Premixed low-temperature combustion of blends of diesel and gasoline in a high speed compression ignition engine

This study experimentally demonstrates the potential of using blends of diesel and gasoline to simultaneously reduce nitrogen oxides (NOx) and soot emissions in premixed low-temperature combustion (LTC) mode. Blends of diesel and gasoline have lower cetane numbers than diesel, and can provide more time for fuel/air mixing prior to combustion by extending ignition delay. When diesel is replaced by blends of diesel and gasoline, the simultaneous reduction of NOx and soot emissions can be achieved without significantly reducing local combustion temperatures as commonly done in conventional LTC strategies. With increased gasoline proportion, soot emissions become insensitive to the change of the intake oxygen concentration and remain at a low level as NOx emissions gradually decrease. Furthermore, effects of high injection pressure on reduction in soot emissions are limited when blends of diesel and gasoline are used. (C) 2010 The Combustion Institute. Published by Elsevier Inc. All rights reserved.