A STUDY ON IGNITION CRITERION OF A LARGE CARBON CHAR PARTICLE

During the study on the ignition process of large carbon/char particle s, we have made the discovery throught experiments and numerical simul ation, that the ignition of a large carbon/char particle, different fr om that of fine particle, has no sudden rising in temperature, thus th ere has no existence of the d(2)T/dt(2) = 0. Based on the characterist ics of the large carbon/char particle ignition process, this paper put s forward a new ignition criterion, according to which we set up ignit ion model of a large carbon/char particle and deduce its ignition expr ession identical with that of a fine carbon/char particle. It is prove d throught experiments that the generalized relationship between the i gnition temperature and coal properties deduced in the fine particle c arbon/char model is still suitable to use in the ignition of large car bon/char particles.