Browse Topic: Evaporative emissions control systems (EVAP)

Items (110)
Find
Simulation and Experimental Study of Filler Pipe of Automobile Fuel Tank Based on ORVR Technology2019-01-08004/2/2019
A filler pipe of vehicle fuel tank has been simulated and optimized about refueling smoothness which is based on On-board Refueling Vapor Recovery (ORVR). Both liner of filler pipe and straight pipe section at the bottom of filler pipe have been studied. The results show that extending the end of the liner to the first elbow of the filler pipe can effectively control the phenomenon of fuel spit-back in the refueling process and promote the refueling process to be smoother. Compared with the bottom of the original filler pipe, extending the bottom length to 100 mm, adding the upper open form in check valve structure, the result shows that in the process of refueling, dynamic fluid sealing can be formed to meet the design requirements. After that, the fuel system bench test was carried out, and conducted a bench test to verify the simulation results. The final filling in the tank is 50.8 L, which meets the 85% filling requirement of the regulations; the canister has gain 67.38 g, the emission result is 0.0141 g/L, which meets the requirements of the regulation of 0.05 g/L.
Fu, Tieqiang, Zhong, Chongzhi, Zhang, Taiyu, Meng, Shuaiqi, Wu, Ke
The Root Cause Analysis of Steel Fuel Tank Cracking at a Fatigue Point and Test Method Development of Durability2017-01-03933/28/2017
Fuel tank in vehicle must hold the fuel in a stable way under any driving condition. However, the fuel tank might not conserve the fuel firmly in case a crack emerged while the fuel tank is exposed to different driving condition. Basically, when the engine is in purging at a normal ambient temperature before fuel boiling, the pressure inside the fuel tank decreases. However, the pressure inside a fuel tank increases while a vehicle is driven at extreme hot ambient temperature as fuel is boiling. This repetitive pressure change in the fuel tank comes with fuel tank’s physical expansion and shrink, which would cause a damage to the fuel tank. The main purpose of this research is to investigate the root cause of why fuel tank cracks at a fatigue point. We also aim to set up the method of how to test durability of the fuel tank in association with the pressure inside the tank.
Kim, Keunsoo
Effects of 7, 9, and 10 psi Vapor Pressure Fuels on Multi-Day Diurnal Evaporative Emissions of Tier 2 and LEV II Vehicles2013-01-10574/8/2013
In order to meet more stringent evaporative emissions requirements, multiple advancements in vehicle fuel system and carbon canister technologies have been made. Regardless of technological advancements, the vapor pressure of the fuel remains a vital property in controlling evaporative emissions. A series of tests were performed to explore the effects of vapor pressure on multiday diurnal evaporative emissions for 9 and 10 psi Reid Vapor Pressure (RVP) 10% ethanol (E10) gasoline-blend fuels, followed by tests with 7 psi RVP E10 gasoline on a subset of the same vehicles. A test procedure was developed to monitor evaporative emissions, canister loading profiles and breakthrough emissions for each of the fuels. A total of five vehicles were tested on all 3 fuels, blended to represent 7, 9, and 10 psi at sea level. Tests were run over 14 days using the United States (U.S.) Federal Diurnal Cycle (72°F to 96°F) in a Sealed Housing for Evaporative Determination (SHED) at a test facility in Colorado. Two of the five vehicles had evaporative emissions systems that met the California Air Resources Board (CARB) requirements for a Partial Zero Emission Vehicle (PZEV), while the other three vehicles were certified to U.S. Tier 2 evaporative emissions standards. The data collected throughout the testing provide a correlation between the hydrocarbon slip from the vehicle canister and the fuel vapor pressure. The data indicate that achieving lower evaporative emissions can be accomplished through the use of decreased vapor pressure fuels.
Dolch, Johanna, Reek, Aaron, Glinsky, Gerard, Dicicco, Dominic, Ughetta, Valerie
Estimated Cost of Emission Control Technologies for Light-Duty Vehicles Part 1 - Gasoline2013-01-05344/8/2013
The cost of meeting standards for conventional pollutant emissions is a perennial bone of contention in arguments over vehicle emission regulations. The public health benefits of the most stringent standards have been repeatedly and conclusively demonstrated, and the control technologies are readily available. Nevertheless, countries with the largest vehicle markets worldwide differ greatly in the rates at which they are willing to adopt the most stringent emission standards-and some of those whose populations would benefit most lag furthest behind. Among the reasons often given for delaying the implementation of stricter standards is the extra cost added to the vehicle by the emission control system. This two-part series paper assesses separately the cost of emission control technologies for gasoline and diesel light duty vehicles. In part one, the paper addresses the cost of gasoline light-duty emission control technology by regulatory level, from early stages to upcoming levels. Focus is given to Three-Way Catalytic converters. Technologies and costs are studied for the two main regulatory programs followed globally, the European and the U.S. emission standards. The paper presents an update on early U.S. and EU emission standards compliance costs as the original estimates have never been updated to reflect actual experience and incorporate the substantial improvements in emission control technologies and reductions in cost that have occurred over time. The paper assesses the costs of required technologies in current terms, using both direct and indirect methods to account for technology changes, correct for inflation, and pull in feedback from experts. Estimates reveal that the cost of taking a 2.0 L, 4-cylinder vehicle, from Euro 1 technology controls to the most stringent proposed EU standard (Euro 6) is close to US$150. Similar costs are found for technologies following the US program.
Posada, Francisco, Bandivadekar, Anup, German, John
Small SI Engine Evaporative Emission Control2012-32-003910/23/2012
New regulations require small gasoline engine evaporative diurnal emission control. In the past, it was not possible to design a proper evaporative emission control system (it was mostly trial and error design). In this study, a mathematical model was developed for estimating activated carbon canister size and nomographs were developed for estimating canister purge air requirements and diurnal bleed emissions. The model and the nomographs can be used to design an evaporative emission control system for any SI engine fuel system.
Reddy, Sam
Emissions Terminology and NomenclatureJ1145_201109 (Current)9/6/2011
This SAE Recommended Practice applies to nomenclature of emissions and emissions reduction apparatus as applied to various engines and vehicles. Modifying adjectives are omitted in some cases for the sake of simplicity. However, it is considered good practice to use such adjectives when they add to clarity and understanding.
SAE IC Powertrain Steering Committee
Fault Model-Based Interactive Service Procedure Tool2011-01-07494/12/2011
This paper presents an interactive, fault model-based prototype diagnostic tool that will assist service technicians in isolating the root cause of vehicle problems and performing corrective repairs. Current automotive service procedures are driven primarily by static service manuals that inform technicians on the service steps in case a specific diagnostic trouble code (DTC) is set in a vehicle. Although comprehensive, these service procedures usually require technicians to gather and integrate diagnostic information from several sources, such as DTCs, customer complaints and manual test results. This can lead to increased repair time and labor costs. The fault model-based interactive service procedure tool discussed in this paper will guide the technician to isolate the fault and provide him/her with recommendations for the correct repair actions. The tool uses a fault model, built using service procedures information, historical repair data and engineering inputs. This fault model captures dependencies between multiple symptoms such as DTCs, vehicle operational parameters, customer complaints, and technician test outcomes and relates them to probable faults. In the service bay, this tool will employ the fault model and vehicle symptoms to provide a ranked list of suspect components, related repairs and the next steps necessary to further isolate the fault. In effect, as the technician collects and inputs more symptoms or test outcomes into the tool, it will further isolate the fault to specific components and recommend further actions till the fault is isolated to one specific component; and then recommend the correct repair. The capabilities of this system are demonstrated on an automotive fuel evaporative emission control system. This tool will enable correct and efficient first-time repairs leading to a reduction in warranty costs and repeat visits.
