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Technical Paper
2014-11-11
Marcus Bonifer, Rainer Kiemel
In Europe the next level of emission regulation for motorcycles, Euro IV, is on the verge of introduction, followed by Euro V around 2021. Together with the new emission regulation the ECE R 40 testing cycle will become obsolete and the more realistic WMTC will be introduced. Current catalytic solutions consist of so called three way catalysts (TWC) that are able to reduce the emissions of CO, NOx and hydrocarbons below the regulatory emission limit. These catalysts mostly contain platinum (Pt), palladium (Pd) and rhodium (Rh) in different relations and concentrations. Another important component is the so-called oxygen storage material (OSC) that is compensating the fluctuations in lambda during acceleration and deceleration. Currently existing catalyst formulations must be modified to fulfil the more stringent emission limits with simultaneous consideration of a more realistic test cycle. In this paper we will present the modification of an existing Euro 3 catalytic formulation for a 690cc motorcycle.
Technical Paper
2014-11-11
Luiz Carlos Daemme, Renato Penteado, Fatima Zotin, Marcelo Errera
Research and/or Engineering Questions/Objective The motorcycle sales have improved consistently during the last decade mostly in developing and BRICS countries. There are many reasons for it such as their low cost and less fuel consumption comparing to cars, associated to the economic growth on those cited countries. New emissions limits have been reduced and the use of gas after treatment devices is widely present in new models. Additionally Flex Fuel motorcycles have been offered to the market and a combination of diverse gasoline/ethanol blends and their effect on the emissions still an open issue to be fully understood. The objective of the paper is to present recent results regarding regulated and unregulated emissions from a Flex Fuel motorcycle fuelled with 4 different gasoline/ethanol blends. Methodology One motorcycle was fuelled with gasoline blended with 22, 61 and 85% ethanol. Additionally a 100% ethanol fuel was used. Regulated emissions (CO, HC, and NOx) have been measured with 7000 series Horiba benches.
Technical Paper
2014-11-11
Juergen Tromayer, Gerd Neumann, Marcus Bonifer, Rainer Kiemel
Looking at upcoming emission legislations for two-wheelers, it is quite obvious that the fulfilment of these targets will become one of the biggest challenges within the engine development process. The gradual harmonization of emission limits for two-wheelers with existing automotive standards will subsequently lead to new approaches regarding mixture preparation and exhaust gas aftertreatment. Referring to these future scenarios, the authors want to demonstrate the possible achievements by the application of state of the art technology to a standard small capacity two-wheeler engine being representative for the current market situation. After choosing a suitable test carrier, which has already been equipped with EFI components including an oxygen sensor for λ=1 operation mode, a basic injection system calibration was used to optimize the combustion process. Based on this setup, a variable exhaust system was manufactured to be able to integrate different catalyst configurations. Thus, the possibility for investigations on the optimization of exhaust gas aftertreatment was given.
Technical Paper
2014-11-11
Stefano Bernardi, Marco Ferrari, Dario Catanese
Many two stroke engines for hand-held applications are equipped with muffler that contain a catalyst in order to reduce exhaust gas emissions. However, one of the main problems, is to mantain the performances of the catalyst over time; this often leads to the adoption of systems with increased culling oversized issues related to weight , dimensions and temperature . One of the major causes of degradation of the catalyst is derived from elements of poison present in the oil mixture. This study showed the results obtained by comparing different types of oils of mixture, through durability tests carried out on an engine of a brush cutter .
Technical Paper
2014-11-11
Jan Czerwinski, Markus Kurzwart, Andreas Mayer, Pierre Comte
The progressing exhaust gas legislation for on- and off-road vehicles includes gradually the nanoparticle count limits. The invisible nanoparticles penetrate like a gas into the living organisms and 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), granulometry SMPS (PN) and differential analysis of filter residue. In this way the reduction potentials with application of the best material 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 considerably influenced by the lube oil quality and reduced with an oxidation catalyst.
