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Viewing 1 to 30 of 248
2011-04-12
Technical Paper
2011-01-0627
Jim Steppan, Brett Henderson, Kent Johnson, M. Yusuf Khan, Timothy Diller, Matthew Hall, Anthoniraj Lourdhusamy, Klaus Allmendinger, Ronald D. Matthews
EmiSense Technologies, LLC (www.emisense.com) is commercializing its electronic particulate matter (PM) sensor that is based on technology developed at the University of Texas at Austin (UT). To demonstrate the capability of this sensor for real-time PM measurements and on board diagnostics (OBD) for failure detection of diesel particle filters (DPF), independent measurements were performed to characterize the engine PM emissions and to compare with the PM sensor response. Computational fluid dynamics (CFD) modeling was performed to characterize the hydrodynamics of the sensor's housing and to develop an improved PM sensor housing with reproducible hydrodynamics and an internal baffle to minimize orientation effects. PM sensors with the improved housing were evaluated in the truck exhaust of a heavy duty (HD) diesel engine tested on-road and on a chassis dynamometer at the University of California, Riverside (UCR) using their Mobile Emissions Laboratory (MEL).
2011-04-12
Technical Paper
2011-01-0692
Hamid R. Rahai, Ehsan Shamloo, Jeremy Ralph Bonifacio
The effects of humid air on the performance of a naturally aspired three-cylinder diesel engine with low sulfur diesel fuel have been investigated. The additions of the humidity to intake air were performed with a variable steam generator using distilled water, where the relative humidity levels of the intake air were changed from the ambient conditions of 65% to 75% and 95% levels. The tests were performed at two approximate engine output brake horse powers (BHP) of 5.9, and 8.9. Results showed approximately 3.7% and 22.5% reduction in NO x emissions when the relative humidity of the air was increased from 65% (the ambient relative humidity) to 75% and 95% respectively. The addition of the humidity results in increases in the CO, CO₂, and particulate matter (PM), by approximately 3.7, 3.55, 14.9 percents at 5.9 BHP and 22, 2.8, and 9.3 percents at 8.9 BHP. There was no change in the brake specific fuel consumption (BSFC) at 5.9 BHP and about 2.7 increase in the BSFC at 8.9 BHP.
2013-09-24
Technical Paper
2013-01-2385
N. Santosh Datta
With evolution of emission norms in diesel engines, NOx emission limits became more stringent and can be met only with specific NOx emission control systems. The NOx control systems in heavy duty diesel engines are monitored for OBD regulations in on-highway applications. Additionally driver warning and inducement requirements for NOx emission control systems are to be complied in both on-highway and off-highway applications. The driver inducement requirements are defined with intent to enforce and ensure correct operation of NOx control system. The NOx control systems and inducement measures are implemented in engine Electronic Control Unit (ECU) software to be compliant to legislation. The paper focuses on driver inducement requirements for NOx emission control systems. The paper summarizes the inducement requirements with a system overview and software design to meet driver inducement requirements for EUVI legislation and CARB/EPA compliance.
2004-06-08
Technical Paper
2004-01-1939
Paul Richards, B. Terry, J. Chadderton, M. W. Vincent
In an attempt to improve ambient air quality, retrofit programmes have been encouraged; targeting reductions in PM emissions by means of diesel particulate filters (DPFs). However depending on the DPF design and operating conditions increased nitrogen dioxide (NO2) emissions have been observed, which is causing concern. Previous work showed that retrofitting a DPF system employing a fuel borne catalyst (FBC) to facilitate regeneration, reduced NO2 emissions. This paper outlines the investigation of a base metal coated DPF to enhance the reduction of NO2. Such a DPF system has been fitted to older technology buses and has demonstrated reliable field performance.
