Experimental Study Of Electronic Controlled Gasoline Engine Fueled With M100 Methanol

Methanol is a kind of chemical products,and can be used in internal combustion engine, it is a promising oxygenated alternative fuel. Methanol is generally applied on spark-ignition engine because of its low cetane number. A gasoline engine were converted into a M100 methanol engine on the basis of physicochemical property differences of methanol and gasoline. The effects of different structure parameters and operating parameters on methanol engine power, fuel economy and emission were experimentally studied, and the effect of hydrocarbon additives on methanol engine cold start performance were experimentally studied.Based on the properties of methanol, the engine fuel supply system was modified, the re-selection and calibration of sensors and actuators were conducted. An engine calibration system including ECU, communication unit, engine test bench system were built, the MAP of the volumetric efficiency, the ignition timing, the intake valve timing and other parameters were re-calibrated experimentally.The full load characteristics and load characteristics of M100 methanol engine were carried out. The gasoline engine and methanol engine dynamic performance, fuel economy were compared. The results showed that, the M100 methanol engine torque was lower than that of gasoline engine when speed is less than 2500r/min at full load, with the engine speed increased, the methanol engine torque was higher than that of gasoline engine; the load characteristics showed the equivalent fuel consumption rate of M100 methanol engine was lower than that of gasoline at speed of 2000r/min.The effects of the excess air ratio, ignition timing and compression ratio on methanol engine performance were experimentally investigated, the engine torque, methanol consumption and emission were measured. The results showed that, at 2500r/min, partial load condition, with the excess air ratio increased from 0.75 to 1.3, engine torque increased first and then decreased, equivalent break specific fuel consumption reduced after the rise, NO emission showed a single peak shape, HC, CO emissions decreased; with the increase of the advanced ignition angle from 15.4°CA to 34.5°CA, methanol engine torque increased, equivalent break specific fuel consumption reduced, NO emission was increased by about 80%, changes in advanced ignition angle had less effect on HC, CO emissions. With the engine compression ratio increased from 10.0 to 11.5, the methanol engine torque was increased by up to 6.4% at full load condition, the load characteristics showed the methanol consumption was reduced by about 2% and the thermal efficiency was increased by about 1% at speed of 2000r/min.The cold start behavior of methanol engine is a common problem, iso-pentane, gasoline, petroleum ether were added to the methanol respectively, the cold start test were carried out at different ambient temperatures fueled with methanol containing hydrocarbon additives. The results showed that, the engine successfully started within 4s at-20 ℃; petroleum ether has a better effect on improving the cold start performance of methanol engine.