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Viewing 1 to 30 of 550
2011-04-12
Technical Paper
2011-01-0692
Hamid R. Rahai, Ehsan Shamloo, Jeremy Ralph Bonifacio
The effects of humid air on the performance of a naturally aspired three-cylinder diesel engine with low sulfur diesel fuel have been investigated. The additions of the humidity to intake air were performed with a variable steam generator using distilled water, where the relative humidity levels of the intake air were changed from the ambient conditions of 65% to 75% and 95% levels. The tests were performed at two approximate engine output brake horse powers (BHP) of 5.9, and 8.9. Results showed approximately 3.7% and 22.5% reduction in NO x emissions when the relative humidity of the air was increased from 65% (the ambient relative humidity) to 75% and 95% respectively. The addition of the humidity results in increases in the CO, CO₂, and particulate matter (PM), by approximately 3.7, 3.55, 14.9 percents at 5.9 BHP and 22, 2.8, and 9.3 percents at 8.9 BHP. There was no change in the brake specific fuel consumption (BSFC) at 5.9 BHP and about 2.7 increase in the BSFC at 8.9 BHP.
2013-09-24
Technical Paper
2013-01-2462
Reza Torbati, Marco Federico Pidria, Giovanni Cerciello, Davide Rodonò
Partial flow filters (PFF) are devices that can capture particulate matter (PM) for a period of time sufficient for its catalytic oxidation. The filter consists of alternating layers of corrugated metal foil and porous sintered metal fleece which captures the particulates. The captured particles are then re-generated passively by nitrogen dioxide (NO2) produced by the oxidation of NO on a diesel oxidation catalyst (DOC) placed before the filter. The filter's robust design and the ability to operate without any maintenance, i.e. no vehicle downtime, have led to an increasing demand for both heavy duty (HD) and light duty (LD) retrofit applications worldwide. Unlike diesel particulate filter (DPF), the PFF will not plug once filled with soot to its maximum capacity in the absence of passive regeneration (low load and low exhaust temperature conditions). Instead, the PM conversion efficiency will gradually decrease, allowing PM emissions to pass through.
2013-09-24
Technical Paper
2013-01-2424
Jyotirmoy Barman
Exhaust gas recirculation is one important measure to achieve the Bharat Stage IV, Bharat Stage V as well as the Euro V emissions legislation. EGR is one of the most promising solutions to reduce NOx to achieve Bharat Stage IV emission norms for any high specific power engine. An emissions and performance study was conducted to explore the effects of EGR and multiple injections on particulate, NOx, and BSFC. Recent work has shown that multiple injections are effective at reducing particulate. Thus, it was of interest to examine the possibility of simultaneously reducing particulate and NOx with the combined use of EGR and multiple injections. The tests were conducted on a four cylinder four valve light duty truck engine. Tests were done at emission modes (A, B & C Modes) with EGR are variation along with different injection strategies. The fuel system used was an electronically controlled, common rail injector and supporting hardware.
2013-11-27
Technical Paper
2013-01-2759
Pedro Manuel Barroso Guzman, Xavier Ribas, José María García Sr, Mario Pita Sr
The objective of this study is to describe the results on Particle Matter and CO2 emissions when an existing Heavy-Duty diesel engine for on-highway truck applications is converted to a Dual-fuel engine (diesel + Natural Gas) during the freeway part of transient worldwide emission tests. A Dual-fuel engine with Homogeneous Gas Charge Injection in the intake line before turbocharger was considered. The results showed the feasibility of this kind of technology for transient operation reaching a significant reduction of Particle Matter plus a decrement in CO2 emissions compared to diesel baseline engine. The results of gas energy replacement ratio, brake fuel conversion efficiency, CO and unburned hydrocarbons in the exhaust gases are also shown.
2013-09-08
Technical Paper
2013-24-0150
Georgios Fontaras, Martin Rexeis, Panagiota Dilara, Stefan Hausberger, Konstantinos Anagnostopoulos
Following its commitment to reduce CO2 emissions from road transport in Europe, the European Commission has launched the development of a new methodology for monitoring CO2 emissions from heavy-duty vehicles (HDV). Due to the diversity and particular characteristics of the HDV sector it was decided that the core of the proposed methodology will be based on a combination of component testing and vehicle simulation. A detailed methodology for the measurement of each individual vehicle component of relevance and a corresponding vehicle simulation is being elaborated in close collaboration with the European HDV manufacturers, component suppliers and other stakeholders. Similar approaches have been already adopted in other major HDV markets such as the US, Japan and China.
