CFD Modeling of Combustion Air Systems for Wood-Fired Boilers, 2001 Engineering / Finishing & Converting Conference Proceedings

A. R. Walsh--Considerable effort has been spent on developing CFD-based models of industrial boilers. Improvements in computer hardware, solution algorithms, fundamental data, and end-user acceptance has made CFD models practical for engineering evaluations of boilers. CFD-based models for hog fuel combustion have lagged behind those for other fuels such as coal or black liquor. However, the use of these models for wood-fired boilers has become more commonplace as air emission regulations have tightened, the need to dispose of sludges and non-condensable gases in these boilers has intensified, and the cost of fossil fuels has increased.

Case studies of wood-fired boilers show model predictions of CO burnout, flue gas temperatures, O2 distribution, flue gas velocities, particle carryover, and NO and SO2 profiles in the boiler. In cases where boiler air system modifications have been made, the results have supported the CFD model predictions. The desire to ensure that a wood-fired boiler upgrade will match expectations should drive the continued application and development of CFD-based models.