Comparison the Rate of Energy Consumption between Gasoline95 and LPG in Spark Ignition Engine under Real Driving Conditions

摘要

The use of Gasoline95 and liquefied petroleum gas (LPG) as an alternative fuel in spark ignition engines under driving at constant speed showed the best fuel consumption was driving at an average speed of 100 km/hr. The result from the tested vehicle consumed an average energy of 2.27 MJ/km and 1.96 MJ/km of Gasoline95 and LPG respectively. The difference of the energy consumption was the properties of LPG that had the rate of flame speed faster than Gasoline95. Moreover, LPG was injected in the gas phase which resulted in a good mixture preparation. Therefore, a high pressure was generated in the combustion chamber and gave more output energy than Gasoline95 under part load. However, the low heating value (LHV) of LPG had an effect on acceleration test. The Gasoline95 allowed the vehicle accelerated from 0 to 120 km/hr within 24.5 seconds which was faster than the acceleration speed of LPG 1.2 seconds under full throttle position. The reason was the stoichiometric ratio of Gasoline95 allowed more fuel to be injected into the combustion chamber under full throttle position than the LPG. The research proved that the use of LPG as an alternative had fast flame speed and good mixture preparation as a benefit over Gasoline95.