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Technical Paper
2014-10-13
Matthias Stark, Richard Mittler
Tribodynamic Effects on Particulate Matter Concentrations in the Exhaust Gas of Large Two Stroke Marine Diesel Engines Upcoming emission regulations and power demands for large two stroke marine diesel engines call for a detailed investigation focusing on cylinder lubrication impacts on the exhaust gas composition. The content of the foreseen paper focuses on recent developments towards the design of an emission optimized lubrication concept, helping to significantly reduce lube oil consumption and related particulate matter concentrations in the exhaust gas. The described approach involves the application of substantially modified engine components in a full scale engine test, as well as the application of dedicated measurement technologies combined with intensive simulation activities in order to derive the desired correlation between lubrication system parameters and the exhaust gas composition. The foreseen paper highlights measures to enhance lubrication system performance considering key components of the tribosystem.
Technical Paper
2014-10-13
Anders Widd, Magnus Lewander
The Selective Catalytic Reduction (SCR) catalyst with ammonia as reducing agent plays a central role in today’s exhaust after-treatment systems for heavy-duty vehicles and there is a wide selection of possible catalytic materials to use. In order to facilitate the design of future catalysts, several aspects of the materials must be evaluated both in steadystate and transient operation. To this end, this paper presents a methodology for comparing the dynamic properties of different catalysts using full-size engine testing. The studied characteristics include the ammonia storage capacity, the effect on starting with an empty catalyst, the transient response to temperature gradients and changes in the urea dosing level. The temperature response is of particular importance in transient operation, where temperature increases may lead to substantial ammonia slip. A vanadium catalyst is compared to a Cu SAPO catalyst on the same substrate, and they show significant differences in their dynamic response.
Technical Paper
2014-10-13
Tao Tang, Jun Zhang, Shi-jin Shuai, Dongxiao Cao
Selective catalytic reduction (SCR) has been demonstrated as one of the most promising technologies to reduce NOx emissions from heavy-duty diesel engines. To meet the Euro VI regulations, SCR system should achieve high NOx reduction efficiency even at low temperatures. In SCR system NH3 is usually supplied by the injection of urea water solution (UWS), therefore it is important to improve the evaporation and decomposition efficiency of UWS at low temperatures and minimize urea deposits. In this study, UWS spray, urea decomposition, and the UWS interaction with pipe wall at low temperatures were investigated by engine test bench experiment and CFD simulation. The decomposition of urea and deposits was analyzed using Thermal Gravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC) and Fourier Transform Infrared Spectroscopy (FTIR). Urea decomposition started at about 180℃ in TGA test, and exhibited two stages of rapid mass loss. The off-gas in each stage was mainly NH3 and HNCO successively.
Technical Paper
2014-10-13
Christophe Barro, Philipp Meyer, Konstantinos Boulouchos
Past research has shown that post injections have the potential to reduce Diesel engine exhaust PM concentration without any significant influence in the NOx emissions. However, an accurate and general rule of how to parameterize a post injection such that it provides a maximum reduction of PM emissions does not exist. Moreover, the underlying mechanisms are not understood thoroughly. In earlier research it was observed that soot reduction due to a post injection is mainly based on two reasons: increased turbulence from the post injection during soot oxidation and lower soot formation due to lower amount of fuel in the main combustion at similar load conditions. A third effect of heat addition during the soot oxidation is debated in the literature. The experimental investigation presented in the current work provides insight into the underlying mechanisms of soot formation and reduction using post injections under different operating conditions. The measurements aim to provide additional understanding in the sources of PM reduction, which will allow the optimization of post injection settings.
Technical Paper
2014-10-13
Paul Schaberg, Mark Wattrus
In many countries fuel standards permit the limited addition of FAME to diesel fuel. For example, in Europe, diesel fuel complying with the EN590:2009 regulation may contain up to 7% FAME, and the low carbon fuel standards being considered in many regions encourage the consideration of even higher levels of FAME addition. Standards organisations such as CEN, ASTM, and CARB are also contemplating standards for paraffinic diesel fuels such as GTL (Gas-to-Liquids) diesel and HVO (Hydrogenated Vegetable Oil), an example being CEN Technical Standard 15940:2012. Since these standards may also allow the addition of FAME, it was decided to perform an extensive evaluation of the properties and performance of blends of GTL diesel and FAME, including emissions performance which is reported on in this paper. Fuels that were variously considered in the study were blends of GTL and EN590 diesel containing 0, 7, and 20 vol% of SME and RME (Soy and Rapeseed Methyl Ester). Part of the study focussed on European engine technology, and tests were performed on a Euro 4 passenger vehicle and engine, and a Euro V heavy-duty engine.
