EXPERIMENTAL STUDIES OF HEAT TRANSFER IN A CIRCULATING FLUIDIZED BED BOILER

Heat transfer to the wall and fluid dynamics were studied in a ۱۲ MW circulating fluidized bed boiler and several types of measurements were carried out. Local heat transfer coefficients were measured with a calibrated conduction plug type of heat flow meter. The thermal boundary layer at the wall was investigated with a set of thermo- couples located at different distances from the fin and from the crest of an adjacent tube. The results indicate a thermal boundary layer thickness in the order of ۰.۰۶ m. The downward velocity of the particles near the wall was measured with a double thermocouple probe. It was found to be around ۱.۸ m٫s.