Browse Topic: Evaporative emissions control systems (EVAP)

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Simulation and Experimental Study of Filler Pipe of Automobile Fuel Tank Based on ORVR Technology2019-01-080004/02/2019
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
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 Durability2017-01-039303/28/2017
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 Vehicles2013-01-105704/08/2013
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
Dolch, Johanna, Reek, Aaron, Glinsky, Gerard, Dicicco, Dominic, Ughetta, Valerie
Estimated Cost of Emission Control Technologies for Light-Duty Vehicles Part 1 - Gasoline2013-01-053404/08/2013
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
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)09/06/2011
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 Tool2011-01-074904/12/2011
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
Pattada, Kallappa, Singh, Satnam, Bandyopadhyay, Pulak
Development of Exhaust and Evaporative Emissions Systems for Toyota THS II Plug-in Hybrid Electric Vehicle2010-01-083104/12/2010
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
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)08/13/2009
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
Fuel Systems Standards Committee
Quick Connect Coupling Specification for Liquid Fuel and Vapor/Emissions SystemsJ2044_200908-TEST-REC (Historical)08/13/2009
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
Fuel Systems Standards Committee
Cost Effective Emissions Control Based on Optimized Flex Fuel Electronic Injection for PROCONVE-L5 in Brazil2008-36-037910/07/2008
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
Rodrigues, Saulo, Ferreira, Rafael Peixoto
Opportunities for Brazilian OBD in the Context of I/M2008-36-016810/07/2008
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
Alves, Michel Zambon, Baltusis, Paul, Burgos, Eduardo
Requirements for Built-In Service Port for On Board DiagnosticsJ2744_200808 (Historical)08/11/2008
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
A Parametric Vehicle Fuel Tank Filling System Model2007-01-174104/16/2007
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 Levels2007-01-109004/16/2007
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
Mancini, Douglas J.
Design Considerations & Characterization Test Methods for Activated Carbon Foam Hydrocarbon Traps in Automotive Air Induction Systems2007-01-142904/16/2007
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
Schaffer, Scott A., Arruda, Anthony, Bielicki, James, Bugli, Neville
Nonmetallic Fuel System Tubing with One or More LayersJ2260_200411 (Current)11/01/2004
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
Fuel Systems Standards Committee
Nonmetallic Fuel System Tubing with One or More LayersJ2260_200411-TEST-REC (Historical)11/01/2004
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
Fuel Systems Standards Committee
Durability of Low-Emissions Small Off-Road Engines2004-32-005809/27/2004
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
White, Jeff J., Lela, Chad, Lourenco, Jackie, Salardino, David
Development of Two-Layer Fuel Tube System Consisting of Adhesive-ETFE And Modified-PA122004-01-144003/08/2004
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
Evaporative Leak Check System by Depressurization Method2004-01-014303/08/2004
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
Modeling and Simulation of N-butane Adsorption/Desorption in a Carbon Canister2004-01-168003/08/2004
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.
Multidimensional, Time-Accurate CFD Simulation of Adsorption/Desorption in a Carbon Canister2003-01-100303/03/2003
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)09/13/2002
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
Fuel Systems Standards Committee
A Purge Solenoid Structure-borne Noise Model2001-01-142304/30/2001
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
Kuxhaus, Laurel, Grimmer, Michael J.
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
Matsushima, Hideyuki, Iwamoto, Akio, Ogawa, Masahiro, Satoh, Tomoyuki, Ozaki, Katsunori
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
Brogan, M. S., Swallow, D., Brisley, R. J., Worth, D., Yang, KC.
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
Lyons, James M., Lee, John M., Heirigs, Philip L., McClement, Dennis, Welstand, Steve
Evaporative Leakage from Gas Caps2000-01-117103/06/2000
The AirCare® vehicle emissions inspection and maintenance program is briefly described, together with the benefits which the program has already achieved. Additional benefits have been projected should the program include some more sophisticated assessment of evaporative emission control systems. The feasibility of including such an assessment has been investigated, and a pilot study has been conducted in the regular inspection lanes. The operational and systems implications are described. The pilot study has resulted in an analysis of the incidence of faulty gas caps in the Lower Fraser Valley light-duty vehicle fleet, and how this relates to other vehicle characteristics such as vehicle make, model, model year, mileage etc.; and inspection data including emission control system components tampering and tailpipe emissions. Approximately 10% of all gas caps tested failed the pressure test, compared to the 1% that were failed by visual inspection. Correlation with other vehicle and
Stewart, S. J., Jang, Leon, Hui, Conway, Meggy, David, Wong, Jimmy
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
Lyons, James M., Lax, David, Welstand, Steve
Diurnal Emissions from In-Use Vehicles1999-01-146305/03/1999
One hundred fifty-one vehicles were recruited from the I/M lane in Mesa, AZ during the summer of 1996, and their 24 hour diurnal emissions were measured in a variable temperature SHED (VT-SHED). The fleet selection included the earliest applications of evaporative emission control, and later technologies that had at least 5 years of exposure. Model years 1971 through 1991 were tested. Fifty-three percent of the sample tested had daily emissions of more than 10 grams. Five of the 151 were over 50 grams per day, and had significant liquid leaks. Twenty-six (17%) of the vehicles had emissions exceeding one gram per hour. Thirty-two of the 151 tested (21%) had identifiable liquid leaks. Carburetor systems had higher emissions than fuel injection systems. The highest emitters had resting losses of more than 0.8 g/hr. These eight highest emitters were considered outliers for the purposes of general analysis, and were not used, as is noted in the report. “Resting Losses” were estimated for
Haskew, Harold M., Liberty, Thomas F.
Vapor and Liquid Composition Differences Resulting from Fuel Evaporation1999-01-037703/01/1999
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
Greenfield, Michael L., Rossi, Giuseppe
Proportional Ambient Sampling: A CVS Improvement for ULEV and Lean Engine Operation1999-01-015403/01/1999
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
Lavoie, George A., Imai, Yash A., Johnson, Philip J.
RVP Reduction for Control of Wintertime CO98137305/04/1998
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)12/01/1997
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
Fuel Systems Standards Committee
Activated Carbon Canister Performance During Diurnal Cycles: An Experimental and Modeling Evaluation97165105/01/1997
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.
European Programme on Emissions, Fuels and Engine Technologies - Objectives and Design96106505/01/1996
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
Hublin, Martial, MacKinven, Robert
Carbon Canister Modeling for Evaporative Emissions: Adsorption and Thermal Effects96121005/01/1996
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
Johnson, Philip J., Hood, Jeffrey F., Lavoie, George A.
The Effects of Oxygen-Enriched Intake Air on FFV Exhaust Emissions Using M8596117105/01/1996
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
Baudino, John H., Colucci, Christopher P., Poola, Ramesh B., Sekar, Raj, Ng, Henry K.
Model-Based Fuel Injection Control System for SI Engines96118805/01/1996
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
Emissions with E85 and Gasolines in Flexible/Variable Fuel Vehicles - The Auto/Oil Air Quality Improvement Research Program95250810/01/1995
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
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 Car95243910/01/1995
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.
Gasoline Reformulation and Vehicle Technology Effects on Emissions - Auto/Oil Air Quality Improvement Research Program95250910/01/1995
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
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 Program95251010/01/1995
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
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.
Real World Hot Soak Evaporative Emissions - A Pilot Study95100702/01/1995
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
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)06/01/1994
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
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