Pattada, Kallappa, Singh, Satnam, Bandyopadhyay, Pulak
Development of Exhaust and Evaporative Emissions Systems for Toyota THS II Plug-in Hybrid Electric Vehicle2010-01-08314/12/2010
Exhaust and evaporative emissions systems have been developed to match the characteristics and usage of the Toyota THS II plug-in hybrid electric vehicle (PHEV). Based on the commercially available Prius, the Toyota PHEV features an additional external charging function, which allows it to be driven as an electric vehicle (EV) in urban areas, and as an hybrid electric vehicle (HEV) in high-speed/high-load and long-distance driving situations. To reduce exhaust emissions, the conventional catalyst warm up control has been enhanced to achieve emissions performance that satisfies California's Super Ultra Low Emissions Vehicle (SULEV) standards in every state of battery charge. In addition, a heat insulating fuel vapor containment system (FVS) has been developed using a plastic fuel tank based on the assumption that such a system can reduce the diffusion of vapor inside the fuel tank and the release of fuel vapor in to the atmosphere to the maximum possible extent. As a result, these measures have enabled the mass-production of the world's first PHEV that satisfies California's SULEV and zero evaporative emissions standards.
Takagi, Naoya, Watanabe, Takashi, Fushiki, Shunsuke, Yamazaki, Makoto, Asou, Shuichi, Nishimura, Yuusaku
Quick Connect Coupling Specification for Liquid Fuel and Vapor/Emissions SystemsJ2044_200908 (Current)8/13/2009
This SAE Recommended Practice defines the minimum functional requirements for quick connect couplings used for supply, return, and vapor/emission fuel system connections. This document also defines standard male tube end form dimensions, so as to guarantee interchangeability between all connector designs of the same male tube end form size. This document applies to automotive and light truck applications under the following conditions: a Gasoline and diesel fuel delivery systems or their vapor venting or evaporative emission control systems. b Operating pressure up to 500 kPa, 5 bar, (72 psig). c Operating vacuum down to −50 kPa, −0.5 bar (−7.2 psi). d Operating temperatures from −40 °C (−40 °F) to 115 °C (239 °F). Quick connect couplings function by joining the connector to a mating tube end form, then pulling back to assure a complete connection. The requirements stated in this document apply to new connectors in assembly operations unless otherwise indicated. For service operations, the mating tube should be lubricated with SAE 30-weight oil before re-connecting. Vehicle OEM fuel system specifications may impose additional requirements beyond the scope of this general SAE document. In those cases, the OEM specification takes precedence over this document.
Fuel Systems Standards Committee
Cost Effective Emissions Control Based on Optimized Flex Fuel Electronic Injection for PROCONVE-L5 in Brazil2008-36-037910/7/2008
From January 2009 the new PROCONVE L5 emissions legislation will be in place in Brazil, reducing significantly the current emissions levels. In order to comply with this new legislation, all automakers have to take actions on hardware and electronic fuel injection calibration to meet these new standards. Hardware changes can be efficient, such as increasing the amount of precious metals in the catalyst; however, the cost penalty may turn it unfeasible. The objective of this text is to introduce how an efficient electronic fuel injection calibration, focused on emissions control can be a decisive way to reduce overall product cost. The influence of electronic fuel injection becomes more evident in the current Brazilian reality, where the overwhelming majority of vehicle sales are flexible fuel powered, increasing the challenge and difficulty to correctly control emissions. The text shows the hardware changes that aim combustion stability, generating lower raw emissions of HC, CO and NOx, and focus on electronic fuel injection calibration to optimize cost and to refine combustion management. The lessons learned during the development, methods to control the gases, ways of optimizing the cold and hot EPA-75 Phases, influences and difficulties of each fuel blend - E22, E63 and E93 - and also the methods of evaporative emissions control are described and analyzed.
Rodrigues, Saulo, Ferreira, Rafael Peixoto
Opportunities for Brazilian OBD in the Context of I/M2008-36-016810/7/2008
This paper presents a comprehensive overview of Brazilian On-Board Diagnostic (OBD) regulations, Inspection and Maintenance (I/M) Programs and Aftermarket Catalyst regulations as well as an overview of similar regulations in the United States and Europe. Opportunities and technical risks are described in this context. Regulatory information contained in this Paper is intended to serve as reference only. Updated and complete rules and regulations must be used for official purposes. The implementation of the second stage of Brazilian OBD (OBDBr-2), starting in 2010, represents a significant improvement towards exhaust emission control and on-board diagnostic monitoring. Its effectiveness and credibility will be heavily influenced by how this new technology is integrated into I/M programs and how well it meshes with aftermarket catalyst regulations. Currently, Brazilian I/M regulations do not incorporate any OBD requirements and only Rio de Janeiro State has implemented an I/M Program. In the absence of an effective I/M program, emission controls tampering can go undetected (e.g. aftermarket catalysts with no ceramic substrate inside). Having OBD checks integrated into an I/M program is an important factor that should be considered in the next stages of Brazilian emission control programs. The US EPA completely replaced traditional tailpipe exhaust tests with OBD checks. EPA experience, however, has shown that it takes a long time to roll out a credible I/M regulation because its credibility strongly depends on the correlation between OBD checks and I/M tailpipe exhaust tests. Finally, it should be pointed out that to work effectively in an I/M program, OBD requirements need to consider the vehicle population as a whole and include spark-ignition and compression-ignition engines, aftermarket catalysts as well as various evaporative and exhaust emission controls.
Alves, Michel Zambon, Baltusis, Paul, Burgos, Eduardo
Requirements for Built-In Service Port for On Board DiagnosticsJ2744_200808 (Historical)8/11/2008
This document presents the requirements for a built-in service port to be used in vehicles intended to comply with Enhanced Evaporative Emissions Requirements. The primary function of the Service Port (Valve Assembly-Evaporative Emission Canister Purge Harness Service) is to provide non-destructive access to the evaporative emissions system to enable testing of the integrity of the system. The Service Port is used to introduce air pressure or fuel vapors into, or evacuates them out of, the system. This access may be used for the following evaluations: • Evaporative System Certifications Canister Loading and Purging • End-of-line Testing System Integrity • Service (e.g. OBD MIL on) Leak Location and Repair Verification • In-Use Compliance Testing Canister Loading and Purging • Inspection/Maintenance Testing System Integrity and Purge Check
Fuel Systems Standards Committee
Evaporative Emissions Control System for Walk Behind Lawnmowers2007-32-005310/30/2007
This paper discusses an evaporative emissions control system which significantly reduces diurnal evaporative emissions in walk behind lawnmower engines equipped with float carburetors. The system also maintains engine startability, run quality, and a simplistic user interface. The system consists of low-permeation fuel line and a multi-layer fuel tank using an EVOH barrier as well as a carbon canister integrated in the lawnmower's push-handle and an Automatic Bowl Drain System (ABDS). A prototype of the system resulted in a 90% reduction in diurnal evaporative emissions when compared to a pre-regulation walk behind lawnmower using the CARB TP-902 sealed housing for evaporative determination test. This paper demonstrates a practical solution to reduce diurnal evaporative emissions and hydrocarbon running losses below the level emitted from a state of the art, float carbureted, walk behind lawnmower engine.
