Design of a 0.3 MW Atmospheric Fluidized Bed Combustor with a Concentric Air Heat Exchanger

Abstract

ABSTRACT Heat transfer mathematical modeling is used to scale up an existing 44 kW Atmospheric Fluidized Bed Combustor (AFBC) to 0.3 MW capacity range. The fluidized bed relies on an external cooling air jacket to maintain bed temperatures instead of conventional in-bed transfer surfaces. The mathematical model of heat transfer is presented along with computer simulation results of the effect of fluidized bed diameter, cooling jacket air gap size, cooling air flow rates and temperature on the optimum number of combustion modules to achieve a 0.3 MW AFBC utilizing a concentric shell heat exchanger. Results indicate clustering four 20.3 cm diameter tubes could provide 0.3 MW while requiring only one-tenth the operating power of a single tube 40.6 cm diameter tube system.