Application of thermal ignition theory to determination of spontaneous ignition temperature limits of hydrocarbon-oxygen mixtures

Abstract

Measurements of temperature changes in decane-air mixtures near the critical boundary for spontaneous ignition indicate that, under conditions where heat transfer in the reacting gases takes place solely by conduction, temperature limits for ignition are in excellent agreement with predictions according to the conductive theory of thermal ignition. It is shown, however, that, by use of a derived relation between the dimensionless rate of heat release and the Rayleigh number, thermal ignition theory can be extended to the prediction of temperature limits under conditions where considerable convective heat transfer also takes place. Furthermore, the overall activation energy of the initial reactions involved in the oxidation of other alkanes has been shown to be a useful parameter for the prediction of the corresponding spontaneous ignition temperature limits.