Criteria

Text:
Display:

Results

Viewing 1 to 30 of 2328
2017-09-04
Technical Paper
2017-24-0066
Maria Cristina Cameretti, Roberta De Robbio, Raffaele Tuccillo
Abstract The present study deals with the simulation of a Diesel engine fuelled by natural gas/diesel in dual fuel mode to optimize the engine behaviour in terms of performance and emissions. In dual fuel mode, the natural gas is introduced into the engine’s intake system. Near the end of the compression stroke, diesel fuel is injected and ignites, causing the natural gas to burn. The engine itself is virtually unaltered, but for the addition of a gas injection system. The CO2 emissions are considerably reduced because of the lower carbon content of the fuel. Furthermore, potential advantages of dual-fuel engines include diesel-like efficiency and brake mean effective pressure with much lower emissions of oxides of nitrogen and particulate matter. In previous papers, the authors have presented some CFD results obtained by two 3D codes by varying the diesel/NG ratio and the diesel pilot injection timing at different loads.
2017-09-04
Technical Paper
2017-24-0123
Christopher Eck, Futoshi Nakano
Abstract Small commercial vehicles (SCV) with Diesel engines require efficient exhaust aftertreatment systems to reduce the emissions while keeping the fuel consumption and total operating cost as low as possible. To meet current emission legislations in all cases, a DOC and DPF and some NOx treatment device (e,g. lean NOx trap or SCR) are required. Creating a cost-effective SCV also requires keeping the cost for the exhaust aftertreatment system as low as possible because the contribution to total vehicle cost is high. By using more sophisticated and more robust operating strategies and control algorithms, the hardware cost can be reduced. To keep the calibration effort at a low level, it is necessary to apply only algorithms which have a time-efficient calibration procedure. This paper will focus on the active regeneration of the DPF. For safe and efficient DPF regeneration, a very reliable and stable DOC out temperature control is required.
2017-07-10
Technical Paper
2017-28-1927
Saurav Roy, Jyotirmoy Barman, Rizwan Khan
Abstract The urea NOx selective catalytic reduction (SCR) is an effective technique for the reduction of NOx emitted from diesel engines. Urea spray quality has significant effect on NOx conversion efficiency. Air less injection is one of effective, less complex way of injecting urea spray into the Exhaust stream. Further with air less injection it become more challenging in an engine platform of ~3 to 4L where Exhaust mass flow and temperature are relatively less. The droplet diameter and velocity distribution of De-Nox system has taken as input along with Engine raw emission data for a numerical model. The atomization and evaporation of airless urea injection systems were modeled using computational fluid dynamics. The numerical model was validated by the experimental results.
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
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.
2017-01-10
Technical Paper
2017-26-0125
Sougato Chatterjee, Mojghan Naseri, Jianquan Li
Abstract The next generation advanced emission regulations have been proposed for the Indian heavy duty automotive industry for implementation from 2020. These BS VI emission regulations will require both advanced NOx control as well as advanced PM (Particulate Matter) control along with Particle Number limitations. This will require implementation of full DPF (Diesel Particulate Filter) and simultaneous NOx control using SCR technologies. DPF technologies have already been successfully implemented in Euro VI and US 10 HDD systems. These systems use low temperature NO2 based passive DPF regeneration as well as high temperature oxygen based active DPF regeneration. Effective DPF and DOC designs are essential to enable successful DPF regeneration (minimize soot loading in the DPF) while operating HDD vehicles under transient conditions. DOC designs are optimized to oxidize engine out NO into NO2, which helps with passive DPF regeneration.
2017-01-10
Technical Paper
2017-26-0127
Antoine Lacarriere, Thierry Seguelong, David Spivey, Ashish DAS
Abstract India is moving to Bharat Stage VI (BS-VI) from 2019 significantly lowering particulate mass (PM) , particle number (PN) and Nitrogen Oxides NOx emissions limits, as well as Carbon Dioxide CO2. BSVI’s particulate limits will require the use of diesel particulate filters (DPFs), which will need to operate properly under the driving conditions prevalent in India. Furthermore, NOx and CO2 emissions control will include advanced combustion modes with advanced fuel injectiontechnologies based on high pressure fuel injection and smaller injector holes, in combination with active NOx reduction measures. These advanced technologies will increase sensitivity to fuel quality, so will require tighter control of sulfur content, water contamination, fuel stability, lubricity and corrosion. These are real challenges for the robustness and durability of strategies developed for BS-VI and beyond.
