Combustion of “A/C” Blended Fuels by High Speed Diesel Engine

Abstract

The combustion of “A/C” blend fuels in a high speed, four-stroke, direct-injection engine have been investigated by using a high speed photo-system.
Three kinds of fuel (A heavy oil, 70% A heavy oil + 30% C heavy oil and 30% A heavy oil + 70% C heavy oil) were used. The combustion performance was measured in this experiment, also the influence of injection timing and of fuel temperature was discussed.
It is shown that the ignition lag of blend fuels mixed with 30% C heavy oil was almost the same as that of A heavy oil. In the range of tests, only small differences of ignition lag were found by heating the fuels.
Up for the 30% C heavy oil in blend fuel, the combustion phenomena showed almost the same as A heavy oil, but for 70% C heavy oil, the different combustion phenomena were observed in the growth of initial flame and termination of combustion in the cylinder.
With increasing the content of C heavy oil in blend fuels, the combustion efficiency and the concentration of NOx in exhaust gas decreased.
For the three kinds of fuel above, the combustion phenomena and combustion performance had the same tendency with changing of injection timing.