Technical Paper
2014-10-13
Isaline Lefort, Jose Herreros, Athanasios Tsolakis
This study investigates the behaviour of a partial flow filter (PFF) under different engine operating conditions as well as the mechanisms governing the filtration efficiency depending on the particulate size. Some exhaust gas characteristics such as flow rate and engine-out particulate matter (PM) profile (size and concentration) were varied, which affected the total mass and number filtration efficiency of the partial flow filter. The effects of these exhaust characteristics were also different for the filtration of small (10-30 nm), medium (30-200 nm) or large particulates (200-400 nm). An increase in medium-large PM concentration reduced small size particulate filtration. On the other hand, the filtration of medium-large particulates remained unaffected when varying either small or medium-large exhaust PM concentrations. It was also observed that high space velocities promoted medium and large particulate filtration, while degrading the filter trapping efficiency for small particulates.
Technical Paper
2014-10-13
Om Parkash Bhardwaj, Bernhard Lüers, Bastian Holderbaum, Thomas koerfer, Stefan Pischinger, Markku Honkanen
The present work is a continuation to the earlier published results on the investigation of the Hydrogenated Vegetable Oil (HVO) on a High Efficiency Diesel Combustion System. These results suggest a significant reduction of engine out carbon monoxide (CO), total hydrocarbons (THC), particulate matter (PM) and engine noise emissions using HVO as compared to petroleum based diesel fuel (SAE Technical Paper: 2013-01-1677). The test program was further extended to analyze the impact of HVO fuel properties on the soot physico-chemical characteristics and its consequences on the oxidation behavior in DPF. The initial study regarding the soot structure and oxidation behavior indicates a higher oxidative reactivity for HVO soot as published in Part-1 (JSAE Technical Paper No. 283-20145128). In order to further validate and interpret the previously published results of soot structure and oxidation behavior, the test program was further extended to analyze the impact of soot composition, optical properties, microstructure and physical properties on the oxidation behavior.
Technical Paper
2014-10-13
Rong Ma, Chao He, Jiaqiang Li
A simulation model of catalyzed diesel particulate filter (CDPF) is established based on the CFD software FIRE and has been validated through a series of experimental comparison. This model simulates the CDPF continuity regeneration process, and the factors that influence the exhaust NO2 concentration from CDPF including oxygen concentration, exhaust temperature, space velocity, proportion of NO2/NOX and soot mass fraction are studied. The results show that the higher oxygen concentration causes an increase in NO2/NOX. The NO2/NOX is significantly increased when the exhaust temperature is about 350℃. The space velocity in a certain degree leads higher NO2/NOX. There is no significant influence of increasing proportion of the NO2/NOX, and the soot mass fraction in the exhaust on the NO2/NOX at the CDPF outlet
Technical Paper
2014-10-13
Qian Feng, Diming Lou, Piqiang Tan, Zhiyuan Hu
In this study, durability and performance evaluation of the ageing catalyzed continuously regenerating trap (CCRT) on solid and volatile particulate emissions from urban diesel bus was studied by means of a set of on board measurement, transient TSI engine exhaust particle sizer spectrometer. During fourteen months, the CCRT had successfully reached self-regeneration. Three typical urban bus operating conditions, idling, stepped steady and transient conditions were carried out on-real world tests. In all evaluation tests, the average filtration efficiency of particle number was 93.3% at least under idling and stepped steady conditions. The CCRT of different ageing phase had different effect on nuclei mode particle. As the CCRT aging increase, the total particle number concentrations showed a declining trend while proportion of nuclei mode number concentration presented rising trend increasingly. This’s mainly due to the development of filtration mechanism: deep bed filtration, transitory and granular bed filtration.
