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Viewing 151 to 180 of 24446
2017-03-28
Journal Article
2017-01-0773
Dan DelVescovo, Sage Kokjohn, Rolf Reitz
Abstract Engine experiments were conducted on a heavy-duty single-cylinder engine to explore the effects of charge preparation, fuel stratification, and premixed fuel chemistry on the performance and emissions of Reactivity Controlled Compression Ignition (RCCI) combustion. The experiments were conducted at a fixed total fuel energy and engine speed, and charge preparation was varied by adjusting the global equivalence ratio between 0.28 and 0.35 at intake temperatures of 40°C and 60°C. With a premixed injection of isooctane (PRF100), and a single direct-injection of n-heptane (PRF0), fuel stratification was varied with start of injection (SOI) timing. Combustion phasing advanced as SOI was retarded between -140° and -35°, then retarded as injection timing was further retarded, indicating a potential shift in combustion regime. Peak gross efficiency was achieved between -60° and -45° SOI, and NOx emissions increased as SOI was retarded beyond -40°, peaking around -25° SOI.
2017-03-28
Journal Article
2017-01-0909
Zhe Zhang, Mats Abom, Hans Boden, Mikael Karlsson, David Katoshevski
Abstract Air pollution caused by exhaust particulate matter (PM) from vehicular traffic is a major health issue. Increasingly strict regulations of vehicle emission have been introduced and efforts have been put on both the suppression of particulate formation inside the engine cylinders and the development of after-treatment technologies such as filters. With modern direct injected engines that produce a large number of really small sub-micron particles, the focus has increased even further and now also includes a number count. The problem of calculating particle trajectories in flow ducts like vehicle exhaust systems is challenging but important to further improve the technology. The interaction between particles and oscillating flows may lead to the formation of particle groups (regions where the particle concentration is increased), yielding a possibility of realizing particle agglomeration.
2017-03-28
Journal Article
2017-01-0946
Nathan Ottinger, Yuanzhou Xi, Christopher Keturakis, Z. Gerald Liu
Abstract Low-temperature (T ≤ 200°C) NOx conversion is receiving increasing research attention due to continued potential reductions in regulated NOx emissions from diesel engines. At these temperatures, ammonium salts (e.g., ammonium nitrate, ammonium (bi)sulfate, etc.) can form as a result of interactions between NH3 and NOx or SOx, respectively. The formation of these salts can reduce the availability of NH3 for NOx conversion, block active catalyst sites, and result in the formation of N2O, a regulated Greenhouse Gas (GHG). In this study, we investigate the effect of hydrothermal aging on the formation and decomposition of ammonium nitrate on a state-of-the-art Cu/zeolite selective catalytic reduction (SCR) catalyst. Reactor-based constant-temperature ammonium nitrate formation, temperature programmed oxidation (TPO), and NO titration experiments are used to characterize the effect of hydrothermal aging from 600 to 950°C.
2017-03-28
Journal Article
2017-01-0942
Joseph R. Theis, Christine Lambert
Abstract Model low temperature NOx adsorbers (LTNA) consisting of Pd on a ceria/zirconia washcoat on monoliths were evaluated for low temperature NOx storage under lean conditions to assess their potential for adsorbing the cold-start NOx emissions on a diesel engine during the period before the urea/SCR system becomes operational. A reactor-based transient test was performed with and without C2H4, CO/H2, and H2O to assess the effects of these species on the NOx storage performance. In the absence of C2H4 or CO/H2, H2O severely suppressed the NOx storage of these model LTNAs at temperatures below 100°C, presumably by blocking the storage sites. When C2H4 was included in the feedgas, H2O still suppressed the NOx storage below 100°C. However, the C2H4 significantly increased the NOx storage efficiency above 100°C, attributable to the formation of alkyl nitrites or alkyl nitrates on the catalyst.
