Modelling of Heat Transfer in a Fluidized Bed Reactor Irradiated Indirectly by Concentrated Solar Energy

A two phases model of air heating in bubbling fluidized bed of sand particles with concentrated solar radiation as source of energy is developed. This model is based on the Kato and Wen's model (1969) for the hydrodynamic aspect which was modified to take account the thermic aspect. Nine algebraic equations were established in permanent regime for different heat and mass balances as well as heat losses against surrounding media. The Newton Raphson's method was used to solve this system of equations. Results have shown that the model developed is able to predict the temperature profiles of gas and particles in the bubble and emulsion phases, the wall temperature along the reactor, the heat flux transferred to the bed and heat losses by forced convection and radiation to surrounding air. The effects of the fluidizing air velocity, total mass of particles and the wind velocity on the thermal behaviours were examined. Model predictions seem reasonable looking for its comparison agreement with bibliographical data.