Combustion and emission characteristics of a premixed charge compression ignition engine by DMM port injection

This paper presents a study of controllable premixed combustion in a diesel engine. An electrically controlled fuel injection system was installed in the intake manifold of the engine. Methylal (DMM) fuel with low cetane number and low boiling point was injected into the manifold. The homogeneous mixture was formed in the compression stroke and ignited by a small amount of injected diesel fuel near the TDC. The effects of pre-mixed fuel ratio, engine load, CO2 Concentration in the intake gas and nozzle hole diameter on the engine combustion and emissions were investigated. The results show that The premixed combustion by DMM fuel port injection exhibits substantial reduction of NOx and smoke emissions simultaneously, which may possible develop into a technique for controlling diesel engine exhaust emissions.