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Viewing 91 to 120 of 21878
2017-03-28
Technical Paper
2017-01-0592
Robin Holmbom, Bohan Liang, Lars Eriksson
1 Turbocharging plays an important role in the downsizing of engines. Model-based approaches for boost control are going to increasing the necessity for controlling the wastegate flow more accurately. In today’s cars, the wastegate is usually only controlled with a duty cycle and without position feedback. Due to nonlinearities and varying disturbances a duty cycle does not correspond to a certain position. Currently the most frequently used feedback controller strategy is to use the boost pressure as the controller reference. This means that there is a large time constant from actuation command to effect in boost pressure, which can impair dynamic performance. In this paper, the performance of an electrically controlled vacuum-actuated waste-gate, subsequently referred to as vacuum wastegate, is compared to an electrical servo-controlled wastegate, also referred to as electric wastegate.
2017-03-28
Technical Paper
2017-01-0593
Ivan Arsie, Rocco Di Leo, Cesare Pianese, Matteo De Cesare
Abstract The development of more affordable sensors together with the enhancement of computation features in current Engine Management Systems (EMS), makes the in-cylinder pressure sensing a suitable methodology for the on-board engine control and diagnosis. Since the 1960’s the in-cylinder pressure signal was employed to investigate the combustion process of the internal combustion engines for research purposes. Currently, the sensors cost reduction in addition to the need to comply with the strict emissions legislation has promoted a large-scale diffusion on production engines equipment. The in-cylinder pressure signal offers the opportunity to estimate with high dynamic response almost all the variables of interest for an effective engine combustion control even in case of non-conventional combustion processes (e.g. PCCI, HCCI, LTC).
2017-03-28
Technical Paper
2017-01-0591
Andreas Thomasson, Xavier Llamas, Lars Eriksson
1 In modern turbocharged engines the power output is strongly connected to the turbocharger speed, through the flow characteristics of the turbocharger. Turbo speed is therefore an important state for the engine operation, but it is usually not measured or controlled directly. Still the control system must ensure that the turbo speed does not exceed its maximum allowed value to prevent damaging the turbocharger. Having access to a turbo speed signal, preferably by a cheap and reliable estimation instead of a sensor, could be beneficial for over speed protection and supervision of the turbocharger. This paper proposes a turbo speed observer that only utilizes the conditions around the compressor and a model for the compressor map. These conditions are either measured or can be more easily estimated from available sensors compared the conditions on the turbine side.
2017-03-28
Technical Paper
2017-01-0588
Adithya P Reddy Ranga, Gopichandra Surnilla, Joseph Thomas, Ethan Sanborn, Mark Linenberg
Abstract Dual fuel injection systems, like PFI+DI (port fuel injection + direct injection system) are being increasingly used in gasoline engine applications to increase the engine performance, fuel efficiency and reduce emissions. At a given engine operating condition, the air/fuel error is a function of the fraction of fuel injected by each of the fuel systems. If the fraction of fuel from each of the fuel system is changed at a given operating condition, the fuel system error will change as well making it challenging to learn the fuel system errors. This paper aims at describing the adaptive fueling control algorithm to estimate the fuel error contribution from each individual fuel system. Considering the fuel injection system slope errors to be the significant cause for air-fuel errors, a model structure was developed to calculate the fuel system adaptive correction factor as a function of changing fraction of fueling between the fuel systems.
2017-03-28
Technical Paper
2017-01-0604
Christian Friedrich, Yves Compera, Matthias Auer, Gunnar Stiesch, Georg Wachtmeister
Abstract Improving fuel efficiency while meeting relevant emission limits set by emissions legislation is among the main objectives of engine development. Simultaneously the development costs and development time have to be steadily reduced. For these reasons, the high demands in terms of quality and validity of measurements at the engine test bench are continuously rising. This paper will present a new methodology for efficient testing of an industrial combustion engine in order to improve the process of decision making for combustion-relevant component setups. The methodology includes various modules for increasing measurement quality and validity. Modules like stationary point detection to determine steady state engine behavior, signal quality checks to monitor the signal quality of chosen measurement signals and plausibility checks to evaluate physical relations between several measurement signals ensure a high measurement quality over all measurements.
