MODELING OF KRAFT RECOVERY BOILERS

The subject of this work is the modeling of recovery boilers. A three- dimensional, steady-state computer simulation of the flow and combusti on process in a recovery boiler is presented here. The numerical algor ithm of the original code was modified and extended to cater for certa in special aspects of recovery boilers, such as the in-flight combusti on of black liquor droplets and char bed burning. To represent the fin e structure of numerous air ports, a higher level of grid topology tha n in the conventional, structured grid system is required. In this wor k, a highly flexible, unstructured and mixed cell topology grid with l ocal mesh refinement was employed. A number of computations were carri ed out using various firing arrangements including the ROTAFIRE system . The results show considerable potential and reliability in the use o f computer simulations for the improvements and optimization of recove ry boilers. (C) 1997 Elsevier Science Ltd.