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Viewing 31 to 60 of 22391
Technical Paper
2014-10-13
Amar Deep, Naveen Kumar, Ashish Karnwal, Dhruv Gupta, Vipul Vibhanshu, Abhishek Sharma, Jitesh Singh Patel
The interest of using alternative fuels in diesel engines has been accelerated exponentially due to a foreseen scarcity in world petroleum reserves, increase in the prices of the conventional fossil fuels and restrictions on exhaust emissions such as greenhouse gases from internal combustion (IC) engines initiated by environmental concerns. The constant trade-off between efficiency and emissions should be in proper balance with the conventional fuels in a fuel design process for future combustors. Unlike gasoline and diesel, alcohols act as oxygenated fuels. Adding alcohols to petroleum products allows the fuel to combust properly due to the presence of oxygen, which enhances premixed combustion phase, improves the diffusive combustion phase which increases the combustion efficiency and reduces air pollution. The higher activation energy of alcohols leads to better resistance to engine knocking that allows higher compression ratios and greater engine thermal efficiencies. Direct use of alcohol/diesel fuel blends is one of the most interesting possibilities because of their lower viscosity and similar physio-chemical properties to mineral diesel; most importantly, prior modifications on diesel engine are not required.
Technical Paper
2014-10-13
Jonathan Stewart, Andrew Woods, Roy Douglas, Richard O’Shaughnessy
With emission legislation becoming ever more stringent, automotive companies are forced to invest heavily in solutions to meet the targets set. To date, the most effective way of treating emissions is through the use of catalytic converters. Since the introduction of these converters as the main method of reducing automotive emissions, catalyst performance testing has become a major part of automotive research and development. One of the most critical aspects of the performance testing process is catalyst ageing. Legislation has been introduced stating that catalytic converters must meet the set emissions standards legislation up to a lifetime of 150,000 miles (LEV 2014-2022). The catalytic converter will deactivate over its lifetime due to a number of different factors, such as, thermal deactivation, poisoning, fouling and structural breakdown of the catalyst. It is therefore of the utmost importance for automotive companies to evaluate the performance of the catalytic converters under these conditions.
Technical Paper
2014-10-13
Kristin Götz, Anja Singer, Olaf Schröder, Christoph Pabst, Axel Munack, Jürgen Bünger, Jürgen Krahl
The political and economic major aim in Europe is the increase of the use of renewable energy resources up to 10 % till 2020. This means a reduction in crude oil dependency. Already well known in diesel fuel area are fatty acid methyl esters, named biodiesel. However, this biogenic component has not only advantages, as a further raise of the amount of biodiesel content in diesel fuel higher than seven percent can lead to an increase of the engine oil dilution in passenger cars with diesel particulate filters. Because of the regeneration of the particulate filters, the entry of fuel components increases. This may induce sludge formation in the engine oil. A promising approach to reduce this problem is a new type of biogenic fuel, called HVO (hydrotreated vegetable oil). This is also produced from vegetable oil or animal fat and it is chemically quite similar to fossil diesel fuel. Like biodiesel, HVO is free of sulfur or any aromatics. HVO has a higher cetane number in comparison to biodiesel and most diesel fuels.
Technical Paper
2014-10-13
Jinyoung Jang, Young-Jae Lee, Ohseok Kwon, Minseob Lee, Jeonghwan Kim
The emissions from vehicle are affected by engine type, fuel and engine oil making particulate matter (PM) 13% of total PM. In this study, engine oil is focused to show the effect of engine oils on PM and other emission. Group III base oil, Group III base oil with additives and poly alpha olefins (PAO’s) with additives are tested and have identical SAE grad for same vehicle. Gasoline vehicle, which has direct injection system, and diesel vehicle, which has no PM trap, were selected because those vehicles clearly emit PM more than port fuel type gasoline and diesel with PM trap vehicle. Combined mode test, consisting of FTP 75 and highway drive mode, are used to assess exhaust emission and fuel economy. The number of PM was counted using PPM-S, which is based on the measurement of electrical charge carried by particles. Regulated emissions and fuel economy for gasoline vehicle were analyzed by HORIBA gas analyzer with sampling bags. Diesel vehicle’s emissions and fuel economy were analyzed by PIERBURG gas analyzer.