2017-03-28
Journal Article
2017-01-0945
Markus Dietrich, Carsten Steiner, Gunter Hagen, Ralf Moos
Abstract The radio-frequency (RF) or microwave-based catalyst state determination offers the opportunity to operate an automotive catalyst at its optimal point. This has already been proven for the oxidation state of TWCs, the soot loading state on DPFs/GPFs, and the ammonia storage state of vanadium and zeolite based SCR catalysts. However, the latter has only been demonstrated in laboratory scale with synthetic exhaust using gaseous ammonia. This work presents first results on an engine test bench with a serial-type zeolite-based SCR catalyst, using urea solution and the RF tool to detect the current ammonia loading in real time and to control directly the urea dosing system without any additional sensors. The original catalyst volume was reduced by 50 % to operate deliberately the SCR system under high space velocities and to challenge its function. Stationary conditions and operation points with continuously changing NOx emissions and space velocities were observed.
2017-03-28
Journal Article
2017-01-0939
Ashok Kumar, Krishna Kamasamudram, Neal Currier, Aleksey Yezerets
Abstract Copper- and Iron- based metal-zeolite SCR catalysts are widely used in US and European diesel aftertreatment systems to achieve drastic reduction in NOx emission. These catalysts are highly selective to N2 under wide range of operating conditions. Nevertheless, the type of transition metal has a significant impact on the key performance and durability parameters such as NOx conversion, selectivity towards N2O, hydrothermal stability, and sensitivity to fuel sulfur content. In this study, we explained the differences in the performance characteristics of these catalysts based on their relative acidic-basic nature of transition metal present in these catalysts using practically relevant gas species present in diesel exhaust such as NO2, SOx, and NH3. These experiments show that Fe-zeolite has relatively acidic nature as compared to Cu-zeolite that causes NH3 inhibition and hence explains low NOx conversion on Fe-zeolite at low temperature under standard SCR conditions.
2017-03-28
Journal Article
2017-01-0919
Takeru Yoshida, Hiromasa Suzuki, Yuki Aoki, Naohiro Hayashi, Kenichi Ito
Abstract Emission regulations in many countries and regions around the world are becoming stricter in reaction to the increasing awareness of environment protections, and it has now become necessary to improve the performance of catalytic converters to achieve these goals. A catalytic converter is composed of a catalytically active material coated onto a ceramic honeycomb-structured substrate. Honeycomb substrates play the role of ensuring intimate contact between the exhaust gas and the catalyst within the substrate’s flow channels. In recent years, high-load test cycles have been introduced which require increased robustness to maintain low emissions during the wide range of load changes. Therefore, it is extremely important to increase the probability of contact between the exhaust gas and catalyst.
2017-03-28
Journal Article
2017-01-0911
Krishna Chilumukuru, Aniket Gupta, Michael Ruth, Michael Cunningham, Govindarajan Kothandaraman, Lasitha Cumaranatunge, Howard Hess
Abstract Future light duty vehicles in the United States are required to be certified on the FTP-75 cycle to meet Tier 3 or LEV III emission standards [1, 2]. The cold phase of this cycle is heavily weighted and mitigation of emissions during this phase is crucial to meet the low tail pipe emission targets [3, 4]. In this work, a novel aftertreatment architecture and controls to improve Nitrogen Oxides (NOx) and Hydrocarbon (HC) or Non Methane Organic gases (NMOG) conversion efficiencies at low temperatures is proposed. This includes a passive NOx & HC adsorber, termed the diesel Cold Start Concept (dCSC™) catalyst, followed by a Selective Catalytic Reduction catalyst on Filter (SCRF®) and an under-floor Selective Catalytic Reduction catalyst (SCR). The system utilizes a gaseous ammonia delivery system capable of dosing at two locations to maximize NOx conversion and minimize parasitic ammonia oxidation and ammonia slip.