2017-03-28
Technical Paper
2017-01-0601
Huayi Li, Kenneth Butts, Kevin Zaseck, Dominic Liao-McPherson, Ilya Kolmanovsky
Abstract The development of advanced model-based engine control strategies, such as economic model predictive control (eMPC) for diesel engine fuel economy and emission optimization, requires accurate and low-complexity models for controller design validation. This paper presents the NOx and smoke emissions modeling of a light duty diesel engine equipped with a variable geometry turbocharger (VGT) and a high pressure exhaust gas recirculation (EGR) system. Such emission models can be integrated with an existing air path model into a complete engine mean value model (MVM), which can predict engine behavior at different operating conditions for controller design and validation before physical engine tests. The NOx and smoke emission models adopt an artificial neural network (ANN) approach with Multi-Layer Perceptron (MLP) architectures. The networks are trained and validated using experimental data collected from engine bench tests.
2017-03-28
Technical Paper
2017-01-0611
Viktor Leek, Kristoffer Ekberg, Lars Eriksson
1 ABSTRACT Today’s need for fuel efficient vehicles, together with increasing engine component complexity, makes optimal control a valuable tool in the process of finding the most fuel efficient control strategies. To efficiently calculate the solution to optimal control problems a gradient based optimization technique is desirable, making continuously differentiable models preferable. Many existing control-oriented Diesel engine models do not fully posses this property, often due to signal saturations or discrete conditions. This paper offers a continuously differentiable, mean value engine model, of a heavy-duty diesel engine equipped with VGT and EGR, suitable for optimal control purposes. The model is developed from an existing, validated, engine model, but adapted to be continuously differentiable and therefore tailored for usage in an optimal control environment. The changes due to the conversion are quantified and presented.
2017-03-28
Technical Paper
2017-01-0606
Ashley Wiese, Anna Stefanopoulou, Julia Buckland, Amey Y. Karnik
Abstract Low-Pressure Exhaust Gas Recirculation (LP-EGR) has been shown to be an effective means of improving fuel economy and suppressing knock in downsized, boosted, spark ignition engines. LP-EGR is particularly beneficial at low-speed, high-load conditions, but can lead to combustion instability at lower loads. The transport delays inherent in LP-EGR systems slow the reduction of intake manifold EGR concentrations during tip-out events, which may lead to excessive EGR concentrations at low load. This paper explores leveraging Variable Valve Timing (VVT) as a means of improving the rate of reduction of intake manifold EGR concentration prior to tip-out. At higher boost levels, high valve overlap may result in intake manifold gas passing directly to the exhaust manifold. This short-circuiting behaviour could potentially improve EGR evacuation rates.
2017-03-28
Technical Paper
2017-01-0775
Robert Draper, Brendan Lenski, Franz-Joseph Foltz, Roderick Beazley, William Tenny
Abstract With environmental policies becoming ever more stringent, there is heightened interest in natural gas (NG) as a viable fuel for medium to heavy duty engines. Typically, the industry has seen minor changes to the base engine when converting to run on NG, which, in turn historically provides degraded performance. In utilizing the positive properties of NG, Westport Fuel Systems has developed the High Efficiency Spark Ignition (HESI) combustion technology that has been shown to significantly improve performance. The HESI technology leverages a proven combustion system that is capable of generating a knock resistant charge motion while cooling the flame face. In conjunction with high boost for driving high pressure exhaust gas recirculation (EGR), this technology demonstrates the possibility for downsizing strategies while maintaining performance.
2017-03-28
Technical Paper
2017-01-1400
Keyu Qian, Gangfeng Tan, Renjie Zhou, Binyu Mei, Wanyang XIA
Abstract Downhill mountain roads are the accident prone sections because of their complexity and variety. Drivers rely more on driving experience and it is very easy to cause traffic accidents due to the negligence or the judgment failure. Traditional active safety systems, such as ABS, having subjecting to the driver's visual feedback, can’t fully guarantee the downhill driving safety in complex terrain environments. To enhance the safety of vehicles in the downhill, this study combines the characteristics of vehicle dynamics and the geographic information. Thus, through which the drivers could obtain the safety speed specified for his/her vehicle in the given downhill terrains and operate in advance to reduce traffic accidents due to driver's judgment failure and avoid the brake overheating and enhance the safety of vehicles in the downhill.