2013-09-08
Journal Article
2013-24-0177
Philipp Vögelin, Peter Obrecht, Konstantinos Boulouchos
Future engine emission legislation regulates soot from Diesel engines strictly and requires improvements in engine calibration, fast response sensor equipment and exhaust gas aftertreatment systems. The in-cylinder phenomena of soot formation and oxidation can be analysed using a pyrometer with optical access to the combustion chamber. The pyrometer collects the radiation of soot particles during diffusion combustion, and allows the calculation of soot temperature and a proportional value for the in-cylinder soot density (KL). A four-cylinder heavy-duty Diesel engine was equipped in all cylinders with prototype pyrometers and state of the art pressure transducers. The cylinder specific data was recorded crank angle-resolved for a set of steady-state and transient operating conditions, as well as exhaust gas recirculation (EGR) addition and over a wide range of soot emissions.
2013-09-08
Journal Article
2013-24-0016
Daniele Farrace, Michele Bolla, Yuri M. Wright, Konstantinos Boulouchos
Numerical simulations of in-cylinder soot evolution in the optically accessible heavy-duty diesel engine of Sandia National Laboratories have been performed with the multidimensional conditional moment closure (CMC) model using a reduced n-heptane chemical mechanism coupled with a two-equation soot model. Simulation results are compared to the high-fidelity experimental data by means of pressure traces, apparent heat release rate (AHRR) and time-resolved in-cylinder soot mass derived from optical soot luminosity and multiple wavelength pyrometry in conjunction with high speed soot cloud imaging. In addition, spatial distributions of soot relevant quantities are given for several operating conditions.
2013-09-24
Technical Paper
2013-01-2385
N. Santosh Datta
With evolution of emission norms in diesel engines, NOx emission limits became more stringent and can be met only with specific NOx emission control systems. The NOx control systems in heavy duty diesel engines are monitored for OBD regulations in on-highway applications. Additionally driver warning and inducement requirements for NOx emission control systems are to be complied in both on-highway and off-highway applications. The driver inducement requirements are defined with intent to enforce and ensure correct operation of NOx control system. The NOx control systems and inducement measures are implemented in engine Electronic Control Unit (ECU) software to be compliant to legislation. The paper focuses on driver inducement requirements for NOx emission control systems. The paper summarizes the inducement requirements with a system overview and software design to meet driver inducement requirements for EUVI legislation and CARB/EPA compliance.
2004-06-08
Technical Paper
2004-01-1939
Paul Richards, B. Terry, J. Chadderton, M. W. Vincent
In an attempt to improve ambient air quality, retrofit programmes have been encouraged; targeting reductions in PM emissions by means of diesel particulate filters (DPFs). However depending on the DPF design and operating conditions increased nitrogen dioxide (NO2) emissions have been observed, which is causing concern. Previous work showed that retrofitting a DPF system employing a fuel borne catalyst (FBC) to facilitate regeneration, reduced NO2 emissions. This paper outlines the investigation of a base metal coated DPF to enhance the reduction of NO2. Such a DPF system has been fitted to older technology buses and has demonstrated reliable field performance.
2004-03-08
Technical Paper
2004-01-0923
E. G. Pariotis, D. T. Hountalas
This work is a part of an extended investigation conducted by the authors to validate and improve a newly developed quasi-dimensional combustion model. The model has been initially applied on an old technology, naturally aspirated HSDI Diesel engine and the results were satisfying as far as performance and pollutant emissions (Soot and NO) are concerned. But since obviously further and more extended validation is required, in the present study the model is applied on a new technology, heavy-duty turbocharged DI Diesel engine equipped with a high pressure PLN fuel injection system. The main feature of the model is that it describes the air-fuel mixing mechanism in a more fundamental way compared to existing multi-zone phenomenological combustion models, while being less time consuming and complicated compared to the more accurate CFD models. The finite volume method is used to solve the conservation equations of mass, energy and species concentration.
2004-10-26
Technical Paper
2004-01-2658
William Wangard, Aleksandra Egelja, Hossam Metwally
A transient, 3-dimensional, continuum CFD model of soot loading and regeneration has been developed for a single channel unit in a diesel particulate filter. The detailed model is used to predict the soot loading, velocity, temperature, and species distributions in both the air channels and porous walls of the filter. The simulation is performed in two phases: loading and regeneration. In the loading phase, soot profiles are estimated for a clean filter using a steady-state simulation. In the second phase, transient regeneration is modeled using a single-step, irreversible heterogeneous mechanism is used to predict the formation of carbon monoxide and carbon dioxide products during the regeneration process, incorporating a fractionization scheme. Reaction rates are predicted via an Arrhenius rate law, but may be tempered due to diffusion-limiting conditions in the porous reaction zone. Simulations are performed with a commercial CFD package and user-defined functions.
