1986 Volume 48 Issue 1 Pages 15-23
When sunflower oil (or plant oil, in general) was used for diesel engine fuel, the ignitability under low temperature condition was much poorer than for No. 2 diesel oil. In addition, unburned carbon was accumulated in the combustion chamer when the engine was operated under idling operation. The research reported in this paper was conducted to investigate the causes of these problems.
A single fuel droplet set at the tip of a combustion thread was inserted into an electric furnace and ignited. The behavior of the combustion was observed and analyzed by a rotary video camera. The fuels tested were sunflower oil, No. 2 diesel oil, sunflower methyl ester and fish oil methyl ester.
As a result, even if the droplet size of sunflower oil was the same as that of No. 2 diesel oil, its ignition delay was much longer than No. 2 diesel oil. This may be the main cause of poor ignitability of sunflower oil under low temperature condition.
When the temperature in the electric furnace was low, sunflower oil did not ignite but formed a cenosphere (a net structure). This seemed to be the cause of carbon deposits during idle running.