Bejcek, Andrew
Design Considerations & Characterization Test Methods for Activated Carbon Foam Hydrocarbon Traps in Automotive Air Induction Systems2007-01-14294/16/2007
As OEMs race to build their sales fleets to meet ever more stringent California Air Resources Board (CARB) mobile source evaporative emissions requirements, new technologies are emerging to control pollution. Evaporative emissions emanating from sources up-stream in the induction flow and venting through the ducts of the engine air induction system (EIS) need to be controlled in order classify a salable vehicle as a Partial Zero Emissions Vehicle (PZEV) in the state of California. As other states explore adopting California's pollution control standards, demand for emissions control measures in the induction system is expected to increase. This paper documents some of the considerations of designing an adsorbent evaporative emissions device in to a 2007 production passenger car for the North American and Asian markets. This new evaporative emissions device will be permanently installed in the vehicle's air cleaner cover without requiring service for 150K miles (expected vehicle life). Addressed are many of the questions and concerns associated with integrating emissions control technology into the EIS. Testing techniques for characterizing the emissions control functions of hydrocarbon traps are discussed in detail. This paper also illustrates and discusses the need to write a uniform and accepted test standard for EIS based emissions technology. This effort is currently being pursued at the SAE and ISO working groups.
Schaffer, Scott A., Arruda, Anthony, Bielicki, James, Bugli, Neville
A Parametric Vehicle Fuel Tank Filling System Model2007-01-17414/16/2007
The purpose of this study is to present a parametric fuel tank filling model from first principles. The aim is to build a tool that can help with the initial tank layout, to make sure the design does not promote premature shut off. The governing equations of the model are detailed and results for a test case are presented. The model is based on a common set of parameters enabling it to be adapted to a set of design constrains. Additionally, the model is validated by experimental data where available and a sensitivity analysis on critical design parameters that promote premature shut off is performed.
Godbille, A., Bayliss, M. T., Pierson, S.
The Design for Six Sigma Approach for the Development of a Carbon Canister for Tier II, LEV II and PZEV Emission Levels2007-01-10904/16/2007
Global concerns involving smog, ozone formation, carcinogens and greenhouse gases have produced increasingly stringent governmental emission regulations worldwide. In the United States, the Environmental Protection Agency (EPA) introduced Tier II emissions regulations and the California Air Resources Board (CARB) established Low Emission Vehicles (LEV II) and Partial Zero Emission Vehicles (PZEV) legislation. These initiatives have created the most stringent emissions regulations to date. Vehicle manufacturers have had to improve their evaporative emission control systems to comply with these standards. The evaporative emission control system is engineered to protect our environment from fuel vapor emissions. The carbon canister is the most important component of the evaporative emissions system due to its ability to capture fuel vapors continuously during the life of the vehicle. Ford Motor Company redesigned its carbon canisters after utilizing Experimental Design techniques. These Experimental Design techniques used Design for Six Sigma methodologies.
Mancini, Douglas J.
Nonmetallic Fuel System Tubing with One or More LayersJ2260_200411 (Current)11/1/2004
This SAE Standard presents the minimum requirements for nonmetallic tubing with one or more layers manufactured for use as liquid-carrying or vapor-carrying component in fuel systems for gasoline, or alcohol blends with gasoline. Requirements in this document also apply to monowall tubing (one layer construction). When the construction has one or more layers of polymer-based compounds in the wall, the multilayer constructions are primarily for the purpose of improvement in permeation resistance to hydrocarbons found in various fuels. The tube construction can have a straight-wall configuration, a wall that is convoluted or corrugated, or a combination of each. It may have an innermost layer with improved electrical conductivity for use where such a characteristic is desired. The improved electrical conductivity can apply to the entire wall construction, if the tubing is a monowall. (For elastomeric based MLT constructions, refer to SAE J30 and SAE J2405). Unless otherwise agreed to by suppliers and users this document applies to tubing for any portion of the fuel system that might operate continuously at temperatures above −40 °C and below 90 °C and up to a maximum working gage pressure of 450kPa. The tubing can be used at the peak intermittent temperature up to 115 °C. This document can apply to systems that operate at higher pressures and/or are exposed to higher temperatures. For higher pressures, the acceptance criteria of section 7.2 must be correspondingly changed. For higher temperatures, the acceptance criteria of sections 7.2 and 7.14 remain the same, but apply at the higher temperature. The selection of higher temperatures and pressures that could be used for this document would be the decision of the end user and supplier of the specific fuel/fuel vapor system in question. There are three types of tubing covered by this specification, based on the type of application for which the tubing is intended to be used: High pressure, liquid fuel line is tubing that handles liquid fuel at pressures up to 450 kPa pressure, and can handle the maximum pressure requirements identified in sections 7.1 and 7.2. These are typically the smaller diameter tubes identified in Table A1. Low pressure, liquid fuel line is tubing that is regularly exposed to liquid fuel, but is subjected to pressures that are under 50 kPa (e.g. fuel filler pipes). These are typically the larger diameters identified in Table A1. Fuel vapor tubing is tubing that handles fuel in vapor form or some liquid condensed from vapor, and operates at a working gauge pressure that does not exceed 20 kPa. In some cases, a distinction is made in the criteria that apply to tubing used to carry liquid fuel compared to tubing used to carry fuel vapor. These are identified separately in each section.
Fuel Systems Standards Committee
Durability of Low-Emissions Small Off-Road Engines2004-32-00589/27/2004
The goal of the project was to reduce tailpipe-out hydrocarbon (HC) plus oxides of nitrogen (NOx) emissions to 50 percent or less of the current California Air Resources Board (CARB) useful life standard of 12 g/hp-hr for Class I engines, or 9 g/hp-hr for Class II engines. Low-emission engines were developed using three-way catalytic converters, passive secondary-air induction (SAI) systems, and in two cases, enleanment. Catalysts were integrated into the engine's mufflers, where feasible, to maintain a compact package. Due to the thermal sensitivity of these engines, carburetor calibrations were left unchanged in four of the six engines, at the stock rich settings. To enable HC oxidation under such rich conditions, a simple passive supplemental air injection system was developed. This system was then tuned to achieve the desired HC+NOx reduction. Engines were then aged for either 250 hours (Class 1), or 500 hours (Class 2), with emission testing at intervals to track muffler-out emissions and catalyst performance. Results demonstrated that emissions from these engines could be significantly reduced.
White, Jeff J., Lela, Chad, Lourenco, Jackie, Salardino, David
Electronic Engine Control Technologies, 2nd EditionPT-1103/13/2004
In this second edition of Electronic Engine Control Technologies, the latest advances and technologies of electronic engine control are explored in a collection of 99 technical papers, none of which were included in the book's first edition. Editor Ronald K. Jurgen offers an informative introduction, "Neural Networks on the Rise," clearly explaining the book's overall format and layout. The book then closely examines the many areas surrounding electronic engine control technologies, including: specific engine controls, diagnostics, engine modeling, innovative solid-state hardware and software systems, communication techniques for engine control, neural network applications, and the future of electronic engine controls.
Jurgen, Ronald K.
Development of Two-Layer Fuel Tube System Consisting of Adhesive-ETFE And Modified-PA122004-01-14403/8/2004
As the evaporative emission control of cars becomes severe year by year, lower fuel permeation comes to be required as fuel tube in order to clear the regulation. Although the multi-layer fuel tube that has ETFE as an inner layer and PA12 as an outer layer is used now, development of a fuel tube with lower fuel permeation and better adhesion durability is required. Considering these requirements, we introduced a functional group into ETFE, modified PA12, and successfully developed new two-layer fuel tube systems. The systems do not need any internal adhesive layer. The design of the systems is quite simple, and provides excellent fuel permeability, durability of adhesion and processability.
