There is growing interest in hybrid electric vehicles using alternative fuels in heavy truck applications. This project developed and demonstrated a Class 8 hybrid electric heavy truck tractor powered by a natural gas fueled, intercooled-recuperated microturbine engine. The research project used forward-looking simulation models and acquired field data to determine hybrid type and commercial heavy haul applications.
Research was conducted to identify suppliers with heavy truck and hybrid vehicle applications, leverage technology developed to date and integrate the components onto a chassis with the shortest possible wheelbase. The short wheelbase was selected as it was the most challenging to package, thus allowing the component layout to be applicable to a broad range of heavy truck chassis designs of various wheelbases and applications.
The type of hybrid selected is a series hybrid in which the engine is mechanically decoupled from the drive train. The microturbine engine is directly coupled to a generator, which then supplies electric power either directly to the power train or indirectly through an energy storage and retrieval system. The micro-turbine output was designed to compete with similarly-sized diesel engines used in this same application. A hybrid drive assembly was powered by the energy storage system and power was managed by a programmable power distribution box and a vehicle control system.
Once assembled and site tested, the Class 8 natural gas intercooled microturbine serial hybrid electric vehicle, through simulation, is predicted to have better fuel economy in pick-up and delivery applications and should compete well in short haul/regional applications. Further testing is required to validate simulation results.
