Numerical comparative study on performance and emissions characteristics fueled with methanol, ethanol and methane in high compression spark ignition engine

Abstract

Methane, methanol and ethanol are three common high-octane alternative fuels. As fuels for high compression ratio engines, they can improve thermal efficiency while preventing knocking. However, each of these three fuels has its own physicochemical properties and presents different engine performance. This study compares in detail the performance, combustion and emissions of a high-compression-ratio SI engine fueled by methanol, ethanol and methanol. A 4-cylinder high compression ratio SI engine simulation model was built based on 1-D simulation platform. The engine was converted from a CI diesel engine with a CR of 17.5, and the methanol, ethanol of methane injector was installed in the intake port. The results showed that for the methanol, ethanol and methane fuels, under the same engine speeds and equivalence ratios, the BP and BT of methanol were higher than ethanol and methane fuels, methane has the lowest BP and BT; methane has a lower BSFC and BTE than methanol and ethanol, with methanol having the highest BSFC and BTE; the CO and NOx emissions of methanol were lower than ethanol and methane fuels; the HC and CO2 emissions of methane were lower than methanol and ethanol fuels.