In thiswork, the mass balance model for the circulating fluidized bed
takes into account the following physical processes (i.e. attrition, segregation,
fragmentation, coagulation) and chemical processes (i.e. fuel
combustion) that usually occur in the CFB boiler. The parameters used
in the mass balance model were optimized from the field test data
under full load operation. In this paper, the concept of mass balance
modeling at steady-state operation of the boiler was applied. This
approach allows to study the sensitivity of state variables due to the
character of the particle size distribution,which is not possible to obtain
in the classical models based on average balance sheet values of state
variables. The model allowed to simulate the steady state operation
for a supercritical CFB boiler. Therefore, there was a feasible diagnostics
of CFB boiler in a large-scale. The energy balance during combustion is
not considered in this paper.