1. Advancement of GDCI Engine Technology for US 2025 CAFE and Tier3 Emissions.
- Author
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Sellnau, M., Foster, M., Moore, W., Hoyer, K., Sinnamon, J., and Klemm, B.
- Subjects
AUTOMOBILE industry ,DIESEL motors ,SPARK ignition engines - Abstract
The automotive industry is facing tremendous challenges to improve the fuel economy and emissions of the internal combustion engine. In the US, 2025 standards for fuel economy and CO
2 emissions are extremely stringent. Simultaneously, vehicles must comply with new US Tier3 emissions targets. Increasing world demand for diesel, jet fuel, and heavier distillates means that gasoline-like fuels will have longterm cost advantages. In all market segments, there is a need for clean and efficient engines operating on gasoline-like fuels. One approach is Gasoline Direct Injection Compression Ignition (GDCI). In this combustion process, gasoline is injected directly into the cylinder and partially but not fully premixed prior to the start of heat release. As part of two United States Department of Energy programs, Delphi has developed a 3rd generation GDCI engine that utilizes partially premixed compression ignition (PPCI) "fulltime" without combustion mode switching. Injection parameters are used to control mixture stratification and combustion phasing using a multiple-late injection strategy with GDi-like injection pressures. Key program objectives include ultra-low fuel consumption (200 g/kWh) and a "wetless" combustion system for low smoke at any injection timing. The engine is compatible with less processed, low-octane, gasoline fuels for lower life-cycle C02 emissions. Preliminary test results using RON91 gasoline with 10% ethanol (E10) indicated very low fuel consumption of 205 g/kWh at medium loads, while meeting targets for engine out emissions, combustion noise and stability. BSFC at the 2000rpm- 2 bar BMEP global test point was 250 g/kWh. At 1500rpm-6bar IMEP, BSFC was 11 percent lower than a competitive 2.0L European diesel engine. The wetless Gen3 combustion system reduced smoke levels greatly for late injection timings relative to the previous Gen2 engines. At low load, exhaust rebreathing was effective to increase both mixture and exhaust temperatures, while maintaining good catalyst efficiency, dditional work is needed to develop the engine calibration ahead of vehicle testing. [ABSTRACT FROM AUTHOR]- Published
- 2017