Energy and Exergy Analysis on Spark Ignition Engines under Varying Ignition Timing with Pure Bioethanol Fuel

Abstract

The first and second laws of thermodynamics analysis used to show the rate of energy and exergy as a performance of SI-PFI engine with the variation of fuel ignition between 10 and 26 BTDC (before top dead Centre) at interval 4 BTDC. The engine was performed on eight levels of speed in intervals 2000--8000 RPM (increment of 1000 RPM) with pure bioethanol fuel (E100) and 13:1 of compression ratio. The effect of fuel ignition on energy and exergy analysis of E100 fuel will be compared with E0 as reference fuel that performed in 11:1 of compression ratio and 10 BTDC. The results show that the maximum efficiency of energy and exergy for the E100 are 46.59 and 41.90 % at 18 BTDC and 6000 RPM. Meanwhile, the maximum efficiency of energy and exergy for E0 were 43.33 and 31.76 % at 5000 RPM. Moreover, the minimum BSFC for the E100 is 0.2867 kg/(kW•h) at 6000 RPM and 18 BTDC while for the E0 is 0.1960 kg/(kW•h) at 5000 RPM. These results indicate that E100 is more effectivein transferring heat into useful work although it is 30 % more wasteful than E0