2013-10-07
Technical Paper
2013-36-0209
Anibal Godoy Machado, Nilton Mitsuro Shiraiwa
With the purpose of minimizing the gaseous emissions impacts on the metropolitan areas, many alternative fuel resources has been developed as alternatives to fossil fuels. An environmentally and economical interesting alternative for the Brazilian market is the diesel made from sugar cane (Farnesene - C15H32). The Farnesene, made by sugar cane juice fermentation in presence of a genetically modified yeast is basically a saturated hydrocarbon molecule (C15H32) with more than 98% purity and that presents properties comparable to fossil diesel and when used in regular diesel cycle engines can bring significantly reductions not only in soot levels (Particulate Matter - PM) but also on the Nitrogen Oxides (NOx), unlike the biodiesel, that is well known that it brings increases on NOx emission level due its physic-chemical properties. Reduction on CO2 levels on life cycle is another important benefit of using such fuel since it's made by renewable feedstock.
2011-04-12
Technical Paper
2011-01-1140
Julian Tan, Charles Solbrig, Steven J. Schmieg
Diesel engines have the potential to significantly increase vehicle fuel economy and decrease CO₂ emissions; however, efficient removal of NOx and particulate matter from the engine exhaust is required to meet stringent emission standards. A conventional diesel aftertreatment system consists of a Diesel Oxidation Catalyst (DOC), a urea-based Selective Catalyst Reduction (SCR) catalyst and a diesel particulate filter (DPF), and is widely used to meet the most recent NOx (nitrogen oxides comprising NO and NO₂) and particulate matter (PM) emission standards for medium- and heavy-duty sport utility and truck vehicles. The increasingly stringent emission targets have recently pushed this system layout towards an increase in size of the components and consequently higher system cost. An emerging technology developed recently involves placing the SCR catalyst onto the conventional wall-flow filter.
2011-04-12
Technical Paper
2011-01-1329
Mario Castagnola, Jonathan Caserta, Sougato Chatterjee, Hai-Ying Chen, Raymond Conway, Joseph Fedeyko, Wassim Klink, Penelope Markatou, Sandip Shah, Andrew Walker
Since early 2010, most new medium- and heavy-duty diesel vehicles in the US rely on urea-based Selective Catalytic Reduction (SCR) technology for meeting the most stringent regulations on nitrogen oxides (NOx) emissions in the world today. Catalyst technologies of choice include Copper (Cu)- and Iron (Fe)-based SCR. In this work, the performances of Fe-SCR and Cu-SCR were investigated in the most commonly used DOC + CSF + SCR system configuration. Cu-SCR offered advantages over Fe-SCR in terms of low temperature conversion, NO₂:NOx ratio tolerance and NH₃ slip, while Fe-SCR demonstrated superior performance under optimized NO₂:NOx ratio and at higher temperatures. The Cu-SCR catalyst displayed less tolerance to sulfur (S) exposure. Reactor testing has shown that Cu-SCR catalysts deactivate at low temperature when poisoned by sulfur.
2011-04-12
Journal Article
2011-01-1383
Clément Chartier, Oivind Andersson, Bengt Johansson, Mark Musculus, Mohan Bobba
Post-injection strategies aimed at reducing engine-out emissions of unburned hydrocarbons (UHC) were investigated in an optical heavy-duty diesel engine operating at a low-load, low-temperature combustion (LTC) condition with high dilution (12.7% intake oxygen) where UHC emissions are problematic. Exhaust gas measurements showed that a carefully selected post injection reduced engine-out load-specific UHC emissions by 20% compared to operation with a single injection in the same load range. High-speed in-cylinder chemiluminescence imaging revealed that without a post injection, most of the chemiluminescence emission occurs close to the bowl wall, with no significant chemiluminescence signal within 27 mm of the injector. Previous studies have shown that over-leaning in this near-injector region after the end of injection causes the local equivalence ratio to fall below the ignitability limit.