2017-03-28
Journal Article
2017-01-0947
Athanasios G. Konstandopoulos, Dimitrios Zarvalis, Leonidas Chasapidis, Danis Deloglou, Nickolas Vlachos, Adam Kotrba, Ginette Anderson
Abstract Evolving marine diesel emission regulations drive significant reductions of nitrogen oxide (NOx) emissions. There is, therefore, considerable interest to develop and validate Selective Catalytic Reduction (SCR) converters for marine diesel NOx emission control. Substrates in marine applications need to be robust to survive the high sulfur content of marine fuels and must offer cost and pressure drop benefits. In principle, extruded honeycomb substrates of higher cell density offer benefits on system volume and provide increased catalyst area (in direct trade-off with increased pressure drop). However higher cell densities may become more easily plugged by deposition of soot and/or sulfate particulates, on the inlet face of the monolithic converter, as well as on the channel walls and catalyst coating, eventually leading to unacceptable flow restriction or suppression of catalytic function.
2017-03-28
Journal Article
2017-01-0535
Chih-Kuang Kuan, Daniel Styles, Mitchell Bieniek, John Hoard
Abstract Thermal effectiveness of Exhaust Gas Recirculation (EGR) coolers used in diesel engines can progressively decrease and stabilize over time due to inner fouling layer of the cooler tubes. Thermophoretic force has been identified as the major cause of diesel exhaust soot fouling, and models are proposed in the literature but improvements in simulation are needed especially for the long-term trend of soot deposition. To describe the fouling stabilization behavior, a removal mechanism is required to account for stabilization of the soot layer. Observations from previous experiments on surrogate circular tubes suggest there are three primary factors to determine removal mechanisms: surface temperature, thickness, and shear velocity. Based on this hypothesis, we developed a 1D CFD fouling model for predicting the thermal effectiveness reduction of real EGR coolers. The model includes the two competing mechanisms mentioned that results in fouling balance.
2017-03-28
Journal Article
2017-01-0540
Vincenzo De Bellis, Fabio Bozza, Luigi Teodosio, Gerardo Valentino
Abstract In this work, a promising technique, consisting of a liquid Water Injection (WI) at the intake ports, is investigated to overcome over-fueling and delayed combustions typical of downsized boosted engines, operating at high loads. In a first stage, experimental tests are carried out in a spark-ignition twin-cylinder turbocharged engine at a fixed rotational speed and medium-high loads. In particular, a spark timing and a water-to-fuel ratio sweep are both specified, to analyze the WI capability in increasing the knock-limited spark advance. In a second stage, the considered engine is schematized in a 1D framework. The model, developed in the GT-Power™ environment, includes user defined procedures for the description of combustion and knock phenomena. Computed results are compared with collected data for all the considered operating conditions, in terms of average performance parameters, in-cylinder pressure cycles, burn rate profiles, and knock propensity, as well.
2017-03-28
Journal Article
2017-01-0610
Nicolo Cavina, Francesco Ranuzzi, Matteo De Cesare, Enrico Brugnoni
Abstract The most recent European regulations for two- and three-wheelers (Euro 5) are imposing an enhanced combustion control in motorcycle engines to respect tighter emission limits, and Air-Fuel Ratio (AFR) closed-loop control has become a key function of the engine management system also for this type of applications. In a multi-cylinder engine, typically only one oxygen sensor is installed on each bank, so that the mean AFR of two or more cylinders rather than the single cylinder one is actually controlled. The installation of one sensor per cylinder is normally avoided due to cost, layout and reliability issues. In the last years, several studies were presented to demonstrate the feasibility of an individual AFR controller based on a single sensor. These solutions are based on the mathematical modelling of the engine air path dynamics, or on the frequency analysis of the lambda probe signal.
2017-03-28
Journal Article
2017-01-0584
Haksu Kim, Jaewook Shin, Myoungho Sunwoo
Abstract With fuel efficiency becoming an increasingly critical aspect of internal combustion engine (ICE) vehicles, the necessity for research on efficient generation of electric energy has been growing. An energy management (EM) system controls the generation of electric energy using an alternator. This paper presents a strategy for the EM using a control mode switch (CMS) of the alternator for the (ICE) vehicles. This EM recovers the vehicle’s residual kinetic energy to improve the fuel efficiency. The residual kinetic energy occurs when a driver manipulates a vehicle to decelerate. The residual energy is commonly wasted as heat energy of the brake. In such circumstances, the wasted energy can be converted to electric energy by operating an alternator. This conversion can reduce additional fuel consumption. For extended application of the energy conversion, the future duration time of the residual power is exploited.
