Consequences of varying compression ratio and ignition timing on engine fueled with E-MEBANOL

Abstract

Alcohols are oxygenated renewable fuels responsible for low carbon emission and high H/C ratio. In the present study, a blend of methanol, ethanol, and n-butanol in equal proportion by volume (E-MEBANOL) is tested as a sustainable fuel for SI engines under variable compression ratio (CR) and ignition timing (SOI). The performance of the engine is found to improve by increasing CR as well as advancing the SOI, as the brake power (BP), brake thermal efficiency (BTE), and volumetric efficiency are found to increase by increasing CR to 15 from 11 at an advanced SOI of 24°CA before top dead center (BTDC) from 16°CA BTDC by 17.54%, 17.47%, and 10.53% respectively. Similarly, combustion is also enhanced with increasing CR and advancing SOI as the peak cylinder pressure (Pmax), and maximum net heat release rate (NHRmax) are found to increase by 60% and 27.64%, respectively, while positions of these peaks are advanced by 17°CA and 18°CA respectively by increasing CR from 11 to 15 and SOI advanced to 24°CA BTDC. The flame development period (CA10) increases with advancing SOI and decreases with increasing CR, while the flame development period (CA10-90) and total combustion duration decrease with both increasing CR and advancing SOI. The CO & HC emissions improve with increasing CR and advancing SOI, while NOx increases drastically, but EGT decreases continuously.