Análise do atraso de ignição e da fração de combustível queimada na combustão pré-misturada utilizando-se misturas biodiesel-diesel

Abstract

The impact on ignition delays and combustion characteristics of biodiesel into diesel blends derived from soy oil, castor oil and bovine tallow were conducted on this paper. The ignition delay was found by using experimental data of derived pressure and injection pump pressure. The combustion was analyzed by the fuel fraction burnt on pre-mixed combustion phase employing experimental data of heat release rate together with the method of a single Wiebe function. Experimental data was measured in dynamometric test under three different loads conducted on a medium size turbocharged diesel engine. The tested fuels were B20 blends of biodiesel and mineral diesel. The results indicate that biodiesel blends show shorter ignition delays due to its higher cetane number, being bovine tallow the shortest one. The values of fuel fraction burnt for B20 were lower than those for mineral diesel, castor being an exception. The unlike behavior of castor could be explained by its longer spray penetration.