2017-03-28
Technical Paper
2017-01-1721
Ho Teng, Ruigang Miao, Liming Cao, Xuwei Luo, Tingjun Hu, Min Wu
Abstract In order to improve low speed torques, turbocharged gasoline direct injection (TGDI) engines often employ scavenging with a help of variable valve timing (VVT) controlled by the cam phasers. Scavenging improves the compressor performance at low flows and boosts low-speed-end torques of the engines. Characteristics of the engine combustion in the scavenging zone were studied with a highly-boosted 1.5L TGDI engine experimentally. It was found that the scavenging zone was associated with the highest blowby rates on the engine map. The blowby recirculation was with heavy oil loading, causing considerable hydrocarbon fouling on the intake ports as well as on the stem and the back of the intake valves after the engine was operated in this zone for a certain period of time. The low-speed pre-ignition (LSPI) events observed in the engine tests fell mainly in the scavenging zone.
2017-03-28
Technical Paper
2017-01-0511
Tianhao Yang, Lianhao Yin, Gabriel Ingesson, Per Tunestal, Rolf Johansson, Wuqiang Long
Abstract In this paper, a control-oriented soot model was developed for real-time soot prediction and combustion condition optimization in a gasoline Partially Premixed Combustion (PPC) Engine. PPC is a promising combustion concept that achieves high efficiency, low soot and NOx emissions simultaneously. However, soot emissions were found to be significantly increased with high EGR and pilot injection, therefore a predictive soot model is needed for PPC engine control. The sensitivity of soot emissions to injection events and late-cycle heat release was investigated on a multi-cylinder heavy duty gasoline PPC engine, which indicated main impact factors during soot formation and oxidation processes. The Hiroyasu empirical model was modified according to the sensitivity results, which indicated main influences during soot formation and oxidation processes. By introducing additional compensation factors, this model can be used to predict soot emissions under pilot injection.
2017-03-28
Technical Paper
2017-01-0163
Gursaran D. Mathur
The author has developed a model that can be used to predict build-up of cabin carbon dioxide levels for automobiles based on many variables. There are a number of parameters including number of occupants that dictates generation of CO2 within the control volume, cabin leakage (infiltration or exfiltration) characteristics, cabin volume, blower position or airflow rate; vehicle age, etc. Details of the analysis is presented in the paper. Finally, the developed model has been validated with experimental data. The simulated data follows the same trend and matches fairly well with the experimental data.
2017-03-28
Technical Paper
2017-01-1275
David Hobbs, Charles Ossenkop, Andy Latham
Abstract Global sales of electric and hybrid vehicles continue to grow as emission legislation forces vehicle manufacturers to build cleaner vehicles, with some 8 million already in service. Hybrid and Electric vehicles contain some of the most complex systems ever used in the automotive field, sophisticated and unique electric hybrid systems are added to modern motor vehicles which are already quite complex. As these vehicles reach the end of their lives they will be processed by the global vehicle recycling industry and the high voltage components will be reused, recycled or re-purposed. This paper explores safe working practices for businesses involved in a global marketplace who are completing battery disabling, removal, disassembly, storage and shipping; includes the various technologies and safe working practices along with some of the legal restrictions on dismantling, storage and shipping of high voltage batteries around the world.
2017-03-28
Journal Article
2017-01-1639
Gerard W. Malaczynski, Gregory Roth
Abstract Onboard diagnostic regulations require performance monitoring of diesel particulate filters used in vehicle aftertreatment systems. Delphi has developed a particulate matter (PM) sensor to perform this function. The objective of this sensor is to monitor the soot (PM) concentration in the exhaust downstream of the diesel particulate filter which provides a means to calculate filter efficiency. The particulate matter sensor monitors the deposition of soot on its internal sensing element by measuring the resistance of the deposit. Correlations are established between the soot resistance and soot mass deposited on the sensing element. Currently, the sensor provides the time interval between sensor regeneration cycles, which, with the knowledge of the exhaust gas flow parameters, is correlated to the average soot concentration.
2017-03-28
Technical Paper
2017-01-0944
Ryuji Ando, Takashi Hihara, Yasuyuki Banno, Makoto Nagata, Tomoaki Ishitsuka, Nobuyuki Matsubayashi, Toshihisa Tomie
Abstract Modern diesel emission control systems often use Urea Selective Catalytic Reduction (Urea-SCR) for NOx control. One of the most active SCR catalysts is based on Cu-zeolite, specifically Cu-Chabazite (Cu-CHA), also known as Cu-SSZ-13. The Cu-SCR catalyst exhibits high NOx control performance and has a high thermal durability. However, its catalytic performance deteriorates upon long-term exposure to sulfur. This work describes our efforts to investigate the detailed mechanism of poisoning of the catalyst by sulfur, the optimum conditions required for de-sulfation, and the recovery of catalytic activity. Density functional theory (DFT) calculations were performed to locate the sulfur adsorption site within the Cu-zeolite structure. Analytical characterization of the sulfur-poisoned catalyst was performed using Extreme Ultraviolet Photoelectron Spectroscopy (EUPS) and Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS).
