Harry L. Husted

Comparative study of new on-board power generation technologies for automotive applications

The increasing use of electrical and electronic features to improve vehicle performance, fuel economy, emissions, passenger comfort, safety, and convenience has resulted in the growth of electrical loads in the vehicle. In order to meet these electrical load demands and also to meet the requirement of power generation when the engine is off, several technologies are on the horizon for on-board power generation in the vehicles. In this paper, new onboard power generation technologies based on the solid oxide fuel cell (SOFC), proton exchange membrane (PEM) fuel cell, Thermo-photovoltaic (TPV) system, and Diamond or Carbon Nanostructures are compared in terms power density, cost, and long term feasibility for automotive applications.

The Effects of GDi Fuel Pressure on Fuel Economy

To meet future particulate number regulations, one path being investigated is higher fuel pressures for direct injection systems. At operating pressures of 30 MPa to 40 MPa, the fuel system components must be designed to withstand these pressures and additional power is required by the pump to pressurize the fuel to higher pressures than the nominal 15MPa to 20MPa in use today. This additional power to the pump can affect vehicle fuel economy, but may be partially offset by increases in combustion efficiency due to improved spray mixture preparation. This paper examines the impact on fuel economy from increased system fuel pressures from a combination of test results and simulations. A GDi pump and valvetrain model has been developed and correlated to existing pump torque measurements and subsequently used to predict the increase in torque and associated impact on fuel economy due to higher GDi system pressures.

Logistics and Capability Implications of a Bradley Fighting Vehicle with a Fuel Cell Auxiliary Power Unit

Abstract : Modern military ground vehicles are dependent not only on armor and munitions, but also on their electronic equipment. Advances in battlefield sensing, targeting, and communications devices have resulted in military vehicles with a wide array of electrical and electronic loads requiring power. These vehicles are typically designed to supply this power via a main internal combustion engine outfitted with a generator. Batteries are also incorporated to allow power to be supplied for a limited time when the engine is off. It is desirable to use a subset of the battlefield electronics in the vehicle while the engine is off, in a mode called silent watch. Operating time in this mode is limited, however, by battery capacity unless an auxiliary power unit (APU) is used or the main engines are restarted. Integration of a solid oxide fuel cell (SOFC) auxiliary power unit into a military vehicle has the potential to greatly extend silent watch operating time and capabilities while significantly reducing fuel use. In this paper the results of a study are presented which show the fuel usage and capability impacts of incorporating a fuel cell APU into the electrical system of a Bradley M2A3 Diesel Infantry Fighting Vehicle. Several APU sizes are presented with varying levels of electrical equipment and engine-off capability. Complete off-loading of engine-driven accessories is also studied as a scenario with the resulting impact on available engine power presented. The silent watch operating scenario shows an 86% reduction in fuel use. With fuel costing several hundred dollars per gallon as deployed on the battlefield, such a reduction is valuable. Furthermore, the SOFC APU offers 36 days of continuous silent watch using the same JP-8 fuel tank as the M2A3 without the need for a secondary fuel supply.

New On-Board Power Generation Technologies for Automotive Auxiliary Power Units

Improving fuel economy, emissions, passenger comfort and convenience, safety, and vehicle performance in the automobile is resulting in the growth of electrical loads. In order to meet these electrical load demands and tomeet the requirement of power generation when the engine is off, several technologies are on the horizon for on-board power generation in the vehicles. In this paper, new on-board power generation technologies based on the solid oxide fuel cell (SOFC), proton exchange membrane (PEM) fuel cell, thermo-photovoltaic (TPV) system, and diamond or carbon nanostructures are compared in terms power density, cost, and long term feasibility for automotive applications.