2017-01-10
Technical Paper
2017-26-0120
Kevin Hallstrom, Sandip D. Shah
Abstract The legislative decision to accelerate the implementation of regulations requiring advanced emissions control in India have accelerated the need to advanced emissions control systems. Particulate filters and NOx abatement technology will be needed to meet the new BSVI standards. Integration of these emission control technologies into engine design poses new challenges to the Indian Heavy Duty Diesel Truck Industry. Each new market that implements advanced emission regulations faces challenges that are unique to the local regulation, the local vehicle design, and the local operating conditions. This paper will review the technology options available for BSVI, their strengths and weaknesses, and potential system designs. Additionally this paper will review how critical design factors such as filter regeneration conditions, duty cycle temperatures, and urea injection can affect the system design and catalyst selection.
2017-01-10
Technical Paper
2017-26-0133
Ashok Kumar, Junhui Li, Jinyong Luo, Saurabh Joshi, Aleksey Yezerets, Krishna Kamasamudram, Niklas Schmidt, Khyati Pandya, Prachetas Kale, Thangaraj Mathuraiveeran
Abstract Advanced emission control systems for diesel engines usually include a combination of Diesel Oxidation Catalyst (DOC), Diesel Particulate Filter (DPF), Selective Catalytic Reduction (SCR), and Ammonia Slip Catalyst (ASC). The performance of these catalysts individually, and of the aftertreatment system overall, is negatively affected by the presence of oxides of sulfur, originating from fuel and lubricant. In this paper, we illustrated some key aspects of sulfur interactions with the most commonly used types of catalysts in advanced aftertreatment systems. In particular, DOC can oxidize SO2 to SO3, collectively referred to as SOx, and store these sulfur containing species. The key functions of a DOC, such as the ability to oxidize NO and HC, are degraded upon SOx poisoning. The impact of sulfur poisoning on the catalytic functions of a DPF is qualitatively similar to DOC.
2017-01-10
Technical Paper
2017-26-0144
Dominik Lamotte, Peter Neumann, Klaus Schrewe
Abstract Emissions of diesel engine are considered to be harmful to health especially particulate emissions. Therefore, the introduction of diesel particulate filters (DPF) were successively forced by government due to reducing the emission limits to a level where inner engine measures are not sufficient anymore. To limit additional fuel consumption by increasing backpressure over the DPF, the collected soot has to be regenerated continuously or discrete by active regeneration. Active regeneration is usually realized by injecting additional fuel either due to the engines injection system into the combustion chamber (late post injection) or via an additional fuel injection device in the exhaust line. This enables increasing exhaust temperature and / or an exothermic reaction in the diesel oxidation catalyst (DOC) of the aftertreatment system.
2017-01-10
Journal Article
2017-26-0121
Grigorios C. Koltsakis, Ioannis Kandylas, Vaibhav Gulakhe
Abstract Modern ‘DOC-cDPF’ systems for diesel exhaust are employing Pt-, Pd- as well as Pt/Pd alloy- based coatings to ensure high conversion efficiency of CO, HC even at low temperatures. Depending on the target application, these coatings should be also optimized towards NO2 generation which is involved in low temperature soot oxidation as well as in SCR-based deNOx. Zeolite materials are also frequently used to control cold-start HC emissions. Considering the wide variety of vehicles, engines and emission targets, there is no single optimum coating technology. The main target is therefore to maximize synergies rather than to optimize single components. At the same time, the system designer has nowadays a wide range of technologies to choose from, including PGM alloyed combinations (Pt/Pd), multiple layers and zones applicable to both DOCs and DPFs.