2011-08-30
Journal Article
2011-01-1961
Takashi Hara, Naoki Shimazaki, Naoki Yanagisawa, Takeshi Seto, Shigehisa Takase, Takeshi Tokumaru, Takurou Mita, Takeshi Okamoto, Yoshio Sato
Study of DME diesel engines was conducted to improve fuel consumption and emissions of its. Additionally, DME trucks were built for the promotion and the road tests of these trucks were executed on EFV21 project. In this paper, results of diesel engine tests and DME truck driving tests are presented. As for DME diesel engines, the performance of a DME turbocharged diesel engine with LPL-EGR was evaluated and the influence of the compression ratio was also explored. As for DME trucks, a 100,000km road test was conducted on a DME light duty truck. After the road test, the engine was disassembled for investigation. Furthermore, two DME medium duty trucks have been developed and are now the undergoing practical road testing in each area of two transportation companies in Japan.
2011-08-30
Technical Paper
2011-01-1962
Fredrik Konigsson, Per Stalhammar, Hans-Erik Ångström
Diesel Dual Fuel, DDF, is a concept where a combination of methane and diesel is used in a compression ignited engine, maintaining the high compression ratio of a diesel engine with the resulting benefits in thermal efficiency. One benefit of having two fuels on board the vehicle is the additional degree of freedom provided by the ratio between the fuels. This additional degree of freedom enables control of combustion phasing for combustion modes such as Homogenous Charge Compression Ignition, HCCI, and Partly Premixed Compression Ignition, PPCI. These unconventional combustion modes have great potential to limit emissions at light load while maintaining the low pumping losses of the base diesel engine. A series of tests has been carried out on a single cylinder lab engine, equipped with a modern common rail injection system supplying the diesel fuel and two gas injectors, placed in the intake runners.
2011-08-30
Technical Paper
2011-01-2087
Nobuhiro Yanagisawa, Keiko Shibata, Kenji Enya, Kaoru Satou
In order to reduce fine particle emission, a diesel particulate filter (DPF) has begun to be equipped to a diesel engine. During regeneration of DPF, nanoparticles are known to be formed downstream of DPF. VOCs emission during regeneration is of interest in view of toxicity and formation mechanism of nanoparticles. A heavy duty diesel engine equipped with DPF was investigated to measure particle and VOCs emissions using PTR-TOFMS (Proton Transfer Reaction - Time of Flight Mass Spectrometer). PTR-TOFMS is a new on-line mass spectrometer using chemical ionization and its application to engine exhaust measurements is new. During active regeneration of the DPF, fine particle emission was increased by nucleation. But VOCs as well as THC emissions increased prior to particle increase. After the regeneration the particle and VOCs emissions decreased immediately to the level of normal operation.
2011-04-12
Technical Paper
2011-01-0295
Makoto Kimura, Toshikatsu Muramatsu, Eiji Kunishima, Jun Namima, Wilbur Crawley, Tony Parrish
EPA 2010 emissions regulations - currently the strictest standards in the world - place particular emphasis on exhaust gas thermal control technology. The Burner System, a device developed to control exhaust gas temperatures, is the most effective means of raising exhaust gas temperature, as this system can function under any engine conditions, including low engine speed and torque. The Burner System begins operating immediately when the engine is started, activating the Diesel Exhaust Fluid (DEF) - Selective Catalytic Reduction (SCR) System immediately, because the Burner System is active, it enables the diesel particulate filter active regeneration under any engine operating conditions as well. This technical paper reports Burner System (ActiveClean™ Thermal Regenerator) development results.
1999-10-25
Technical Paper
1999-01-3560
Irene Begsteiger, Klaus Richter, Eberhard Jacob, Gerhard Emmerling
A new type of catalyst for exhaust emission control of Diesel engines has been developed by a catalyst producer in cooperation with engine/heavy duty truck manufacturers. This so-called Sorption/Oxidation (“SO”)-catalyst is an extruded TiO2-type and works as a HC-trap as well as oxidation catalyst for hydrocarbons. In addition, a certain amount of particle matter was reduced, depending on type of engine, fuel sulfur content and test cycle. Due to its unique composition, i.e. oxides of titanium (80 wt %), tungsten and vanadium, the catalytic selectivity results in very low formation of sulfates as well as excellent resistance against sulfur compounds. The geometry of the catalyst prototypes corresponds to standard monoliths of 5,66″(144mm) in diameter and suitable lengths to be installed in standard mufflers. Since 1996, several buses and trucks have been equipped with SO-catalysts and are still in operation without problems.
