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1
EN
Testing of real driving emissions (RDE) with portable emission measuring system (PEMS) in an appropriate road circuit became an obligatory element of new type approval of passenger cars since September 2017. In several projects the Laboratory for Exhaust Emissions Control (AFHB) of the Berne University of Applied Sciences (BFH) performed comparisons on passenger cars with different PEMS’s on chassis dynamometer and on road, considering the quality and the correlations of results. Particle number measuring systems (PN PEMS) were also included in the tests. The present paper informs about influences of E85 on RDE on two flex-fuel-vehicles, discusses some aspects of different ways of evaluation with different programs, shows comparison of different types of PN PEMS and represents the effects of simulation of slope on the chassis dynamometer.
EN
Increasing the sustainability of individual transportation and replacing a part of fossil energy in traffic by renewable energy carriers are worldwide important objectives. Bioalcohols are generally recognized as one of very useful alternatives. 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, the emissions of two gasoline vehicles – with older and with newer technology – were investigated in dynamic-, stationary and cold start operation.
EN
The dynamic development of transport recorded in recent decades is an important factor in the economic development of the world on the one hand, and on the other hand, it is a significant source of nuisance and environmental problems. The adverse impact of transport can be felt both in the natural environment and in society, where the dynamic development of this sector has enabled significant civilization development, with the effects varying depending on the level of economic development, the degree of advancement and use of the various transport sectors, geographical location (including climate), and also the sensitivity of the elements of the environment. Considering contemporary transport hazards, it is important to prevent them from occurring, and when that is not possible – limiting their impact on the environment and reducing the scale and extent of negative impacts. In the article, the environmental and social nuisance of transport of goods loaded in semitrailers was analysed. The transport of semitrailers using intermodal wagons pulled by the diesel locomotive in accordance with the assumptions adopted in the railway with the maximum length of train composition was taken into account.
EN
The particle number (PN) emissions are increasingly considered in the progressing exhaust gas legislation for onand off- road vehicles. The invisible nanoparticles penetrate like a gas into the living organisms and cause several health hazards. The present paper shows how the PN- and gaseous emissions of a modern GDI (Abbreviations see at the end of this paper) vehicle change, when there is an in-creased lube oil consumption. What are the potentials of a gasoline particle filter to reduce the emissions? The lube oil consumption was simulated by mixing 2% vol. lube oil into the fuel. A non-coated GPF was mounted at tailpipe, so only the filtration effects were indicated. The tests were performed at transient (WLTC) and at stationary (SSC) operating conditions. It has been shown that the increased lube oil consumption significantly increases the PN-emissions and the applied high quality GPF eliminates these emissions very efficiently.
5
EN
The nanoparticles (NP) count concentrations are limited in EU for all Diesel passenger cars since 2013 and for gasoline cars with direct injection (GDI) since 2014. For the particle number (PN) of MPI gasoline cars there are still no legal limitations. In the present paper some results of investigations of nanoparticles from five DI and four MPI gasoline cars are represented. The measurements were performed at vehicle tailpipe and in CVS-tunnel. Moreover, five variants of “vehicle – GPF” were investigated. 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 1/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 1/km. The modern MPI vehicles also emit a considerable amount of PN, which in some cases can attain the level of Diesel exhaust gas without DPF and can pass over the actual limit value for GDI (6.0 × 1012 1/km). The GPF-technology offers in this respect further potentials to reduce the PN-emissions of traffic.
EN
In the present paper, the results and experiences of testing different PEMS on the chassis dynamometer and on-road are presented. In the first part of work the measuring systems were installed on the same vehicle (Seat Leon 1.4 TSI ST) and the results were compared on the chassis dynamometer in the standard test cycles: NEDC, WLTC and CADC. in the second part of work the nanoparticle emissions of three Diesel cars were measured with PN-PEMS. PN-PEMS showed an excellent correlations with CPC in the tests on chassis dynamometer and it indicated very well the efficiency of DPF in eliminating the nanoparticles in real world driving.