Technical Paper
2014-11-11
Sayaka Yasoshina, Ryo Saito
With environmental issues such as global warming getting acute, the demand of engine exhaust gas emission reduction is increasing. The purpose of this study is the reduction of exhaust gas emissions for small size generators by using after-treatment device. The requirement of small size generators are portability, so they must be lightweight and compact. After-treatment device should be housed in the compact package. And sometimes generators are used near a house, so CO discharge amount should be a little under the condition of fuel rich mixture for high specific power. To meet these conditions, a catalytic converter with secondary air induction is adopted. Secondary air is used for oxidization of CO. However before this study, sufficient amount of secondary air couldn’t be inducted because of the shortage of minus pressure in exhaust pipe which caused by high-load operating and the shortness of an exhaust pipe. But high-load operating is inevitable in generator and adoption of a long exhaust pipe is impossible to compact casing.
Technical Paper
2014-11-11
Saager Paliwal, Alex S. Bare, Katherine J. Lawrence, Marc Anderson, Glenn Bower
This study looks at the application of a titanium dioxide (TiO2) catalytic nanoparticle suspension to the surface of the combustion chamber as a coating, as well as the addition of hydrogen gas to a four-stroke spark-ignited carbureted engine as a possible technique for lowering engine-out emissions. The experiments were conducted on two identical Generac gasoline powered generators using two, four and six halogen work lamps to load the engine. One generator was used as a control and the second had key components of the combustion chamber coated with the catalytic suspension. In addition to the coating, both engines were fed a hydrogen and oxygen gas mixture and tested at low, medium and high loads. Using an unmodified engine as a control set, the following three conditions were tested and compared: addition of hydrogen only, addition of coating only, and addition of hydrogen to the coated engine. Operating the engines on standard gasoline in a laboratory, emission gases were transferred via a heated line to be analyzed by an FTIR.
Technical Paper
2014-11-11
Silvana Di Iorio, Francesco Catapano, Paolo Sementa, Bianca Maria Vaglieco, Salvatore Florio, Elena Rebesco, Pietro Scorletti, Daniele Terna
The small gasoline engines are widely used as prime movers in the urban areas. For this reason great efforts have been paid to improve their efficiency as well as to reduce the pollutant emissions. The direct injection allows to improve the engine efficiency; on the other hand, the GDI combustion produces larger particle emissions because of the non-uniform mixture preparation and piston wetting. The properties of fuels play an important role both on engine performance and pollutant emissions. In particular, great attention was paid to the octane number. In this sense, ethanol is becoming even more attractive for spark ignition fuels as more resistant to knock phenomena due to its higher octane number. Moreover, ethanol is also expected to play an important role in PM emission reduction. In this study was analyzed the effect of fuels with different RON and with ethanol content. The analysis was performed on a small GDI engine. It was investigated two operating condition representative of the typical EUDC.
Technical Paper
2014-10-13
Andrew Smallbone, Amit Bhave, Peter Man
In this paper we combine experimental data, physics-based models and advanced numerical techniques to investigate 1) sources of friction losses in heavy-duty IC engines and, 2) fuel efficiency losses (and CO2 sources) in an engine and vehicle model over 160 ‘real-world’ and legislated drive cycles. These two applications are both typical examples where a multi-dimensional design space means that it is challenging to interpret and communicate the influence of each design parameter effectively and identify those of most importance for your chosen objective. In this paper, the authors present new methods to support a) the parameter estimation (model calibration) with respect to experimental data and, b) advanced global sensitivity analysis using a High Dimensional Model Representation (HDMR).
Technical Paper
2014-10-13
Xinyu Wang, Yadong Deng
Automotive exhaust-based thermoelectric generators (TEGs) effectively convert exhaust heat into electrical energy, which gradually improve utilization efficiency of the fuel. In this paper, a newly heat exchanger with the shape of regular-octagon cylinder box in TEG is designed. Through building three-dimensional models of different TEGs , it is available to calculate thermal stress field distribution of them separately in ANSYS software and test the reliability of expected TEG .By conducting multi -ordered temperature - fluid - solid coupling of heat exchanger in FLUENT software , adopting different heat exchanger structures, setting different parameters of length, width, height, thickness of the distributing fins, guiding fins, converging fins in the heat exchanger, and installing different distribution angles and spacing of these fins, the temperature field, pressure field and flow field simulation results are gained to explore the influence of air current resistance and the thermal performance of TEG caused by diverse heat exchanger structures and various physical-dimension and distribution of the fins.
