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Viewing 1 to 30 of 15151
2015-09-29
Technical Paper
2015-01-2880
Fabio Luz Almeida, Philip Zoldak, Marcos de Mattos Pimenta, Pedro Teixeira Lacava
The use of numerical simulations in the development processes of engineering products has been more frequent, since it enables us to predict premature failures and to study new promising and valuable concepts. In industry, numerical simulation usually has the function of reducing the necessary number of validation tests before spending huge amount of resources on alternatives with less chance to succeed. In the context of an economically committed country, the matter of cargo transportation is of great importance, since it affects the trading of consumer goods between cities, states and their flow towards exportation. Thus, the internal combustion (ICE) Diesel cycle engines play an important role in Brazil, since they are extensively used in automotive applications and commercial cargo transportation, mainly due to their relevant advantage in fuel consumption and reliability.
2015-09-29
Technical Paper
2015-01-2889
R. Saravana Venkatesh, Sunil Pandey, Sathyanandan Mahadevan
In heavy duty diesel engines, Exhaust Gas Recirculation (EGR) is often preferred choice to contain NOx emissions. Critical to such EGR fitted engines is the design of air intake pipe and intake manifold combination in view of proper EGR gas mixing with intake air. The variation in EGR mass fraction at each intake ports should be as minimal as possible and this variation must be contained within +/- 10% band to have a minimal cylinder to cylinder variation of pollutants. EGR homogeneity for various intake configurations were studied using 3D CFD for a 4 cylinder 3.8 L diesel fuel, common rail system, turbocharged and intercooled heavy duty engine. Flow field was studied in the computational domain from the point before EGR mixing till all the four intake ports. EGR mass fraction variation at each intake port was calculated from this analysis after carrying out an experimental validation of the CFD model.
2015-09-29
Journal Article
2015-01-2803
Anuj Kumar, Valentin Rougé, Nathalie Luu, Steven Yu, Valerie Bossoutrot, Steve Hagen, Tracey Jacksier
Abstract The Flame Ionization Detection (FID) is the most sensitive and widely used technology for the measurement of total hydrocarbons (THC). In the automotive emission testing of hydrocarbons, the fuel used for the flame in the FID analyzer is a mixture of hydrogen and helium in the ratio of 40:60. The Environmental Protection Agency (EPA) revised 40CFR part 1065 in April 2014 to include nitrogen as a balance gas alternative to helium for FID fuel mixtures used in the automotive industry. In addition to the balance gas alternative, the FID fuel blend tolerance was decreased from 40±2% to 40±1% (0.39 to 0.41mol/mol) hydrogen to minimize the impact on analyzer response. The feasibility of nitrogen as a FID fuel balance gas was studied and compared with a helium balance gas to understand the relative impact on emission testing. The study evaluated multiple hydrogen concentrations ranging from 38-42% in both balance gases.
2015-09-29
Technical Paper
2015-01-2814
Rakhesh Bharathan
Simultaneous reduction of NOx and PM from engine exhaust of a diesel engine is an interesting area of research due to the implementation of stringent emission regulations all over the world. Cost involved in expensive after treatment systems such as DPF and SCR necessitate minimization of engine out pollutants. With minimum engine out emission achieved through engine hardware and combustion parameter optimization, possibility of elimination or downsizing of the after treatment system can be explored. The paper presents the effect of fuel injection parameters and EGR rate on exhaust emission of a boosted diesel engine. Effects of parameters such as rail pressure, pilot-post injections, SOI, EGR rate and EGR temperature on a 4 cylinder two valve direct injection diesel engine is studied. Present study reveals the possibility of elimination of after treatment systems at BS IV level with optimization of engine hardware and combustion parameters.