Iwasa, Tsuyoshi, Funaki, Atsushi, Nishi, Eiichi, Laganis, Evan, Isobe, Noriyuki, Nishioka, Tomoyuki, Nakamura, Koji
Modeling and Simulation of N-butane Adsorption/Desorption in a Carbon Canister2004-01-16803/8/2004
As a part of developing automotive fuel vapor emission control, a two dimensional, time-accurate simulation capability for adsorption/desorption in a carbon canister has been developed. Dubinin-Polanyi adsorption potential model has been used for n-butane (a surrogate for gasoline vapor) adsorption at ambient pressure on activated carbon adsorbent of Westvaco product BAX 950, and nitrogen was chosen as the carrier gas. Linear driving force model is used for heat and mass transfer rates. The impacts of different n-butane concentration on the adsorption phenomena and different initial carbon bed equilibrium adsorption states on desorption phenomena are studied. Results such as adsorption breakthrough curve, desorption curve, adsorption amount, n-butane mole fraction and temperature profiles are provided. Comparisons with results from previous work are made to verify the current model.
Bai, Xingyan, Isaac, K. M., Banerjee, R., Klein, D., Breig, W., Oliver, L.
Evaporative Leak Check System by Depressurization Method2004-01-01433/8/2004
Changes to OBDII regulations in North America are requiring more frequent leak checks to the evaporative emissions system. Conventional methods are unable to comply with the required 0.26 performance ratio due to various factors such as unstable tank pressure and fuel evaporation. These strict regulations require an innovative detection device. Utilizing a vacuum pump, a leak check module with high detection frequency, leak diagnostic accuracy, and reliability has been developed. In the present paper, the details of ELCM based on the depressurization method are reported together with the results of study on the pressurization method.
Kobayashi, Mitsuyuki, Yamada, Yoshichika, Kano, Masao, Nagasaki, Kenji, Miyahara, Hideki, Amano, Noriyasu
Multidimensional, Time-Accurate CFD Simulation of Adsorption/Desorption in a Carbon Canister2003-01-10033/3/2003
Computational fluid dynamics simulations of fixed-bed adiabatic adsorption/desorption processes are presented in this paper. Linear driving force model is used for heat and mass transfer rates. A two-dimensional cylindrical canister and three-dimensional automotive production canister geometry are used to study the adsorption/desorption processes of carbon dioxide in helium carrier gas on Norit B4 activated carbon. The two-dimensional results compare well with the results of Hwang et al. [1]. Computational results as breakthrough curve, adsorption amount and temperature profiles are provided. Results show that non-adiabatic model should be used to fully utilize the activated carbon bed capacity prior to breakthrough.
Bai, Xingyan, Isaac, K. M., Klein, D., Banerjee, R., Edson, J., Breig, W., Oliver, L.
Instrumentation and Techniques for Vehicle Refueling Emissions MeasurementJ1045_200210 (Current)10/21/2002
This SAE Recommended Practice describes a procedure for measuring the hydrocarbon emissions occurring during the refueling of passenger cars and light trucks. It can be used as a method for investigating the effects of temperatures, fuel characteristics, etc., on refueling emissions in the laboratory. It also can be used to determine the effectiveness of evaporative emissions control systems to control refueling emissions. For this latter use, standard temperatures, fuel volatility, and fuel quantities are specified.
SAE IC Powertrain Steering Committee
Quick Connect Coupling Specification for Liquid Fuel and Vapor/Emissions SystemsJ2044_200209 (Historical)9/13/2002
This SAE Recommended Practice defines standard tube end form dimensions so as to guarantee interchangeability between all connector designs of the same size and the standard end form. This document also defines the minimum functional requirements for quick connect couplings between flexible tubing or hose and rigid tubing or tubular fittings used in supply, return, and vapor/emissions in fuel systems. This document applies to automotive and light truck applications under the following conditions: a. Gasoline and diesel fuel delivery systems or their vapor venting or evaporative emission control systems. b. Operating pressure up to 500 kPa, 5 bar, (72 psig). c. Operating vacuum down to -50 kPa, -0.5 bar (-7.2 psi). d. Operating temperatures from -40 °C (Ð40 °F) to 115 °C (239 °F). Quick connect couplings function by joining the connector to a mating tube end form then pulling back to assure a complete connection. The requirements stated in this document apply to new connectors in assembly operations unless otherwise indicated. For service operations, the mating tube should be lubricated with SAE 30-weight oil before re-connecting. NOTE--New connector designs using the same materials as previously tested connectors may use the original results as surrogate data for 7.1, 7.2, 7.3, and 7.4. Vehicle OEM fuel system specifications may impose additional requirements beyond the scope of this general SAE document. In those cases, the OEM specification takes precedence over this document.
Fuel Systems Standards Committee
A Purge Solenoid Structure-borne Noise Model2001-01-14234/30/2001
Evaporative emission control system purge solenoid valves in passenger cars and light-duty trucks are a noise source that engenders customer complaint. Valveonly noise tests produce results that are inconsistent with measured system noise. Such tests fail to account for variables introduced in situ. This study investigates valve-induced structure-borne noise as the major source of system noise. It researches a theoretical method to relate structure-borne purge solenoid system noise requirements, valve-only, and vehicle mounting system dynamic requirements. It aims to validate the researched method and determine the nature of a valve-only bench test and a mounting system dynamic test. Several systems' noise levels, inertance, and acoustic responses were measured. The bench test vibration for each solenoid valve was also measured. This study discovered that the internal force of the purge solenoid may change with the mounting system compliance. To produce an accurate bench test, it might be necessary to account for this fluctuation. The data collected by provisional tests validated the proposed methods. These tests, while more accurate than any previous tests, still require modification in order to predict with an accuracy demanded by today's competitive market.
Kuxhaus, Laurel, Grimmer, Michael J.
Evaporative Emissions from Late-Model In-Use Vehicles2000-01-295810/16/2000
Evaporative hydrocarbon emissions from gasoline-powered vehicles continue to be a major concern in areas where the national ambient air quality standard for ozone is violated. As a result, accurate estimates of real-world emissions from in-use motor vehicles are of vital importance in assessing the progress made in reducing emissions, as well as in determining the need for and required magnitude of additional emissions reductions. In this study, real-world evaporative emissions testing was performed on 50 late-model vehicles (30 passenger cars and 20 light-duty trucks), ranging in age from the 1992 to 1997 model year. Six of the 50 vehicles were equipped with enhanced evaporative emission control systems. Forty-nine of the 50 vehicles were procured from an Arizona State Inspection and Maintenance (I/M) Program test lane located in Mesa, Arizona, and one vehicle was procured from an employee of the test facility. Hot soak, running loss, and real-time diurnal testing was performed using tank fuel that averaged 6.5 Dry Vapor Pressure Equivalent (DVPE). Hot soak and running loss testing was performed at about 95 °F and one- and three-day diurnal testing was done using a diurnal heating range of 72-96 °F. The data collected indicate that the small percentage of the vehicle fleet with evaporative emission control system defects contributes disproportionately to the total evaporative emissions of the fleet. This observation, which has also been noted in previous studies examining real-world evaporative emissions from older vehicles, suggests that a few very high emitting vehicles produce the majority of the total fleet emissions. Identification and repair of vehicles with evaporative control system problems is required to fully achieve the intended reductions in real-world evaporative emissions. Comparison of the data collected from late-model vehicles with data from older vehicles in previous related studies indicates that, after the few extremely vehicles (referred to as high emitters) are eliminated, evaporative emissions from newer vehicles are, as expected, lower than those from older vehicles. Although only a limited number of vehicles with enhanced evaporative emission control systems were included in this test program, a comparison of data from those vehicles with the data from vehicles with the preceding generation of non-enhanced (basic) evaporative emission control systems indicates that the improvements in evaporative emission controls mirror what would be expected based on the differences in the evaporative emissions certification standards applicable to the two systems. Comparisons of the data collected in this study with emission predictions from U.S. EPA's MOBILE5b and CARB's MVEI7G models showed mixed results. The biggest discrepancies identified were the overprediction of running loss emission rates from vehicles with basic evaporative emission control systems by both models; the overprediction of total diurnal and resting loss emissions for vehicles with basic evaporative systems, which was more pronounced with MOBILE5b than for MVEI7G; and the overprediction of day 2 and day 3 diurnal emission rates by MOBILE5b for vehicles with both types of evaporative control systems.
