Modelling and simulation of transient coal combustion processes in fixed and moving grates

A time dependent mathematical model and a computer program have been developed to simulate coal combustion on moving and fixed grates. The physical models for both, the combustion of a single coal particle and the combustion of continues bed of coal, have allowed a better approach to reality. The partial differential equations of the model are solved using implicit collocation and relaxation techniques, with finite differences for time advance. The program MTCC can predict several important parameters that describe the coal combustion processes in fixed and moving grates, such as composition, heat of reaction and temperature profiles for gaseous and solid phases, in the bed and the particle's interior. In addition, the program can simulate non-isothermal particles with the exposed core and non-reactive core models. The basic structure of the model includes a system of six differential equations which represent the mass and energy balances for all phases at any point along the bed.