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Video

SCR Deactivation Study for OBD Applications

2012-06-18
Selective catalytic reduction (SCR) catalysts will be used to reduce oxides of nitrogen (NOx) emissions from internal combustion engines in a number of applications [1,2,3,4]. Southwest Research Institute® (SwRI)® performed an Internal Research & Development project to study SCR catalyst thermal deactivation. The study included a V/W/TiO2 formulation, a Cu-zeolite formulation and an Fe-zeolite formulation. This work describes NOx timed response to ammonia (NH3) transients as a function of thermal aging time and temperature. It has been proposed that the response time of NOx emissions to NH3 transients, effected by changes in diesel emissions fluid (DEF) injection rate, could be used as an on-board diagnostic (OBD) metric. The objective of this study was to evaluate the feasibility and practicality of this OBD approach.
Video

Brief Investigation of SCR High Temperature N2O Production

2012-06-18
Nitrous Oxide (N2O) is a greenhouse gas with a Global Warming Potential (GWP) of 298-310 [1,2] (298-310 times more potent than carbon dioxide (CO2)). As a result, any aftertreatment system that generates N2O must be well understood to be used effectively. Under low temperature conditions, N2O can be produced by Selective Catalytic Reduction (SCR) catalysts. The chemistry is reasonably well understood with N2O formed by the thermal decomposition of ammonium nitrate [3]. Ammonium nitrate and N2O form in oxides of nitrogen (NOx) gas mixtures that are high in nitrogen dioxide (NO2)[4]. This mechanism occurs at a relatively low temperature of about 200°C, and can be controlled by maintaining the nitric oxide (NO)/NO2 ratio above 1. However, N2O has also been observed at relatively high temperatures, in the region of 500°C.
Video

Evaluation of a NOx Transient Response Method for OBD of SCR Catalysts

2012-01-30
OBD requirements for aftertreatment system components require monitoring of the individual system components. One such component can be an NH3-SCR catalyst for NOx reduction. An OBD method that has been suggested is to generate positive or negative spikes in the inlet NH3 concentration, and monitor the outlet NOx transient response. A slow response indicates that the catalyst is maintaining its NH3 storage capacity, and therefore it is probably not degraded. A fast response indicates the catalyst has lost NH3 storage capacity, and may be degraded. The purpose of the work performed at Southwest Research Institute was to assess this approach for feasibility, effectiveness and practicality. The presentation will describe the work performed, results obtained, and implications for applying this method in test laboratory and real-world situations. Presenter Gordon J. Bartley, Southwest Research Institute
Technical Paper

Emissions From Snowmobile Engines Using Bio-based Fuels and Lubricants

1997-10-27
978483
Snowmobile engine emissions are of concern in environmentally sensitive areas, such as Yellowstone National Park (YNP). A program was undertaken to determine potential emission benefits of use of bio-based fuels and lubricants in snowmobile engines. Candidate fuels and lubricants were evaluated using a fan-cooled 488-cc Polaris engine, and a liquid-cooled 440-cc Arctco engine. Fuels tested include a reference gasoline, gasohol (10% ethanol), and an aliphatic gasoline. Lubricants evaluated include a bio-based lubricant, a fully synthetic lubricant, a high polyisobutylene (PIB) lubricant, as well as a conventional, mineral-based lubricant. Emissions and fuel consumption were measured using a five-mode test cycle that was developed from analysis of snowmobile field operating data.
Technical Paper

Toward the Environmentally-Friendly Small Engine: Fuel, Lubricant, and Emission Measurement Issues

1991-11-01
911222
Small engines which are friendly toward the environment are needed all over the world, whether the need is expressed in terms of energy efficiency, useful engine life, health benefits for the user, or emission regulations enacted to protect a population or an ecologically-sensitive area. Progress toward the widespread application of lower-impact small engines is being made through engine design, matching of engine to equipment and task, aftertreatment technology, alternative and reformulated fuels, and improved lubricants. This paper describes three research and development projects, focused on the interrelationships of fuels, lubricants, and emissions in Otto-cycle engines, which were conducted by Southwest Research Institute. All the work reported was funded internally as part of a commitment to advance the state of small engine technology and thus enhance human utility.
Technical Paper

Performance Test Results of a New On Board Emission Measurement System Conformed with CFR Part 1065

