Preignition Oxidation Characteristics of Hydrocarbon Fuels

摘要

A research program to study the preignition oxidation characteristics of hydrocarbon fuels has been carried out. A static reactor test facility and gas chromatographic analysis techniques were used to assess the preignition oxidation chemistry by determining the stable reaction intermediates and products formed during the preignition process. Comprehensive studies were made of the oxidation of propane and propene at low and intermediate temperatures (550-750 K) and at subatmospheric pressures. The experimental results for each of these fuels demonstrated a clear transition in the oxidation chemistry from a low temperature regime to an intermediate temperature regime, separated by a region of negative temperature coefficient. The main characteristics and features of the oxidation mechanisms were determined for each fuel in each temperature regime. Increasing the vessel surface-to-volume ratio had the effect of enhancing heterogeneous termination, but did not affect the main reaction paths of the mechanism. The experimental results for propene were used to modify and extend the high temperature mechanism of Westbrook and Pitz to low and intermediate temperatures. Studies were also made of the preignition behavior of dodecane and binary mixtures of dodecane and the aromatic component tetraline. Addition to the tetralin to dodecane had the overall effect of decreasing the ignition tendency, although the magnitude of this effect was not proportional to the amount added. (Author)