2000-03-06
Technical Paper
2000-01-0479
Ray Conway, Sougato Chatterjee, Hassan Windawi
The EPA implemented the Urban Bus Retrofit/Rebuild (UBRR) Program for transit buses built before 1994 in an effort to lower the amount of PM emissions in densely populated urban areas. The objective of the program is to provide certified emission control technologies that reduce PM emissions from older buses by 25% or to below 0.1 g/bhp-hr. This paper reviews the development of a retrofit kit that has been certified under the UBRR program to meet the 0.1 g/bhp-hr PM emission requirements on DDC 6V92TA engines with both mechanical (MUI) and electronic (DDEC) fuel injection controls. The kit is a combination of specific and modified engine parts and a catalytic exhaust after-treatment device. The kit replaces existing parts with a new camshaft, a uniquely configured cylinder kit and specified turbocharger, blower and injector. For the MUI engines the cam timing, injector height and fuel modulator are set at specific values to achieve the lowest possible PM level.
2000-03-06
Technical Paper
2000-01-0705
Susumu Kohketsu, Keiki Tanabe, Koji Mori
Injection rate shape control is one feature of a diesel fuel injection system that is strongly desired at this time. However, in the conventional Common Rail System (CRS), it is difficult to control the injection rate because the injection pressure is constant during the injection period, resulting in a nearly rectangular rate shape. Thus, in order to achieve injection rate control in a CRS, a Next-generation Common Rail System (NCRS) was designed and the prototype system was fabricated. With two common rails, one for low pressure fuel, and the other for high pressure fuel, the NCRS achieves injection rate shape control by controlling the fuel injector supply pressure, from the two rails. The NCRS can achieve a clear “boot” shaped injection rate, and injection rig tests confirmed that the shape could be flexibly controlled via several control parameters.
2011-09-11
Technical Paper
2011-24-0186
Stefano Cordiner, Francesco mecocci, Vincenzo Mulone, Matteo Nobile
In 2011-2013, regulations will be tightened for non-road vehicles, via the application of Stage III-B standards in Europe. With state-of-the-art technology (high pressure common rail, cooled EGR), non-road diesel engines will require DPFs to control PM, as 90% reduction is requested with respect to STAGE III-A standards. Additional challenges may also foresee the obtainment of STAGE III-B standards with STAGE III-A engine technology, by means of retrofit systems for PM control. In that case, retrofit systems must furthermore guarantee simple control systems, and must be robust especially in terms of limited back pressure increase during normal operation. Moreover, retrofit systems must offer flexibility from the design point of view, in order to be correctly operated with several engines of same class, possibly characterized by totally different PM flow rates, temperature, NOx and O₂ availability.
2010-10-06
Technical Paper
2010-36-0407
Tadeu Cavalcante Cordeiro de Melo, Jose Roberto de Souza Rocha, Renato de Arruda Penteado Neto, Rodrigo Soares Ferreira
In 2005, it was published a paper in Brazil reporting significant values of aldehydes emissions for some old Brazilian diesel SUVs (Sport Utility Vehicles). In 2008, PETROBRAS (Brazilian Oil Company) together with LACTEC (Institute of Technology for Development) decided to study methods for measuring aldehydes from diesel vehicles, including SUVs and heavy-duty engines. In 2008, National Environmental Council (CONAMA) published legislation 408/08, establishing that IBAMA (Brazilian National Environmental Institute) must provide a procedure for aldehyde measurement at the end of December 2010 and that engine manufacturers must report typical aldehyde emission values of diesel vehicles before the end of December 2012. A technical group was created in 2009 by the Brazilian Automotive Engineering Association (AEA) to discuss and elaborate a new method for aldehyde measurement in diesel vehicles and heavy-duty engines. The new procedure must be published before the end of 2010.