2007-04-16
2007-01-1326
A new on-board portable emission measurement system (PEMS) for gaseous emissions has been designed and developed to meet CFR Part 1065 requirements. The new system consists of a heated flame ionization detector (HFID) for the measurement of total hydrocarbon, a heated chemiluminescence detector (HCLD) for the measurement of NOx, and a heated non-dispersive infra-red detector (HNDIR) for the measurement of CO and CO2. The oxygen interference and relative sensitivity of several hydrocarbon components have been optimized for the HFID. The CO2 and H2O quenching effect on the HCLD have been compensated using measured CO2 and H2O concentration. The spectral overlap and molecular interaction of H2O on the HNDIR measurement has also been compensated using an independent H2O concentration measurement. The basic performance of the new on-board emission measurement system has been verified accordingly with CFR part 1065 and all of the performances have met with CFR part 1065 requirement.
Technical Paper

The Potential for Achieving Low Hydrocarbon and NOx Exhaust Emissions from Large Light-Duty Gasoline Vehicles

2007-04-16
2007-01-1261
Two large, heavy light-duty gasoline vehicles (2004 model year Ford F-150 with a 5.4 liter V8 and GMC Yukon Denali with a 6.0 liter V8) were baselined for emission performance over the FTP driving cycle in their stock configurations. Advanced emission systems were designed for both vehicles employing advanced three-way catalysts, high cell density ceramic substrates, and advanced exhaust system components. These advanced emission systems were integrated on the test vehicles and characterized for low mileage emission performance on the FTP cycle using the vehicle's stock engine calibration and, in the case of the Denali, after modifying the vehicle's stock engine calibration for improved cold-start and hot-start emission performance.
Technical Paper

Aging of Zeolite Based Automotive Hydrocarbon Traps

2007-04-16
2007-01-1058
This paper analyzes the aging of zeolite based hydrocarbon traps to guide development of diagnostic algorithms. Previous research has shown the water adsorption ability of zeolite ages along with the hydrocarbon adsorption ability, and this leads to a possible diagnostic algorithm: the water concentration in the exhaust can be measured and related to aging. In the present research, engine experiments demonstrate that temperature measurements are also related to aging. To examine the relationship between temperature-based and moisture-based diagnostic algorithms, a transient, nonlinear heat and mass transfer model of the exhaust during cold-start is developed. Despite some idealizations, the model replicates the qualitative behavior of the exhaust system. A series of parametric studies reveals the sensitivity of the system response to aging and various noise factors.
Technical Paper

An Engine Start/Stop System for Improved Fuel Economy

2007-04-16
2007-01-1777
During city traffic or heavily congested roads, a vehicle can consume a substantial amount of fuel idling when the vehicle is stopped. Due to regulation enforcement, auto manufacturers are developing systems to increase the mileage and reduce emissions. Turning off the engine at traffic lights and regenerative braking systems are simple ways to reduce emissions and fuel consumption. In order to develop strong manufacturer and consumer interest, this type of operation needs to be automated such that the stop/start functionality requires no driver interaction and takes place without the intervention of the vehicle operator. Valeo Electrical Systems has developed such a system that replaces the OEM engine alternator with a starter/alternator driven by a standard multi-ribbed V belt. To avoid a break and dual voltage network, this system is based on a 12V electrical system using an Enhanced Power Supply.
Technical Paper

Locomotive Emissions Measurements for Various Blends of Biodiesel Fuel

2013-09-08
2013-24-0106
The objective of this project was to assess the effects of various blends of biodiesel on locomotive engine exhaust emissions. Systematic, credible, and carefully designed and executed locomotive fuel effect studies produce statistically significant conclusions are very scarce, and only cover a very limited number of locomotive models. Most locomotive biodiesel work has been limited to cursory demonstration programs. Of primary concern to railroads and regulators is understanding any exhaust emission associated with biodiesel use, especially NOX emissions. In this study, emissions tests were conducted on two locomotive models, a Tier 2 EMD SD70ACe and a Tier 1+ GE Dash9-44CW with two baseline fuels, conventional EPA ASTM No. 2-D S15 (commonly referred to as ultra-low sulfur diesel - ULSD) certification diesel fuel, and commercially available California Air Resource Board (CARB) ULSD fuel.
Technical Paper

Deploying Connected VehicleSM using the FDOT SunGuide® Software: Technology Leadership Brief