Technical Paper
2014-10-13
Chunxing Lin, Brian Hillman, Andrew Williams
Stringent IC engine PM emission regulation requires development of future filter substrate materials to achieve high filtration efficiency, low filter pressure drop, low cost and highly durable solutions. Monolithic wall flow filters perform well as they achieve high filtration efficiency due to the formation of the PM cake structure while maintaining low substrate face velocities due to the large filtration area. Within the process industry, MicroporeTM slotted metallic membrane filters offer both large surface areas and low filter pressure drops while maintaining the durability of metal substrates. The pore structure and pore arrangement can be readily tailored to suit specific applications. This paper characterizes a 300 μm thickness MicroporeTM metallic membrane with slots of 10 μm by 400 μm in size in the context of application as an engine exhaust particulate filter. The investigation was based on single layer of MicroporeTM slotted metallic membrane with size of 52 mm in diameter.
Technical Paper
2014-10-13
Jianye Su, Min Xu, Peng Yin, Yi Gao, David Hung
Spark-ignition direct-injection (SIDI) gasoline engine, especially in downsized boosted engine platform, has proven to be one of the most promising concepts to improve vehicle fuel economy, and are increasing their market share relative to port fuel injection (PFI) engines in U.S., European and Chinese vehicles. However, higher particle number emission associated with operating the engine at higher loads provide additional challenges for meeting future stringent emission regulations. In this study, the potential of using multiple injection strategies (double injection and triple injection strategy during the intake stroke in homogeneous combustion mode) to reduce particle number emission was investigated using Horiba Mexa SPCS1000 in a 2.0 liter boosted SIDI gasoline engine at 1000 rpm, 11 bar BMEP condition. To clarify the mechanism for the particle emission benefit by multiple injection strategies, three-dimensional (3D) Computational Fluid Dynamics (CFD) model of the in-cylinder process was realized using CONVERGE software with the inputs from GT-Power® engine simulation.
Technical Paper
2014-10-13
Mohammad Reza Hamedi, Athanasios Tsolakis, Jose Martin Herreros
Recent developments in diesel engines lead to increased fuel efficiency and reduced exhaust gas temperature. Therefore more energy efficient aftertreatment systems are required to comply with tight emission regulations. In this study, a computational fluid dynamics package was used to investigate the thermal behaviour of diesel aftertreatment system. A parametric study was carried out to identify the most influential piping material and insulation characteristics in terms of thermal performance. In case of aftertreatment piping and canning material effect, an array of different potential materials was selected and their effects on the emission conversion efficiency of a Diesel Oxidation Catalyst (DOC) were numerically investigated over a driving cycle. Results indicate that although the piping material volumetric heat capacity was decreased by a factor of four, the total emission reduction was only considerable during the cold start. Since the piping system heat up and cool down periods were accelerated by reducing the system thermal inertia.
Technical Paper
2014-10-13
Haichao Fu, Yinhui Wang, Xinyan Li, Shi-Jin Shuai
An experimental study on particulate emission was conducted on four cars from Chinese market, three of which powered by gasoline direct injection (GDI) engines and the other one powered by port fuel injection (PFI) engine. Experiments were performed on a chassis dynamometer over new European driving cycle (NEDC). Particulate mass and number were measured using PMP system, and transient particulate number and size distribution were measured through DMS500 Fast Particulate Spectrometer. Three kinds of gasoline with RON 91.9, 94.0 and 97.4 were tested on these four cars to find impacts of RON on particulate emission. In order to get what extent cold start influences the particulate emission, both cold and hot start NEDCs were tested. Large scale of particles were emitted from both GDI and PFI cars during cold start condition (first 200s of NEDC). Compared with cold start NEDC, hot start NEDC particulate mass of these three GDI cars decreased by 65.1%, 27.9% and 66.3% respectively, and particulate number of these three GDI cars decreased by 58.5%, 34.0% and 53.3% respectively.