2016-11-08
Technical Paper
2016-32-0063
Marc Cyrill Besch, April Nicole Covington, Derek Johnson, Nathan Fowler, Robert Heltzel
Abstract The aim of this investigation was to improve understanding and quantify the impact of exhaust gas recirculation (EGR) as an emissions control measure onto cyclic variability of a small-bore, single-cylinder, diesel-fueled compression-ignition (CI) power generation unit. Of special interest were how cycle-to-cycle variations of the CI engine affect steady-state voltage deviations and frequency bandwidths. Furthermore, the study strived to elucidate the impact of EGR addition onto combustion parameters, as well as gaseous and particle phase emissions along with fuel consumption. The power generation unit was operated over five discrete steady-state test modes, representative of nominal 0, 25, 50, 75, and 100% engine load (i.e. 0-484kPa BMEP), by absorbing electrical power via a resistive load bank. The engine was equipped with a passive EGR system that directly connected the exhaust and intake runners through a small passage.
2016-10-17
Technical Paper
2016-01-2320
Tsuyoshi Asako, Ryuji Kai, Tetsuo Toyoshima, Claus Vogt, Shogo Hirose, Shiori Nakao
Abstract Ammonia Selective Catalytic Reduction (SCR) is adapted for a variety of applications to control nitrogen oxides (NOx) in diesel engine exhaust. The most commonly used catalyst for SCR in established markets is Cu-Zeolite (CuZ) due to excellent NOx conversion and thermal durability. However, most applications in emerging markets and certain applications in established markets utilize vanadia SCR. The operating temperature is typically maintained below 550°C to avoid vanadium sublimation due to active regeneration of the diesel particulate filter (DPF), or some OEMs may eliminate the DPF because they can achieve particulate matter (PM) standard with engine tuning. Further improvement of vanadia SCR durability and NOx conversion at low exhaust gas temperatures will be required in consideration of future emission standards.
2016-10-17
Technical Paper
2016-01-2213
Tomoaki Ito, Makoto Nagata
Abstract Diesel exhaust emission control systems often contain DOC (Diesel Oxidation Catalyst) + CSF (Catalyzed Soot Filter) components. In this system PM (particulate matter) is filtered and accumulated in the CSF and such filtered PM is periodically combusted by supplying heat to the CSF. The heat to CSF is generated within the DOC by an exothermic reaction with extra fuel supplied to the DOC. Here the exothermic performance of DOC depends on not only the active catalytic site (such as Pt and/or Pd) but also on the characteristics of the porous material supporting the precious metals. Various properties of Al2O3, i.e. pore diameter, pore volume, BET surface area, acidity, basicity and the Ea (activation energy) of fuel combustion, used in DOCs and PGM particle size of each DOC were measured. The fuel combustion performance of each DOC was evaluated by diesel engine bench.
2016-10-17
Journal Article
2016-01-2179
Marius Zubel, Om Parkash Bhardwaj, Benedikt Heuser, Bastian Holderbaum, Sebastian Doerr, Jukka Nuottimäki
Abstract This work is a continuation of earlier results presented by the authors. In the current investigations the biofuels hydrogenated vegetable oil (HVO) and 1-octanol are investigated as pure components and compared to EN 590 Diesel. In a final step both biofuels are blended together in an appropriate ratio to tailor the fuels properties in order to obtain an optimal fuel for a clean combustion. The results of pure HVO indicate a significant reduction in CO-, HC- and combustion noise emissions at constant NOX levels. With regard to soot emissions, at higher part loads, the aromatic free, paraffinic composition of HVO showed a significant reduction compared to EN 590 petroleum Diesel fuel. But at lower loads the high cetane number leads to shorter ignition delays and therefore, ignition under richer conditions.
