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Vehicles that meet the Federal Tier II and the California LEV II Vehicle Standards (e.g. ULEV and SULEV) are a rapidly growing percentage of the fleet. Sales weighted fleet average emissions of new vehicles are already below the LEV certification levels and should be below ULEV certification levels within two years. ULEV and SULEV vehicles represent the “typical” vehicle future for the next decade or two. Data on particulate emissions from these vehicles are currently very limited. In this study, emission tests using the standard Federal Test Procedure (FTP) were conducted on a small in-use vehicle fleet of ULEV and SULEV vehicles to determine their particulate matter mass emission rates, chemical compositions, particle numbers, and particle size distributions. Particulate sampling utilized Teflon filters for mass determination and quartz filters + PUF-XAD cartridges for chemical speciation. Each bag of the test was sampled separately.

Fuel induction techniques have been found to be playing a very sensitive role in the operation of a gas-fueled engine. This paper describes the experimental evaluation of an electronic injector for operating a spark ignition (SI) engine using clean-burning alternative fuels such as compressed natural gas and hydrogen. Test data have also been generated with a blend of the two fuels (hydrogen and CNG) in various proportions to determine the flow characteristics of the blend for engine operation. Results show that the electronic injectors for gaseous fuel operation can be conveniently adapted to existing engines. A precise and accurate control of flow was achieved at pressure levels of 3.44 bar and 9.31 bar (absolute pressure).

Although studies have shown benefits in both emissions and fuel renewability for hydrogen fuelled vehicles, implementation of such a vehicle has been slow due, in part, to a limited hydrogen infrastructure. This situation, along with the proven benefits associated with natural gas and natural gas/hydrogen fuelled vehicles resulted in the need to develop a vehicle capable of operating on any blend of natural gas/hydrogen, at anytime. Such a vehicle dubbed; Variable Gaseous Fuel (VGF) vehicle, in principle, could use a thermal conductivity sensing device developed at the University of California, Riverside, College of Engineering - Center for Environmental Research and Technology (CE-CERT) to directly measure the composition of a natural gas/hydrogen blend. The resulting electrical signal from this device can, in turn, be used as an input to “multiple map” engine control module to control fuel injection and ignition timing.

FTP-UDDS (urban dynamometer driving schedule) exhaust particulate matter (PM) emission rates were determined for 361 light-duty gasoline (LDGV) and 49 diesel passenger vehicles ranging in model year (MY) from 1965 to 1997. LDGVs were recruited into four MY categories. In addition, special effort was made to recruit LDGVs with visible smoke emissions, since these vehicles may be significant contributors to the mobile source PM emission inventory. Both light and heavy-duty diesels where included in the passenger diesel test fleet, which was insufficient in size to separate into the same MY categories as the LDGVs. Vehicles were tested as-received in three areas: Denver, Colorado; San Antonio, Texas; and the South Coast Air Quality Management District, California. The average PM emission rates were 3.3, 79.9, 384 and 558 mg/mi for 1991-97 MY LDGVs, pre-1981 LDGVs, smoking LDGVs and the diesel vehicles, respectively.

This paper discusses the design and strategy for conversion of a vehicle to dedicated E85 (85% ethanol, 15% indolene clear) operation for participation in the 1998 Ethanol Vehicle Challenge by the University of California, Riverside. The primary focus of the design consists of: Development of a -7°C cold starting system utilizing a distillation process. Development of a close-coupled catalyst and secondary air injection system to decrease FTP cold start emissions. This paper begins with a theoretical description and design of a novel distillation system that can provide gasoline- enriched fuel for starting in cold weather. This is followed by a description of modifications to the engine, emission control system, and other vehicle components. Modifications included engine changes to increase thermal efficiency, to improve handling, and to reduce friction. Suspension modifications were made to improve handling.

This paper describes an evaluation of a series of commercially available natural gas fuel injectors, originally designed for heavy-duty diesel application, for use with hydrogen fuel in an electronic fuel-injected internal combustion engine. Results show that sonic flow, pulse-width-modulated electronic gaseous fuel injectors provide accurate and stable metering of hydrogen gas at fuel pressures between 25 and 200 psig. A linear flow rate of hydrogen was observed with a low standard deviation error during pulse width modulation. Plots of flow rate of hydrogen (mg/injection) versus pulse width (PW) are presented for inlet pressures from 25 to 200 psig for selected injectors. In addition, injector response tests were conducted and found to have time delays (time it takes the injector to open) between 2.6 ms and 2.3 ms at 25 psig inlet pressure. Time-delay times increased linearly between 4.0 ms and 3.0 ms at 200 psig.

A University of California, Riverside (UCR) 1992 Ford Ranger truck was converted to operate on hydrogen which is produced from water electrolysis at the UCR College of Engineering-Center for Environmental Research and Technology (CE-CERT) Solar Hydrogen Research Facility (SHRF). The Ford Ranger's 2.3L engine was modified to operate as a lean-burn, hydrogen fuel internal combustion (IC) engine, using a Constant Volume Injection (CVI) system with closed-loop control and exhaust oxygen feedback. The vehicle had excellent starting, idle, and shut-down operation; a range in excess of 161km (100 miles); and initially operated with virtually no preignition problems typical of hydrogen fuel engines. At speeds above 64 km/ h (40 mph), the vehicle exhibited performance characteristics similar to comparable gasoline-powered vehicles, although further improvements are needed at lower speeds.