This is an excerpt from EERE Network News, a weekly electronic newsletter.
DOE Awards $87.5 Million to 12 Vehicle Efficiency Projects
DOE announced on February 16th that it will award $87.5 million to 12 projects that will develop more fuel-efficient passenger and commercial vehicles. Seven of the 12 projects will involve research in advanced combustion technologies, and three of those seven relate to homogeneous charge compression ignition (HCCI). In HCCI engines, fuel is pre-mixed with air, as in spark-ignition engines, but the engine combusts the mixture using compression, like a diesel engine. HCCI engines burn with high efficiency and low emissions, but the combustion process is difficult to control. The seven advanced-combustion projects will also explore such technologies as premixed charge compression ignition (like HCCI, but with a non-homogeneous mixture of fuel and air), variable valve timing, variable compression ratios, variable nozzle turbocharging, and low-pressure loop-cooled exhaust gas recirculation (EGR). In addition, Mack Trucks, Inc will develop and demonstrate an air-power-assist system that works with a commercial diesel engine.
The remaining five projects relate to technologies that convert waste heat from engines into useful electrical or mechanical energy. One promising technology—under examination by three of the five projects—is "turbocompounding," in which exhaust gas from a conventional turbocharger is passed through a second turbocharger to provide more torque and energy to the engine's crankshaft.
DOE's FreedomCAR and Vehicle Technologies Program is providing funding for the 12 projects. See the DOE press release, and for more information about HCCI engines, see Sandia National Laboratories' Combustion Research Facility Web site. A detailed diagram of a turbocompound system is also available on the Web site from Scania, a Swedish manufacturer of heavy vehicles and engines.