2016-10-17
Journal Article
2016-01-2281
Simon Dosda, David Berthout, Gilles Mauviot, Adeline Nogre
Abstract With the upcoming Euro 6c emission regulations, the performance of Diesel exhaust lines needs to be improved to meet NOX and soot emission targets. A promising exhaust line architecture to reach these requirements is the association of a Diesel Oxidation Catalyst (DOC), a Selective Catalytic Reduction coated on a particulate filter (SCR-F) and a Selective Catalytic Reduction (SCR) catalyst. To develop this system, the car manufacturers have to face several challenges. One of the first is the design of the exhaust line volumes, which has a strong impact on the light-off temperatures of the catalysts and so on system performance. Then, urea injection has to be optimized with an adapted control system to maximize NOx reduction while keeping low tailpipe ammonia emission. Moreover, performance degradation of catalysts due to harsh exhaust conditions during vehicle life time have to be detected by OBD system.
2016-10-17
Journal Article
2016-01-2322
Michael Lance, Andrew Wereszczak, Todd J. Toops, Richard Ancimer, Hongmei An, Junhui Li, Leigh Rogoski, Petr Sindler, Aaron Williams, Adam Ragatz, Robert L. McCormick
Abstract For renewable fuels to displace petroleum, they must be compatible with emissions control devices. Pure biodiesel contains up to 5 ppm Na + K and 5 ppm Ca + Mg metals, which have the potential to degrade diesel emissions control systems. This study aims to address these concerns, identify deactivation mechanisms, and determine if a lower limit is needed. Accelerated aging of a production exhaust system was conducted on an engine test stand over 1001 h using 20% biodiesel blended into ultra-low sulfur diesel (B20) doped with 14 ppm Na. This Na level is equivalent to exposure to Na at the uppermost expected B100 value in a B20 blend for the system full-useful life. During the study, NOx emissions exceeded the engine certification limit of 0.33 g/bhp-hr before the 435,000-mile requirement.
2016-10-07
Magazine
The Best of COMVEC 2016 Autonomous vehicles, improved fuel efficiency and thermal management are among the pressing topics detailed in this select group of technical papers from the SAE Commercial Vehicle Engineering Congress. Autonomous solutions in agriculture Pneumatically shifted air suspension loading on 6x2 trucks Optimizing waste heat recovery for long-haul trucks Downsizing a HD diesel engine for off-highway applications Fan-shroud optimization for enhanced thermal performance Touch takes hold, switches lend a hand Touch screens are becoming the norm, but knobs and switches are often used to improve operator comfort. U.S. Army marches toward driverless future TARDEC targets vehicle autonomy with new V2V / V2X test bed in Michigan.
2016-04-08
Magazine
Software's role continues to expand Design teams use different technologies to create new software and link systems together. Emissions regulations and engine complexity With the European Commission announcing a Stage V criteria emissions regulation for off-highway, scheduled to phase-in as earlly as 2019, there will be an end to a brief era of harmonized new-vehicle regulations. Will this affect an already complex engine development process? Evaluating thermal design of construction vehicles CFD simulation is used to evaluate two critical areas that address challenging thermal issues: electronic control units and hot air recirculation.
2016-04-05
Technical Paper
2016-01-0194
Yici Li, Wei Tian
Abstract The exhaust cooling is an important index which measures the performance of the flameproof diesel engine. In this paper, a modification model is built for enhancing the cooling performance of exhaust, based on the reference model of the dry cooling equipment. The annular nozzle direction, extend plate of guide, bellows and elbow are introduced and studied in the model as the modification way. Considering the Coanda and Venturi effects, the comprehensive comparison of fluid velocity, temperature, pressure and mixture coefficient is implemented, and the optimum horizontal dimension of throat is summarized. The simulation results indicate the modification model shows better performance in reducing exhaust temperature and pressure than the reference model.
2016-04-05
Technical Paper
2016-01-0953
Homayoun Ahari, Michael Smith, Michael Zammit, Brad Walker
In order to meet LEV III, EURO 6C and Beijing 6 emission levels, Original Equipment Manufacturers (OEMs) can potentially implement unique aftertreatment systems solutions which meet the varying legislated requirements. The availability of various washcoat substrates and PGM loading and ratio options, make selection of an optimum catalyst system challenging, time consuming and costly. Design for Six Sigma (DFSS) methodologies have been used in industry since the 1990s. One of the earliest applications was at Motorola where the methodology was applied to the design and production of a paging device which Consumer Reports called “virtually defect-proof”.[1] Since then, the methodology has evolved to not only encapsulate complicated “Variation Optimization” but also “Design Optimization” where multiple factors are in play. In this study, attempts are made to adapt the DFSS concept and methodology to identify and optimize a catalyst for diesel applications.