Lyons, James M., Lee, John M., Heirigs, Philip L., McClement, Dennis, Welstand, Steve
A New Approach to Meeting Future European Emissions Standards with the Orbital Direct Injection Gasoline Engine2000-01-291310/16/2000
This paper discusses the development of a new approach to achieving EURO 4 emission standards with a simplified exhaust after-treatment system in combination with an air-assisted lean stratified Direct Injection system. The results presented demonstrate the ability of the air-assist DI system to operate in highly stratified conditions at very lean A/F ratios, with excellent control of the raw HC and NOx emissions. In most cases the authors illustrate that with good stratified combustion control, the HC emissions can be lower than the baseline port injected stoichiometric engine. Further, the high tolerance to EGR and accurate A/F control at the spark plug enable the raw NOx emissions to be reduced by up to 85% over the European drive cycle in comparison to the baseline port injected engine with EGR. The vehicle calibration strategy is discussed in detail, with particular attention being paid to the catalyst light-off strategy developed for the air-assist system, which enables feed exhaust gas temperatures to reach 600°C during the first 10 second idle period, while also maintaining good control of raw emissions. Also highlighted is the development of the ability to control canister vapour purge throughout both lean stratified and stoichiometric operation. This further enables good control of HC emissions while maintaining a high purge flow through the catalyst, independent of any specific catalyst regeneration requirements. The low raw emissions of the vehicle are then applied to a single underbody catalytic converter located 1.3m from the cylinder head face. This was fitted with a combination of three-way and lean NOx traps, which had been aged under lean hydrothermal conditions. The authors discuss the systematic approach applied to the catalyst choice, in combination with the understanding of the air-assist DI modal raw HC and NOx emissions. In particular, the very low raw NOx emission burden during stratified operation is discussed, which enabled a reduced reliance on the Lean NOx trap (hereinafter LNT) storage function. Euro 4 emissions compliance is demonstrated with aged catalysts where the degradation of NOx emissions is considered to be very low, due to reduced reliance on the NOx catalyst efficiency. The results show how, with a systematic approach, the combined ability of the underbody TWC/LNT catalyst and air-assist DI combustion system can meet future emissions standards.
Brogan, M. S., Swallow, D., Brisley, R. J., Worth, D., Yang, KC.
Development of a Gasoline-Fueled Vehicle with Zero Evaporative Emissions2000-01-292610/16/2000
…Technologies for reducing evaporative emissions generated from gasoline vapors have been developed. To reduce evaporative emissions, both permeation from fuel and vapor lines and breakthrough from the evaporative canister need to be diminished. Fewer fuel line connections are used and hose and valve materials have been modified to reduce permeation. Component test results confirm that permeation is substantially reduced from the level of previous parts. A new type of activated charcoal, which has a high specific heat characteristic and improves adsorption and desorption performance, has been applied to reduce canister breakthrough. Additionally, the amount of purge air has been increased by applying purge control using an air-fuel ratio sensor. The problem of canister breakthrough has thus been resolved by the new evaporative canister combined with increased purge flow to the engine. Endurance mode tests equivalent to 15 years/150,000 miles of driving were conducted on the fuel evaporative system parts and the results confirmed that this level of emission durability could be assured. The new system has been developed for the Sentra CA sold in the U.S. market. This vehicle satisfies the zero evaporative emission regulations as a result of adopting this combination of new technologies.
Matsushima, Hideyuki, Iwamoto, Akio, Ogawa, Masahiro, Satoh, Tomoyuki, Ozaki, Katsunori
Investigation of Sulfur Sensitivity and Reversibility in Late-Model Vehicles1999-01-367610/25/1999
The emissions impact associated with increasing gasoline sulfur content was investigated using eight late-model vehicles, most of which were equipped with advanced emission control systems and certified as California Low-Emission Vehicles. The effect of returning to operation on low-sulfur fuel on emissions was also investigated. Vehicle testing was performed using California Phase 2 Certification test fuels with nominal sulfur levels of 40 and 540 ppm in combination with the LA4 and US06 driving cycles. In addition to exhaust emission measurements, engine-out emissions, air-fuel ratio, catalyst composition, and catalyst temperature data were collected. The data showed that most of the vehicles were sensitive to gasoline sulfur content as emissions increased when the vehicles were operated on the higher-sulfur test fuel; however, the degree of sensitivity varied from vehicle to vehicle. In addition, the data showed that the effects of operation on high-sulfur fuel were largely reversible for all pollutants following a return to operation on low-sulfur fuel on the LA4 driving cycle. Use of low-sulfur fuel with the more severe US06 driving cycle generally led to a more complete reversal of sulfur effects in those cases where complete recovery was not achieved on the LA4 cycle. Overall, the results of the study indicated that operation on high-sulfur gasoline did not result in permanent, adverse impacts on the emission performance of late-model vehicles. Although the study was not designed to evaluate the importance of factors related to vehicle design and operation with respect to sulfur sensitivity, a statistical analysis of the data suggested that differences in sulfur sensitivity may be related to differences in engine-out emissions and other factors.
Lyons, James M., Lax, David, Welstand, Steve
Vapor and Liquid Composition Differences Resulting from Fuel Evaporation1999-01-03773/1/1999
Liquid fuels and the fuel vapors in equilibrium with them typically differ in composition. These differences impact automotive fuel systems in several ways. Large compositional differences between liquid and vapor phases affect the composition of species taken up within the evaporative emission control canister, since the canister typically operates far from saturation and doesn't reach equilibrium with the fuel tank. Here we discuss how these differences may be used to diagnose the mode of emission from a sealed container, e.g., a fuel tank. Liquid or vapor leaks lead to particular compositions (reported here) that depend on the fuel components but are independent of the container material. Permeation leads to emissions whose composition depends on the container material. If information on the relative permeation rates of the different fuel components is available, the results given here provide a tool to decide whether leakage or permeation is the dominant mode of emission. Using well-established methods based on vapor-liquid equilibria, generalized vapor-phase correlations, and the UNIFAC model for liquid-phase nonideality, we have calculated the magnitude of the compositional difference for each species in several model fuel mixtures, as a function of temperature. In fuel C, a binary iso-octane/toluene mixture (of 1:1 volume ratio or 4:5 mass ratio), we find that the vapor is enriched in iso-octane to a 2:1 mass ratio. In ternary mixtures that contain alcohols at low concentrations (e.g., CM15), the vapor mass fraction of alcohol exceeds its liquid-phase mass fraction by a factor of three or more. In the same mixtures at high alcohol concentrations, the vapor mass fraction of iso-octane exceeds its liquid-phase mass fraction by a factor of 5 or more. The relative vapor mass fractions (on an air-free basis) of each species change with increasing temperature: the relative iso-octane fraction decreases, the relative toluene fraction increases slightly, and the relative alcohol fraction increases significantly. Results for ternary mixtures that contain MTBE and for a model indolene fuel are also presented.
