Abstract :
The concept that 100% vegetable oil cannot be used safely in a directinjection
diesel engine for long periods of time has been stressed by many
researchers. Short-term engine tests indicate good potentialfor vegetable oil
fuels. Long-term endurance tests may show serious problems in injector
coking, ring sticking, gumformation, and thickening of lubricating oil. These
problems are related to the high viscosity and non volatility of vegetable oils,
which cause inadequate fuel atomization and incomplete combustion. Fuel
blending is one method of reducing viscosity. This paper presents the results
of an engine test on three fuel blends. Test runs were also made on neat
rapeseed oil and diesel fuel as bases for comparison. There were no significant
problems with engine operation using these alternative fuels. The test
results showed increases in brake thermal efficiency as the amount of rapeseed
oil in the blends increases. Reduction of power-output was also noted
with increased amount of rapeseed oil in the blends. Test results include data
on performance and gaseous emissions. Crankcase oil analyses showed a
reduction in viscosity. Friction power was noted to increase as the amount of
diesel fuel in the blend increases. Copyright