2016-04-05
Technical Paper
2016-01-0966
Yujun Wang, Carl Kamp
It has been observed that a certain percentage of diesel particulate filters (DPFs) from the field form mid-channel ash plugs both in light duty and heavy duty applications. As revealed in a post mortem study, some field samples have ash plugs of 3-10 cm length in the middle of DPF inlet channels, which can potentially reduce the inlet channel volume by more than 50%. As a result, the mid-channel ash plug reduces the effective filtration area and decreases the effective channel open width in the middle of the channel. This explains why these filters are reported as having large increases in pressure drop. Moreover, the mid-channel ash deposits reduce the DPF service life and render the filter cleaning process ineffective. In the present study, an open source CFD tool is applied to study the 3D flow crossing two representative inlet and outlet DPF channels where the inlet channels have mid-channel ash plugs.
2016-04-05
Technical Paper
2016-01-0962
Sadashiva Prabhu S, Nagaraj S Nayak, N. Kapilan
Selective Catalytic Reduction (SCR) is a most promising technique for reduction of nitrogen oxides (NOx) emitted from the exhaust of diesel engines. Urea Water Solution (UWS) is injected to hot exhaust gas stream to generate reducing agent ammonia. The droplet evaporation of Urea Water Solution (UWS) is investigated for single droplet in heated environment ranging temperatures 373K-873K theoretically. The theoretical methods which are implemented into CFD code Fire 8.3 from AVL Corp. involve Rapid Mixing model and Diffusion Limit model which consider stationary droplet and variable properties of the UWS. The UWS droplet revealed different evaporation characteristics depending on its ambient temperatures which are numerically predicted by simulated results. The simulated results are validated with experimental values of Wang et al. [9] which are helpful in predicting the evaporation and UWS dosing strategy at different exhaust gas temperatures in real SCR system.
2016-04-05
Journal Article
2016-01-0961
Satish Narayanan Ramachandran, Gillis Hommen, Paul Mentink, Xander Seykens, Frank Willems, Frank Kupper
Abstract Heavy-duty diesel engines are used in a wide range of applications. For varying operating environments, the engine and aftertreatment system must comply with the real-world emission legislation limits. Simultaneously, minimal fuel consumption and good drivability are crucial for economic competitiveness and usability. Meeting these requirements takes substantial development and calibration effort, and complying with regulations results in a trade-off between emissions and fuel consumption. TNO's Integrated Emission Management (IEM) strategy finds online, the cost-optimal point in this trade-off and is able to deal with variations in operating conditions, while complying with legislation limits. Based on the actual state of the engine and aftertreatment system, an optimal engine operating point is computed using a model-based optimal-control algorithm.
2016-04-05
Technical Paper
2016-01-0954
Jason Jacques, Thomas Pauly, Michael Zammit, Homayoun Ahari, Michael Smith
Significant reduction in Nitrogen Oxide (NOx) emissions will be required to meet LEV III Emissions Standards for Light Duty Diesel passenger vehicles (LDD). As such, Original Equipment Manufacturers (OEMs) are exploring all possible aftertreatment options to find the best balance between performance, robustness and cost. The primary technology adopted by OEMs in North America to achieve low NOx levels is Selective Catalytic Reduction (SCR) catalyst. The critical parameters needed for SCR to work properly are: an appropriate reductant such as ammonia (NH3) typically provided as urea, adequate operating temperatures, and optimum Nitrogen Dioxide (NO2) to NOx ratios (NO2/NOx). The NO2/NOx ratio is mostly influenced by Precious Group Metals (PGM) containing catalysts located upstream of the SCR catalyst. Different versions of zeolite based SCR technologies are available on the market today and these vary in their active metal type (iron, copper, vanadium), and/or zeolite type.
