Cfd model of an industrial circulating fluidized bed boiler

Circulating Fluidized Bed (CFB) coal fired steam boilers, due to their low sensitivity to fuel quality, robustness and simple desulphurization become a competitive technology to the conventional Pulverized Coal (PC) units. Recent years have seen significant growth in the number of placed into service new CFB units. The aim of this paper is to develop and validate CFD simulation technique applied to large industrial CFB boilers. Despite their importance, the simulation techniques of large scale CFB boilers lags behind the needs of engineering community. The reason for this seems to the complexity of the physical and chemical phenomena taking place in the fluidized bed, specifically the hydrodynamic of the dense particular matter and multistage combustion. Moreover, even significantly simplified simulation models lead to prohibitive usage of computing resources. An additional difficulty encountered in the computational process is the poor convergence of the procedure. Thus, the contemporary designing process of large industrial CFB plants bases mainly on experience of the engineers rather than on in depth mathematical description of the process.