2012-10-08
2012-01-9016
The State of Florida initiated the SunGuide® Advanced Traffic Management System (ATMS) software development program in October 2003; that software is deployed in over 15 Traffic Management Centers (TMCs) throughout the major cities in Florida. One of SunGuide's biggest strengths is a software architecture that allows for short development times for new functionality. This paper describes the system design, implementation, and lessons learned from the development of the SunGuide Connected Vehicle Subsystem (CVS). The SunGuide CVS receives real-time speed, location, and heading data from instrumented vehicles and uses that data in a manner similar to its use of traffic detector data to provide information to the TMC. In addition to the vehicle providing data to the TMC, the TMC may create and publish Traveler Advisory Messages to the vehicle as part of the SunGuide Event Management response plans.
Technical Paper

The Use of Radioactive Tracer Technology in Studying Lubricant Chemistry to Enhance Bearing and Ring Wear Control in an Operating Engine

1994-10-01
941982
Radioactive tracer technology (RAT) is an important tool in measuring component wear in an operating engine on a real-time basis. This paper will discuss the use of RAT to study and evaluate boundary lubricant and surfactant chemistries aimed at providing benefits in wear control. In particular, RAT was employed to study ring and bearing wear as a function of engine operating condition (speed, load, and temperature) and lubricant characteristics. Prior to testing, the engine's compression rings and connecting rod bearings were subjected to bulk thermal neutron bombardment in a nuclear reactor to produce artificial radioisotopes that were separately characteristic of the ring and bearing wear surfaces. The irradiated parts were installed in the test engine, after which testing to a specific test matrix was accomplished.
Technical Paper

Transient Emissions from Two Natural Gas-Fueled Heavy-Duty Engines

1993-10-01
932819
The use of compressed natural gas as an alternative to conventional fuels has received a great deal of attention as a strategy for reducing air pollution from motor vehicles. In many cases, regulatory action has been taken to displace diesel fuel with natural gas in truck and bus applications. Emissions results of heavy-duty transient FTP testing of two Cummins L10-240G natural gas engines are presented. Regulated emissions of non-methane hydrocarbons, total hydrocarbons, CO, NOx, and particulate were characterized, along with emissions of formaldehyde. The effects of air/fuel ratio adjustments on these emissions were explored, as well as the effectiveness of catalytic aftertreatment in reducing exhaust emissions. Compared to typical heavy-duty diesel engine emissions, CNG-fueled engines using exhaust aftertreatment have great potential for meeting future exhaust emission standards, although in-use durability is unproven.
Technical Paper

Effects of Increased Altitude on Heavy-Duty Diesel Engine Emissions

1994-03-01
940669
Concern over emissions from heavy-duty diesel engines at high altitudes prompted an investigation into the effects of increasing altitude on gaseous and particulate emissions. On behalf of the Engine Manufacturers Association, emissions from a Detroit Diesel Corporation Series 60 at local test conditions (barometer 98.9 kPa), and two simulated altitudes, Denver (82.6 kPa) and Mexico City (77.9 kPa) were examined using a special altitude simulation CVS. Transient torque output and full load steady-state torque, for this turbocharged aftercooled engine, decreased slightly with increasing altitude. Although, the DDC Series 60 compensates for variation in barometer, transient composite emissions of HC, CO, CO2, smoke, and particulate matter generally increased with increasing altitude for both transient and steady-state operation.
Technical Paper

Effects of Cetane Number, Aromatics, and Oxygenates on Emissions From a 1994 Heavy-Duty Diesel Engine With Exhaust Catalyst

1995-02-01
950250
A Coordinating Research Council sponsored test program was conducted to determine the effects of diesel fuel properties on emissions from two heavy-duty diesel engines designed to meet EPA emission requirements for 1994. Results for a prototype 1994 DDC Series 60 were reported in SAE Paper 941020. This paper reports the results from a prototype 1994 Navistar DTA-466 engine equipped with an exhaust catalyst. A set of ten fuels having specific variations in cetane number, aromatics, and oxygen were used to study effects of these fuel properties on emissions. Using glycol diether compounds as an oxygenated additive, selected diesel fuels were treated to obtain 2 and 4 mass percent oxygen. Cetane number was increased for selected fuels using a cetane improver. Emissions were measured during transient FTP operation of the Navistar engine tuned for a nominal 5 g/hp-hr NOx, then repeated using a 4 g/hp-hr NOx calibration.
Technical Paper