Technical Paper
2014-10-13
S. Reifarth, V. Rajagopal, K. Gritzun, H.-E. Angstrom
The distribution of EGR between the cylinders of an internal combustion engine has been shown to have large impact on the engine emissions. Especially at high EGR, the combustion reacts sensibly to variations in the EGR-rate. A cylinder that receives excessive EGR produces soot particles while a cylinder with too little EGR has increased NOx-emission. It is therefore important to have knowledge about the mixing in an engine. This study compares two different EGR-mixing measurement methods. The first is based on CO2 measurement with standard probes, placed at 36 different locations in the intake manifold of the engine. The second method uses a laser beam and a detector to gain information about the mixing with a high time-resolution, placed at six positions of the intake manifold. Additionally, 1-D simulations are used to gain information about the mixing process. To vary the mixing process on the engine, two different air/EGR mixers are used and their mixing performance is evaluated.
Technical Paper
2014-10-13
S. Reifarth, E. Kristensson, J. Borggren, A. Sakowitz, H.-E. Angstrom
The use of EGR for NOX reduction is today a standard technology for diesel engines. The mixing of air and EGR is an important issue, especially for high-pressure EGR systems. An uneven distribution of EGR between the cylinders can lead to higher overall engine emissions when some cylinders produce more soot, others more NOX than they would with a perfectly even distribution. It is therefore important to understand the processes that control the mixing between air and EGR. The mixing is influenced by both the geometry of the mixing area and the pulsating nature of the flow. The aim of this work is to point out the high importance of the pulses present in the EGR-flow. By simulation in 1-D and 3-D as well as by a fast measurement method, it is shown that the EGR is transported in the air flow in packets. This implies that the timing between intake valve opening and the positioning of the EGR packets has a high influence of the distribution of EGR between the cylinders. The ability of 1-D and 3-D simulation to predict the behavior is evaluated.
Technical Paper
2014-10-13
Paul Schaberg, Mark Wattrus
In many countries fuel standards permit the limited addition of FAME to diesel fuel. For example, in Europe, diesel fuel complying with the EN590:2009 regulation may contain up to 7% FAME, and the low carbon fuel standards being considered in many regions encourage the consideration of even higher levels of FAME addition. Standards organisations such as CEN, ASTM, and CARB are also contemplating standards for paraffinic diesel fuels such as GTL (Gas-to-Liquids) diesel and HVO (Hydrogenated Vegetable Oil), an example being CEN Technical Standard 15940:2012. Since these standards may also allow the addition of FAME, it was decided to perform an extensive evaluation of the properties and performance of blends of GTL diesel and FAME, including emissions performance which is reported on in this paper. Fuels that were variously considered in the study were blends of GTL and EN590 diesel containing 0, 7, and 20 vol% of SME and RME (Soy and Rapeseed Methyl Ester). Part of the study focussed on European engine technology, and tests were performed on a Euro 4 passenger vehicle and engine, and a Euro V heavy-duty engine.
Technical Paper
2014-10-13
Ossi Kaario, Teemu Sarjovaara, Olli Ranta, Tuomo Hulkkonen, Karri Keskinen, Martti Larmi, Sauli Halonen, Arno Amberla
In the present study, we analyze urea solution spray mixing and evaporation in a novel selective catalytic reduction (SCR) system. In typical SCR systems, low urea solution injection pressures are used. This may result in low evaporation rates implying that some additional methods need to be used to obtain feasible mixing and evaporation rates in the system. However, the aim in the present study is to use very high injection pressure for the solution in order to enhance droplet breakup, mixing, and evaporation and thus remove the need to use additional mixing enhancement techniques. We measure the spray characteristics of the urea solution, namely the spray penetration, opening angle, and droplet sizes from several distances from the nozzle and with various nozzle hole sizes and injection pressures. We focus our experiments on low gas density setting which is typically the SCR system operating environment. This kind of experimental data (low gas density, high injection pressure) is scarce in literature.
