A Parametric Study on Combustion and Exhaust Emissions of Diesel Engines Operating with Ultra-High EGR Rates 18ICES/065
Authors
Tie Li - Hokkaido University
Hideyuki Ogawa - Hokkaido University
Shingo Kido - Kanto Automobile
Noboru Miyamoto - Hokkaido University
Hajime Shimizu - Toyota Motor Corporation
Abstract
This research investigates the influences of the injection timing, injection pressure, and compression ratio on the combustion and exhaust emissions in a single cylinder 1.0 L DI diesel engine operating with ultra-high EGR rate. Increases in ignition delays with both advancing and retarding the injection timing reduce the smoke emissions, but advancing the injection timing has the advantages of maintaining the thermal efficiency and preventing misfiring. Smokeless combustion is realized with an intake oxygen content of 9-10% regardless of the injection pressure. Reduction in the compression ratio is effective to reduce the in-cylinder temperature and increase the ignition delay as well as to expand the smokeless combustion range of EGR and IMEP, however, the thermal efficiency deteriorates with excessively low compression ratios.