Greenfield, Michael L., Rossi, Giuseppe
Proportional Ambient Sampling: A CVS Improvement for ULEV and Lean Engine Operation1999-01-01543/1/1999
As motor vehicle emissions have been reduced to meet requirements of the clean air acts, they have become low enough to be difficult to measure accurately. This is especially the case for hydrocarbons, because after warm-up, there are fewer hydrocarbons emitted from a modern vehicle's tailpipe than in the surrounding air. It is therefore important to correctly compensate for the ambient hydrocarbon levels of the air used to dilute the collected exhaust. In estimating the accuracy of the federally required testing procedures, previously published error analyses have examined the effects of random errors. This study examines the systematic errors inherent in the CVS (Constant Volume Sampling) technique specified in federal regulations, estimates their sizes, and proposes a method using proportional ambient sampling whereby they can be avoided.
Silvis, William M., Chase, Richard E.
The OBD-II System in the Hyundai Accent98255110/19/1998
This paper presents a system concept of the On-Board Diagnostics system (OBD-II) in the Hyundai Accent. New-α and α-DOHC engine developed by Hyundai are installed in the Accent. The ECU (Engine Control Unit) developed by BOSCH is adopted for this vehicle. To comply with the OBD-II regulation mandated by CARB (California Air Resources Board), some monitoring algorithms originally developed by BOSCH were introduced and modified for the Hyundai Accent. Using modified algorithms, many kinds of test were carried out during more than four years. Through the demonstration test and various field tests, it was confirmed that the OBD-II system fulfilled the regulation and had good performance.
Park, Simsoo, Chung, Youngkyo, Park, Jaekook
A Fuel Vapor Model (FVSMOD) for Evaporative Emissions System Design and Analysis98264410/19/1998
A fuel vapor system model (FVSMOD) has been developed to simulate vehicle evaporative emission control system behavior. The fuel system components incorporated into the model include the fuel tank and pump, filler cap, liquid supply and return lines, fuel rail, vent valves, vent line, carbon canister and purge line. The system is modeled as a vented system of liquid fuel and vapor in equilibrium, subject to a thermal environment characterized by underhood and underbody temperatures and heat transfer parameters assumed known or determined by calibration with experimental liquid temperature data. The vapor/liquid equilibrium is calculated by simple empirical equations which take into account the weathering of the fuel, while the canister is modeled as a 1-dimensional unsteady absorptive and diffusive bed. Both fuel and canister submodels have been described in previous publications. This paper presents the system equations along with validation against experimental data. Some typical vapor system applications are also presented including a simulation of the EPA three day enhanced evaporative test procedure.
Lavoie, George A., Imai, Yash A., Johnson, Philip J.
RVP Reduction for Control of Wintertime CO9813735/4/1998
A vehicle emissions test program was conducted to evaluate the impact of gasoline RVP reduction on CO emissions under conditions that are typical of CO exceedance days in Las Vegas and Los Angeles. Test results showed that CO emissions were reduced in the Las Vegas fleet when RVP was changed from 12 to 9 psi. In the Los Angeles fleet, the results were less consistent, perhaps due to the poorer integrity of evaporative emissions control systems on these vehicles. This suggests that an optimum emissions control strategy might include both RVP reduction and an effective vehicle inspection and maintenance (I&M) program.
Hoekman, S. Kent, MacArthur, Rory S., Rutherford, James A., Naylor, Michael
Quick Connector Specification for Liquid Fuel and Vapor/Emissions SystemsJ2044_199712 (Historical)12/1/1997
This SAE Recommended Practice defines standard tube end form dimensions so as to guarantee interchangeability between all connector designs of the same size and the standard end form. This document also defines the minimum functional requirements for quick connect couplings between flexible tubing or hose and rigid tubing or tubular fittings used in supply, return, and vapor/emissions in fuel systems. This document applies to automotive and light truck applications under the following conditions: a. Gasoline and diesel fuel delivery systems or their vapor venting or evaporative emission control systems. b. Operating pressure up to 500 kPa, 5 bar, (72 psig). c. Operating vacuum down to –50 kPa, –0.5 bar (–7.2 psi). d. Operating temperatures from –40 °C (–40 °F) to 115 °C (239 °F). Quick connect couplings function by joining the connector to a mating tube end form then pulling back to assure a complete connection. The requirements stated in this document apply to new connectors in assembly operations unless otherwise indicated. For service operations, the mating tube should be lubricated with SAE 30-weight oil before re-connecting. Vehicle OEM fuel system specifications may impose additional requirements beyond the scope of this general SAE document. In those cases, the OEM specification takes precedence over this document.
Fuel Systems Standards Committee
Activated Carbon Canister Performance During Diurnal Cycles: An Experimental and Modeling Evaluation9716515/1/1997
A vehicle's evaporative emission control system is continuously working, even when the vehicle is not running, due to generation of vapors from the fuel tank during ambient temperature variations. Diurnal temperature cycles cause the fuel tank to breathe the fuel vapor in and out, and thus the activated carbon canister is constantly loading and purging the hydrocarbon vapors. This paper discusses a study undertaken at Ford to evaluate the relationship between carbon canister condition and fuel tank vapor generation during diurnal cycles. The results of an extensive set of experiments are presented, and the data from these experiments are compared to the output of a fuel vapor system model also developed at Ford. Key parameters relating to the migration of hydrocarbons during the experimental conditions studied, including initial canister condition, canister volume, and canister geometry, are discussed.
Johnson, Philip J., Jamrog, James R., Lavoie, George A.
Model-Based Fuel Injection Control System for SI Engines9611885/1/1996
An advanced and practical fuel injection control system to reduce exhaust gas emissions has been developed. This control uses an exhaust air-fuel ratio (EAFR) sensor and a heated exhaust oxygen (HEO) sensor. The air fuel ratio of exhaust gas is precisely converged to stoichiometry. The integrated deviation of the mass of fuel inducted into the cylinder is rapidly converged to zero, so as to maximize the conversion efficiency of catalysts. The controller is derived from the models that express the dynamic phenomena. The experimental results show the effectiveness of this system for future exhaust emissions and enhanced evaporative emissions.
Nasu, Masahiro, Ohata, Akira, Abe, Shinichi
European Programme on Emissions, Fuels and Engine Technologies - Objectives and Design9610655/1/1996
The quality of the environment is a continuing concern of the public in Europe and has been the driving force for much research, development and expenditure by the European Vehicle and Oil Industries. Legislation that has already been implemented and planned provides substantial improvements in air quality. Further improvements however are harder to achieve. Consequently, it has been accepted that a variety of measures, including vehicle/fuel changes need to be investigated together to make further air quality improvements. This paper describes the principles and organisational structure of a co-operative programme carried out by the European automobile industry (represented by ACEA), and the European oil industry (represented by EUROPIA). This programme, building on US AQIRP, is an important input into the process for developing environmental Legislation for the European Union (the European Auto/Oil process). It represents a new way of working that permits the costs and the effectiveness of different vehicle/fuel scenarios to be assessed and compared to other measures for improving air quality.