2015-09-29
Technical Paper
2015-01-2810
Piotr Lijewski, Jerzy Merkisz, Pawel Fuc, Maciej Siedlecki, Andrzej Ziolkowski
Abstract The paper describes the measurement of PM emission from an excavator engine under actual operating conditions. The exploration of the relations between the engine operating parameters and its emissions requires measurements under actual conditions of engine operation. The specificity of the emission measurements, PM in particular, requires technologically advanced measuring devices. The situation gets even more complicated when, beside the PM mass. The particle size distribution and number (PN) also need to be measured. An important technical issue is the difficulty in fitting the measurement equipment in/on the vehicle in operation (e.g. excavator), which is why the presented investigations were carried out in a laboratory under simulated operation. The laboratory technicians applied load to the engines through the excavator hydraulic system.
2015-09-29
Technical Paper
2015-01-2819
Vasu Kumar, Dhruv Gupta, Mohd Waqar Naseer Siddiquee, Aksh Nagpal, Naveen Kumar
Abstract The growing energy demand and limited petroleum resources in the world have guided researchers towards the use of clean alternative fuels like alcohols for their better tendency to decrease the engine emissions. To comply with the future stringent emission standards, innovative diesel engine technology, exhaust gas after-treatment, and clean alternative fuels are required. The use of alcohols as a blending agent in diesel fuel is rising, because of its benefits like enrichment of oxygen, premixed low temperature combustion (LTC) and enhancement of the diffusive combustion phase. Several researchers have investigated the relationship between LTC operational range and cetane number. In a light-duty diesel engine working at high loads, a low-cetane fuel allowed a homogeneous lean mixture with improved NOx and smoke emissions joint to a good thermal efficiency.
2015-09-29
Journal Article
2015-01-2874
Marius-Dorin Surcel, Adime Kofi Bonsi
Lift axles increase the load capacity of a vehicle, allowing it to carry the extra load without the need for multiple vehicles, hence reducing operational costs. Furthermore, additional axles help to distribute the truck’s load across the road surface, reducing the chances of damage to the infrastructure. Lift axles can be raised when the vehicle has lighter load to save fuel and reduce wear and tear to the tires and axles. They can be deployed to improve traction especially in icy off-road applications. The main objective of this project was to assess the fuel-saving potential of lifting axles on unloaded semi-trailers. Part of the mandate was to identify and analyze regulations of various jurisdictions with respect to lift/loadable axles and studies leading to the setting up of these regulations. The SAE Fuel Consumption Test Procedures Type II (J1321) was used for fuel consumption track test evaluations.
2015-09-29
Technical Paper
2015-01-2795
Jayesh Mutyal, Sourabh Shrivastava, Rana Faltsi, Markus Braun
Abstract Stringent diesel emission regulations have been forcing constant reduction in the discharge of particulate matter and nitrogen oxide (NOx). Current state-of-the-art in-cylinder solutions are falling short of achieving these limits. For this reason engine manufacturers are looking at different ways to meet the emission regulations. Selective catalytic reduction (SCR) of oxides of nitrogen with ammonia gas is emerging as preferred technology for meeting stringent NOx emission standards across the world. SCR system designers face several technical challenges, such as avoiding ammonia slip, urea crystallization, low temperature deposits and other potential pitfalls. Simulation can help to develop a deep understanding of these technical challenges and issues, identify root causes of problems and help develop better designs. This paper describes the modeling approach for Urea Water Solution (UWS) spray and its interaction with canister walls and exhaust gases.
2015-09-29
Technical Paper
2015-01-2794
Meng-Huang Lu, Figen Lacin, Daniel McAninch, Frank Yang
Abstract Diesel exhaust after treatment solutions using injection, such as urea-based SCR and lean NOx trap systems, effectively reduce the emission NOx level in various light vehicles, commercial vehicles, and industrial applications. The performance of the injector is crucial for successfully utilizing this type of technology, and a simulation tool plays an important role in the virtual design, that the performance of the injector is evaluated to reach the optimized design. The virtual test methodology using CFD to capture the fluid dynamics of the injector internal flow has been previously developed and validated for quantifying the dosing rate of the test injector. In this study, the capability of the virtual test methodology was extended to determine the spray angle of the test injector, and the effect of the manufacturing process on the injector internal nozzle flow characteristics was investigated using the enhanced virtual test methodology.
