Influência da adição de etanol anidro no desempenho da combustão da gasolina

Abstract

The present study conducted an evaluation of an internal combustion engine of the Otto cycle, which operates with blends of Gasoline C and Anhydrous Ethanol in proportions of E27, E40, E60, E85, and E100. Important characteristics of the combustion that occurs inside the engine cylinder and design factors that influence the engine's performance and efficiency were addressed. To carry out the experimental tests, the single-cylinder Ricardo Protheus research engine was used, which was adapted to operate in the Otto cycle and instrumented in a way that allows for the obtainment of precise and detailed data on the combustion characteristics and engine performance. The tests were carried out by keeping the ignition advance fixed at 14° APMS, and the engine rotation speed was set at 1400 revolutions per minute, with the fuel mixture maintained at stoichiometric lambda. The results obtained allow for a more detailed description of the combustion of these blends, identifying that combustion is influenced by several factors, mainly by the fuel mixture. It was observed that ethanol requires a higher ignition advance than gasoline to ensure arrival at MBT, and fuel consumption was shown to be very unfavorable for operations in which the fuel blends had a higher ethanol concentration. A possible cause of ethanol's low performance could be the effects of mixture formation, which could have created a fuel film on the intake manifold wall. The cylinder temperature at the time of ignition was the best parameter to verify this phenomenon.