EN
Public concern and complaints regarding ambient air in zones of dense traffic pertains to two compounds of nitrogen, nitrogen dioxide (NO2) and ammonia (NH3); both are toxic and strongly irritant, such that legal limitations are under discussion. This paper contributes to measuring methods as already in part proposed by GRPE subgroup WLTP-DTP (Worldwide Light Duty Test Procedures – Diesel Test Procedures) for NO2. Despite legally lowered NOx emission levels, lumping both, NO2 and NO, levels of NO2 have risen in cities and agglomerations as a result of both, deployed catalytic exhaust after-treatment devices and low sulphur Diesel fuels. In present tests two different combinations of NO2 measuring methods as proposed by WLTP were checked on Diesel cars for practicability in handling and accuracy. These integral, indirect methods (NO2 = NOx – NO) have been found as useful tools for estimate of NO2 and with use of appropriate analyzers a satisfactory accuracy was attained. Furthermore, attention was brought to ammonia (NH3) emitted by gasoline engines with three way catalysts (TWC) which ought not to be ignored while on the other hand SCR systems for Diesel engines are strictly regulated. Emission levels of more recent TWC turned out to be mostly below 20 ppm NH3. Vehicle of older technology exhibited significantly higher levels, about 10 times more. As chemical reactions depend on pressure and temperature (= i.e. flow condition in CVS-tunnel) as well as concentrations, doubts need to be considered on accuracy of results based on chemical reactive substances. Nevertheless, clear tendencies regarding changes of concentrations of NO2 and NH3 along the path-way could not be observed.
EN
The well-balanced use of alternative fuels worldwide is an important objective for the sustainable development of individual transportation. Several countries have set 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- thanol blend fuel, have been performed in the present work according to the measuring procedures, which were established in the previous research, in the Swiss Network. The investigated fuel contained ethanol (E), in portions of 10% and 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). Since there is special concern about particle emissions of gasoline cars with direct injection, the nanoparticle counts measurements were systematically performed with Scanning Mobility Particle Sizer (SMPS) at stationary and with Condensation Particle Counter (CPC) at dynamic operation. The non-legislated gaseous emissions were tested with Fourier Transform Infrared Spectroscopy (FTIR), with special focus on NH3, N2O and HCHO (Formaldehyde). The main results to be mentioned are: • the particle counts emissions are generally significantly reduced with Ethanol blend fuels at all operating conditions, • in Worldwide Light-duty Test Cycle (WLTC) there is a clear increase of NH3 with E85 and an insignificant tendency of increasing NH3 with E10, • with all fuels (E0, E10 & E85) there are no emissions of N2O and no increase of HCHO (below 1 ppm) observed, in WLTC warm. The present research did not address the durability aspects and cold startability in extreme conditions.
EN
Alcohol-based fuels are promising substitutes for petrol-based fuels to be used in internal combustion engines. Blending of ethanol with gasoline increases the oxygen content of the fuel, allowing a more complete combustion and hence reducing the emissions of several pollutants, but it is not clear if emissions of genotoxic compounds and therefore, the genotoxic potential of an exhaust are also reduced. The gasoline direct injection technology is quickly replacing traditional port fuel injection technologies due to enhanced fuel efficiency and lower CO2 emissions. However, substantial emissions of soot-like particles have been reported in literature. In this study we compared emissions of a Euro-5 GDI vehicle (1.6 L) when operated with gasoline (EO) and two ethanol/gasoline blends (E10 and E85) under transient conditions and study the effects on particle and emissions of polycyclic aromatic hydrocarbons, including those reported to be genotoxic.