2015-09-29
Journal Article
2015-01-2778
Thomas Reinhart, Coralie Cooper, John Whitefoot, James MacIsaac
Medium- and Heavy Duty Truck fuel consumption and the resulting greenhouse gas (GHG) emissions are significant contributors to overall U.S. GHG emissions. Forecasts of medium- and heavy-duty vehicle activity and fuel use predict increased use of freight transport will result in greatly increased GHG emissions in the coming decades. As a result, the National Highway Traffic Administration (NHTSA) and the United States Environmental Protection Agency (EPA) finalized a regulation requiring reductions in medium and heavy truck fuel consumption and GHGs beginning in 2014. The agencies are now proposing new regulations that will extend into the next decade, requiring additional fuel consumption and GHG emissions reductions. To support the development of future regulations, a research project was sponsored by NHTSA to look at technologies that could be used for compliance with future regulations.
2015-09-29
Technical Paper
2015-01-2797
Meichun Peng, Yue Zheng, Xiaoyan Jiang, Jiahao Wang
Abstract This paper studies the characteristics of fuel consumption and exhaust emission of city transit buses, and analyzes the fuel saving rate and exhaust pollutants reduction effect of LPG-HEV buses relative to LPG buses. The running speed, fuel consumption, exhaust emission and other variables of 3 LPG-HEV buses that aren't plug-in hybrid, and 2 LPG buses were measured by a portable emission measurement system (PEMS) under real driving situations of city transit buses in Guangzhou, China. The test data was analyzed to make a comparison between LPG-HEV and LPG buses. The study results show that the running speed of city buses in real driving modes is mainly distributed in the range of 0 to 35 km/h, and the average value is 18km/h, while the acceleration is distributed in a range from −0.5 to 0.5m/s2 mainly. The average fuel consumption of LPG-HEV buses is 51.02 l/100km, and is 6.23% lower than that of LPG buses.
2015-09-29
Journal Article
2015-01-2777
Gary Salemme, Erik Dykes, Daniel Kieffer, Michael Howenstein, Matthew Hunkler, Manik Narula
Simulations used to estimate carbon dioxide (CO2) emissions and fuel consumption of medium- and heavy-duty vehicles over prescribed drive cycles often employ engine fuel maps consisting of engine measurements at numerous steady-state operating conditions. However, simulating the engine in this way has limitations as engine controls become more complex, particularly when attempting to use steady-state measurements to represent transient operation. This paper explores an alternative approach to vehicle simulation that uses a “cycle average” engine map rather than a steady state engine fuel map. The map contains engine CO2 values measured on an engine dynamometer on cycles derived from vehicle drive cycles for a range of generic vehicles. A similar cycle average mapping approach is developed for a powertrain (engine and transmission) in order to show the specific CO2 improvements due to powertrain optimization that would not be recognized in other approaches.
2015-09-29
Journal Article
2015-01-2771
Kevin A. Newman, Paul Dekraker, Houshun Zhang, James Sanchez, Prashanth Gururaja
In designing a regulatory vehicle simulation program for determining greenhouse gas (GHG) emissions and fuel consumption, it is necessary to estimate the performance of technologies, verify compliance with the regulatory standards, and estimate the overall benefits of the program. The agencies (EPA/NHTSA) developed the Greenhouse Gas Emissions Model (GEM) to serve these purposes. GEM is currently being used to certify the fuel consumption and CO2 emissions of the Phase 1 rulemaking for all heavy-duty vehicles in the United States except pickups and vans, which require a chassis dynamometer test for certification. While the version of the GEM used in Phase 1 contains most of the technical and mathematical features needed to run a vehicle simulation, the model lacks sophistication. For example, Phase 1 GEM only models manual transmissions and it does not include engine torque interruption during gear shifting.