2017-03-28
Technical Paper
2017-01-0938
Gillis Hommen, Frank Kupper, Xander Seykens
Abstract This article describes a NOx sensor based urea dosing control strategy for heavy-duty diesel aftertreatment systems using Selective Catalytic Reduction. The dosing control strategy comprises of a fast-response, model-based ammonia storage control system in combination with a long-timescale tailpipe-feedback module that adjusts the dosing quantity according to current aftertreatment conditions. This results in a control system that is robust to system disturbances such as biased NOx sensors and variations in AdBlue concentrations. The cross-sensitivity of the tailpipe NOx sensor to ammonia is handled by a novel, smart signal filter that can reliably identify the contributions of NOx and NH3 in the tailpipe sensor signal, without requiring an artificial perturbation of the dosing signal.
2017-03-28
Technical Paper
2017-01-1004
Jan Czerwinski, Pierre Comte, Norbert Heeb, Andreas Mayer, Volker Hensel
Abstract In the present paper some results of investigations of nanoparticles from five DI gasoline cars are represented. The measurements were performed at vehicle tailpipe and in CVS-tunnel. Moreover, five variants of “vehicle - GPF” were investigated. These results originate from the project GasOMeP (Gasoline Organic & Metal Particulates), which focused on metal-nanoparticles (including sub 20nm) from gasoline cars with different engine technologies. The PN-emission level of the investigated GDI cars in WLTC without GPF is in the same range of magnitude very near to the actual limit value of 6.0 × 1012 #/km. With the GPF’s with better filtration quality, it is possible to lower the emissions below the future limit value of 6.0 × 1011 #/km. There is no visible nuclei mode and the ultrafine particle concentrations below 10mm are insignificant. Some of the vehicles show at constant speed operation a periodical fluctuation of the NP-emissions, as an effect of the electronic control.
2017-03-28
Technical Paper
2017-01-0968
Anand Srinivasan, Saurabh Joshi, Yadan Tang, Di Wang, Neal Currier, Aleksey Yezerets
Abstract Commercial Cu-Zeolite SCR catalyst can store and subsequently release significant amount of H2O. The process is accompanied by large heat effects. It is critical to model this phenomenon to design aftertreatment systems and to provide robust tuning strategies to meet cold start emissions and low temperature operation. The complex reaction mechanism of water adsorption and desorption over a Cu-exchanged SAPO-34 catalyst at low temperature was studied through steady state and transient experiments. Steady state isotherms were generated using a gravimetric method and then utilized to predict water storage interactions with respect to feed concentration and catalyst temperature. Transient temperature programmed desorption (TPD) experiments provided the kinetic information required to develop a global kinetic model from the experimental data. The model captures fundamental characteristics of water adsorption and desorption accompanied by the heat effects.
2017-03-28
Technical Paper
2017-01-0634
Schoeffmann Wolfgang, Helfried Sorger, Siegfried Loesch, Wolfgang Unzeitig, Thomas Huettner, Alois Fuerhapter
Abstract In order to achieve future CO2 targets - in particular under real driving conditions - different powertrain technologies will have to be introduced. Beside the increasing electrification of the powertrain, it will be essential to utilize the full potential of the internal combustion engine. In addition to further optimization of the combustion processes and the reduction of mechanical losses in the thermal- and energetic systems, the introduction of Variable Compression Ratio (VCR) is probably the measure with the highest potential for fuel economy improvement. VCR systems are expected to be introduced to a considerable number of next generation turbocharged Spark Ignited (SI) engines in certain vehicle classes. The basic principle of the AVL VCR system described in this paper is a 2-stage variation of the conrod length and thus the Compression Ratio (CR).