2013-10-07
Technical Paper
2013-36-0319
Glécia Virgolino da Silva Luz, Pilar Hidalgo, Carlos Gurgel Veras, Simona Merola, Luigi Allocca, Alessandro Montanaro, Luca Marchitto
The use of biodiesel as alternative to fossil fuel for light duty CI engines to reduce greenhouse gas emissions was widely investigated. However, poor stability of biodiesel - diesel mixture limits the use of biodiesel to low volume concentrations. This paper presents the results concerning the use of a novel fuel additive package containing antioxidant (AS), pour-point depressant (D) and biocide (Bi) with the aim to increase the quality and amount of biodiesel in the diesel-biodiesel blends. Some of the goals are linked to the degradative effects due to free radicals oxidation, contamination by water and microorganisms. The interaction between two different additive packages and two biodiesel (soybean and rapeseed) - diesel blends at 20% in volume was investigated. Optical studies have been performed to characterize the spatial and temporal spray evolution both in a high pressure quiescent vessel and in an optically-accessible single-cylinder 2-stroke CI engine.
2013-10-07
Technical Paper
2013-36-0571
B. Heuser, M. Jakob, F. Kremer, Stefan Pischinger, B. Kerschgens, H. Pitsch
In order to deeply investigate and improve the complete path from biofuel production to combustion, the cluster of excellence “Tailor-Made Fuels from Biomass” was installed at RWTH Aachen University in 2007. Recently, new pathways have been discovered to synthesize octanol [1] and di-n-butylether (DNBE). These molecules are identical in the number of included hydrogen, oxygen and carbon atoms, but differ in the molecular structure: for octanol, the oxygen atom is at the end of the molecule, whereas for DNBE it is located in the middle. In this paper the utilization of octanol and DNBE in a state-of-the-art single cylinder diesel research engine will be discussed. The major interest has been on engine emissions (NOx, PM, HC, CO, noise) compared to conventional diesel fuel.
2011-08-30
Technical Paper
2011-01-1998
Vilmar AEsoy, Per Magne Einang, Dag Stenersen, Erik Hennie, Ingebrigt Valberg
The maritime transportation sector is facing new international restrictions on exhaust emissions. NOx and SOx emissions from traditional marine fuels are a major challenge, which make natural gas a promising new clean alternative. Since the late 1980s, new concepts for medium-speed natural gas-fuelled engines have been developed, primarily for stationary power generation. This technology is currently entering the mobile sector, where Spark Ignition engines, Dual-Fuel engines and High Pressure Gas engines offer advantages such as high efficiency, low emissions and fuel flexibility. The availability of liquefied natural gas (LNG) is increasing, not least via small-scale distribution systems. In Norway, 23 coastal traffic vessels operate on LNG supplied by a distribution system that also supplies city bus fleets. This paper discusses the development of natural gas engines and fuel system technology, and describes experiences from LNG-fuelled ships in operation in Norway.
2011-09-13
Technical Paper
2011-01-2224
Sundarapandian S
Diesel engines dominate the field of commercial transportation and agricultural machinery on account of its superior fuel efficiency. Cost and limited reserves of conventional fossil fuels have intensified the search for alternative fuels for use in internal combustion engines. A possible alternative engine fuel is vegetable oil because it is clean burning, renewable, non-toxic, biodegradable and environmentally friendly transportation fuel. It can be used in neat form without any modification of the engine. They can be produced from the plants grown in rural areas. Vegetable oils are produced from crops such as soybean, peanut, sunflower, cotton, jatropha, mahua, neem, coconut, linseed, mustard, karanja, rape and castor. However they cause serious problems such as carbon deposits buildup, poor durability, high density, high viscosity, lower calorific value, more molecular weight and poor combustion. These problems can be rectified by transesterification process.