2004-10-25
Technical Paper
2004-01-3042
Fuming Xiao, Chen Lu, Xichao Zhang, Bin Yang, Zhao Gao, Zhongtai Li, Xinchun Dong, Chuanwen Xue
In this paper, a diesel particulate filter system which uses needle felt as filtering medium to collect diesel particulates has been developed and tested in practical operation of the urban bus. The system includes a bag filter, an exhaust cooler, and a control unit. It was installed under the chassis of a YZL 6730C diesel bus, which operates in a loop route mostly with heavy load. The bus has covered more than 5,000km, during which there was no failure of the filter system to cause bus abnormal operation. It needs to be cleaned for about 50km, and the collected particulate matter has to be discharged for every 1200km. It can operate reliably and easily with very high collection efficiency. The collected particulate matter is analyzed by GC (Gas Chromatography)/MS (Mass Spectrometer), it is found that the collected particulate matter contains many poisonous and carcinogen substances and the filter is also effective to collect some of the SOF.
2012-10-02
Technical Paper
2012-36-0245
Leonardo de Oliveira Costa, Rodrigo Silva Santos
Due to the independent operation between the aftertreatment systems and the engine, the aim of the On Board Diagnostic System (OBD) is to ensure the engine emissions stay within the emissions standards during the whole vehicle useful life. In the case of the heavy duty diesel vehicles that use the Selective Catalytic Reduction System (SCR) or the Exhaust Gas Recirculation System (EGR) as the NOx aftertreatment technologies to meet the stringent emissions levels, the use of sensors in the exhaust pipe is required to control and to monitor the engine emissions. These are new and great challenges to the national diesel engine developers who are working with these systems to get the homologation certification. Accurate mathematic models within the automotive control strategies are becoming ever more important and are strongly used to monitor the NOx emissions directly (in case of SCR systems using the NOx sensor) or indirectly (in case of EGR systems using the Lambda sensor).
2012-09-10
Journal Article
2012-01-1664
Panu Karjalainen, Topi Ronkko, Tero Lahde, Antti Rostedt, Jorma Keskinen, Sanna Saarikoski, Minna Aurela, Risto Hillamo, Aleksi Malinen, Liisa Pirjola, Arno Amberla
The effect of SCR on nanoparticle emissions has been a subject for some recent diesel particle emission related studies. In this study, the effect of after-treatment (DOC and SCR) on particle emissions was studied with a heavy-duty off-road diesel engine (emission level stage 3b with an SCR). A special “transient cold test cycle” (TCTC) was designed to describe the SCR system operation at low exhaust gas temperatures. The particle instrumentation made it possible to measure on-line the particle number concentration, particle size distribution and chemical composition of particles. The largest particle number concentrations were measured after the exhaust manifold. The exhaust after-treatment was observed to reduce the total particle number concentration by 82.5% with the DOC and 95.7% with the DOC+SCR.
2012-09-10
Technical Paper
2012-01-1663
Stefano Cordiner, Francesco Mecocci, Vincenzo Mulone, Vittorio Rocco
The use of biodiesel has been widely accepted as an effective solution to reduce greenhouse emissions. The high potential of biodiesel in terms of PM emission reduction may represent an additional motivation for its wide use. This potential is related to the oxygenated nature of biodiesel, as well as its lower PAH and S, which leads, in general, to lower PM emissions as well as equal or slightly higher NOx emissions. According to these observations a different behavior of the Aftertreatment System (AS), especially as far as control issues of the Diesel Particulate Filter are concerned is also expected. The competition with the food sector is currently under debate, thus, besides second generation biofuels (e.g. from algae), the transesterification of Waste Cooking Oil (WCO) is another option, however needing further insight.