Technical Paper
2014-10-13
Kotaro Tanaka, Masatoshi Takano, Shuji Iimura, Kai Miyamura, Mitsuru Konno
 Ammonia (NH3) contributes to the production of secondary particulate matter (PM) as ammonium nitrate (NH4NO3) and ammonium sulfate ((NH4)2SO4). Recent studies have indicated that NH3 emission from automobiles may increase as a result of using a system for the urea selective catalytic reduction of NOx. In addition, the operating condition of the automobile plays an important role in the formation of NH3 in automobile exhaust. Therefore, it is very important to perform real-time measurements of the NH3 concentration in automobile exhaust.  Recently, highly sensitive near-IR laser absorption spectrometer has been employed to obtain measurement of NH3. This instrument allows in-situ measurements of highly time-resolved NH3 emission levels in automobile exhaust. However, the effect of the CO2 included in automobile exhaust on the measurement of NH3 has not been evaluated in detail. Because the CO2 concentration in automobile exhaust has been 2 or 3 orders of magnitude higher than the NH3 concentration, there is a possibility that spectral overlap by CO2 lines and/or the spectral broadening of NH3 by CO2 could have an influence on the measurement of the NH3 concentration.  
Technical Paper
2014-10-13
Barouch Giechaskiel, Urbano Manfredi, Giorgio Martini
Current vehicle exhaust legislation for diesel vehicles prescribes particle number (PN) limits for solid particles >23 nm. The legislation was extended to include gasoline direct injection (G-DI) vehicles since 2014. Target of this paper was to investigate whether smaller than 23 nm solid particles are emitted from engines in considerable concentration focusing on G-DI engines. The literature survey and the experimental investigation of 5 vehicles showed that engines emit solid sub-23 nm particles. The average percentage over a cycle (WLTP) is higher for G-DIs (40%) compared to diesel engines (20%). These percentages are relatively low considering the emission limit levels (6x10^11 p/km) and the repeatability (10-20%) and reproducibility of the particle number method (50%). These percentages are close to the percentages expected theoretically not to be counted due to the 23 nm cut-off size (5-15%). High emissions can be found when additives are added in the fuel or lubricant. Based on this literature survey, the PN legislation should remain the same.
Technical Paper
2014-10-13
Barouch Giechaskiel, Giorgio Martini
Current heavy-duty engine and light duty vehicle exhaust legislation prescribes particle number (PN) limits for solid particles >23 nm. The legislation was extended to include gasoline direct injection (G-DI) vehicles since 2014 and will be applied to non-road mobile machinery. Target of this paper was to investigate whether existing PN measurement equipment are capable of measuring below 23 nm. More specifically, it was investigated 1) whether all volatile particles can be removed efficiently in the PN measurement systems 2) whether any artifacts happen in the PN systems (e.g. formation of non-volatile particles due to pyrolysis), and 3) whether by lowering the lower size the measurement uncertainty increases significantly. The main conclusions are: 1) The volatiles are not always removed efficiently in the PN measurement systems. The major issue is re-nucleation of sulfuric acid downstream of the evaporation tube. These particles typically do not grow at sizes above 23 nm. 2) There are indications of formation of 10 nm solid particles from hydrocarbons and sulfuric acid in the PN systems. 3) The measurement uncertainty due to differences between commercial systems will increase with lower cut-off size.
Technical Paper
2014-10-13
Ossi Kaario, Teemu Sarjovaara, Olli Ranta, Tuomo Hulkkonen, Martti Larmi
In the present study, we analyze urea solution spray mixing and evaporation in a novel selective catalytic reduction (SCR) system. In typical SCR systems, low urea solution injection pressures are used. This may result in low evaporation rates implying that some additional methods need to be used to obtain feasible mixing and evaporation rates in the system. However, the aim in the present study is to use very high injection pressure for the solution in order to enhance droplet breakup, mixing, and evaporation and thus remove the need to use additional mixing enhancement techniques. We measure the spray characteristics of the urea solution, namely the spray penetration, opening angle, and droplet sizes from several distances from the nozzle and with various nozzle hole sizes and injection pressures. We focus our experiments on low gas density setting which is typically the SCR system operating environment. This kind of experimental data (low gas density, high injection pressure) is scarce in literature.
