Combustion and emission characteristics of a TY1100 diesel operating on high proportion of methanol-diesel dual fuel were investigated when the engine was equipped with an electronically controlled methanol port injection system.Under the same brake mean effective pressure(bmep)and engine speed

the ignition delay increases while the main combustion duration decreases with the increase of methanol mass fraction.The first peak value of heat release rate increases and the second peak value decreases

which indicates that the fraction of premixed burning amount increases while diffusive burning amount decreases.Moreover

the center of heat release rate curve closes to the top-dead-center under high-load condition and diesel equivalent fuel consumption decreases.NO

x

and smoke decrease significantly while HC and CO concentration increase.