EN
Nanoparticles from a HD-Diesel engine and their composition were investigated in the present paper. Three variants of fuel additivities were applied to allow the balances of certain tracer-substances after the tests: 2% of additives-free lube oil; 2% of market lube oil with additive package and Fe-based regeneration additive (FBC) with 40 ppm Fe. The analysed SMPS particle size distributions indicated that by blending of the market lube oil to the fuel the combined effects of metals or metal oxides from the additive packages and of the heavy HC’s from the lube oil matrix contribute the most to the increase of nuclei mode. From the masses of Fe, Zn and Ca, which were introduced with the fuel, only parts were found as integral masses at all ELPI-stages – Fe 43.5%, Zn 36.6%, Ca 65.5%. The majority of mass of some metals, or metal oxides emissions on ELPI-stages (up to 80%) is in the size ranges below 100 nm.
11
Content available Nanoparticle research on four gasoline cars
EN
The invisible nanoparticles (NP) from combustion processes penetrate easily into the human body through the respiratory and olfactory ways 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 x 1012 #/km. 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 present paper, some results of investigations of nanoparticles from four gasoline cars – an older one with MPI and three never with DI – are represented. The measurements were performed at vehicle tailpipe and in CVS-tunnel. The results show that the older vehicle with MPI emits high particle count concentrations. The size distributions of this vehicle are decisively bimodal with high numbers in nuclei mode. The emissions of the newer vehicles with DI show sometimes no typical uniform shape of particle size distributions and are at lower level, than for the older vehicle. There is no visible nuclei mode and the ultrafine particle concentrations below 10 nm are insignificant. Some of the newer, low-emitting vehicles show at constant speed operation a periodical fluctuation of the NPemissions. Increased NP-emissions at cold start were confirmed.
12
Content available NOX-reduction on HD-vehicles-low cost quality check
EN
The NOx reduction of recent HD-vehicle is performed mostly by means of the selective catalytic reduction SCR. There are some manufactures 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. In the present paper the test procedures will be described and some examples of specific results will be presented. As general conclusions it can be stated: – the foundations for the quality verification procedures of SCR-systems are established, – the SCR-systems are not active at lower temperatures < 200°C, – SCR-testing on vehicle is a simple & low-cost tool for quality check, – the overall average NOx reduction rate depends on the operating profile of the vehicle – for low-load, for cold operation and for interrupted operation (HEV) there are lower NOx reduction efficiencies.
EN
BOSMAL recently hosted the 1st Workshop on Particulate Matter Emissions from Engine and Automobile Sources, entitled Current trends in measurement and control of particle emissions from engines, which featured a series of specially-selected presentations from experts on emissions of particulate matter from automotive sources, with both industry and academia represented. The workshop's technical programme consisted of one keynote address, five presentations and an expert panel discussion. In common with the emissions symposium hosted by BOSMAL somewhat earlier in the year, the Particulate Matter Workshop formed part of a series of events to commemorate BOSMAL's 40th anniversary. The event built upon and the achievements of BOSMAL's three emissions symposia hosted to date, but altered the format somewhat to cover a concrete subject in great depth. Some of the most important trends mentioned during the symposium included: problems encountered in accurately measuring particle emissions from vehicles, the particle mass and particle number metrics and the relationship between them, particle size profile and surface area and aftertreatment systems for elimination of particles (including for direct injection petrol engines).