Technical Paper
2014-10-13
Mohammad Reza Hamedi, Athanasios Tsolakis, Jose Martin Herreros
Recent developments in diesel engines lead to increased fuel efficiency and reduced exhaust gas temperature. Therefore more energy efficient aftertreatment systems are required to comply with tight emission regulations. In this study, a computational fluid dynamics package was used to investigate the thermal behaviour of diesel aftertreatment system. A parametric study was carried out to identify the most influential piping material and insulation characteristics in terms of thermal performance. In case of aftertreatment piping and canning material effect, an array of different potential materials was selected and their effects on the emission conversion efficiency of a Diesel Oxidation Catalyst (DOC) were numerically investigated over a driving cycle. Results indicate that although the piping material volumetric heat capacity was decreased by a factor of four, the total emission reduction was only considerable during the cold start. Since the piping system heat up and cool down periods were accelerated by reducing the system thermal inertia.
Technical Paper
2014-10-13
Jinyoung Jang, Young-Jae Lee, Ohseok Kwon, Minseob Lee, Jeonghwan Kim
The emissions from vehicle are affected by engine type, fuel and engine oil making particulate matter (PM) 13% of total PM. In this study, engine oil is focused to show the effect of engine oils on PM and other emission. Group III base oil, Group III base oil with additives and poly alpha olefins (PAO’s) with additives are tested and have identical SAE grad for same vehicle. Gasoline vehicle, which has direct injection system, and diesel vehicle, which has no PM trap, were selected because those vehicles clearly emit PM more than port fuel type gasoline and diesel with PM trap vehicle. Combined mode test, consisting of FTP 75 and highway drive mode, are used to assess exhaust emission and fuel economy. The number of PM was counted using PPM-S, which is based on the measurement of electrical charge carried by particles. Regulated emissions and fuel economy for gasoline vehicle were analyzed by HORIBA gas analyzer with sampling bags. Diesel vehicle’s emissions and fuel economy were analyzed by PIERBURG gas analyzer.
Technical Paper
2014-10-13
Haichao Fu, Yinhui Wang, Xinyan Li, Shi-Jin Shuai
An experimental study on particulate emission was conducted on four cars from Chinese market, three of which powered by gasoline direct injection (GDI) engines and the other one powered by port fuel injection (PFI) engine. Experiments were performed on a chassis dynamometer over new European driving cycle (NEDC). Particulate mass and number were measured using PMP system, and transient particulate number and size distribution were measured through DMS500 Fast Particulate Spectrometer. Three kinds of gasoline with RON 91.9, 94.0 and 97.4 were tested on these four cars to find impacts of RON on particulate emission. In order to get what extent cold start influences the particulate emission, both cold and hot start NEDCs were tested. Large scale of particles were emitted from both GDI and PFI cars during cold start condition (first 200s of NEDC). Compared with cold start NEDC, hot start NEDC particulate mass of these three GDI cars decreased by 65.1%, 27.9% and 66.3% respectively, and particulate number of these three GDI cars decreased by 58.5%, 34.0% and 53.3% respectively.
Technical Paper
2014-10-13
Dave OudeNijeweme, Paul Freeland, Markus Behringer, Pavlos Aleiferis
Particulate emissions are of growing concern due their negative health impacts. Many urban areas around the world currently have levels exceeding the World Health Organisation safe limits. Gasoline engines, especially when equipped with direct injection systems, contribute to this pollution. In recognition of this fact European limits on particulate mass and number are being introduced. A number of ways to meet these new stringent have been under investigation at MAHLE Powertrain, with this paper focussing on the improvement potential of the injection equipment. This investigation is part of MAHLE’s ongoing particulate research and method development that includes optical engine spray and combustion visualisation, CFD method development, engine and vehicle testing with the aim to move particulate emission development upstream in the development process. As part of this work, a spark eroded and a laser drilled injector were fully characterised in a spray vessel under key engine running conditions.