2017-03-28
Journal Article
2017-01-0643
Thompson Lanzanova, Macklini Dalla Nora, Hua Zhao
Abstract The more strict CO2 emission legislation for internal combustion engines demands higher spark ignition (SI)engine efficiencies. The use of renewable fuels, such as bioethanol, may play a vital role to reduce not only CO2 emissions but also petroleum dependency. An option to increase SI four stroke engine efficiency is to use the so called over-expanded cycle concepts by variation of the valve events. The use of an early or late intake valve closure reduces pumping losses (the main cause of the low part load efficiency in SI engines) but decreases the effective compression ratio. The higher expansion to compression ratio leads to better use of the produced work and also increases engine efficiency. This paper investigates the effects of early and late intake valve closure strategies in the gas exchange process, combustion, emissions and engine efficiency at unthrottled stoichiometric operation.
2017-03-28
Journal Article
2017-01-0639
Michael H. Shelby, Thomas G. Leone, Kevin D. Byrd, Frank K. Wong
Abstract Increasing compression ratio (CR) is one of the most fundamental ways to improve engine efficiency, but the CR of practical spark ignition engines is limited by knock and spark retard at high loads. A variable CR mechanism could improve efficiency by using higher CR at low loads, and lower CR (with less spark retard) at high loads. This paper quantifies the potential efficiency benefits of applying variable CR to a modern downsized, boosted gasoline engine. Load sweeps were conducted experimentally on a multi-cylinder gasoline turbocharged direct injection (GTDI) engine at several CRs. Experimental results were compared to efficiency versus CR correlations from the literature and were used to estimate the fuel economy benefits of 2-step and continuously variable CR concepts on several engine/vehicle combinations, for various drive cycles.
2017-03-28
Journal Article
2017-01-0644
Michael Pontoppidan, Adm José baeta
Abstract In a torch ignition engine system the combustion starts in a prechamber, where the pressure increase pushes the combustion jet flames through calibrated nozzles to be precisely targeted into the main combustion chamber. The paper presents the layout of the prototype engine and the developed fuel injection system. It continues with a detailed description of the performance of the torch ignition engine running on a gasoline/ethanol blend for different mixture stratification levels as well as engine speeds and loads. Also detailed analyses of specific fuel consumption, thermal and combustion efficiency, specific emissions of CO2 and the main combustion parameters are carried out. A supplementary decrease in NOX emissions was obtained by use of Brazilian pure hydrated fuel. The paper concludes presenting the main results obtained in this work, which show significant increase of the torch ignition engine performance in comparison with the commercial baseline engine.
2017-03-28
Journal Article
2017-01-0647
Bradley Denton, Christopher Chadwell, Raphael Gukelberger, Terrence Alger
Abstract The Dedicated EGR (D-EGR®) engine has shown improved efficiency and emissions while minimizing the challenges of traditional cooled EGR. The concept combines the benefits of cooled EGR with additional improvements resulting from in-cylinder fuel reformation. The fuel reformation takes place in the dedicated cylinder, which is also responsible for producing the diluents for the engine (EGR). The D-EGR system does present its own set of challenges. Because only one out of four cylinders is providing all of the dilution and reformate for the engine, there are three “missing” EGR pulses and problems with EGR distribution to all 4 cylinders exist. In testing, distribution problems were realized which led to poor engine operation. To address these spatial and temporal mixing challenges, a distribution mixer was developed and tested which improved cylinder-to-cylinder and cycle-to-cycle variation of EGR rate through improved EGR distribution.