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
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
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
Dave OudeNijeweme, Paul Freeland, Markus Behringer, Pavlos Aleiferis
Particulate emissions are of growing concern due their negative health impacts. Many urban areas around the world currently have levels exceeding the World Health Organisation safe limits. Gasoline engines, especially when equipped with direct injection systems, contribute to this pollution. In recognition of this fact European limits on particulate mass and number are being introduced. A number of ways to meet these new stringent have been under investigation at MAHLE Powertrain, with this paper focussing on the improvement potential of the injection equipment. This investigation is part of MAHLE’s ongoing particulate research and method development that includes optical engine spray and combustion visualisation, CFD method development, engine and vehicle testing with the aim to move particulate emission development upstream in the development process. As part of this work, a spark eroded and a laser drilled injector were fully characterised in a spray vessel under key engine running conditions.
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
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
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
Jing Qin, Xiang Li, Yiqiang Pei
Abstract The aim of this detailed research is to experimentally investigate the effects of ignition timings, injection timings, excess air ratio (λ) and lubricating oil on particulate matter (PM) emissions from a 2.0 L turbo-charged gasoline direct injection (T-GDI) engine fueled with gasoline, methanol/gasoline blends and pure methanol. The results of this paper show that the PM number concentration mostly presents a typical bimodal or trimodal distribution in figures. The particle number concentration mainly concentrates in the nucleation mode. With the increase of methanol volume fraction in the blended fuel, the PM emissions decrease significantly. Furthermore, there are few particles when the engine fueled with pure methanol. As advancing ignition timing, the total PM number rises by over about 200%. Under the pre-ignition condition, the higher in-cylinder temperature may also accelerate the formation of the nucleation mode particles. As advancing injection timing, PM emissions decrease first, and then increase.
Technical Paper
2014-10-13
Christoph Menne, Simon Galbraith, Alan Jones, Lars Henning, Thomas Koerfer
In September 2013 the Jaguar XF 2.2l ECO sport brake and saloon were introduced to the European market. They are the first Jaguar vehicles to realize CO2 emissions below 130 g/km. To achieve the significantly reduced fuel consumption values with an existing 2.2l I4 Diesel engine architecture selected air path and fuel path components were optimized for increased engine efficiency. Hardware selection and development in the available short time frame were only enabled by the consequent utilization of the most advanced CAE tools throughout the design phase but also during the complete vehicle application process. Changes to the base engine architecture were ruled out at the beginning of the project due to the implications on manufacturing complexity and the limited given time frame for realization. To allow a fuel consumption reduction of more than 10% vs. the first introduction of the 2.2l I4 Diesel in XF the following measures were identified: - Improved combustion efficiency due to more advanced centre of combustion for most engine operating points - Improved fuel spray and mixture preparation - Air path with reduced pressure losses especially for the high pressure exhaust gas recirculation - significantly enhanced cooling performance of the high pressure exhaust recirculation path - downspeeding with advanced transmission control The potential of the listed measures and their interactions, the chosen hardware components and the used development and application methodologies shall be presented in this paper.
Technical Paper
2014-10-13
Arjun Prakash, Edward Nelson, Aaron Jones, James Macias, Matthew Hinojosa, Eugene Jimenez
Particulate mass (PM) emissions from DISI engines can be reduced via fuels technology that facilitates injector deposit clean-up. A significant drawback of DISI engines is that they can have higher particulate matter emissions than PFI gasoline engines. Soot formation in general is dependent on the air-fuel ratio, combustion chamber temperature and the chemical structure and thermo-physical properties of the fuel. In this regard, PM emissions and DISI injector deposit clean-up were studied in three identical high-selling vehicles. The tests compared the effects of a fuel (Fuel A) containing a market generic additive at lowest additive concentration (LAC) against a fuel formulated with a novel additive technology (Fuel B). The fuels compared had an anti-knock index value of 87 containing upto 10% ethanol. The vehicles were run on Fuel A for 20,000 miles followed by 5,000 miles on Fuel B using a chassis dynamometer. It was observed that Fuel A gave rise to an increase in PM emissions indicative of DISI injector deposit build-up.
