EMISSION CONTROL AND PERFORMANCE CALIBRATION FOR BIOETHANOL BASED FUEL COMBUSTION IN SPARK IGNITION ENGINES UNDER IDLE AND LOW LOAD CONDITIONS

摘要

Fuel crisis over the past few decades encourages the use of alternative fuels, particularly forrntransportation. Bioethanol derived from edible sources have been widely used as a partial substitute to gasoline. In therndistillation process to separate bioethanol, a hydrous bioethanol has to be dehydrated at a cost to yield anhydrousrnethanol. Anhydrous ethanol is blended with gasoline in different proportions to fuel current gasoline engines, forrninstance, E85 (15% gasoline with 85% anhydrous ethanol). This work presents the effects of preheating anhydrousrnand hydrous E85 fuels on exhaust gas emissions, combustion characteristics and performance of a four-cylinder portrnfuel injection gasoline engine, calibrated for maximum brake torque timing and stoichiometric fuel-to-air equivalencernratio at low load condition. Additionally, the effects of minimizing fuel quantity injected to the combustion chamberrnof the engine running with hydrous bioethanol are revealed, under lean-burn idle conditions. The results suggest torncalibrate the engine for performance and emissions by adjusting ignition timing and injection duration, or adding fuelrnpreheating element for bioethanol based fuels.