POWER PERFORMANCE AND FUEL CONSUMPTION OF A SPARK IGNITION ENGINE USING DIFFERENT BLENDS OF ETHANOL GASOLINE

Abstract

The Philippine Government Alternative Fuel Program now mandates a 10% bioethanol blend for commercial gasolines sold at the pumps. Numerous laboratory studies of different kinds of bioethanol in different countries exist but none yet in the Philippines, specifically, in vehicle use. A research was conduct ed at the UPME Vehicle Research and Testing Laboratory (VRTL) to investigate experimentally the effects on engine’s power performance and specific fuel consumption (SFC) of E5 (5% ethanol), E10 (10%), E12.5 (12.5%), E15 (15%), E20 (20%), E25 (25%) and E30 (30%) ethanol gasoline blends by volume as compared to neat gasoline (E0). The vehicle was driven in road load simulation at standard Japanese driving
cycle while measuring fuel consumption and power developed. Each blend test passed three trials using the AVL Chassis Dynamometer equipped with fuel mass flow meter with temperature control. Test showed positive correlation between mass specific fuel consumption (MSFC) and ethanol amount in the fuel mixture. From 44.68 g/km at E0, it raised continuously to 45 .58g/km(E5), 45.79g/km(E10), 45.89g/km(E12.5), 46.11g/km(E15), 46.33g/km(E20), 46.71(E25) and 49.14g/km(E30). Lower energy content of ethanol gasoline fuel caused an increase in the engine’s MCSF or a decrease in mileage in all blended fuels. However, the energy specific fuel consumption (ESFC) gives a better picture of the efficiency on fuel conversion. There was an improved maximum power obtained for E5, E12.5, E20 and E25 of about 1.9%, 0.55%, 1.64% and 3.4% respectively, while E10 and E15 decreased in o utputs by 0.78% and 0.32% respectively. These blends show relatively comparable output to neat gasoline due to oxygen content of ethanol outweighing lower heating value. E30 showed the biggest reduction at 3.43% lower than neat gasoline. In general, during the experiment, no significant problem was encountered in the engine performance. This means that all blends tested were suitable to the vehicle