Technical Paper
2014-10-13
Seyed Ali Hadavi, Hu Li
Biodiesel have attracted a growing interest worldwide. Biodiesel (Fatty Acid Methyl Ester-FAME) is currently one of the most popular biofuel for reducing greenhouse gas (GHG) emissions for road transport vehicles with in the capabilities of current engine designs. There is a clear need to explore the feasibility of maximising the carbon reduction potentials of plant and vegetable oils by using oils directly in engines with out transesterification. The fuel additives was added to UCO renewable fuel. The largest benefit of using UCO directly is the carbon reduction potentials .A Euro 5 ,11.9 litre heavy duty truck, Mercedes Benz AXOR-C 6x2 with Turbo-intercooler, in-line six cylinders ,Water cooled with electromagnetic fan, and Exhaust Stainless steel ,SCR catalytic converter was used. This study measured Regulated tailpipe exhaust Emission under real world driving condition, and compared with HDV emissions standards. An on-board FTIR (Fourier Transform Infrared) was used for exhaust emission measurement system which can measure up to 51 species with detection limits of 3 to 5 ppm and accuracy of 2% within the calibrated measurement range depending on application and compound.
Technical Paper
2014-09-30
Nils Olof Nylund, Veikko Karvonen, Hannu Kuutti, Juhani Laurikko
Over the years, natural gas has been promoted as a clean-burning fuel, especially for transit buses. VTT Technical Research Centre has monitored the performance of both diesel and natural gas buses for more than a decade, and has a very comprehensive data base on bus performance. VTT also has carried out work on buses for the Energy Technology Network of the International Energy Agency. A decade ago one could claim that natural gas buses deliver significant emission benefits over diesel buses, especially regarding particulate emissions. The spread in nitrogen oxide emissions has always been significant for natural gas engines, high for lean-burn engines and low for three-way catalyst equipped stoichiometric engines. With the introduction of US 2010 and Euro VI exhaust emission regulations, independent of the fuel, the regulated emissions of all engines, have, in a historical perspective, been brought close to zero level. This means that the competitive advantage of natural gas as a clean fuel is diminishing, especially in a situation where electric city buses are also entering the market.
Technical Paper
2014-09-30
Abhishake goyal, Nadeem Yamin, Naveen Kumar
Fuel cells are a promising energy source on account of their high efficiency and low emissions. Proton Exchange Membrane fuel cells (PEMFC) are clean and environmentally-friendly power sources, which can become future energy solutions especially for transport vehicles. They exhibit good energy efficiency and high power density per volume. Working at low temperatures (<90 0C), hydrogen fueled proton exchange membrane fuel cells (PEMFCs) are identified as promising alternatives for powering autos, houses and electronics. At the heart of the PEM fuel cell is the membrane electrode assembly (MEA). The MEA consists of a proton exchange membrane, catalyst layers, and gas diffusion layers (GDL). However, it is believed that PEMFC are not competitive enough to rechargeable lithium ion battery with respect to price because of the rare metal used such as platinum in it. Presence of platinum in PEM fuel cells is one of the reasons why fuel cells are excluded from commercialization. Therefore, reducing the amount of platinum used in fuel cells is very important for their commercialization.
Technical Paper
2014-09-30
Sauhard Singh, Reji Mathai, Ved singh, A K Sehgal, B basu, R K Malhotra, S Nagarajan, S Yoganandam, G Senthil kumar, G Gopal
Air Pollution is a serious global problem. Increase in population the growing demands further aggravates it. This has resulted in exploring alternative fuel for internal combustion (IC) engines. Some of the promising alternative fuels are Compressed Natural Gas (CNG), Hydrogen, LPG, Ethanol etc. CNG is gaining popularity as fuel in transport sector due to lower carbon to hydrogen ratio, cost & infrastructure. Hydrogen (H2) for IC engines is considered as a future fuel due to carbonless structure. But several obstacles need to be overcome before commercialization of H2 as an IC engine fuel for transport sector. Presently, lack of hydrogen infrastructure and refuelling stations prevent widespread introduction of hydrogen vehicles. One of the solutions is to blend hydrogen to CNG. Such types of blends acquire benefit of the unique combustion properties of hydrogen and at the same time reduce the demand for pure hydrogen. Also these blends can use the existing natural gas infrastructure and existing CNG engine without any major hardware modification.