2017-03-28
Journal Article
2017-01-0648
Dennis Robertson, Christopher Chadwell, Terrence Alger, Jacob Zuehl, Raphael Gukelberger, Bradley Denton, Ian Smith
Abstract Dedicated EGR (D-EGR) is an EGR strategy that uses in-cylinder reformation to improve fuel economy and reduce emissions. The entire exhaust of a sub-group of power cylinders (dedicated cylinders) is routed directly into the intake. These cylinders are run fuel-rich, producing H2 and CO (reformate), with the potential to improve combustion stability, knock tolerance and burn duration. A 2.0 L turbocharged D-EGR engine was packaged into a 2012 Buick Regal and evaluated on drive cycle performance. City and highway fuel consumption were reduced by 13% and 9%, respectively. NOx + NMOG were 31 mg/mile, well below the Tier 2 Bin 5 limit and just outside the Tier 3 Bin 30 limit (30 mg/mile).
2017-03-28
Journal Article
2017-01-0674
Benjamin Matthew Wolk, Isaac Ekoto
Abstract Pulsed nanosecond discharges (PND) can achieve ignition in internal combustion engines through enhanced reaction kinetics as a result of elevated electron energies without the associated increases in translational gas temperature that cause electrode erosion. Atomic oxygen (O), including its electronically excited states, is thought to be a key species in promoting low-temperature ignition. In this paper, high-voltage (17-24 kV peak) PND are examined in oxygen/nitrogen/carbon dioxide/water mixtures at engine-relevant densities (up to 9.1 kg/m3) through pressure-rise calorimetry and direct imaging of excited-state O-atom and molecular nitrogen (N2) in an optically accessible spark calorimeter, with the anode/cathode gap distance set to 5 mm or with an anode-only configuration (DC corona). The conversion efficiency of pulse electrical energy into thermal energy was measured for PND with secondary streamer breakdown (SSB) and similar low-temperature plasmas (LTP) without.
2017-03-28
Journal Article
2017-01-0704
Noriyuki Takada, Takeshi Hashizume, Terutoshi Tomoda, Kazuhisa Inagaki, Kiyomi Kawamura
Abstract Generally, soot emissions increase in diesel engines with smaller bore sizes due to larger spray impingement on the cavity wall at a constant specific output power. The objective of this study is to clarify the constraints for engine/nozzle specifications and injection conditions to achieve the same combustion characteristics (such as heat release rate and emissions) in diesel engines with different bore sizes. The first report applied the geometrical similarity concept to two engines with different bore sizes and similar piston cavity shapes. The smaller engine emitted more smoke because air entrainment decreases due to the narrower spray angle. A new spray design method called spray characteristics similarity was proposed to suppress soot emissions. However, a smaller nozzle diameter and a larger number of nozzle holes are required to maintain the same spray characteristics (such as specific air-entrainment and penetration) when the bore size decreases.
2017-03-28
Journal Article
2017-01-0691
Louis-Marie Malbec, Julian Kashdan
Abstract Previous experimental data obtained in constant volume combustion vessels have shown that soot-free diffusive flames can be achieved in a Diesel spray if the equivalence ratio at the flame lift-off location is below 2. The so-called Leaner Lifted-Flame Combustion (LLFC) strategy is a promising approach to limit the levels of in-cylinder soot produced in Diesel engines. However, implementing such strategies in light-duty engines is not straightforward due to the effects of charge confinement , non-steady boundary conditions and spray-spray interactions compared to the simplified configuration of a free-jet in a constant-volume combustion vessel. The present study aims at trying to gain a better understanding of the requirements in terms of injector and engine settings in order to reach the LLFC regime in a light-duty engine. Experiments were performed on a 0.5L single-cylinder optical engine.