2017-03-28
Journal Article
2017-01-0925
Tatsuro Sugino, Eriko Tanaka, Huong Tran, Norihiko Aono
Abstract Diesel particulate filters (DPFs) are an essential aftertreatment component for reducing the PM emissions of diesel engine vehicles. Installation of a DPF can achieve high filtration efficiency, but PM filtration also causes a high pressure drop due to deep bed filtration. Consequently, periodic PM regeneration is necessary to keep a low pressure drop, but this causes significant deterioration in fuel efficiency. Improving the efficiency of PM regeneration and keeping the pressure drop low are major challenges faced by DPF manufacturers in meeting future CO2 emissions regulations. This paper presents a novel morphological catalyst layer for DPFs, which is located in the surface of the inlet DPF channels and has been formed into a highly porous and three-dimensional meshwork shape. These features enhanced not only the prevention of deep bed filtration to reduce the pressure drop, but also the soot-catalyst contact for a faster PM regeneration rate.
2017-03-28
Journal Article
2017-01-0926
Kentaro Iwasaki
Abstract The diesel particulate filter (DPF) has been used in the automobile industry for around a decade. As a key technology for emissions control the DPF design needs to be increasingly optimized to expand its function to deal with any emission not just particulate matter (PM). NOx emission regulations need to be met as well as CO2 targets through minimizing any fuel penalty. Cost is extremely important to deliver an effective after-treatment catalyst. Aluminum titanate and cordierite-based material DPFs are very cost effective in part because their properties allow monolith-manufacturing. Furthermore, geometrical design of the DPF channel structure can contribute to multi-functionalization of the DPF to provide further advantages. Square and asymmetric square-designed channel structures have been utilized on current after-treatment DPF systems.
2017-03-28
Technical Paper
2017-01-0921
Bharadwaj Sathiamoorthy, Alex Graper, Andrew McIntosh, William Kaminski
Abstract The automotive aftermarket industry is an extremely cost competitive market to say the least. Aftermarket manufacturers are sought by customers primarily for their ability to replace an OES (Original Equipment Supplier) for a fraction of the cost. This forces the manufacturers to yield on performance abilities to get a share in the market place. The TWC system in gasoline vehicles not only acts as an emissions reduction device but is an integral part of the overall vehicle performance itself, especially since the introduction of OBD (On-Board Diagnostics) II systems in 1995. An inefficient catalyst not only leads to excessive tailpipe emissions but also acts detrimental to vehicle fueling and hence overall performance. The aftermarket catalyst industry which is regulated by EPA (United States Environmental Protection Agency) and CARB (California Air Resource Board) for gasoline engines is subject to meeting a mandatory performance standard for the same reason.
2017-03-28
Journal Article
2017-01-0935
Christoph Boerensen, Dirk Roemer, Christian Nederlof, Evgeny Smirnov, Frank Linzen, Felix Goebel, Brendan Carberry
Abstract The most significant challenge in emission control for compression ignited internal combustion engines is the suppression of NOx. In the US, NOx-levels have faced a progressive reduction for several years, but recently the introduction of the Real Driving Emissions legislation (RDE) in Europe has not only significantly increased the severity of the required emission reduction but now is in the advent of stretching technology to its limits. Emission control is based on engine-internal optimization to reduce the engine-out emissions in conjunction with aftertreatment technologies, that are either Selective Catalytic Reduction (SCR) or Lean NOx Trap (LNT) based systems. Due to its ability to control high amounts of NOx, SCR is widely used in heavy-duty applications and is becoming more popular in light-duty and passenger car applications as well.
2017-03-28
Technical Paper
2017-01-0933
Yunhua Zhang, Diming Lou, Piqiang Tan, Zhiyuan Hu, Qian Feng
Abstract Biodiesel as a renewable energy is becoming increasingly attractive due to the growing scarcity of conventional fossil fuels. Meanwhile, the development of after-treatment technologies for the diesel engine brings new insight concerning emissions especially the particulate matter pollutants. In order to study the coupling effects of biodiesel blend and CCRT (Catalyzed Continuously Regeneration Trap) on the particulate matter emissions, the particulate matter emissions from an urban bus with and without CCRT burning BD0 and BD10 respectively was tested and analyzed using electrical low pressure impactor (ELPI). The operation conditions included steady state conditions and transient conditions. Results showed that the particulate number-size distribution of BD10 and BD0 both had two peaks in nuclei mode and accumulation mode at the conditions of idle, low speed and medium speed while at high speed condition the particulate number-size distribution only had one peak.
