| The combustion behaviors of coal-char dust particles are studied analytically. Several mathematical models are developed to describe the burning behaviors of a single (nonporous) carbon particle, a single (porous) char particle, and a particle-suspension system. Numerical techniques for solving these dynamic models are presented and many representative results are given. In particular, the ignition and extinction phenomena of char particle combustion are examined via the thermal ignition theory of a chemically reactive system. The optical properties of char particles and the radiative heat transfer through a particle-suspension are also included in this study. The purpose of the current modeling efforts is to facilitate experimental studies, as well as to acquire a better understanding of the coal combustion processes in the hope that this abundant energy source can be efficiently and cleanly utilized. |
