DIESEL INJECTOR CARBONIZATION BY 3 ALTERNATIVE FUELS

Three alternative diesel fuels were screened by analysis of fuel injec tor tip deposits. The test engines were operated on the Peterson (torq ue) test cycle; the average carbon deposit volume on an injector tip w as measured by a computer vision method. Relative coke deposit quantit y was obtained by area analysis of injector tip images. Repetitive ima ge areas varied less than 1%. Coke deposit areas for repetitive fuel t ests also varied less than 1%. Injector coking tendencies of tested fu els decreased in the following order: peanut oil, no. 2 diesel, tricap rylin, and tributyrin/no. 2 diesel blend. The observed dependence of t he relative coke quantity on fuel type was consistent with the results from a photographic technique used previously for fuel screening.