AN ANALYTICAL EMPIRICAL-MODEL TO PREDICT HEAT-TRANSFER COEFFICIENTS IN CIRCULATING FLUIDIZED-BED COMBUSTORS

An analytical-empirical model was developed to predict local heat transfer coefficients in circulating fluidized bed (CFB) combustors. The fluid is considered to be composed of a dispersed phase and cluster of particles. Both convection and thermal radiation are taken into account. The estimation of the parameters in the model is discussed and suggestions as well as a sensitivity analysis are given. The model is applied to predict heat transfer coefficients on membrane walls of a CFB boiler for which an experimental investigation had been carried out previously. The predictions were in good agreement with experimental results.