ABSTRACT
During the study on the ignition process of large carbon/char particles, we have made the discovery throught experiments and numerical simulation, that the ignition of a large carbon/char particle, different from that of fine particle, has no sudden rising in temperature, thus there has no existence of the d2 T/dt 2 = 0. Based on the characteristics of the large carbon/char particle ignition process, this paper puts forward a new ignition criterion, according to which we set up ignition model of a large carbon/char particle and deduce its ignition expression identical with that of a fine carbon/char particle. It is proved throught experiments that the generalized relationship between the ignition temperature and coal properties deduced in the line particle carbon/char model is still suitable to use in the ignition of large carbon/char particles.
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