2011-09-13
Technical Paper
2011-01-2183
Meisam Mehravaran, Giles Brereton
EGR coolers are used in combustion engines to reduce NOx emissions. However, heat transfer in these coolers also results in thermophoresis-temperature-gradient driven motion of suspended particles towards cooler regions-which leads to significant soot deposition. A simple one-dimensional model is proposed to predict the deposition velocity and soot layer thickness that compares reasonably well with experimental data. The behavior of soot deposits on cooled surfaces is complex, with the thickness of the soot layer stabilizes after around 100 hours, reaching a uniform, thickness over the entire heat-exchanger surface. An analysis of this trend and a tentative mechanism to explain this type of behavior is given, based on experimental observations.
2011-04-12
Technical Paper
2011-01-0310
Shinya Sato, Yoshihiro Kawada, Satoshi Sato, Mitsuru Hosoya, Akira Mizuno
To reduce NOx emissions from a heavy-duty engine at low exhaust temperature conditions, the plasma-assisted SCR (Selective Catalytic Reduction) system was evaluated. The plasma-assisted SCR system is mainly composed of an ammonia gas supply system and a plasma reactor including a pellet type SCR catalyst. The preliminary test with simulated gases of diesel exhaust showed an improvement in the NOx reduction performance by means of the plasma-assisted SCR system, even below 150°C conditions. Furthermore, NOx reduction ratio was improved up to 77% at 110°C with increase in the catalyst volume. Also NOx emissions from a heavy-duty diesel engine over the transient test mode in Japan (JE05) were reduced by the plasma-assisted SCR system. However, unregulated emissions, e.g., aldehydes, were increased with the plasma environment. This paper reports the advantages and disadvantages of the plasma-assisted SCR system for a heavy-duty diesel engine.
2011-04-12
Technical Paper
2011-01-0369
Masayuki Kobayashi, Yuzo Aoyagi, Takayuki Adachi, Tetsuya Murayama, Munemasa Hashimoto, Yuichi Goto, Hisakazu Suzuki
Reduction of exhaust emissions and BSFC was studied for high pressure, wide range, and high EGR rates in a Super-clean Diesel six-cylinder heavy duty engine. The GVW 25-ton vehicle has 10.52 L engine displacement, with maximum power of 300 kW and maximum torque of 1842 Nm. The engine is equipped with high-pressure fuel injection of a 200 MPa level common-rail system. A variable geometry turbocharger (VGT) was newly designed. The maximum pressure ratio of the compressor is about twice that of the previous design: 2.5. Additionally, wide range and a high EGR rate are achieved by high pressure-loop EGR (HP-EGR) and low pressure-loop EGR (LP-EGR) with described VGT and high-pressure fuel injection. The HP-EGR can reduce NOx concentrations in the exhaust pipe, but the high EGR rate worsens smoke. The HP-EGR system layout has an important shortcoming: it has great differences of the intake EGR gas amount into each cylinder, worsens smoke.
1999-10-25
Technical Paper
1999-01-3560
Irene Begsteiger, Klaus Richter, Eberhard Jacob, Gerhard Emmerling
A new type of catalyst for exhaust emission control of Diesel engines has been developed by a catalyst producer in cooperation with engine/heavy duty truck manufacturers. This so-called Sorption/Oxidation (“SO”)-catalyst is an extruded TiO2-type and works as a HC-trap as well as oxidation catalyst for hydrocarbons. In addition, a certain amount of particle matter was reduced, depending on type of engine, fuel sulfur content and test cycle. Due to its unique composition, i.e. oxides of titanium (80 wt %), tungsten and vanadium, the catalytic selectivity results in very low formation of sulfates as well as excellent resistance against sulfur compounds. The geometry of the catalyst prototypes corresponds to standard monoliths of 5,66″(144mm) in diameter and suitable lengths to be installed in standard mufflers. Since 1996, several buses and trucks have been equipped with SO-catalysts and are still in operation without problems.
2000-03-06
Technical Paper
2000-01-0479
Ray Conway, Sougato Chatterjee, Hassan Windawi
The EPA implemented the Urban Bus Retrofit/Rebuild (UBRR) Program for transit buses built before 1994 in an effort to lower the amount of PM emissions in densely populated urban areas. The objective of the program is to provide certified emission control technologies that reduce PM emissions from older buses by 25% or to below 0.1 g/bhp-hr. This paper reviews the development of a retrofit kit that has been certified under the UBRR program to meet the 0.1 g/bhp-hr PM emission requirements on DDC 6V92TA engines with both mechanical (MUI) and electronic (DDEC) fuel injection controls. The kit is a combination of specific and modified engine parts and a catalytic exhaust after-treatment device. The kit replaces existing parts with a new camshaft, a uniquely configured cylinder kit and specified turbocharger, blower and injector. For the MUI engines the cam timing, injector height and fuel modulator are set at specific values to achieve the lowest possible PM level.