2017-03-28
Journal Article
2017-01-0695
Ezio Spessa, Stefano D'Ambrosio, Daniele Iemmolo, Alessandro Mancarella, Roberto Vitolo, Gilles Hardy
Abstract In the present work, different combustion control strategies have been experimentally tested in a heavy-duty 3.0 L Euro VI diesel engine. In particular, closed-loop pressure-based and open-loop model-based techniques, able to perform a real-time control of the center of combustion (MFB50), have been compared with the standard map-based engine calibration in order to highlight their potentialities. In the pressure-based technique, the instantaneous measurement of in-cylinder pressure signal is performed by a pressure transducer, from which the MFB50 can be directly calculated and the start of the injection of the main pulse (SOImain) is set in a closed-loop control to reach the MFB50 target, while the model-based approach exploits a heat release rate predictive model to estimate the MFB50 value and sets the corresponding SOImain in an open-loop control. The experimental campaign involved both steady-state and transient tests.
2017-03-28
Journal Article
2017-01-0951
Paul Mentink, Xander Seykens, Daniel Escobar Valdivieso
Abstract To meet future emission targets, it becomes increasingly important to optimize the synergy between engine and aftertreatment system. By using an integrated control approach minimal fluid (fuel and DEF) consumption is targeted within the constraints of emission legislation during real-world operation. In such concept, the on-line availability of engine-out NOx emission is crucial. Here, the use of a Virtual NOx sensor can be of great added-value. Virtual sensing enables more direct and robust emission control allowing, for example, engine-out NOx determination during conditions in which the hardware sensor is not available, such as cold start conditions. Furthermore, with use of the virtual sensor, the engine control strategy can be directly based on NOx emission data, resulting in reduced response time and improved transient emission control. This paper presents the development and on-line implementation of a Virtual NOx sensor, using in-cylinder pressure as main input.
2017-03-28
Journal Article
2017-01-0952
Michael B. Hopka, David Bilby, Michiel Van Nieuwstadt
Abstract The resistive particulate matter sensor (PMS) is rapidly becoming ubiquitous on diesel vehicles as a means to diagnose particulate filter (DPF) leaks. By design the device provides an integrated measure of the amount of PM to which it has been exposed during a defined measurement period within a drive cycle. The state of the art resistive PMS has a large deadband before any valid output related to the accumulated PM is realized. As a result, most DPF monitors that use the PMS consider its output only as an indicator that a threshold quantity of PM has amassed rather than a real-time measure of concentration. This measurement paradigm has the unfortunate side effect that as the PM OBD threshold decreases, or the PMS is used on a vehicle with a larger exhaust volume flow, a longer measurement is required to reach the same PM sensor output. Longer PMS measurement times lead to long particulate filter monitoring durations that may reduce filter monitor completion frequency.
2017-03-28
Journal Article
2017-01-0954
Christopher Sharp, Cynthia C. Webb, Gary Neely, Michael Carter, Seungju Yoon, Cary Henry
Abstract The most recent 2010 emissions standards for heavy-duty engines have established a tailpipe limit of oxides of nitrogen (NOX) emissions of 0.20 g/bhp-hr. However, it is projected that even when the entire on-road fleet of heavy-duty vehicles operating in California is compliant with 2010 emission standards, the National Ambient Air Quality Standards (NAAQS) requirement for ambient particulate matter and Ozone will not be achieved without further reduction in NOX emissions. The California Air Resources Board (CARB) funded a research program to explore the feasibility of achieving 0.02 g/bhp-hr NOX emissions.
2017-03-28
Journal Article
2017-01-0955
Hai-Ying Chen, Donna Liu, Erich Weigert, Lasitha Cumaranatunge, Kenneth Camm, Patrick Bannon, Julian Cox, Louise Arnold
Abstract The phase-in of US EPA Tier 3 and California LEV III emission standards require further reduction of tailpipe criteria pollutants from automobiles. At the same time, the mandate for reducing Green House Gas (GHG) emissions continuously lowers the exhaust temperature. Both regulations pose significant challenges to emission control catalyst technologies, especially for cold start emissions. The recently developed diesel cold start concept technology (dCSC™) shows promising results. It stores NOx and HC during the cold start period until the downstream catalytic components reach their operating temperatures, when the stored NOx/HC are subsequently released and converted. The technology also has oxidation functions built in and acts as a diesel oxidation catalyst under normal operating conditions. In a US DOE funded project, the diesel cold start concept technology enabled a high fuel efficiency vehicle to achieve emissions targets well below the SULEV30 emission standards.
