バイオディーゼル燃料の燃焼特性に及ぼす脂肪酸メチルエステル組成の影響(熱工学,内燃機関,動力など)  [in Japanese] Influence of Fatty Acid Methyl Ester Composition on the Combustion Characteristics of Biodiesel Fuels(Thermal Engineering)  [in Japanese]

This paper investigates the performance, combustion characteristics, and emissions of a small single cylinder DI diesel engine with biodiesel fuels derived from unused rape oil, soybean oil, and palm oil. Compared with gas oil, all the BDF showed slightly higher brake thermal efficiencies and considerably reduced smoke densities while the NO_x emissions were somewhat higher. The rape oil BDF and Palm oil BDF used in the tests are mainly composed of Methyl Oleate (OME) and Methyl Palmitate (PME). Therefore, the combustion characteristics were examined using neat OME and OME-PME blends. As a result, the neat OME and OME-PME blends showed good ignitability and combustion stability like that of gas oil operation. To discuss the influence of PME addition on evaporation, ignition, and combustion characteristics, basic experiments with single droplets were also performed. The results showed that the ignition delay and combustion duration tend to decrease when PME is blended with OME.