Hublin, Martial, MacKinven, Robert
The Effects of Oxygen-Enriched Intake Air on FFV Exhaust Emissions Using M859611715/1/1996
This paper presents the results of emission tests of a flexible fuel vehicle (FFV) powered by an SI engine, fueled by M85, and supplied with oxygen-enriched intake air containing nominal 21%, 23%, and 25% oxygen (by volume). Emission data were collected by following the standard federal test procedure (FTP) and U.S. Environmental Protection Agency's (EPA's) “off-cycle” test EPA-REP05. Engine-out total hydrocarbons (THCs) and unburned methanol were considerably reduced in the entire FTP cycle when the oxygen content of the intake air was either 23% or 25%. However, CO emissions did not vary appreciably, and NOx emissions were higher. Formaldehyde emissions were reduced by about 53% in bag 1, 84% in bag 2, and 59% in bag 3 of the FTP cycle when 25% oxygen-enriched intake air was used. During the cold-phase FTP, reductions of about 42% in THCs, 40% in unburned methanol, 60% in nonmethane hydrocarbons (NMHCs), and 45% in nonmethane organic gases (NMOGs) were observed when 25% oxygen-enriched intake air was used. The corresponding NOx emissions increased by about 78%. In general, converter-out emissions obtained were also reduced when oxygen-enriched intake air was used, but to a lesser degree. Off-cycle, bag 3 converter-out emissions were reduced when 23% oxygen-enriched intake air was used; CO emissions were reduced by about 67%, and THCs were reduced by about 52%. The FFVs operating on M85 that use 25% oxygen-enriched intake air during only the initial 127 s of the cold-phase FTP or that use 23% or 25% oxygen-enriched intake air during only the cold-phase FIP can meet (without adjusting for catalyst deterioration factors) the reactivity-adjusted NMOG, CO, NOx, and formaldehyde emission standards of the transitional low-emission vehicle (TLEV).
Baudino, John H., Colucci, Christopher P., Poola, Ramesh B., Sekar, Raj, Ng, Henry K.
Carbon Canister Modeling for Evaporative Emissions: Adsorption and Thermal Effects9612105/1/1996
A one-dimensional carbon canister adsorption model (CANMOD) has been developed to assist in the prediction of the performance of carbon bed canisters in vehicle evaporative emissions control systems. The model accounts for mass transfer and transient thermal phenomena, both of which are found to be essential in accurately describing canister behavior. The model assumes the vapor above the carbon to be in equilibrium with the adsorbed mass while the local temperature is determined by the dynamic balance between the heat of adsorption, carbon heat capacity and heat loss to ambient. The results of the model compare well with laboratory data on a 1L canister under load and purge conditions typical of vehicle operation. Variables investigated include: load level, feedgas concentration, and purge rate. The model accurately predicts the hydrocarbon mass adsorbed by the canisters, as well as breakthrough times, and hydrocarbon removal rates. Less accurate predictions are obtained for details of the breakthrough curve and local bed temperatures at the highest loading and purge rates, indicating a need for refinement of the model by including transient vapor-carbon mass transfer, and two-dimensional effects.
Johnson, Philip J., Hood, Jeffrey F., Lavoie, George A.
Gasoline Reformulation and Vehicle Technology Effects on Emissions - Auto/Oil Air Quality Improvement Research Program95250910/1/1995
Engine-out and tailpipe exhaust, and hot soak evaporative emissions of two reformulated test gasolines and an Industry Average reference gasoline were compared in four vehicle fleets designed for progressively lower emission standards. The two reformulated gasolines included: 1) a gasoline meeting 1996 California Phase 2 regulatory requirements, and 2) a gasoline blended to the same specifications but without an oxygenated component. These two gasolines were compared with the Auto-Oil Air Quality Improvement Research Program's (AQIRP) Industry Average gasoline representing 1988 national average composition. The vehicle fleets were the AQIRP Older (1983 to 85MY) and Current (1989MY) vehicle fleets used in prior studies, and two new AQIRP test fleets, one designed to 1994 Federal Tier 1 standards and a prototype Advanced Technology fleet designed for lower emission levels of 1995 and later. The California Phase 2 gasoline (C2) was compared to the Industry Average gasoline (A) in the Older, Current, and Federal Tier 1 fleets. NMHC emissions were 12 to 27% lower with reformulated gasoline C2 than with gasoline A. Carbon monoxide was 21 to 28% lower, and NOx was 7 to 16% lower. All of these differences were highly or marginally statistically significant according to AQIRP criteria. Ozone-forming reactivity, expressed as reactivity-weighted emissions and specific reactivity, was calculated using 1991 SAPRC MIR factors. Reactivity-weighted emissions (RWE) were significantly lower by 16 to 30% with gasoline C2 vs. gasoline A in all three fleets. Specific reactivity of the tailpipe emissions varied from 3 to 9% lower with gasoline C2 across the fleets. The 3% reduction in the Federal Tier I fleet was marginally significant. The effects in the other two fleets were significant. Total toxic air pollutant emissions were 8 to 32% lower with gasoline C2 than with gasoline A. These differences were statistically significant and represent the net effect of changes in the two predominant species, benzene and formaldehyde, and two minor species, 1,3-butadiene and acetaldehyde. Significant decreases in benzene outweighed smaller and not always significant increases in formaldehyde. Differences between reformulated test gasoline C2 with oxygenate (MTBE) and similar gasoline C1 without oxygenate were generally not statistically significant. These gasolines were tested in the Current, Federal Tier 1, and Advanced Technology fleets. The Current fleet showed the largest differences, and the results were generally consistent with earlier Auto/Oil results found to be significant when testing was conducted in a fleet twice as large. The only significant effect in this study was a 13% decrease in formaldehyde emissions from the Advanced fleet when the fuel had no oxygenate. Comparison of tailpipe emissions from 4-cylinder passenger cars in the various fleets when using fuel C2 showed progressively lower NMHC in later model years, lower CO and NOx emissions in the newest vehicles, and lowest NMHC, CO, and NOx in the Advanced Technology vehicles. These reductions are attributed mainly to advances in catalyst technology and better fuel control in the modern cars.
Burns, Vaughn R., Rapp, Larry A., Koehl, William J., Benson, Jack D., Hochhauser, Albert M., Knepper, Jay C., Leppard, William R., Painter, Louis J., Reuter, Robert M., Rippon, Brian, Rutherford, James A.
Effects of Gasoline Properties on Emissions of Current and Future Vehicles - T50, T90, and Sulfur Effects - Auto/Oil Air Quality Improvement Research Program95251010/1/1995
Exhaust emissions were measured using a matrix of fuels designed to expand on prior AQIRP work by investigating potential interactive effects of fuel distillation parameters T50 and T90, and of T90 and fuel sulfur content. (T50 and T90 represent the temperature at which 50 or 90% of the fuel distills in a standard test.) This fuel matrix was used also to investigate whether fuel effects found in prior work with then-current vehicle technology can be expected to continue in future lower emission vehicles. An additional pair of fuels was included to extend the range of T50. The vehicles were half of the AQIRP Current fleet (ten vehicles) used in prior studies, and two new fleets of six vehicles each. One of the new fleets was designed to 1994 Federal Tier 1 standards, and the other was Advanced Technology prototypes targeted for lower emission levels of 1995 and later. A set of six fuels was tested in all three fleets. In these six fuels, T50 and T90 were designed to vary independently at a fixed low sulfur level. Two additional fuels with a higher sulfur content were tested in the Current and Federal Tier 1 fleets. Along with two fuels from the matrix of six T50/T90 fuels, these higher sulfur fuels made up a four-fuel matrix in which T90 and sulfur varied independently. Two fuels intended to extend the range of T50 beyond the main experiment were tested in the Current and Federal Tier 1 fleets. Overall, the observed fuel effects appear sufficiently consistent among the test fleets that fuel effect predictions based on Current fleet data should continue to be generally valid for vehicles equipped with newer emission control technology. This tentative conclusion remains to be validated by detailed ozone modeling planned later in the AQIRP program.
Rutherford, James A., Koehl, William J., Benson, Jack D., Burns, Vaughn R., Hochhauser, Albert M., Knepper, Jay C., Leppard, William R., Painter, Louis J., Rapp, Larry A., Rippon, Brian, Reuter, Robert M.