2016-04-05
Journal Article
2016-01-0956
Amin Reihani, Benjamin Corson, John W. Hoard, Galen B. Fisher, Evgeny Smirnov, Dirk Roemer, Joseph Theis, Christine Lambert
Abstract Lean NOx Traps (LNTs) are one type of lean NOx reduction technology typically used in smaller diesel passenger cars where urea-based Selective Catalytic Reduction (SCR) systems may be difficult to package . However, the performance of lean NOx traps (LNT) at temperatures above 400 C needs to be improved. The use of Rapidly Pulsed Reductants (RPR) is a process in which hydrocarbons are injected in rapid pulses ahead of a LNT in order to expand its operating window to higher temperatures and space velocities. This approach has also been called Di-Air (diesel NOx aftertreatment by adsorbed intermediate reductants) by Toyota. There is a vast parameter space which could be explored to maximize RPR performance and reduce the fuel penalty associated with injecting hydrocarbons. In this study, the mixing uniformity of the injected pulses, the type of reductant, and the concentration of pulsed reductant in the main flow were investigated.
2016-04-05
Technical Paper
2016-01-1003
Fabian Fricke, Om Parkash Bhardwaj, Bastian Holderbaum, Terrence Scofield, Elmar Grußmann, Marco Kollmeier
Abstract Improvements in the efficiency of internal combustion engines has led to a reduction in exhaust gas temperatures. The simultaneous tightening of exhaust emission limits requires ever more complex emission control methods, including aftertreatment whose efficiency is crucially dependent upon the exhaust gas temperature. Double-walled (also called air-gap) exhaust manifold and turbine housing modules made from sheet metal have been used in gasoline engines since 2009. They offer the potential in modern Diesel engines to reduce both the emissions of pollutants and fuel consumption. They also offer advantages in terms of component weight and surface temperatures in comparison to cast iron components. A detailed analysis was conducted to investigate the potential advantages of insulated exhaust systems for modern diesel engines equipped with DOC and SCR coated DPF (SDPF).
2016-04-05
Technical Paper
2016-01-1004
Somendra Pratap Singh, Shikhar Asthana, Shubham Singhal, Naveen Kumar
Abstract The energy crisis coupled with depleting fuel reserves and rising emission levels has encouraged research in the fields of performance enhancement, emission reduction technologies and engineering designs. The present paper aims primarily to offset the problem of high emissions and low efficiencies in low cost CI engines used as temporary power solutions on a large scale. The investigation relates to the low cost optimization of an intake runner having the ability to vary the swirl ratio within the runner. Test runs reveal that NOx and CO2 follow a relatively smaller gradient of rise and fall in their values depending on the configuration; whereas UHC and CO have a rapid changes in values with larger gradients. However, in a relative analysis, no configuration was able to simultaneously reduce all emission parameters and thus, there exists a necessity to find an optimized configuration as a negotiation between the improved and deteriorated parameters.
2016-04-05
Technical Paper
2016-01-0995
Michael A. Robinson, Jacob Backhaus, Ryan Foley, Z. Gerald Liu
Abstract Introduction of modern diesel aftertreatment, primarily selective catalytic reduction (SCR) designed to reduced NOx, has increased the presence of urea decomposition byproducts, mainly ammonia, in the aftertreatment system. This increase in ammonia has been shown to lead to particle formation in the aftertreatment system. In this study, a state of the art diesel exhaust fluid (DEF)-SCR system was investigated in order to determine the influence of DEF dosing on solid particle count. Post diesel particulate filter (DPF) particle count (> 23 nm) is shown to increase by over 400% during the World Harmonized Transient Cycle (WHTC) due to DEF dosing. This increase in tailpipe particle count warranted a detailed parametric study of DEF dosing parameters effect on tailpipe particle count. Global ammonia to NOx ratio, DEF droplet residence time, and SCR catalyst inlet temperature were found to be significant factors in post-DPF DEF based particle formation.
Viewing 1 to 30 of 2328

Filter

  • Range:
    to:
  • Year: