the exhaust gas systems during the last decades combined with generalization of using low sulfur fuels. Diesel oxidation catalysts (DOC) and Pt-containing DPF coatings are widely used to support the regeneration of particle filters, being a source of strongly increased production of NO₂. The present work shows some examples and summarizes the experiences in this matter performed at the Laboratories for IC-Engines & Exhaust Emissions Control (AFHB) of the University of Applied Sciences Biel-Bienne, Switzerland, during some research activities on engine dynamometers in the years 2010-2012.
Technical Paper

DPF's Regeneration Procedures and Emissions with RME Blend Fuels

2012-04-16
2012-01-0844
The fatty acid methyl esters (FAME's) - in Europe mostly RME (Rapeseed methyl ester) - are used in several countries as alternative biogene diesel fuels in various blending ratios with fossil fuels (Bxx). Questions often arise about the influences of these biocomponents on the modern exhaust aftertreatment systems and especially on the regeneration of diesel particle filters (DPF). In the present work different regeneration procedures of DPF systems were investigated with biofuels B0, B20 & B100. The tested regeneration procedures were: - passive regenerations: DOC + CSF; CSF alone, and - active regenerations: standstill burner; fuel injections & DOC. During each regeneration on-line measurements of regulated and unregulated emission components (nanoparticles & FTIR) were conducted. It can be stated that the increased portion of RME in fuel provokes longer time periods to charge the filter with soot.
Technical Paper

Metal Oxide Particle Emissions from Diesel and Petrol Engines

2012-04-16
2012-01-0841
All internal combustion piston engines emit solid nanoparticles. Some are soot particles resulting from incomplete combustion of fuels, or lube oil. Some particles are metal compounds, most probably metal oxides. A major source of metal compound particles is engine abrasion. The lube oil transports these abraded particles into the combustion zone. There they are partially vaporized and ultrafine oxide particles formed through nucleation [1]. Other sources are the metallic additives to the lube oil, metallic additives in the fuel, and debris from the catalytic coatings in the exhaust-gas emission control devices. The formation process results in extremely fine particles, typically smaller than 50 nm. Thus they intrude through the alveolar membranes directly into the human organism. The consequent health risk necessitates a careful investigation of these emissions and effective curtailment.
Technical Paper

Influences of Different Exhaust Filter Configurations on Emissions of a 2-Stroke Scooter Peugeot TSDI

2011-09-11
2011-24-0203
Exhaust emissions measurements of a small 2-S Scooter Peugeot TSDI*), 50cc with different particle filters have been performed in this present work according to the measuring procedures, which were established in the previous research in the Swiss Scooter Network, [1, 2, 3, 4, 5, 6, 7, 8, 9]. The investigated particle filtration materials were supplied from different manufacturers as samples without specifications and they were applied by the research laboratory in a special muffler able to be taken apart. The investigated scooter represented a modern (2002) 2-stroke technology with direct injection, with oxidation catalyst and with injection of the lube oil to the intake air. Since there is a special concern about the particle emissions of the small engines, the particle mass and nanoparticle measurements were systematically carried out. The nanoparticulate emissions were measured by means of SMPS (CPC) and NanoMet*).
Technical Paper

Comparative Studies of Particles Deposited in Diesel Particulate Filters Operating with Biofuel, Diesel Fuel and Fuel Blends

2011-09-11
2011-24-0102
Macroscopic studies and scanning electron microscope (SEM), as well as transmission electron microscope (TEM) research were carried out to investigate the nature and properties of particulate matter (PM) deposited in three diesel particulate filters (DPFs) operating with different fuels: 100% rapeseed methyl ester (RME100), a blend of 20% RME and 80% diesel (RME20), as well as 100% diesel (RME0). The DPFs were catalytically coated with V₂O₅/TiO₂. The PM deposits were either extracted from sectioned DPFs or studied "in situ," as deposited. In the RME100-DPF, the lowest soot and highest ash depositions are found. The higher amount of ash in RME100-DPF, as well as the higher participation of the element Ca in the ash from this filter, indicates that in addition to lubricating oil, the RME fuel contributes also to ash formation. Ash is found accumulating in the plugged inlet channels only in RME100 and as a few tens of μm-thick layer on the channel walls of all three filters.
Technical Paper

Diesel Emission with DPF+SCR in VERTdePN - Testing & Potentials

2011-04-12
2011-01-1139
The most efficient way and the best available technology (BAT) to radically reduce the critical diesel emission components particles (PM&NP) and nitric oxides (NOx) are combined exhaust gas aftertreatment systems (DPF+SCR). SCR (selective catalytic reduction) is regarded as the most efficient deNOx-system, diesel particle filters are most efficient for soot abatement. Today, several suppliers offer combined systems for retrofitting of HD vehicles. The presented results are part of the work in the international network project VERT *) dePN (de-activation, de-contamination, disposal of particles and NOx), which has the objectives to establish test procedures and quality standards and to introduce the SCR-, or combined DPF+SCR-systems in the VERT verification procedure.
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