A Study on Ignition Criterion of a Large Carbon/Char Particle

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.

Key Words:

• Ignition
• large carbon/char particle