2015-04-14
Journal Article
2015-01-0992
Mojghan Naseri, Ceren Aydin, Shadab Mulla, Raymond Conway, Sougato Chatterjee
Abstract Selective Catalytic Reduction (SCR) systems have been demonstrated as effective solutions for controlling NOx emissions from Heavy Duty diesel engines. Future HD diesel engines are being designed for higher engine out NOx to improve fuel economy, while discussions are in progress for tightening NOx emissions from HD engines post 2020. This will require increasingly higher NOx conversions across the emission control system and will challenge the current aftertreatment designs. Typical 2010/2013 Heavy Duty systems include a diesel oxidation catalyst (DOC) along with a catalyzed diesel particulate filter (CDPF) in addition to the SCR sub-assembly. For future aftertreatment designs, advanced technologies such as cold start concept (dCSC™) catalyst, SCR coated on filter (SCRF® hereafter referred to as SCR-DPF) and SCR coated on high porous flow through substrates can be utilized to achieve high NOx conversions, in combination with improved control strategies.
2015-04-14
Journal Article
2015-01-0998
Paul Mentink, Rob van den Nieuwenhof, Frank Kupper, Frank Willems, Dennis Kooijman
Abstract Heavy-duty diesel engines are used in different application areas, like long-haul, city distribution, dump truck and building and construction industry. For these wide variety of areas, the engine performance needs to comply with the real-world legislation limits and should simultaneously have a low fuel consumption and good drivability. Meeting these requirements takes substantial development and calibration effort, where an optimal fuel consumption for each application is not always met in practice. TNO's Integrated Emission Management (IEM) strategy, is able to deal with these variations in operating conditions, while meeting legislation limits and obtaining on-line cost optimization. Based on the actual state of the engine and aftertreatment, optimal air-path setpoints are computed, which balances EGR and SCR usage.
2015-04-14
Technical Paper
2015-01-0997
Jonas Jansson, Åsa Johansson, Hanna Sjovall, Mikael Larsson, Gudmund Smedler, Colin Newman, Jason Pless
Abstract This paper will review several different emission control systems for heavy duty diesel (HDD) applications aimed at future legislations. The focus will be on the (DOC+CSF+SCR+ASC) configuration. As of today, various SCR technologies are used on commercial vehicles around the globe. Moving beyond EuroVI/US10 emission levels, both fuel consumption savings and higher catalyst system efficiency are required. Therefore, significant system optimization has to be considered. Examples of this include: catalyst development, optimized thermal management, advanced urea dosing calibrations, and optimized SCR inlet NO:NO2 ratios. The aim of this paper is to provide a thorough system screening using a range of advanced SCR technologies, where the pros and cons from a system perspective will be discussed. Further optimization of selected systems will also be reviewed. The results suggest that current legislation requirements can be met for all SCR catalysts under investigation.
2015-01-14
Journal Article
2015-26-0090
Federico Stola, Matteo De Cesare, Luca Lacchini, Nicolò Cavina, Sandeep Sohal
Abstract The Selective Catalytic Reduction (SCR) system installed on the exhaust line is currently widely used on Diesel heavy-duty trucks and it is considered a promising technique for light and medium duty trucks, large passenger cars and off-highway vehicles, to fulfill future emission legislation. Some vehicles of these last categories, equipped with SCR, have been already put on the market, not only in the US, where the emission legislation on Diesel vehicles is more restrictive, but also in Europe, demonstrating to be already compliant with the upcoming Euro 6. Moreover, new and more stringent emission regulations and homologation cycles are being proposed all over the world, with a consequent rapidly increasing interest for this technology. As a matter of fact, a physical model of the Diesel Exhaust Fluid (DEF) supply system is very useful, not only during the product development phase, but also for the implementation of the on-board real-time controller.
2015-09-29
Technical Paper
2015-01-2794
Meng-Huang Lu, Figen Lacin, Daniel McAninch, Frank Yang
Abstract Diesel exhaust after treatment solutions using injection, such as urea-based SCR and lean NOx trap systems, effectively reduce the emission NOx level in various light vehicles, commercial vehicles, and industrial applications. The performance of the injector is crucial for successfully utilizing this type of technology, and a simulation tool plays an important role in the virtual design, that the performance of the injector is evaluated to reach the optimized design. The virtual test methodology using CFD to capture the fluid dynamics of the injector internal flow has been previously developed and validated for quantifying the dosing rate of the test injector. In this study, the capability of the virtual test methodology was extended to determine the spray angle of the test injector, and the effect of the manufacturing process on the injector internal nozzle flow characteristics was investigated using the enhanced virtual test methodology.