Technical Paper
2014-10-13
Christophe Barro, Philipp Meyer, Konstantinos Boulouchos
Past research has shown that post injections have the potential to reduce Diesel engine exhaust PM concentration without any significant influence in the NOx emissions. However, an accurate and general 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 understood thoroughly. In earlier research it was observed that soot reduction due to a post injection is mainly based on 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. A third effect of heat addition during the soot oxidation is debated in the literature. The experimental investigation presented in the current work provides insight into the underlying mechanisms of soot formation and reduction using post injections under different operating conditions. The measurements aim to provide additional understanding in the sources of PM reduction, which will allow the optimization of post injection settings.
Technical Paper
2014-10-13
Jing Qin, Xiang Li, Yiqiang Pei
Abstract The aim of this detailed research is to experimentally investigate the effects of ignition timings, injection timings, excess air ratio (λ) and lubricating oil on particulate matter (PM) emissions from a 2.0 L turbo-charged gasoline direct injection (T-GDI) engine fueled with gasoline, methanol/gasoline blends and pure methanol. The results of this paper show that the PM number concentration mostly presents a typical bimodal or trimodal distribution in figures. The particle number concentration mainly concentrates in the nucleation mode. With the increase of methanol volume fraction in the blended fuel, the PM emissions decrease significantly. Furthermore, there are few particles when the engine fueled with pure methanol. As advancing ignition timing, the total PM number rises by over about 200%. Under the pre-ignition condition, the higher in-cylinder temperature may also accelerate the formation of the nucleation mode particles. As advancing injection timing, PM emissions decrease first, and then increase.
Technical Paper
2014-10-13
Christoph Menne, Simon Galbraith, Alan Jones, Lars Henning, Thomas Koerfer
In September 2013 the Jaguar XF 2.2l ECO sport brake and saloon were introduced to the European market. They are the first Jaguar vehicles to realize CO2 emissions below 130 g/km. To achieve the significantly reduced fuel consumption values with an existing 2.2l I4 Diesel engine architecture selected air path and fuel path components were optimized for increased engine efficiency. Hardware selection and development in the available short time frame were only enabled by the consequent utilization of the most advanced CAE tools throughout the design phase but also during the complete vehicle application process. Changes to the base engine architecture were ruled out at the beginning of the project due to the implications on manufacturing complexity and the limited given time frame for realization. To allow a fuel consumption reduction of more than 10% vs. the first introduction of the 2.2l I4 Diesel in XF the following measures were identified: - Improved combustion efficiency due to more advanced centre of combustion for most engine operating points - Improved fuel spray and mixture preparation - Air path with reduced pressure losses especially for the high pressure exhaust gas recirculation - significantly enhanced cooling performance of the high pressure exhaust recirculation path - downspeeding with advanced transmission control The potential of the listed measures and their interactions, the chosen hardware components and the used development and application methodologies shall be presented in this paper.
Technical Paper
2014-10-13
Arjun Prakash, Edward Nelson, Aaron Jones, James Macias, Matthew Hinojosa, Eugene Jimenez
Particulate mass (PM) emissions from DISI engines can be reduced via fuels technology that facilitates injector deposit clean-up. A significant drawback of DISI engines is that they can have higher particulate matter emissions than PFI gasoline engines. Soot formation in general is dependent on the air-fuel ratio, combustion chamber temperature and the chemical structure and thermo-physical properties of the fuel. In this regard, PM emissions and DISI injector deposit clean-up were studied in three identical high-selling vehicles. The tests compared the effects of a fuel (Fuel A) containing a market generic additive at lowest additive concentration (LAC) against a fuel formulated with a novel additive technology (Fuel B). The fuels compared had an anti-knock index value of 87 containing upto 10% ethanol. The vehicles were run on Fuel A for 20,000 miles followed by 5,000 miles on Fuel B using a chassis dynamometer. It was observed that Fuel A gave rise to an increase in PM emissions indicative of DISI injector deposit build-up.