2000-03-06
Technical Paper
2000-01-0187
Magdi Khair, Jacques Lemaire, Stefan Fischer
The diesel engine has long been the most energy efficient powerplant for transportation. Moreover, diesels emit extremely low levels of hydrocarbon and carbon monoxide that do not require post-combustion treatment to comply with current and projected standards. It is admittedly, however, difficult for diesel engines to simultaneously meet projected nitrogen oxides and particulate matter standards. Traditionally, measures aimed at reducing one of these two exhaust species have led to increasing the other. This physical characteristic, which is known as NOx/PM tradeoff, remains the subject of an intense research effort. Despite this challenge, there is significant evidence that heavy-duty highway engine manufacturers can achieve substantial emission reductions. Many development programs carried out over the last five years have yielded remarkable results in laboratory demonstrations.
1999-11-15
Technical Paper
1999-01-3738
Bruce E. Finley, Tracy A. Daly
This report details the experiences of two California public transit agencies that replaced aging diesel buses with new compressed natural gas (CNG) buses in 1994. The operating characteristics and costs of 170 natural gas buses are compared with 73 older diesel buses. The natural gas bus fleets have operated well and led to cost reductions in both fleets. The findings are particularly significant because both Sacramento Regional Transit District (RT) and SunLine Transit Agency have been using the same engine-chassis configuration, thus enabling a valid method to combine cost data for a large sample fleet of buses. The data indicate that labor for diesel equipment was almost twice that for CNG vehicles, parts were 25% more and fuel costs were nearly double. In 1997, CNG buses saved RT over $1 million in fuel, maintenance, parts and hazardous waste disposal, a 38% per mile reduction over the cost of their older diesel buses.
1999-11-15
Technical Paper
1999-01-3722
C. J. Brodrick, M. Farsh-chi, H. A. Dwyer, D. Sperling, S. W. Gouse, W. Doelling, J. Hoelzer, M. Jackson
The Institute of Transportation Studies at the University of California, Davis (ITS-Davis) has brought together a group of public and industrial partners to demonstrate and evaluate the Siemens-Westinghouse Urea-Selective Catalyst Reduction System (SINOx™). The SINOx System has the potential to generate major reductions in nitrogen oxides (NOx) and the volatile organic fraction (VOF) of particulate (PM) from heavy-duty diesel engines, without increasing fuel consumption and carbon dioxide (CO2) emissions. This demonstration began with engine bench testing at Detroit Diesel Corporation to calibrate the system to attain 1 g/bhp-hr NOx emissions in the transient portion of the US-FTP on a 1999 Series 60 engine that has a 4 g/bhp-hr emission level. The second phase of the project entails an on-highway demonstration of a set of ten, Freightliner Class 8 heavy-duty diesel vehicles. These vehicles are part of the Valley Material Transport fleet based in French Camp, California.
2011-10-06
Technical Paper
2011-28-0064
Carsten Kaup, Thomas Pels, Peter Ebner, Raimund Ellinger, Kurt Gschweitl, Engelbert Loibner, Richard Schneider, Lukas Walter
The reduction of CO₂ emissions represents a major goal of governments worldwide. In developed countries, approximately 20% of the CO₂ emissions originate from transport, one third of this from commercial vehicles. CO₂ emission legislation is in place for passenger cars in a number of major markets. For commercial vehicles such legislation was also already partly published or is under discussion. Furthermore the commercial vehicles market is very cost sensitive. Thus the major share of fuel cost in the total cost of ownership of commercial vehicles was already in the past a major driver for the development of efficient drivetrain solutions. These aspects make the use of new powertrain technologies, specifically hybridization, mandatory for future commercial powertrains. While some technologies offer a greater potential for CO₂ reduction than others, they might not represent the overall optimum with regard to the total cost of ownership.
2011-10-06
Technical Paper
2011-28-0048
Shigeru Ueki, Yutaka Takada
Eco-Driving which is environmentally friendly driving manner is greatly effective way to prevent global warming and to improve air pollution caused by exhaust emissions from vehicles. LEVO has been conducting the EMS promotion program for freight companies etc. since 2005. This program aims at implementing Eco-Driving continuously and well-systematically for drivers. More than 96,000 trucks and buses in 5,140 companies have been joined the program and implementing environmentally friendly driving manner by using Eco-Driving support devices. In this paper, the outcome of Eco-Driving promotion conducted by LEVO is described and the effects on fuel saving and the effect of CO2 reduction attributed to the Eco-Driving management activities are shown.