PL
Zmniejszenie emisji związków szkodliwych i toksycznych spalin silnikowych, jak również zmniejszenie globalnej, antropogenicznej emisji CO2 są głównymi wyzwaniami dla przemysłu motoryzacyjnego, spowodowanymi czynnikami politycznymi, ekonomicznymi i technicznymi. Coraz większe znaczenie ma również ograniczanie emisji cząstek stałych (PM) obecnych w spalinach nie tylko silników o zapłonie samoczynnym (ZS), ale także o zapłonie iskrowym (ZI), szczególnie wyposażonych w układ bezpośredniego wtrysku paliwa. W ostatnim czasie zwraca się szczególną uwagę na ograniczanie emisji cząstek o małych średnicach - nanocząstek, przez wprowadzenie limitów emisji dotyczących masy emitowanych cząstek, a także ich liczby, a w przyszłości także ich powierzchni całkowitej. Instytut Badań i Rozwoju Motoryzacji BOSMAL sp. z o.o. w Bielsku-Białej był organizatorem, przy współpracy z prof. Janem Czerwińskim z Laboratorium Silników Spalinowych (AFBH) Uniwersytetu Nauk Stosowanych w Biel i dr. Andreasem Mayerem - TTM ze Szwajcarii, oraz gospodarzem pierwszego międzynarodowego spotkania specjalistów zajmujących się ograniczaniem emisji cząstek stałych w gazach spalinowych pojazdów samochodowych - 1st International Workshop on Particulate Matter Emissions from Engine and Automobile Sources, które odbyło się 2 lipca 2012 r. w Bielsku-Białej. Spotkanie to było również jedną z kilku uroczystości związanych z czterdziestoleciem Instytutu BOSMAL, który jest sukcesorem OBR SM BOSMAL w Bielsku-Białej. W pierwszym spotkaniu specjalistów PM uczestniczyli przedstawiciele 14 firm z przemysłu motoryzacyjnego i paliwowego oraz instytutów badawczych i uczelni technicznych z 7 krajów. W czasie tego spotkania był zaprezentowany referat programowy wygłoszony przez znanego światowego eksperta ds. emisji nanocząstek prof. Davida B. Kittelsona z Uniwersytetu Minnesota - USA oraz pięć innych referatów zaprezentowanych przez znanych specjalistów w tym zakresie: Manfereda Linke z AVL - Austria, dr Amandę Lea-Langton z Leeds University - Anglia, dr. Paula Zelenkę z VERT Association - Szwajcaria i prof. Jana Czerwińskiego z AFBH - Szwajcaria, a z ramienia BOSMAL referat dotyczący doświadczeń tej firmy w badaniach emisji cząstek stałych zaprezentowali dr. Piotr Bielaczyc i Joseph Woodburn. Bardzo istotna podczas tego spotkania była dyskusja panelowa, podczas której zaproszeni eksperci oraz przedstawiciele uczestniczących firm odpowiadali na pytania dotyczące podstawowych zagadnień związanych z ograniczaniem emisji cząstek stałych, przygotowane przez zespół prof. Jerzego Merkisza z Politechniki Poznańskiej, zagadnień związanych z porównaniem emisji liczby i masy cząstek stałych i metod ich pomiaru, z emisją cząstek stałych z nowoczesnych silników z bezpośrednim wtryskiem paliwa do komory spalania, możliwością pomiaru liczby cząstek o określonych średnicach, porównaniem laboratoryjnych metod pomiaru emisji cząstek z metodą pomiaru ich rzeczywistej emisji w czasie ruch pojazdu na drodze, a także prowadzili dyskusję na temat dalszych kierunków rozwoju metod pomiarowych i ograniczania emisji PM z różnych typów silników i pojazdów. Ponieważ silniki spalinowe będą przez jeszcze wiele lat podstawowym źródłem napędu różnych pojazdów i maszyn roboczych, więc ograniczanie emisji związków szkodliwych i toksycznych, do których zaliczana jest również emisja cząstek stałych, a szczególnie nanocząstek, pozostaje jednym z najważniejszych problemów do rozwiązania dla konstruktorów tych silników i pojazdów, nie tylko wyposażonych w silniki z zapłonem samoczynnym, ale także z zapłonem iskrowym, z układami bezpośredniego wtrysku benzyny do komory spalania silnika (GDI). Emisja cząstek stałych jest ograniczana przepisami prawnymi dotyczącymi maksymalnej masy emitowanych cząstek zebranych na filtrach pomiarowych podczas specjalnych cykli badawczych i dla niektórych typów silników również liczby emitowanych nanocząstek (PN). Wkrótce będzie ograniczona dla wszystkich typów silników spalinowych w ich różnych zastosowaniach. Korelacja masy (PM) i liczby (PN) cząstek stałych jest bardzo trudna. W przepisach Unii Europejskiej obie te wartości są obecnie limitowane dla silników samochodowych. Dla nowoczesnych pojazdów z silnikami ZS, wyposażonych w filtry cząstek stałych (DPF), które w dużym stopniu ograniczają emisje cząstek, właśnie pomiar ich liczby staje się podstawowym pomiarem do określenia poziomu emisji cząstek stałych silnika w odniesieniu do obowiązujących limitów. Limit maksymalnej dopuszczalnej emisji PN będzie także wyprowadzony w przepisach Euro 6-1 dla pojazdów z silnikami GDI. Trwa obecnie dyskusja nad wprowadzeniem limitowania liczby cząstek PN również w przepisach USA i Japonii.