Technical Paper
2014-10-13
S. F. Benjamin, C. A. Roberts
In an attempt to reduce particulate and NOx emissions from Diesel exhaust, the combined DPF and SCR filter is now frequently chosen as the preferred catalyst. When this device functions effectively it saves valuable packaging space in a passenger vehicle. As part of its development, modelling of its emissions performance is essential. Single channel modelling is the obvious choice for a DPF filter because of its complex geometry. This, however, can be computationally demanding. For a normal flow-through catalyst monolith the porous medium approach is an attractive alternative. This paper attempts to model an SCRF by applying the porous medium approach. The model is essentially 1D but as with all porous medium models, can very easily be applied to 3D cases once developed and validated. The model is described in full in this paper and values for all the key parameters are presented. The filter is assumed to collect soot in the inlet channels, but only the output channels are coated with SCR washcoat, as in the most recent devices.
Technical Paper
2014-10-13
Z. Gerald Liu, Dana McGuffin, Chris M. Cremeens, Nathan Ottinger, Niklas Schmidt
More stringent emission requirements for nonroad diesel engines both in the U.S. and Europe have spurred the development of exhaust aftertreatment technologies. In this study, one such system consisting of a diesel oxidation catalyst, zeolite-based selective catalytic reduction catalyst, and an ammonia oxidation catalyst was evaluated using both nonroad transient and steady-state cycles in order to understand the emission characteristics of this configuration. Criteria pollutants were analyzed and particular attention was given to organic compound and NO2 emissions since both of these could be significantly affected by the absence of a diesel particulate filter that typically helps reduce semi-volatile and particle-phase organics and consumes NO2 via passive soot oxidation. Results are then presented on a detailed speciation of organic emissions including alkanes, cycloalkanes, aromatics, polycyclic aromatic hydrocarbons and their derivatives, and hopanes and steranes. It is shown that each of these groups of species was reduced significantly in comparison to engine out levels.
Technical Paper
2014-10-13
Bhimrao Patil, Vighnesha Nayak, Mohanan Padmanabha
This work aims study on the method of NOx reduction and performance enhancement by analysis of MPFI multi-cylinder gasoline engine running on LPG using gas injection system and vaporized water methanol induction to the intake manifold. For the generation of vaporized water methanol, heat from the exhaust gas has been used. Different percentages of water methanol by mass basis were used with variable engine speed ranging from 2000 to 4500 rpm. The results showed that as the percentage water methanol induction level to the engine increased, there is slight increase in percentage of useful work, while the NOx decreased drastically about 47%. Additionally, the engine brake thermal efficiency increases. The average increase in the brake thermal efficiency for a 20% water methanol with LPG is approximately 1.5% over the use of LPG without water methanol induction.
Technical Paper
2014-10-13
Benjamin Kingsbury, Jonathan Stewart, Zhentao Wu, Roy Douglas, Kang Li
This study describes an innovative monolith structure designed for applications in automotive catalysis using an advanced manufacturing approach developed at Imperial College London. The production process combines extrusion with phase inversion of a ceramic-polymer-solvent mixture in order to design substrate micro-structures that offer improvements in performance, including reduced PGM loading, reduced catalyst ageing and reduced backpressure. The novel substrate is formed from hollow fibres which are fused together to form a ceramic monolith. A highly ordered micro-structure is present, formed from micro-channels which extend from the inner surface to the outer surface of the hollow fibres. The entrances to the micro-channels are in the range of 10 – 90 μm and are directly accessible to the exhaust gas as it passes along the substrate. The designed micro-structure generates a geometric surface area of 32,000 m²/m³, while at the same time achieving a 40-70 % reduction in pressure drop along the length of the substrate.
