21 August 2009
The 15th DEER Conference organized by the US Department of Energy (DOE) was held on August 3-6 in Dearborn, MI. The Conference, which has grown to be one of the primary venues for the exchange of information on state-of-the-art advanced combustion engine R&D, was attended by some 750 delegates. Compared to other conferences in these economic times, this number represented a relatively minor hit in attendance from the previous year. While keeping the acronym DEER, the name of the Conference was changed to “Directions in Engine-Efficiency and Emissions Research” (from “Diesel Engine-Efficiency and Emissions Research”). This change better reflects the trends in energy efficient engine research and opens the door for presentations in such technology areas as gasoline directly injected (GDI) engines, but it feels like a departure from the diesel roots of the DEER Conference.
Regulatory Perspectives. The four-day technical program included two panel discussions, a number of technical sessions, as well as poster sessions. As in previous years, the Conference was opened by a “A view from the bridge” panel which focused on regulatory issues and long term trends in combustion engine technology. As ambitious climate change targets are set by the regulators, CO2 emissions and fuel efficiency become the dominant driving force in engine and vehicle development. California adopted a target of 80% CO2 reduction by 2050, which would require that vehicle efficiency is increased by a factor of 3 (T. Cackette, CARB). It is envisioned that conventional cars will be gradually replaced by hybrid electric vehicles (HEV), plug-in hybrids (PHEV) and “ultra low carbon vehicles” (ULCV). At the same time, there is no relaxation in emission rules for the conventional pollutants: NOx and PM. California is developing the next tier LEV III emission standards for light-duty vehicles, and has a target of cleaning (such as by particulate filter retrofits) most of the existing heavy-duty diesel fleet by 2014.
Nationwide greenhouse gas emission targets for future cars in the United States will be set by the EPA greenhouse gas emission regulations still under development. While it is envisioned that various forms of electric drive will play increasingly important role, a number of issues exist, such as generation of renewable electricity. For example, under current German electrical grid conditions, the electricity consumed by an all-electric vehicle is associated with CO2 emissions of 120 g/km, higher than those possible in an advanced diesel car (J. Rueger, Bosch). Other issues include the impact of the increased energy demand on the grid, or the cost of the electric vehicles. If gasoline is replaced by electricity, new forms of taxation will be also necessary to ensure continuing funding for highway maintenance.
GHG emission requirements will be also adopted for heavy-duty highway and nonroad engines. While the structure of the regulations remains uncertain--it is not a trivial task to regulate GHG emissions from heavy-duty engines--they will likely require a complex approach including not only more efficient engines, but also more efficient vehicle technologies combined with operational requirements. Different mix of technologies will be required depending on the application (J. Wall, Cummins). Recovery of the vehicle kinetic energy, for example through different forms of hybridization, is effective in heavy-duty vehicles operated in stop-and-go traffic in the city. Exhaust gas heat recovery, on the other hand, is more effective in line haul vehicles. Various methods of heat recovery include turbocompounding (mechanical or electrical), thermoelectrics, and bottoming cycles (e.g., Rankine).