2017-03-28
Journal Article
2017-01-0956
Christopher Sharp, Cynthia C. Webb, Seungju Yoon, Michael Carter, Cary Henry
Abstract The 2010 emissions standards for heavy-duty engines have established a limit of oxides of nitrogen (NOX) emissions of 0.20 g/bhp-hr. However, the California Air Resource Board (ARB) projects that even when the entire on-road fleet of heavy-duty vehicles operating in California is compliant with 2010 emission standards, the National Ambient Air Quality Standards (NAAQS) requirement for ambient particulate matter (PM) and Ozone will not be achieved without further reduction in NOX emissions. The California Air Resources Board (CARB) funded a research program to explore the feasibility of achieving 0.02 g/bhp-hr NOX emissions.
2017-03-28
Journal Article
2017-01-0970
Johann C. Wurzenberger, Christoph Triebl, Susanne Kutschi, Christoph Poetsch
The present work describes an existing transient, non-isothermal 1D+1D particulate filter model to capture the impact of different types of particulate matter (PM) on filtration and regeneration. PM classes of arbitrary characteristics (size, composition etc.) are transported and filtered following standard mechanisms. PM deposit populations of arbitrary composition and contact states are used to describe regeneration on a micro-kinetical level. The transport class and deposit population are linked by introducing a splitting deposit matrix. Filtration and regeneration modes are compared to experimental data from literature and a brief numerical assessment on the filtration model is performed. The filter model as part of an exhaust line is used in a concept study on different coating variants. The same exhaust line model is connected to an engine thermodynamic and vehicle model. This system model is run through a random drive cycle in office simulation.
2017-03-28
Journal Article
2017-01-0958
Christopher Sharp, Cynthia C. Webb, Gary Neely, Jayant V. Sarlashkar, Sankar B. Rengarajan, Seungju Yoon, Cary Henry, Bryan Zavala
Abstract Recent 2010 emissions standards for heavy-duty engines have established a limit of oxides of nitrogen (NOX) emissions of 0.20 g/bhp-hr. However, CARB has projected that even when the entire on-road fleet of heavy-duty vehicles operating in California is compliant with 2010 emission standards, the National Ambient Air Quality Standards (NAAQS) requirement for ambient particulate matter and Ozone will not be achieved without further reduction in NOX emissions. The California Air Resources Board (ARB) funded a research program to explore the feasibility of achieving 0.02 g/bhp-hr NOX emissions. This paper details engine and aftertreatment NOX management requirements and model based control considerations for achieving Ultra-Low NOX (ULN) levels with a heavy-duty diesel engine. Data are presented for several Advanced Technology aftertreatment solutions and the integration of these solutions with the engine calibration.
2017-03-28
Journal Article
2017-01-0978
Andrew Auld, Andrew Ward, Kenan Mustafa, Benjamin Hansen
Abstract Since previous publications, Ricardo have continued to investigate the development of advanced after-treatment technologies through model based system simulation using an integrated model based development (IMBD) approach. This paper presents the results of the evaluation of after-treatment systems and management strategies for a range of diesel passenger cars. The targets of this study are applicable to Real Driving Emissions (RDE) legislation, but now targeting emissions levels beyond Euro 6d. The work was carried out as part of the EC Horizon 2020 co-funded REWARD (Real World Advanced technologies foR Diesel engines) project. Owing to the wide variation in feed-gas properties expected over an RDE cycle, the results seen for current production system architectures such as Lean NOX traps (LNT) or actively dosed Selective Catalytic Reduction (aSCR) systems highlight the challenge to adhere to emissions limitations for RDE legislation whilst fulfilling stringent CO2 targets.
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