Wall average heat transfer in CFB boilers

The purpose of this work is to find a correlation for heat transfer to wall s in circulating fluidized bed (CFB) boilers. Heat transfer and suspension density data from six boilers in the range from 12 to 300 MWth, form the ba sis of the correlation. The data were averaged over the entire height of th e heat-receiving wall to facilitate application to boilers. Averaging also reduces uncertainties in the measured data. The correlation of heat transfe r coefficient (HTC) and average suspension density represents the measured heat transfer coefficients within 15%. An attempt to separate radiation and convection was made in order to account for variations in wall and bed tem peratures. The improvement due to the separate treatment is not significant compared to the uncertainty in the experimental data, but the influence of temperature on the heat transfer coefficient is explicitly represented. (C ) 2001 Elsevier Science B.V. All rights reserved.