Experimental study of heat transfer in internal combustion engines using the ethanol-gasoline mixture

Abstract

In the present study, an estimate of the heat transfer in the exhaust system is carried out in a four-stroke internal combustion engine using different mixtures of ethanol and gasoline as fuel, modifying the ethanol concentration from 2 to 8%. The objective of this work is to quantify the percentage differences in the performance of the electric generator, firstly, the variables of electric current and voltage, by the electric generator, then, the thermodynamic variables such as the exhaust temperatures, both, of the gas and the wall, therefore, quantify its effect on the heat transferred to the outside. One-dimensional hypotheses have been adopted to determine heat transfer. The tests are carried out by modifying the degree of load of the generator unit. Results of the power unit performance, current and voltage, under different loads are shown. Moreover, the temperatures recorded under the different fuel concentrations are exposed. On the other hand, in the results obtained there are differences of up to 2.74 and 0.81% of current and voltage respectively in all the tests carried out. Also, differences of less than 4.91, 5.1 and 6.21% were observed in the temperatures of the exhaust gas, external exhaust wall and internal exhaust wall, respectively in all the tests and results obtained. Finally, a parametric study of heat transfer is presented, modifying the convection coefficient, where differences of up to 4.83% in the heat rate are observed with all concentrations of fuel ethanol-gasoline.