Technical Paper
2014-10-13
Matthew McAllister, Stephen Smith, Paul Kapus, Khai Vidmar, Alexander Hochnetz
This paper describes the findings of a design, simulation and test study into how to reduce particulate number (Pn) emissions in order to meet EU6c legislative limits. The objective of the study was to evaluate the Pn potential of a modern 6-cylinder engine with respect to hardware and calibration when fitted to a full size SUV. Having understood this capability, the combustion system was redesigned and the calibration was optimised in order to meet an engineering target Pn value of 3x1011 in the NEDC drive cycle. Extensive design and CFD work was conducted to refine the inlet port, piston crown and injector spray pattern in order to reduce surface wetting and improve air to fuel mixing homogeneity. The design and CFD steps are reported within this paper along with the results compared to target. The ECU software was optimised in order to allow for calibration strategies leading to minimised wall interaction of injected fuel. The Pn optimisation by calibration measures with the improved combustion system followed a specific development process.
Technical Paper
2014-10-13
Achinta Varna, Konstantinos Boulouchos, Alexander Spiteri, Panayotis Dimopoulos Eggenschwiler, Yuri M. Wright
Simulations for a pressure-assisted multi-stream injector designed for urea-dosing in a selective catalytic reduction SCR exhaust gas system have been carried out and compared to measurements taken in an optically accessible high-fidelity flow test rig. The experimental data comprises four different combinations of mass flow rate and temperature for the gas stream with unchanged injection parameters for the spray. First, a parametric study is carried out to determine the importance of various spray sub-models, including atomization, spray-wall interaction, buoyancy as well as droplet coalescence. Optimal parameters are determined using experimental data for one reference operating condition. The model is subsequently applied to all operating conditions with unaltered parameters and validated by means of the measured droplet velocity fields, droplet diameter distributions and spray-tip propagation which have been characterized by means of Particle Image Velocimetry (PIV), Phase Doppler Anemometry (PDA) and shadowgraph imaging.
Technical Paper
2014-10-13
S. F. Benjamin, C. A. Roberts
In an attempt to reduce particulate and NOx emissions from Diesel exhaust, the combined DPF and SCR filter is now frequently chosen as the preferred catalyst. When this device functions effectively it saves valuable packaging space in a passenger vehicle. As part of its development, modelling of its emissions performance is essential. Single channel modelling is the obvious choice for a DPF filter because of its complex geometry. This, however, can be computationally demanding. For a normal flow-through catalyst monolith the porous medium approach is an attractive alternative. This paper attempts to model an SCRF by applying the porous medium approach. The model is essentially 1D but as with all porous medium models, can very easily be applied to 3D cases once developed and validated. The model is described in full in this paper and values for all the key parameters are presented. The filter is assumed to collect soot in the inlet channels, but only the output channels are coated with SCR washcoat, as in the most recent devices.
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
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
Juan J. Hernández, Rosario Ballesteros, Javier Barba, José Guillén-Flores
In order to reduce the pollutant emissions (mainly NOx and PM) of diesel engines, the addition of small gaseous fuel amounts (such as natural gas, biogas, reforming gas, LPG) or dual mode operation (in which a pilot injection of diesel fuel promotes the gaseous fuel combustion) have been proved as potential techniques. This paper is focused on a detailed characterization of the particles emitted from a single cylinder diesel engine when part of the reference diesel fuel (10 and 20% by energy) is replaced by a gaseous fuel (producer gas, mainly composed by H2, CO and CH4) coming from biomass steam gasification (renewable fuel which has not been previously analyzed when used in diesel engines). The engine was operated at constant speed and torque, varying the EGR rate (0 and 15%). Particle samples were collected by means of fiber glass filters placed in a dilution mini-tunnel for both to determine the particle mass and for further characterization. Simultaneously, during tests, part of the exhaust gas was conducted to a system formed by two diluters and a SMPS (Scanning Mobility Particle Sizer) to obtain the particle size distribution.