Heavy-Duty Diesel Hydrocarbon Speciation:Key Issues and Technological Challenges

1993-10-01
932853
Development of methodology for diesel hydrocarbon speciation of C12-C22 compounds and the application of that methodology to determine total ozone forming potential of diesel exhaust emissions is an extremely complicated task. Methodology has already been developed for speciating C1-C12 exhaust emissions from engines and vehicles fueled with gasoline, diesel, and alternate fuels. However, very little or no information is available for exhaust speciation of C12-C22 compounds as sampling and analytical constraints make the collection and analysis of the higher molecular weight compounds extremely challenging. Key issues related to the definition of “hydrocarbons” also need to be addressed prior to promulgation of future reactivity-based legislation for diesels (e.g., Which exhaust hydrocarbon compounds actually exist in gas-phase and participate in atmospheric ozone formation?).
Technical Paper

Intricacies of SAE #2 Computerized Clutch Friction Durability Testing

1993-10-01
932847
This paper discusses the implications of computerizing the SAE #2 clutch friction durability tests that General Motors Corporation and Ford Motor Company require for automatic transmission fluid certification. There are three reasons for this paper. 1) Friction durability testing is a significant part of a much larger battery of tests needed to qualify a fluid. 2)There have been recent modifications concerning computerization of both the Ford and GM tests. 3) Because there are only two OEM qualified testing facilities, the details of certain testing intricacies in the areas of data acquisition, reduction and reporting may not be as understood as well as in other areas of automotive-based standardized testing. Formulators of automatic transmission fluid need to be aware of all details surrounding the collection and evaluation of the data that will result in the final test report.
Journal Article

The Effect of Fuel Composition on Performance and Emissions of a Variety of Natural Gas Engines

2010-05-05
2010-01-1476
Work was performed to determine the feasibility of operating heavy-duty natural gas engines over a wide range of fuel compositions by evaluating engine performance and emission levels. Heavy-duty compressed natural gas engines from various engine manufacturers, spanning a range of model years and technologies, were evaluated using a diversity of fuel blends. Performance and regulated emission levels from these engines were evaluated using natural gas fuel blends with varying methane number (MN) and Wobbe Index in a dynamometer test cell. Eight natural gas blends were tested with each engine, and ranged from MN 75 to MN 100. Test engines included a 2007 model year Cummins ISL G, a 2006 model year Cummins C Gas Plus, a 2005 model year John Deere 6081H, a 1998 model year Cummins C Gas, and a 1999 model year Detroit Diesel Series 50G TK. All engines used lean-burn technology, except for the ISL G, which was a stoichiometric engine.
Technical Paper

Simultaneous Reduction of PM, HC, CO and NOx Emissions from a GDI Engine

2010-04-12
2010-01-0365
Particulate Matter (PM) emissions from gasoline direct injection (GDI) engines are becoming a concern and will be limited by future emissions regulations, such as the upcoming Euro 6 legislation. Therefore, PM control from a GDI engine will be required in addition to effective reduction of HC, CO and NOx emissions. Three different integrated aftertreatment systems were developed to simultaneously reduce PM, HC, CO and NOx emissions from a preproduction Ford 3.5L EcoBoost GTDI engine, with PM reduction as the major focus. PM reduction efficiencies were calculated based on the measurements of PM mass and solid particle number. Test results show that tradeoffs exist in the design of aftertreatment systems to significantly reduce PM emissions from a GDI engine.
Technical Paper

Dependence of Fuel Consumption on Engine Backpressure Generated by a DPF

2010-04-12
2010-01-0535
In recent years, Diesel Particulate Filter (DPF) systems have become the state-of-the-art technology to realize low particulate emission for light, medium or heavy-duty diesel vehicles. In addition to good filtration efficiency and thermo-mechanical robustness, the engine backpressure resulted from the DPF installation is an important parameter which directly impacts the fuel economy of the engine. The goal of this experimental test series was to determine the dependence of fuel consumption on engine backpressure resulted from a DPF installed on a heavy-duty application. The testing was executed on a MY2003 Volvo D12 heavy-duty diesel engine in an engine test cell at Southwest Research Institute (SwRI). Empty DPF cans were used with an exhaust valve to mimic the post turbo pressure levels for two different types of DPF materials at nine selected engine operating points of the European Stationary Cycle (ESC).
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