2015-09-29
Journal Article
2015-01-2772
Amy Kopin, Steven Musselman
Abstract For decades, the medium- and heavy-duty (“MD/HD”) commercial vehicle industry has focused on improving freight efficiency in order to lower customers' total operating costs. To optimize fuel efficiency, most manufacturers no longer focus on discreet components but instead look at the complete vehicle and operations. The path to future efficiency gains is not sufficiently clear when looking towards 2030; what is clear is that one solution will not work for all manufacturers or vehicle applications. Therefore, fuel efficiency regulations must be sufficiently adaptive to allow a variety of technical approaches to ensure the needs of the commercial truck market are met. This paper explores further the ideas presented in other papers that focus on regulation of engine-only emissions as an approach for HD vehicles.
2015-09-15
Technical Paper
2015-01-2477
Alessandro Gardi, Roberto Sabatini
Abstract This paper presents the conceptual design of a new low-cost measurement system for the determination of pollutant concentrations associated with aircraft operations. The proposed system employs Light Detection and Ranging (LIDAR) and passive electro-optics equipment installed in two non-collocated components. The source component consists of a tuneable small-size and low-cost/weight LIDAR emitter, which can be installed either on airborne or ground-based autonomous vehicles, or in fixed surface installations. The sensor component includes a target surface calibrated for reflectance and passive electro-optics equipment calibrated for radiance, both installed on an adjustable support. The proposed bistatic system determines the column-averaged molecular and aerosol pollutant concentrations along the LIDAR beam by measuring the cumulative absorption and scattering phenomena along the optical slant range.
2015-09-15
Journal Article
2015-01-2562
Tak W. Chan, Wajid Chishty, Craig Davison, David Buote
Abstract This study reports gaseous and particle (ultrafine and black carbon (BC)) emissions from a turbofan engine core on standard Jet A-1 and three alternative fuels, including 100% hydrothermolysis synthetic kerosene with aromatics (CH-SKA), 50% Hydro-processed Esters and Fatty Acid paraffinic kerosene (HEFA-SPK), and 100% Fischer Tropsch (FT-SPK). Gaseous emissions from this engine for various fuels were similar but significant differences in particle emissions were observed. During the idle condition, it was observed that the non-refractory mass fraction in the emitted particles were higher than during higher engine load condition. This observation is consistent for all test fuels. The 100% CH-SKA fuel was found to have noticeable reductions in BC emissions when compared to Jet A-1 by 28-38% by different BC instruments (and 7% in refractory particle number (PN) emissions) at take-off condition.
2015-09-15
Technical Paper
2015-01-2426
Anupam Kumari, Tushar Choudhary, Y Sanjay, Pilaka Murty, Mithilesh Sahu
Abstract In comparison to other thermal power cycles, gas turbine based energy conversion cycles exhibit superior thermodynamic performance as well as reduced emission. Gas turbine manufacturers and research & development (R&D) organizations are working on modification in basic gas turbine (BGT) cycle, which are intended to improve the basic gas turbine cycle thermodynamic performance and reduce emissions. The present work reports a comparison of thermodynamic performance, NOx and CO emission for basic and intercooled gas turbine (IcGT) cycles. Various cycle operating parameters such as compressor-pressure-ratio (rp,c), combustor-primary-zone-temperature, equivalence-ratio, and residence time of gas turbine based cycles has been examined. IcGT cycle exhibits higher gas turbine specific work and gas turbine efficiency in comparison to BGT cycle for the same rp,c and turbine rotor inlet temperature.
2015-09-06
Technical Paper
2015-24-2433
Anders N. Johansson, Petter Dahlander
Among many techniques used for increasing fuel efficiency of a modern Gasoline Direct-Injected (GDI) engine are boosting and stratified operation. In modern downsized GDI engines, boosting is standard in order to achieve a high power output. Boosted GDI-engines have however mostly been operated in homogenous mode and little is known on the effects of operating a boosted GDI-engine in stratified mode. This paper presents the influence on combustion, standard emissions and particulate size distribution in a Spray-Guided, Gasoline, Direct-Injected (SGDI), single cylinder, research engine operated with various levels of boost. The engine was operated in steady state mode at five engine operating points of various load and speed. The engine was boosted with a Roots blower and operated at four levels of boost as well as atmospheric pressure for comparison. The engine was fueled with market gasoline (95 RON) blended with 10% ethanol.