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
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
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 environmental-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°C), hydrogen fuelled proton exchange membrane fuel cells (PEMFCs) are identified as promising alternatives for powering autos, houses and electronics. At the middle of the proton exchange membrane (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, most of the researchers have already mentioned 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.
Technical Paper
2014-09-30
Zhiguo Zhao, Guanyu Zheng, Fengshuang Wang, Suying Zhang, Jianhua Zhang
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
Xiangang Wang, Zhangsong ZHAN, Tiegang Hu, Zuohua Huang
Abstract Experiments were conducted in a turbocharged, high-pressure common rail diesel engine to investigate particulate emissions from the engine fueled with biodiesel and diesel blends. An electrical low-pressure impactor (ELPI) was employed to measure the particle size distribution and number concentration. Heated dilution was used to suppress nuclei mode particles and focus on accumulation mode particles. The experiment was carried out at five engine loads and two engine speeds. Biodiesel fractions of 10%, 20%, 40%, 60% and 80% in volume were tested. The study shows that most of the particles are distributed with their diameters between 0.02 and 0.2 μm, and the number concentration becomes quite small for the particles with the diameters larger than 0.2 μm. With the increase of biodiesel fraction, engine speed and/or engine load, particle number concentration decreases significantly, while the particle size distribution varies little. The analysis on heat release rate, excess air ratio and exhaust gas temperature were provided to help interpret the particulate emissions.
Technical Paper
2014-09-30
Britney J. McCoy, Arman Tanman
In-use testing of verified diesel emission control technologies is an integral component of EPA’s verification program. Device manufacturers are required to complete in-use testing once 500 units have been sold. Additionally, EPA conducts test programs on randomly selected retrofit devices from installations used within the National Clean Diesel Campaign grant programs. In this test program, EPA identified and recovered a variety of retrofit devices installed on heavy-duty diesel vehicles (on-highway and off-road) including diesel particulate filters (DPFs) and diesel oxidation catalysts (DOCs). All of the devices were tested at Southwest Research Institute. The goal was to evaluate the emissions performance and durability of retrofit technologies aged in real-world applications. In assessing the emissions reducing performance of these after-treatment technologies, a variety of different test methods were used to characterize the overall performance of the retrofit devices on an engine dynamometer.
Technical Paper
2014-09-30
Manoj K. Sampath, Figen Lacin
Diesel engine combustion process results in harmful exhaust emissions mainly composed of Particulate Matter (PM), Hydro Carbon (HC), Carbon monoxide (CO) and Nitrogen Oxides (NOx). Several technologies utilizing catalyst has been developed in the past decades to control these diesel emissions. Reduction of PM by advanced combustion research often results in increase of NOx due to more complete combustion and hence reducing NOx becomes even more challenging. One of the promising and well matured technology of reducing NOx is to implement Selective Catalytic Reduction (SCR) using ammonia (NH3) as the reducing agent. The generation of NH3, in this case, is from the evaporation of Diesel Exhaust Fluid (DEF) or liquid urea through thermolysis and hydrolysis process. For an effective SCR system, the mal-distribution of ammonia across the SCR Inlet has to be evenly distributed. There are several commercial Computational Fluid Dynamics (CFD) tools available to predict the SCR flow distribution including ammonia formation from the urea decomposition.
Technical Paper
2014-09-30
Guanyu Zheng, Fengshuang Wang, Sheng Wang, Wei Gao, Zhiguo Zhao, Jian Liu, Lin Wang, Lin Wu, 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
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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