Emissions with E85 and Gasolines in Flexible/Variable Fuel Vehicles - The Auto/Oil Air Quality Improvement Research Program95250810/1/1995
Exhaust and evaporative emissions from three flexible/variable fuel vehicles (FFV/VFV) were measured as the vehicles operated on E85 fuel (a mixture of 85% ethanol and 15% gasoline) or on gasoline. One vehicle was a production vehicle designed for ethanol fuels and sold in 1992-93 and the other two vehicles were prototypes which were recalibrated 1992 model year methanol FFV's. The gasolines tested were Industry Average Fuel A and a reformulated gasoline Fuel C2 that met California 1996 regulatory requirements. The gasoline component of Fuel E85 was based on the reformulated gasoline. The major findings from this three-vehicle program were that E85 reduced NOx 49% compared to Fuel A and 37% compared to Fuel C2, but increased total toxics 108% (5 mg/mi) and 255% (20 mg/mi), respectively, primarily by increasing acetaldehyde. The NOx effect was significant for both engine-out and tailpipe emissions. Effects on OMHCE, CO, and reactivity-weighted exhaust emissions were not significant, nor were the effects on hot-soak evaporative emissions and reactivity.
Koehl, William J., Rapp, Larry A., Rippon, Brian, Benson, Jack D., Leppard, William R., Painter, Louis J., Burns, Vaughn R., Reuter, Robert M., Rutherford, James A., Knepper, Jay C., Hochhauser, Albert M.
Development of a Dedicated CNG Compact Car95243910/1/1995
The use of compressed natural gas (CNG) as a fuel for small vehicles presents challenges associated with the vehicle cost, system packaging, and vehicle range. The University of Tennessee with primary support from the Saturn Corporation has adapted a Saturn SL1 to dedicated CNG operation with the objective being to do so with a minimal impact on the production of the base vehicle. The adapted vehicle meets the California ULEV emission values at low mileage, achieves a gasoline-equivalent fuel economy of 21 km per liter (49 miles per gallon) at a steady speed of 90 km/hr (55 miles per hour), and has a range (at 90 km/hr) of over 400 km (240 miles) when fueled with an initial tank fill of 24.8 MPa (3600 psig). As expected, wide-open throttle performance of the adapted vehicle was degraded from the gasoline baseline vehicle. The vehicle design features are compared with two similar pre-production vehicles that have been described in the literature.
Hodgson, Jeffrey W., Luton, Edward N., Lampley, Stephen R.
Real World Hot Soak Evaporative Emissions - A Pilot Study9510072/1/1995
As part of the Auto/Oil Air Quality Improvement Research Program (AQIRP), a fleet of 299 1983-1993 “real world” light duty vehicles and trucks were acquired from inspection and maintenance (I/M) lanes and tested at prevailing ambient temperatures for their hot soak emissions for the first hour after the engine was turned off. When found, high-emitters were repaired and retested to quantify the effectiveness of the repairs. Also, I/M pressure-purge tests were performed to determine whether such tests could properly identify high-emitting vehicles. Measured hot soak emissions ranged from less than 0.1g HC to as high as 49g HC. Twenty percent of the vehicles tested accounted for nearly 80 percent of the total hot soak emissions, with no single common hardware component identified as the primary cause. Of the 299 vehicles tested, 46 produced as-received emissions in excess of 2g HC; roughly 20 percent of these high-emitting vehicles were found to have either been tampered with or malmaintained. Repairs on 41 of the high-emitting vehicles reduced their emissions by 83 percent. Only 35 of the test vehicles failed the inspection/maintenance (I/M) pressure-purge test and the majority of this group had hot soaks in excess of 2 grams. The remaining 264 vehicles passing the pressure-purge test were not all low-emitters; they produced over half the excess hot soak emissions identified in the pilot study with 16 observed at 2g or greater. Information of the type generated by this study can be used in improving the predictive capability of existing VOC emission inventory models and may aid in the formulation of strategies to reduce hot soak emissions from the existing vehicle fleet.
Baldus, Steven L., Peltier, Ronald J., Brooks, David J., Reuter, Robert M., Sprik, Timothy L., Bandy, William J.
Instrumentation and Techniques for Vehicle Refueling Emissions MeasurementJ1045_199406 (Historical)6/1/1994
This SAE Recommended Practice describes a procedure for measuring the hydrocarbon emissions occurring during the refueling of passenger cars and light trucks. It can be used as a method for investigating the effects of temperatures, fuel characteristics, etc., on refueling emissions in the laboratory. It also can be used to determine the effectiveness of evaporative emissions control systems to control refueling emissions. For this latter use, standard temperatures, fuel volatility, and fuel quantities are specified.
Emissions Systems Forum Committee
Performance of Fluorocarbon Elastomers in MTBE/Fuel Blends9409563/1/1994
The drive to reduce automobile emissions has lead to the use of so called “reformulated gasoline.” MTBE (Methyl Tertiary Butyl Ether) is an oxygenate and a typical component of these fuels. Fluorocarbon elastomers are high performance materials commonly used to produce a variety of fuel system components (fuel hoses, O-rings, diaphragms, etc.) This paper will study the effect of MTBE/fuel blends on fluorocarbon elastomers by using a designed experiment. We will systematically and simultaneously evaluate the effects of varying the MTBE level, temperature and fluorine content using a full factorial design scheme. The paper will provide end-users with information regarding the effect of MTBE/fuel blends on fluorocarbon elastomers under various conditions and it will also provide an example of the practical use of designed experiments.
Aloisio, Salvatore
Multiple Diurnal Evaporative Emissions Determinations with a Naturally Controlled Variable Volume Enclosure93267410/1/1993
The successful operation of a naturally controlled variable volume enclosure is dependent upon the ability to adjust volume in response to controlled cyclical temperature changes, as well as asynchronous ambient pressure changes. The ability to naturally adjust internal volume is affected by the physical and operational design of the enclosure. Natural control of volume adjustment is done without the use of any physical control systems and relies solely on the effects of internal enclosure temperature and pressure to operate. The purpose of this paper is to explain the design, construction, and verification issues used not only in constructing such a variable volume enclosure but also in proving the hydrocarbon mass retention integrity of such an enclosure.
Dudek, Walter D., Fisher, Doug
The Potential Benefits of Intake Air Oxygen Enrichment in Spark Ignition Engine Powered Vehicle93280310/1/1993
A production spark ignition engine powered vehicle (3.1-L Chevrolet Lumina, model year 1990) was tested with oxygen-enriched intake air containing 25 and 28% oxygen by volume to determine if (1) the vehicle would run without difficulties and (2) there would be emissions benefits. Standard Federal Test Procedure (FTP) emissions test cycles were run satisfactorily without vehicle performance anomalies. The results of catalytic converter-out (engine with a three-way catalytic converter in place) emissions showed that both carbon monoxide and hydrocarbons were reduced significantly in all three phases of the emissions test cycle, compared with normal air (21 % oxygen). Carbon monoxide emissions from the engine (with the three-way catalytic converter removed) were significantly reduced in the cold-phase of the test cycle. The catalytic converter also had an improved carbon monoxide conversion efficiency under the oxygen-enriched air conditions. Detailed results of hydrocarbon speciation indicated large reductions in 1,3-butadiene, formaldehyde, acetaidehyde, and benzene from the engine with the oxygen-enriched air. The catalytic converter-out ozone was reduced by 60% with the 25%-oxygen-content air. Even though there was a significant increase in NOx both from the engine-out and the catalytic converter-out emissions, we believe that they can be ameliorated in the near future with new control technologies. On the basis of estimates made from current data, several production vehicles that had low NOx emissions could meet the 2004 Tier II emissions standards with the 25%-oxygen-content air. The results indicate that by adding oxygen to the intake air instead of adding it to the fuel (as in oxygenated gasoline), the same emissions reduction goal can be achieved.
Ng, Henry K., Sekar, Raj. R.
Items per page:
1 – 50 of 110