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An innovative carburetor system has been developed for use in single cylinder small engines. The carburetor has been implemented on a 79cc 4 stroke portable gasoline generator for the purposes of illustrating its effect in reducing emissions, engine deposits and improving fuel economy without re-jetting the carburetor. This method of carburetion dynamically tunes the venturi effect in the carburetor, allowing for air density, fuel viscosity and fuel type compensation for optimal AFR. Modified and stock generators were tested at various power levels, elevations and temperatures to simulate operational environments. The improvements in emissions and fuel consumption will be presented. In addition, the system has been designed as a bolt-on, low cost alternative to an EFI method of complying with emissions regulations for existing small engine applications.

Fuel Cell engines have been proposed as alternatives to the internal combustion engine in transportation applications. The dynamics of the fuel cell engine and subsystems are not well understood but play an important role in the proposed application. This study assesses the operation of an indirect methanol fuel cell powertrain from a dynamics perspective and identifies resulting limitations of the system. Relevant data from an indirect methanol fuel cell bus powertrain is presented and discussed. Identification of dynamically limiting processes allows researchers and fuel cell manufacturers to focus on sub-systems that can improve the response times during transient operation. Better understanding also allows for development of control and enhancement methods to mitigate the difficulties associated with the dynamic response of indirect methanol fuel cell vehicles.

Fuel cell engines are expected to deliver greater efficiency and lower emissions than conventional powertrains during operation. However, the projected efficiency and emission benefits of using fuel cell derived power can be significantly reduced if the fuel consumed and emissions produced during start-up and shutdown procedures are included in the analysis of the overall drive cycle. For this reason, an investigation of the drive cycle including the fuel consumed, power required, and emissions produced during the start-up and shutdown of an operational, heavy duty methanol-fueled fuel cell bus has been performed. The fuel consumed and emissions generated during start-up and shutdown were measured and combined with steady operation values to allow mission equivalent fuel mileage and emission outputs to be computed. The results show that the start-up and shutdown contributions can be significant and should be included in fuel efficiency and emission projections.

The shutdown process of an operational phosphoric acid fuel cell transit bus has been investigated. The bus employs a hybrid arrangement of a 50 kW Phosphoric Acid Fuel Cell (PAFC) engine in parallel with Nickel-Cadmium batteries on a 30-foot heavy-duty transit bus chassis manufactured by Bus Manufacturing Inc. The bus uses methanol as the primary fuel, which is processed through a steam-reformer to produce hydrogen used in the fuel cell. Rapid cooling of PAFC power plants will induce component damage. Shutdown of the fuel cell bus is defined as the time that is required for the controlled reduction from operating temperatures within the fuel cell stack and reformer to minimize component degradation. While in general fuel cell vehicles produce low emissions and are very efficient while operating, shutdown of the fuel cell bus represents a significant time requirement, power and fuel consumption, and considerable pollutant emissions with no usable output power.

The start-up process of an operational phosphoric acid fuel cell transit bus has been investigated. The bus employs a hybrid arrangement of a 50 kW Phosphoric Acid Fuel Cell (PAFC) engine in parallel with Nickel-Cadmium batteries on a 30-foot heavy-duty transit bus chassis manufactured by Bus Manufacturing Inc. The bus uses methanol as the primary fuel, which is processed through a steam-reformer to produce hydrogen used in the fuel cell. Start-up of the fuel cell bus is defined as the time that is required to heat up the fuel cell and sub-components to operating temperatures and to establish operating flow conditions. While in general fuel cell vehicles produce low emissions and are very efficient while operating, start-up of the fuel cell bus represents a significant time requirement, power and fuel consumption, and considerable pollutant emissions with no usable output power.