2011-01-19
Technical Paper
2011-26-0078
Thomas E. Reinhart
This paper reviews the technologies available for Bharat Stage 3 and 4 Heavy Duty on-highway emissions standards. Benchmarking data from several existing engines is used to explore the trade-offs between engine/vehicle cost and fuel consumption. Other implications of the available technologies, such as durability / reliability requirements, are also addressed. The paper provides recommendations for low cost approaches to meeting Bharat Stage 3 and 4 standards with good fuel consumption and reliability/ durability characteristics. A brief look ahead to future Bharat Stage 5 requirements is also provided.
2011-10-04
Technical Paper
2011-36-0350
André Sperl
In the past few years the standards for pollutant emission on Diesel Engines in Brazil, especially regarding NOx and Particulate Material, have suffered drastic reductions. These reductions have been driven by international legislations and the fact that Proconve P6, equivalent to Euro IV, has been skipped in Brazil due to the unavailability of low sulfur fuel (50ppm and 10ppm), so now Proconve P7, equivalent to Euro V, would be implemented in 2012. The reductions imposed by Proconve P7(Euro V) as opposed to Proconve P5 (Euro III) the current emission legislation, determines a reduction of 60% on NOx and 80% on Particulate Matter (PM), imposing new challenges in emission control. Those emission levels can only be achieved through significant changes in the engine's hardware and the use of different after-treatment systems like the Particulate Filter (CDPF) and the Oxidation Catalyst (DOC), also using low sulfur fuel.
2010-10-06
Technical Paper
2010-36-0407
Tadeu Cavalcante Cordeiro de Melo, Jose Roberto de Souza Rocha, Renato de Arruda Penteado Neto, Rodrigo Soares Ferreira
In 2005, it was published a paper in Brazil reporting significant values of aldehydes emissions for some old Brazilian diesel SUVs (Sport Utility Vehicles). In 2008, PETROBRAS (Brazilian Oil Company) together with LACTEC (Institute of Technology for Development) decided to study methods for measuring aldehydes from diesel vehicles, including SUVs and heavy-duty engines. In 2008, National Environmental Council (CONAMA) published legislation 408/08, establishing that IBAMA (Brazilian National Environmental Institute) must provide a procedure for aldehyde measurement at the end of December 2010 and that engine manufacturers must report typical aldehyde emission values of diesel vehicles before the end of December 2012. A technical group was created in 2009 by the Brazilian Automotive Engineering Association (AEA) to discuss and elaborate a new method for aldehyde measurement in diesel vehicles and heavy-duty engines. The new procedure must be published before the end of 2010.
2012-09-24
Technical Paper
2012-01-1965
Piotr Lijewski, Jerzy Merkisz, Pawel Fuc
The paper discusses the measurement of the PM emissions from non-road vehicles (a farm tractor and an excavator) under actual operating conditions. Full exploration of the relations between the operating parameters of these vehicles and their emissions requires measurements under actual conditions of their operation. The specificity of the emission measurements, PM in particular, requires technologically advanced measuring devices. The situation gets even more complicated if, beside the PM mass, we also wish to obtain the PM size distribution and particle number (PN). One of the more important technical issues is the difficulty in fitting of the measurement equipment in/on the vehicle in operation (e.g. a farm tractor). That is the reason why the investigations were carried out in a laboratory. The laboratory technicians applied load to the engines through external devices - a hydraulic system for the excavator and a brake coupled to the farm tractor power takeoff.
2012-09-24
Journal Article
2012-01-1984
Michael P. Lammert, Robert L. McCormick, Petr Sindler, Aaron Williams
The objective of this research project was to compare the emissions of oxides of nitrogen (NOx) from transit buses on as many as five different fuels and three standard transit duty cycles to establish if there is a real-world biodiesel NOx increase for transit bus duty cycles and engine calibrations. Prior studies have shown that B20 can cause a small but significant increase in NOx emissions for some engines and duty cycles. Six buses spanning engine build years 1998 to 2011 were tested on the National Renewable Energy Laboratory's Renewable Fuels and Lubricants research laboratory's heavy-duty chassis dynamometer with certification diesel, certification B20 blend, low aromatic [California Air Resources Board (CARB)] diesel, low aromatic B20 blend, and B100 fuels over the Manhattan, Orange County and UDDS test cycles.
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