Technical Paper
2014-10-13
Aayush Mehrotra, Simhachalam Juttu, Siva Subramanian Ravishankar, Ghodke Pundlik Rambhaji, J G Suryawanshi
Cooling EGR & improving its mixing with air has given consistent improvement in diesel emissions, hence the evolution of superior cooling technologies & low pressure EGR helps in meeting stringent diesel emission norms. For the same volume of exhaust gas, cooled exhaust gas occupies lower volume for the same mass; thereby it is possible for engine to digest more amount of EGR or air depending upon the trade off and substantially improve the heat carrying capacity of exhaust gas. Lowering the temperature of EGR gives a great potential in reducing NOx and smoke in diesel engines, it helps in lowering the EGR mixture temperature and hence reducing the in cylinder temperature. An attempt has been made here to lower the EGR temperature downstream of a conventional cooler without changing the cooler design itself. For this, the source for coolant has been taken from radiator outlet unlike the conventional location of cylinder block. A 12 V electric pump circulates coolant to EGR cooler with a bypass from radiator; since the radiator outlet is much cooler than cylinder block outlet the cooling efficiency increases significantly.
Technical Paper
2014-10-13
Qian Feng, Diming Lou, Piqiang Tan, Zhiyuan Hu
In this study, durability and performance evaluation of the ageing catalyzed continuously regenerating trap (CCRT) on solid and volatile particulate emissions from urban diesel bus was studied by means of a set of on board measurement, transient TSI engine exhaust particle sizer spectrometer. During fourteen months, the CCRT had successfully reached self-regeneration. Three typical urban bus operating conditions, idling, stepped steady and transient conditions were carried out on-real world tests. In all evaluation tests, the average filtration efficiency of particle number was 93.3% at least under idling and stepped steady conditions. The CCRT of different ageing phase had different effect on nuclei mode particle. As the CCRT aging increase, the total particle number concentrations showed a declining trend while proportion of nuclei mode number concentration presented rising trend increasingly. This’s mainly due to the development of filtration mechanism: deep bed filtration, transitory and granular bed filtration.
Technical Paper
2014-10-13
Kohei Yoshida, Yusuke Nozaki, Toshihiro Mori, Yuki Bisaiji, Yuki Haba, Kazuhiro Umemoto, Takao Fukuma
To fulfill upcoming stringent worldwide CO2 emission target, engine thermal efficiency should further be increased and diesel engine is one of the promising solutions. Nevertheless to ensure good air quality, NOx emission should be reduced using a specific catalyst. In order to reduce NOx from a diesel engine operation in lean condition, Urea-Selective Catalyst Reduction (SCR) or NOx Storage and Reduction (NSR) systems have been widely adopted in the European market. The NSR system is most efficient for small/mid vehicle size since it requires less packaging space and it is less expensive than a urea SCR system. However, its NOx reduction performance is currently limited under high temperature and high space velocity conditions since the NOx storage ability as nitrate is insufficient under such conditions. For future NSR usage, it is therefore necessary to improve the NOx reduction performance of NSR. DiAir (Diesel NOx After-treatment by Adsorbed Intermediate Reductants) has been introduced as one of the measures to improve NOx conversion performance under high space velocity (SV) and temperature conditions.
Technical Paper
2014-10-13
Kihyung Joo, Jin Woo Park, Jin-ha Lee, Seok-Jae Kim, Seungbeom Yoo
In diesel engine development, the new technology is coming out to meet the stringent exhaust emission regulation. The regulation demands more eco-friendly vehicles. Euro6c demands to meet not only WLTP mode, but also RDE(Real Driving Emission). In order to satisfy RDE mode, the new technology to reduce emissions should cover all operating areas including High Load & High Speed. It is a big challenge to reduce NOx on the RDE mode and a lot of DeNOx technologies are being developed. So the new DeNOx technology is needed to cover widened operating area and strict acceleration/deacceleration. The existing LNT(Lean NOx Trap) and Urea SCR(Selective Catalytic Reduction) is necessary to meet the typical NEDC or WLTP, but the RDE mode demands the powerful DeNOx technology. Therefore, the LNT & Urea SCR on DPF was developed through this study. This complex new technology consists of new catalysts(to reduce emissions), insulation(to improve fuel economy, and catalytic performance) , and logical controller(to control DeNOx and DePM strategy).
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