Combustion characteristics of electronic fuel injection gasoline engine fueled with methanol-gasoline blends

In order to study the effects of methanol-gasoline blends with different methanol ratios on the heat releasing rule of multi-point electric fuel injection gasoline engine, the recorded cylinder pressure of the engine was used to compare and analyze the variation rules of combustion characteristic parameters under the running conditions of the engine.Analysis result indicates that at middle and low engine speeds, the maximum cylinder pressure and the peak of pressure rising rate of blends engine are almost similar to those of gasoline engine under middle and light engine loads, and slightly higher under high engine loads; at high engine speeds, the peak pressure and the pressure rising rate of blends engine are evidently higher than those of gasoline engine.Compared with gasoline engine, the ignition delay period of the engine is longer under all range of loads; the combustion duration of the engine is shorter under light loads, and is the same under middle and high engine loads; the peak heat releasing rate and cyclic variability coefficient are slightly higher under middle and light loads, and are similar under high loads.There is not evident influence of engine speed on the varying trand of chmbustion characteristic parameters with the ratio of methanol in blends.