Emission Characteristics of Diesel Engine Fueled with Ethanol-diesel Blends in Different Altitude Regions

In order to investigate the effects ethanol-diesel blends and altitude on the emissions of diesel engine, the comparative experiments were carried out on the bench of turbo-charged diesel engine fueled with pure diesel (as prototype) and ethanol-diesel blends (E10, E15, E20 and E30) under different atmospheric pressures (81kPa, 90kPa and 100kPa). The experimental results indicate that all the parameters of emissions during 90~100kPa are superior to those of 81~90kPa. At 81kPa, both HC and CO emissions rise greatly with the increasing engine speeds and loads and addition of ethanol, while at 90kPa and 100kPa the effects of engine speeds and loads and usage of ethanol on HC and CO emissions are slightest. The changes of atmospheric pressure and mix proportion of ethanol have no obvious effect on NO_x emissions and NO_x emissions of ethanol-diesel blends have a slight drop in a small scale compared with prototype under most engine conditions.