2015-09-06
Technical Paper
2015-24-2483
Thangaraja Jeyaseelan, Pramod S Mehta
The replacement of fossil diesel with neat biodiesel in a compression ignition engine has advantage in lowering unburned hydrocarbon, carbon monoxide and smoke emissions. However, the injection advance experienced with biodiesel fuel with respect to diesel injection setting increases oxides of nitrogen emission. In this study, the biodiesel-NO control is attempted using charge and fuel modification strategies with retarded injection timing. The experiments are performed at maximum torque speed and higher loads viz. from 60% up to full load conditions maintaining same power between diesel and biodiesel while retarding the timing of injection by 3 deg. crank angle. The charge and fuel modifications are done by recycling 5% by volume of exhaust gas to the fresh charge and 10% by volume of methanol to Karanja biodiesel.
2015-09-06
Technical Paper
2015-24-2408
Nicola Giovannoni, Sebastiano Breda, Stefano Paltrinieri, Alessandro D'Adamo, Stefano Fontanesi, Francesco Pulvirenti
Abstract In spark-ignited direct-injected engines, the formation of fuel pools on the piston is one of the major promoters of unburnt hydrocarbons and soot: in order to comply with the increasingly stringent emission regulations (EU6 and forthcoming), it is therefore necessary to limit fuel deposit formation. The combined use of advanced experimental techniques and detailed 3D-CFD simulations can help to understand the mechanisms driving fuel pool formation. In the paper, a combined experimental and numerical characterization of pool formation in a GDI engine is carried out to investigate and understand the complex interplay of all the mentioned factors. In particular, a low-load low-rpm engine operation is investigated for different ignition phasing, and the impact of both fuel formulation and instantaneous piston temperature variations in the CFD analyses are evaluated.
2015-09-06
Technical Paper
2015-24-2400
Andrea Matrisciano, Anders Borg, Cathleen Perlman, Harry Lehtiniemi, Michal Pasternak, Fabian Mauss
In this work a soot source term tabulation strategy for soot predictions under Diesel engine conditions within the zero-dimensional Direct Injection Stochastic Reactor Model (DI-SRM) framework is presented. The DI-SRM accounts for detailed chemistry, in-homogeneities in the combustion chamber and turbulence-chemistry interactions. The existing implementation [1] was extended with a framework facilitating the use of tabulated soot source terms. The implementation allows now for using soot source terms provided by an online chemistry calculation, and for the use of a pre-calculated flamelet soot source term library. Diesel engine calculations were performed using the same detailed kinetic soot model in both configurations. The chemical mechanism for n-heptane used in this work is taken from Zeuch et al. [2] and consists of 121 species and 973 reactions including PAH and thermal NO chemistry. The engine case presented in [1] is used also for this work.
2015-09-06
Technical Paper
2015-24-2396
Philippe Moreau, Patricia Valerio, Alain Brillard, Valerie Tschamber, Jean-Francois Brilhac, Yves Hohl, Regis Vonarb, L. Germanese, B. Courtalon
Abstract We present an experimental and modelling methodology developed at LGRE research laboratory to characterize soot oxidation in the presence of different atmospheres (NO2, NO2/O2), simulating passive regeneration which occur in a Diesel Particulate Filter (DPF). Based on this methodology which aims at deriving the kinetic parameters for soot combustion, the thermal reactivity of different soot has been studied and compared. Soot were produced from a prototype Liebherr engine and on an engine dynamometer at R&D Moteurs company, under two engine cycles and for two different fuels. Small soot masses (15-30mg) were deposited on the quartz frit of the reactor and submitted to a gas flow (NO2 or NO2/O2), under different temperatures. The mole fractions of NO2, NO, CO2 and CO at the reactor outflow were measured by infrared analyzers. The soot oxidation rate and the sample remaining mass were deduced from CO/CO2 emissions.
