Evaluation of the Energy Balance of a Gasoline Engine Using Ethanol and n-Butanol as Additives

Energy supply is one of the most important current issues in the world. The most uses of fossil fuels are for providing power to internal combustion engines. The increase in the global price of fossil fuels and the environmental concerns have made researchers to look for alternate sources of energies, such as biofuels. The main disadvantage of biofuels is their low heating values. However, they can be used as gasoline additives. The aim of this study was to evaluate the energy balance of a four-cylinder gasoline engine with ethanol and n-butanol alcohols in different volume percentages at three different engine speed of 1000, 1500, 2000 rpm. The results showed that the engine brake power increased in fuel blends that contain bio-alcohols compared to pure gasoline fuel. Also, by increasing the engine speed, the engine brake power of the fuel blends increased so that at 2000 rpm, the G70E15B15 fuel blend had the highest brake power of 47.1 kW. Also, the exhaust heat loss in fuel blends containing ethanol and n-butanol increased compared to pure gasoline, and also increased with the increase in engine speed. The lowest exhaust heat loss of 3.98 kW related to pure gasoline at 1000 rpm and the highest exhaust heat loss of 6.38 kW for G70E15B15 fuel blend at 2000 rpm were obtained. Pure gasoline fuel had lower heat loss of cooling system than other fuel blends. Heat loss of cooling system decreased with increasing speed from 1000 to 2000 rpm. Therefore, the G70E15B15 fuel blend with 11.01 kW and pure gasoline with 2.89 kW had the highest and lowest heat loss of cooling system, respectively.