Technical Paper
2014-09-30
Bryan Roy, Paul Windover, Terry Levinson, Joseph Tario, Eric VanOoyen
A State Department of Transportation is responsible for maintaining a safe, efficient, balanced, and sustainable transportation system. It has many types of on-road vehicles and off-road equipment, which are operated by various personnel. The New York State Department of Transportation (NYSDOT) is also governed by Executive Orders to improve overall fleet efficiency, reducing petroleum consumption and greenhouse gases. While the NYSDOT Region 4 is actively addressing this issue by using more efficient LED hazard warning signs and encouraging personnel to turn off vehicles when not in use, it wanted to do more. Thus, with the support of NYSDOT and the New York State Energy Research and Development Authority, Energetics Incorporated is evaluating the operational, economical, and environmental impacts of advanced technologies to reducing idling in the fleet without compromising functionality. NYSDOT Region 4 has a fleet of 328 on-road vehicles to serve the more than one million customers in seven western New York counties.
Technical Paper
2014-09-30
Antoine Delorme, Jason L. Robert, William Eli Hollowell, Andre M. Strobel, Jason T. Krajewski
In the recent years, Automated Manual Transmissions have become more popular for class 8 heavy trucks. Besides the benefits of smoother gear changes and reduced driver fatigue, AMTs can also greatly reduce fuel consumption by using optimized shifting strategies and advanced controls. The Detroit DT12 AMT demonstrated significant fuel savings due in part to its eCoast feature. eCoast relies on intelligent and advanced electronic controls to safely allow the vehicle to coast on downgrades. While the engine is idling, the drag parasitic energy losses are decreased and the vehicle can fully use its momentum to travel further up and down hill. As one could expect, the type of route profile can greatly affect the fuel savings due to eCoast, since more hilly terrains might offer more opportunities to activate eCoast than flatter roads. In addition, when combined with different vehicle and driving parameters such as vehicle weight and driver desired cruise set speed, the fuel consumption reduction of eCoast is always there, but becomes a more complicated function.
Technical Paper
2014-09-30
Steffen Hoppe, Troy Kantola
Increasingly, the fundamental drivers in the development of commercial vehicle engines are improved fuel efficiency and the need to meet more stringent exhaust emissions legislation. This strategy presents significant challenges in the development of engine components, particularly piston rings. Within the power cylinder, piston rings are significant contributors to friction losses, with the ring pack contributing up to 25 percent of the total mechanical engine friction loss, and a corresponding fuel consumption of up to four percent. The challenge lies in reducing friction power loss while also mastering the increasing thermomechanical and tribological demands that piston rings must endure due to increased power density, smoother cylinder bores, reduced lubrication, and the use of alternative fuels. In this context, the robustness of the piston ring running face, as characterized by wear resistance and scuff resistance in particular, plays an increasing role. As coatings are a crucial surface design element, they inevitably are a primary focus for addressing friction loss and increasing robustness in the piston ring/cylinder tribological system.
Technical Paper
2014-09-30
Ashish Kumar Singh, Abhishek Sharma, Naveen Kumar
Fast depletion of fossil fuels is urgently demanding a carry out work for research to find out the viable alternative fuels for meeting sustainable energy demand with minimum environmental impact. In the future, our energy systems will need to be renewable and sustainable, efficient and cost-effective, convenient and safe. Therefore, researcher has shown interest towards alternative fuels like vegetable oils, alcoholic fuels, LPG, CNG, Producer gas, biogas in order to substitute conventional fuels used in compression ignition (CI) engine. However studies have suggested that trans-esterified vegetable oils retain quite similar physico-chemical properties comparable to diesel. Besides having several advantages, its use is restricted due to trouble like higher NOx emission and engine deposit due to partially incomplete combustion. There is a need of cleaner fuel for diesel engines in the present rigid emissions norms and the fossil depletion. In the current analysis CNG with KOME is used in dual fuel mode for complete combustion of charge so as to reduce emission.