2015-09-06
Technical Paper
2015-24-2468
Kar Mun Pang, Hiew Mun Poon, Hoon Kiat Ng, Suyin Gan, Jesper Schramm
Abstract This work concerns the modelling of soot formation process in diesel spray combustion under engine-like conditions. The key aim is to investigate the soot formation characteristics at different ambient temperatures. Prior to simulating the diesel combustion, numerical models including a revised multi-step soot model is validated by comparing to the experimental data of n-dodecane fuel in which the associated chemistry is better understood. In the diesel spray simulations, a single component n-heptane mechanism and the multi-component Diesel Oil Surrogate (DOS) model are adopted. A newly developed C16-based model which comprises skeletal mechanisms of n-hexadecane, heptamethylnonane, cyclohexane and toluene is also implemented. Comparisons of the results show that the simulated liftoff lengths are reasonably well-matched to the experimental measurement, where the relative differences are retained to below 18%.
2015-09-06
Technical Paper
2015-24-2486
Ajay Singh Verma, M. Muzaffarul Hasan, Ashish Karnwal, Vipul Vibhanshu
Abstract The continuous growth of population and development of industries give rise to massive increase in the global energy demand in recent years. Therefore present work investigated the combustion and emission characteristics of an unmodified four stroke single cylinder variable compression ratio diesel engine utilizing isopropyl alcohol (2-propanol)-diethyl ether blends with diesel. The different fuel samples were prepared using 10% isopropyl, alcohol 5% diethyl ether by volume (IPD15), 15% isopropyl alcohol, 5% diethyl ether by volume (IPD20) and 20% isopropyl alcohol 5% diethyl ether by volume (IPD25) with neat standard diesel. All experiment tests were performed with at variable compression ratio 17 and 18 at different load conditions. The effect of blends and compression ratio on combustion parameters viz. peak cylinder pressure and rate of heat release along with exhaust emissions CO, CO2, HC and NOx, were investigated.
2015-09-06
Technical Paper
2015-24-2497
Pierpaolo Napolitano, Carlo Beatrice, Chiara Guido, Nicola Del Giacomo, Leonardo Pellegrini, Pietro Scorletti
Abstract The present paper describes the results of a research activity aimed at studying the potential offered by the use of Hydrocracked fossil oil (HCK) and Hydrotreated Vegetable Oil (HVO) blends as premium fuels for next generation diesel engines. Five fuels have been tested in a light duty four cylinder diesel engine, Euro 5 version, equipped with closed loop control of the combustion. The set of fuels comprises four experimental fuels specifically formulated by blending high cetane HVO and HCK streams and oneEN590-compliant commercial diesel fuel representative of the current market fuel quality. A well consolidated procedure has been carried out to estimate, for the tested fuels, the New European Driving Cycle (NEDC) vehicle performance by means of the specific emissions at steady-state engine operating points.
2015-09-06
Technical Paper
2015-24-2514
Marco Piumetti, Samir Bensaid, Nunzio Russo
A set of ceria-zirconia nanocatalysts with different Zr-contents and structural properties was prepared to study the effect of both the Zr-amount and surface-dependent activity towards soot combustion in “loose” and “tight” soot-catalyst contact. The properties of the catalysts were examined using several physico-chemical techniques. The best soot oxidation activities were achieved for the Ce0.9Zr0.1O2-NP catalyst (NP means nano-polyhedra and 0.9 indicates the atomic ratio of Ce/Ce+Zr), due to its easier reducibility, compared to high-surface area catalysts with the same Ce/Zr ratio. Moreover, better performances were reached for Ce0.9Zr0.1O2-NP, than similar nano-polyhedra with higher Zr-amounts (denoted as CexZr1-xO2-NP, where x = 0.8 or 0.7). On the other hand, worse activities were obtained for both mesoporous and microporous catalysts with the same Ce/Zr ratio.