14
EN
NO2 is much more toxic than NO. Due to the use of oxidation catalysts and catalytic coatings in the exhaust gas systems in the last decades and due to the use of low sulphur fuels the average NO2-portion in exhaust gases of vehicles increases. Diesel oxidation catalysts (DOC) and Pt-containing DPF-coatings are generally used to support the regeneration of particle filters, which can be a source of strongly increased NO2-production. The present work shows some examples and summarizes the experiences in this matter elaborated 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. In general it can be stated: 1) with a Pt-coated catalyst (DOC), or with catalytic surface filter (CSF) there is a maximum of NO2/ NOx - ratio typically in the exhaust gas temperature range around 350 °C, 2) with higher Pt-content in the coating there is a higher potential for NO2-formation, 3) lower NO2-production appears with: higher spatial velocity, higher S-content in fuel and with DOC/DPF used and/or soot loaded, 4) in some cases of semi active regeneration systems, or with the use of RME conditions with higher NO2-rates can appear.
PL
W ostatnich dziesięcioleciach w układach wylotowych silników spalinowych zastosowano reaktory utleniające z powłokami katalitycznymi oraz wprowadzono paliwa o niskiej zawartości siarki, czego wynikiem jest wzrost zawartości NO2 w gazach wylotowych silników spalinowych. NO2 jest znacznie bardziej toksycznym związkiem niż NO. Katalityczne reaktory utleniające i filtry cząstek stałych z naniesionymi powłokami zawierającymi platynę są przeważnie wykorzystywane w celu ułatwienia regeneracji filtrów cząstek stałych. W niniejszej pracy zawarto wyniki badań podsumowujące działalność badawczą Laboratoriów Silników Spalinowych i Pomiarów Emisji Spalin, prowadzoną na uniwersytecie w Biel-Bienne (Szwajcaria) w latach 2010-2012. Na podstawie wykonanych badań stwierdzono, że: 1) stosując reaktory utleniające z powłokami zawierającymi platynę lub inny materiał katalityczny maksymalna wartość proporcji NO2/NOx jest osiągana przy temperaturze gazów wylotowych wynoszącej ok. 350 °C, 2) zwiększenie zawartości platyny w powłoce katalitycznej sprzyja zwiększeniu intensywności tworzenia NO2, 3) mniejsza intensywność tworzenia NO2 następuje wraz ze zwiększeniem względnej prędkości przepływu spalin, zwiększeniem zawartości siarki w paliwie oraz dzięki zastosowaniu reaktora utleniającego/filtra cząstek stałych i/lub zapełniony filtr cząstek stałych, 4) w niektórych przypadkach regeneracji półaktywnej oraz podczas stosowania estrów metylowych kwasów tłuszczowych może nastąpić zwiększenie emisji NO2.
EN
Nanoparticle emissions of two 2-stroke scooters were investigated along the exhaust- and CVS-system (Constant Volume Sampling) with closed and with open line (cone). Due to their technology, the scooters produce different kind of aerosol (state of oxidation & SOF-content) and in addition to that they were operated with and without oxidation catalyst. The scooters represent a modern technology with direct injection TSDI* ) (two stroke direct injection) and with carburettor. The tests were performed at two constant speeds of the vehicles (20 km/h & 40 km/h) according to the measuring procedures, which were established in the previous research in the Swiss Scooter Network. The nanoparticulate emissions were measured by means of SMPS (CPC) and NanoMet (abbreviations see at the end of this paper). The most important results are: - the changes of the PSD's of the aerosol along the exhaust and CVS-system are connected to the average gas temperature and PC-concentration, which result after the different dilution steps and cooling down in the connecting pipe, - in the "open" variant of exhaust gas extraction there is a dilution step with unfiltered ambient air directly after tailpipe. This causes a stop of agglomeration, reduction of diffusion loses and increased background NPconcentration. There is also lower post oxidation of CO & HC. In some cases spontaneous condensates due to the temperature drop are supposed, - with the "closed" variant there is a stronger reduction of SMPS PC's along the gas way, than with the open variant. This is to explain with the higher temperatures and concentrations in the closed system, which enable more intense thermophoresis - and diffusion losses, - the NP-concentrations measured with "open" variant are always higher, - most intense oxidation is observed with Peugeot Carb: due to the SAS, rich tuning and a relatively high temperature level there are oxidation effects already without catalyst (temp. approx. 350 centigrade). With catalyst the temperature is in the range of 400centigrade and the oxidation is so intense, that the particles are nearly eliminated. The type of sampling: "open", or "closed" as well as the sampling position in the exhaust installation have significant influence on the measured nanoparticles emission results.
16
Content available remote Influences on NO2-emissions from DPF’s with passive regeneration
EN
NO2 is much more toxic than NO. Due to the use of oxidation catalysts and catalytic coatings in the exhaust gas systems in the last decades and due to the use of low sulphur fuels the average NO2 – portion in exhaust gases of vehicles increases. Diesel oxidation catalysts (DOC) and Pt – containing DPF-coatings are generally used to support the regeneration of particle filters, which can be a source of strongly increased NO2 – production. The present paper shows some examples and summarizes the experiences in this matter elaborated 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. In general it can be stated: with a Pt – coated catalyst (DOC), or with catalytic surface filter (CSF) there is a maximum of NO2/NOx – ratio typically in the exhaust gas temperature range around 350°C, with higher Pt – content in the coating there is a higher potential for NO2 – formation, lower NO2 – production appears with: higher spatial velocity, higher S-content in fuel and with DOC/DPF used and/or soot loaded.
PL
NO2 jest znacznie bardziej toksyczne niż NO. Na skutek stosowania w ostatnim czasie katalizatorów utleniających i powłok katalitycznych w układach wydechowych, a także na skutek stosowania paliw o niskiej zawartości siarki, średnia ilość NO2 w spalinach pojazdów wzrasta. Katalizatory utleniające dieslowskie (DOC) i powłoki DPF zawierające Pt są zwykle stosowane wspomagająco w regeneracji filtrów cząstek, co może być źródłem silnego wzrostu NO2. W niniejszej pracy przedstawiono kilka przykładów i podsumowano badania doświadczalne przeprowadzone przy zastosowaniu dynamometrów silnikowych, w Laboratoriach dla IC-Engines & Exhaust Emissions Control (AFHB) Uniwersytetu Nauk Stosowanych Biel-Bienne, w Szwajcarii, w latach 2010–2012. Ogólnie można stwierdzić: – Przy katalizatorze (DOC) powlekanym platyną, lub przy filtrze (CSF) o powierzchni katalitycznej, maksymalny współczynnik NO2/NOx występuje zazwyczaj przy temperaturze spalin ok. 350°, – Przy wyższej zawartości Pt w powłoce, możliwość powstawania NO2 jest większa, – Mniejsze wytwarzanie NO2 występuje przy: wyższej prędkości przestrzennej, wyższej zawartości S w paliwie i przy zastosowaniu DOC/DPF i/lub obciążeniu sadzą.
EN
The fatty acid methyl esters (FAME's) - in Europe mostly RME *) (Rapeseed methyl ester; Abbreviations see at the end of this paper) - are used in several countries as alternative biogenic Diesel fuels in various blending ratios with fossil fuels (Bxx). Questions arise often about the influences of these biocomponents on the modern exhaust after-treatment 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, - active regenerations: standstill burner; fuel injections & DOC. During each regeneration on-line measurements of limited and unlimited emission components (nanoparticles & FTIR) was conducted. It can be stated that the increased portion of RME in fuel provokes longer time periods to charge the filter with soot. This is due to the lower PM-emissions of the engine, as well as to the higher reactivity and higher SOF-portion of the particle mass from RME. With the passive regeneration system with stronger catalytic activity (DOC + CSF) there is a stronger NO2-production with B100 and due to the NO2-supported oxidation of PM the balance point temperature is approx. 20 centigrade lower, than with B0. For the active regenerations the time courses of emissions and temperatures are closely connected with the chosen regeneration strategy - switching, timing and intensity (of burner, or fuel aerosol generator). A higher portion of biocomponent causes usually a stronger break-down of the instantaneous DPF filtration efficiency during the regeneration procedure - this is an effect of stronger artifact of spontaneous condensation after DPF. In summary there is no negative short term effect of bio-blended-fuels on the investigated regeneration procedures. Some recommendations for a successful long term operation, basing on other works and literature are given at the end of the paper.
EN
A new approach is needed to test particle filters for retrofitting Diesel engines. Considering the toxicity of the particles as also the physical and chemical attributes of particle filters, the optimal scheme is to test the components themselves independent of the deployment. That scheme ensures the highest effectiveness with least effort. It also enables evaluation of worst-case situations and assesses the hazards of secondary emissions. The Swiss standard SNR 277 205, which mandates the VERT test procedure, is a first step in that direction. The solution is derived from the physics of the filter media. The filtration of fine particles essentially depends on the particle size and the space velocity. The attributes of the emitting engine are only insignificantly relevant. Hence the physics and chemistry of particle filters can be investigated independent of the engine and its deployment duty. This concept facilitates a very thorough investigation of the size-dependent filtration, aging susceptibility, secondary emissions and extreme situations. Filter systems, which pass this detailed test, perform equally well in every retrofit configuration. This filter test concept was implemented 1998 in the VERT project and is successful for assessing retrofltting [4]. VERT approved fllter systems are already deployed in the Low Emission Zones of Europe, North and South America.
EN
In order to analyze the processes during the gas exchange in the engine, knowledge of pressure states in both inlet and outlet is required. This pressure measuring is known as "low pressure indication ". In the presented work, three examples of controlling the quality of low pressure measurement are presented. The projects performed during the collaboration with Kistler showed the high demands regarding accuracy, dimensions and lifetime of measuring chains and piezoresistive sensors for low pressure measurement. To gain reliable resultsfor use in simulation tools for calculating and modeling gas exchange phase the sensor and measuring chain must be designed in order to consider all possible influences on the signal such as thermal and mechanical stress, electrical parasitic induction and gas dynamic effects. The increasing demand regarding accuracy and low thermal drift for highly dynamic measurements and the restricted space available in most applications are further challenges. It was shown that: a small inaccuracy of measurement, lower than 10 mbar can be attained, the asymmetric course of the exhaust pulse can clearly be verified, and a protection screen for a sensor exposed to the exhaust blow-off pressure wave can be a tool to optimize between longlife and accuracy.
EN
The Oppenheim Correlation (OPC) is an empirical algorithm, which allows a simple estimate of heat losses to the wall during the combustion in IC-engine. In present paper the results ofdifferent applications of OPC will be shown. Even if there are still several needs and ideas for further research it can be stated, that the OPC is a promising possibility of modelling the wali heat losses and due to its simplicity it has to be recommended to the engine community. The OPC can be used not only for didactics purposes, but also for quick simulation of wall heat losses and eventuałły for the on-line regulation of the cooling system. In particular basic milestones of calculation of the working cycle, modelling of heat losses according to Oppenheim (OPC), engines and test procedure, examples of the OPC-application are presented in the paper. The OPC can be recommended to the engine community as a good alternative of modelling and calculation of the heat losses trough the combustion chamber wall.
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