DYNAMIC BEHAVIOR OF A PERFORATED-PLATE MULTISTAGE FLUIDIZED-BED HEAT-EXCHANGER

This study deals with the modeling and analysis of the transient behavior of a perforated-plate three-stage fluidized-bed heat exchanger devoted to hot-air cooling by a countercurrent flow of sand. First, an input-output model is developed; the 12 transfer functions linking the main inlets and outlets of the system (the thermal flows) are experimentally studied. Secondly, two different mechanistic models are presented: the first one, which is based on a RTD approach, shows little agreement with the thermal measurements. The second one, which includes fictitious plates at the top and bottom of the column so as to model end effects, allows the estimation of several physical parameters using nonlinear regression.