2015-09-01
Technical Paper
2015-01-2021
Gen Shibata, Masaki Takahara, Keito Nishikawa, Hideyuki Ogawa
To reduce NOx emissions from diesel engines, the urea-SCR (selective catalytic reduction) system has been introduced commercially. In urea-SCR, the freezing point of the urea aqueous solution, the deoxidizer, is −11°C, and the handling of the deoxidizer under cold weather conditions is a problem. Further, the ammonia escape from the catalyst and the generation of N2O emissions are also problems. To overcome these disadvantages of the urea-SCR system, the addition of a hydrocarbon deoxidizer has attracted attention. In this paper, a micro-reactor SCR system was developed and attached to the exhaust pipe of a single cylinder diesel engine. With the micro-reactor, the catalyst temperature, quantity of deoxidizer, and the space velocity can be controlled, and it is possible to use it with gas and liquid phase deoxidizers. The catalyst used in the tests reported here is Ag(1wt%)-γAl2O3.
2014-04-01
Technical Paper
2014-01-1244
Yiqun Huang, John Colvin, Asanga Wijesinghe, Meng Wang, Deyang Hou, Zuhua Fang
Abstract Dual loop EGR systems (having both a high pressure loop EGR and a low pressure loop EGR) have been successfully applied to multiple light-duty diesel engines to meet Tier 2 Bin 5 and Euro 5/6 emissions regulations [1, 2], including the 2009 model year VW Jetta 2.0TDI. Hyundai and Toyota also published their studies with dual loop EGR systems [3, 4]. More interest exists on the low pressure loop EGR effects on medium to heavy duty applications [5]. Since the duty cycles of light duty diesel and heavy duty diesel applications are very different, how to apply the dual loop EGR systems to heavy duty applications and understanding their limitations are less documented and published. As a specific type of heavy duty application, this paper studied the dual loop EGR effects on the retrofit applications of heavy duty diesel for delivery and drayage applications. The reduction of NOx emissions and the impact on fuel economy and controls are discussed.
2005-11-01
Technical Paper
2005-01-3510
Sivanandi Rajadurai, Shiju Jacob, Chad Serrell, Rob Morin, Zlatomir Kircanski, Mike McCarthy
Due to the large size, high bulk density and high thermal expansion coefficient of the diesel particulate filter substrate; the conventional mounting system cannot provide the necessary radial mounting pressure. Mathematical and experimental results give the vibration and the back pressure force needed to mount the diesel particulate filter in the exhaust system. L-seal mounting support used in diesel particulate filter provides cushion to accommodate the linear tolerance of the substrate and the cone and also the necessary axial and radial mounting forces. L-seal axial and radial mounting forces are altered by type of material, surface characteristics, heat treatment and wire geometry. The proportional increase in compression force per unit weight during cycling shows dimensional consistency of the L-seal. The compression characteristics of A286 tremendously increase (>20%) during heat treatment as precipitation and hardening occurs.
2005-11-01
Technical Paper
2005-01-3508
Sivanandi Rajadurai, Chad Serrell, Shiju Jacob, Rob Morin, Zlatomir Kircanski, Mike McCarthy
Knitted wiremesh along with radial gas tight seals provide reliable mounting system for low temperature underbody converters. The compression characteristics of the wiremesh is modified by wire material, wire diameter, wire geometry, mesh crimp heights; wire density, wiremesh courses per inch, needle count, number of strands, wiremesh temper, wiremesh surface profile and surface characteristics. The radial mounting pressure provided by the wiremesh is matched with the mounting pressure requirement. Wiremesh systems can be tailored to any required radial mounting pressure from conventional to ultra thin-wall substrates. The wiremesh mounting system is proven durable, without any failure on more than 25 million underbody converters in light duty vehicles. Cp and Cpk show the capability of the manufacturing process. Thus the wiremesh mounting support is a viable alternate for low temperature gasoline and diesel applications.
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