Technical Paper
2014-09-30
Alexander Sappok, Leslie Bromberg
Diesel Particulate Filters (DPF) are a key component in many on- and off-road aftertreatment systems to meet increasingly stringent particle emissions limits. Efficient thermal management and regeneration control is critical for reliable and cost-effective operation of the combined engine and aftertreatment system. Conventional control DPF control systems predominantly rely on a combination of filter pressure drop measurements and predictive models to indirectly estimate the soot loading state of the filter. Over time, the build-up of incombustible ash, primarily derived from metal-continuing lubricant additives, accumulates in the filter to levels far exceeding the DPF’s soot storage capacity. The combined effects of soot and ash build-up dynamically impact the filter’s pressure drop response, service life, and fuel consumption, and must be accurately accounted for to optimize engine and aftertreatment system performance. This work applied a radio frequency (RF) sensor to directly monitor diesel particulate filter soot and ash levels, thereby enabling direct feedback control of the filter based on its actual loading state.
Technical Paper
2014-09-30
Guanyu Zheng
In order to satisfy China IV emissions regulations, an unique design was proposed with injector closely coupled with SCR outer body. The benefit of this design is that the system mixing pipe can be shortened, resulting in smaller packaging space and lower cost of decomposition pipe. However, the shorter urea mixing distance generates concerns on lower urea mixing efficiency and higher risks of urea deposits. Aftertreatment systems need to be properly engineered to resolve these technical challenges. Systematic enhancements of the design have been performed to enable multiple designs to meet a set of performance targets, including emission reduction efficiency via improved reagent mixing, evaporation, distribution, back pressure, and removing of urea deposits. The optimized system improved NOx reduction uniformity, eliminated urea deposits, improved NOx conversion efficiency while satisfy existing installation packing space. This study demonstrates that good system performance can be achieved despite the challenges of meeting strict and often-conflicting performance targets.
Technical Paper
2014-09-30
Guanyu Zheng, Hongyu Wang
Urea-based SCR has been the mainstream technology to reduce NOx emissions for on-road vehicles and off-road vehicles. In category II marine applications, urea SCR is being considered as an enabling technology to reduce NOx. A typical urea SCR system includes a urea injector, injector housing, mixer, and appropriate pipe configurations. In applications of the SCR technology, urea mixing and deposit mitigation have become severe challenges. Urea deposit issues were encountered in SCR systems designed for large marine engines. To resolve urea deposits, CFD method and tests were applied to investigate urea spray transport, evaporation and droplet-wall phenomena. In system design, multiple design factors are reviewed: (1) overall geometrical layouts; (2) substrate and catalyst selections; (3) urea injector and nozzle selections; (4) miscellaneous issues such as ash cleaning, fuel switching, and etc.
Technical Paper
2014-09-30
L. Joseph Bachman, Anthony Erb, Jeffry Sellers
Road tests of class 8 tractor trailers were conducted on new and retreaded tires of varying rolling resistance in order to provide estimates of the quantitative relation between rolling resistance and fuel consumption. Reductions in fuel consumption were estimated using the SAE J1321 (reaffirmation of 1986) test method. Vehicle rolling resistance was calculated as a load-weighted average of the rolling resistance (as measured by ISO28580) of the tires in each axle position. Both new and retreaded tires were tested in different combinations to obtain a range of vehicle coefficient of rolling resistance from a baseline of 7.7 kg/ton to 5.3 kg/ton. Reductions in fuel consumption displayed a strong linear relationship with coefficient of rolling resistance, with a maximum reduction of fuel consumption of 10 per cent relative to the baseline. The return factor for the new tires was 3.1:1, that is a 3.1 per cent decrease in rolling resistance yielded a fuel consumption decrease of 1 per cent.
Technical Paper
2014-09-30
Burcu Guleryuz, Cagkan Kocabas, Erkan OZTURK
Remanufacturing is a process in which used products are disassembled, and their components are repaired and used in the production of new products. This study investigates the impact of various remanufacturing decisions on profitability and market cannibalization in an infinite-horizon production scenario for heavy duty vehicle (HDV) clutches. A discrete event simulation model is developed for benchmarking of different scenarios using various factors and their levels. There are two consumer segments as primary customer and grey customer in the market. Three different end of life (EOL) clutch quality conditions are defined, and three different percentages of clutch collect strategies are defined for all EOL products in the market. Therefore, a total of nine combinations (i.e., three quality index and three collecting strategies) are benchmarked in terms of total profit from new and remanufactured HDV clutches, number of customers won, and amount of saved raw material for environmental considerations.
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