2015-09-06
Technical Paper
2015-24-2518
Riccardo Amirante, Elia Distaso, Paolo Tamburrano, Rolf D. Reitz
Due to the new challenge of meeting number-based regulations for particulate matter (PM), a numerical and experimental study has been conducted to better understand particulate formation in engines fuelled with compressed natural gas. The study has been conducted on a Heavy-Duty, Euro VI, 4-cylinder, spark ignited engine, with multipoint sequential phased injection and stoichiometric combustion. For the experimental measurements two different instruments were used: a condensation particle counter (CPC) and a fast-response particle size spectrometer (DMS) the latter able also to provide a particle size distribution of the measured particles in the range from 5 to 1000 nm. Experimental measurements in both stationary and transient conditions were carried out. The data using the World Harmonized Transient Cycle (WHTC) were useful to detect which operating conditions lead to high numbers of particles. Then a further transient test was used for a more detailed and deeper analysis.
2015-09-06
Technical Paper
2015-24-2515
Christophe Barro, Sushant Pandurangi, Philipp Meyer, Konstantinos Boulouchos, Philipp Elbert, Yuri M. Wright
Abstract Past research has shown that post injections have the potential to reduce Diesel engine exhaust PM concentration without any significant influence in NOx emissions. However, an accurate, widely applicable rule of how to parameterize a post injection such that it provides a maximum reduction of PM emissions does not exist. Moreover, the underlying mechanisms are not thoroughly understood. In past research, the underlying mechanisms have been investigated in engine experiments, in constant volume chambers and also using detailed 3D CFD-CMC simulations. It has been observed that soot reduction due to a post injection is mainly due to two reasons: increased turbulence from the post injection during soot oxidation and lower soot formation due to lower amount of fuel in the main combustion at similar load conditions. Those studies do not show a significant temperature rise caused by the post injection.
2015-09-06
Technical Paper
2015-24-2501
Thomas Laible, Stefan Pischinger, Bastian Holderbaum
Abstract Within a project of the Research Association for Combustion Engines e.V., different measures for rising the temperature of exhaust gas aftertreatment components of both a passenger car and an industrial/commercial vehicle engine were investigated on a test bench as well as in simulation. With the passenger car diesel engine and different catalyst configurations, the potential of internal and external heating measures was evaluated. The configuration consisting of a NOx storage catalyst (NSC) and a diesel particulate filter (DPF) illustrates the potential of an electrically heated NSC. The exhaust aftertreatment system consisting of a diesel oxidation catalyst (DOC) and a DPF shows in simulation how variable valve timing in combination with electric heated DOC can be used to increase the exhaust gas temperature and thus fulfill the EU6 emission limits.
2015-09-06
Technical Paper
2015-24-2504
Gerben Doornbos, Emma Adams, Per-Anders Carlsson, Daniel Dahl, Mats Laurell, Håkan Schyllander, Par Gabrielsson, Milica Folic, Ingemar Denbratt, Magnus Skoglundh
Commercial three way catalysts have limited capacity towards reducing NOx in the presence of excessive oxygen. This prevents lean-burn combustion concepts from meeting legislative emission standards. A solution towards decreasing NOx emissions in the presence of excess air is the use of a passive-SCR system. Under rich conditions ammonia is formed over an ammonia formation catalyst, the ammonia is stored in the SCR and in its turn reacts with the NOx under lean engine conditions. Here up-scaled Pt/Al2O3 and Pd/Al2O3 catalysts as well as a commercially Pd-Rh based three-way catalyst (TWC) are evaluated using both engine and further lab-scale tests. The purpose of these tests is to compare the ammonia production for the various catalysts under various lambda values and temperatures by means of engine and lab scale tests. The Pd/Al2O3 showed little sensitivity to temperature both under engine and lab scale experiments.
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