2017-03-28
Technical Paper
2017-01-0936
Pavel Krejza, Jaroslav Pekar, Jiri Figura, Lukas Lansky, Dirk von Wissel, Tianran Zhang
Abstract The paper provides an overview of a developed methodology and a toolchain for modeling and control of a complex aftertreatment system for passenger cars. The primary objective of this work is to show how the use of this methodology allows to streamline the development process and to reduce the development time thanks to a model based semi-automatic control design methodology combined with piece-wise optimal control. Major improvements in passenger car tailpipe NOx removal need to be achieved to fulfil the upcoming post EURO 6 norms and Real Driving Emissions (RDE) limits. Multi-brick systems employing combinations of multiple Selective Catalytic Reduction (SCR) catalysts with an Ammonia Oxidation Catalysts, known also as Ammonia Clean-Up Catalyst (CUC), are proposed to cover operation over a wide temperature range. However, control of multi-brick systems is complex due to lack of available sensors in the production configurations.
2017-03-28
Technical Paper
2017-01-0932
Nehemiah S I Alozie, George Fern, David Peirce, Lionel Ganippa
Abstract The use of diesel particulate filter [DPF] has become a standard in modern diesel engine after treatment technology. However pressure drop develops across the filter as PM accumulates and this requires quick periodic burn-out without incurring thermal runaway temperatures that could compromise DPF integrity during operation. Adequate understanding of soot oxidation is needed for design and manufacture of efficient filter traps for the engine system. In this study, we have examined the impact of blending biodiesel on oxidation of PM generated from a high speed direct injection [HSDI] diesel engine, which was operated with 20% [B20] and 40% [B40] blends of two biodiesel fuels. The PM samples were collected from the engine exhaust using a Pall Tissuquartz filter, the oxidation characteristics of the samples were carried out using thermogravimetric analyzer [TGA]. The biodiesel oxidation data obtained from pure petrodiesel was compared against the fuel blends.
2017-03-28
Journal Article
2017-01-0899
Paul Dekraker, John Kargul, Andrew Moskalik, Kevin Newman, Mark Doorlag, Daniel Barba
Abstract The Environmental Protection Agency’s (EPA’s) Advanced Light-Duty Powertrain and Hybrid Analysis (ALPHA) tool was created to estimate greenhouse gas (GHG) emissions from light-duty vehicles. ALPHA is a physics-based, forward-looking, full vehicle computer simulation capable of analyzing various vehicle types with different powertrain technologies, showing realistic vehicle behavior, and auditing of internal energy flows in the model. In preparation for the midterm evaluation (MTE) of the 2017-2025 light-duty GHG emissions rule, ALPHA has been updated utilizing newly acquired data from model year 2013-2016 engines and vehicles. Simulations conducted with ALPHA provide data on the effectiveness of various GHG reduction technologies, and reveal synergies that exist between technologies. The ALPHA model has been validated against a variety of vehicles with different powertrain configurations and GHG reduction technologies.
2017-03-28
Technical Paper
2017-01-0907
Timothy Johnson, Ameya Joshi
Abstract This review paper summarizes major and representative developments in vehicle engine efficiency and emissions regulations and technologies from 2016. The paper starts with the key regulatory developments in the field, including newly proposed European RDE (real driving emissions) particle number regulations, and Euro 6 type regulations for China and India in the 2020 timeframe. China will be tightening 30-40% relative to Euro 6 in 2023. The California heavy duty (HD) low-NOx regulation is advancing and the US EPA is anticipating developing a harmonized proposal for implementation in 2023+. The US also finalized the next round of HD GHG (greenhouse gas) regulations for 2021-27, requiring 5% engine CO2 reductions. LD (light duty) and HD engine technology continues showing marked improvements in engine efficiency. Key developments are summarized for gasoline and diesel engines to meet both the emerging criteria and greenhouse gas regulations.
2017-03-28
Technical Paper
2017-01-0141
Ray Host, Peter Moilanen, Marcus Fried, Bhageerath Bogi
Abstract Future vehicle North American emissions standards (e.g., North American Tier 3 Bin 30 or LEVIII SULEV 30) require the exhaust catalyst to be greater than 80% efficient by 20 seconds after the engine has been started in the Federal Test Procedure. Turbocharged engines are especially challenged to deliver fast catalyst light-off since the presence of the turbocharger in the exhaust flow path significantly increases exhaust system heat losses. A solution to delivering cost effective SULEV 30 emissions in turbocharged engines is to achieve fast catalyst light-off by reducing exhaust system heat losses in cold start, without increasing catalyst thermal degradation during high load operation. A CAE methodology to assess the thermal performance of exhaust system hardware options, from the exhaust port to the catalyst brick face is described, which enables compliance with future emissions regulations.
Viewing 91 to 120 of 21878