Opportunities of the Fluidized Bed Technology in the Development of Stirling Engines

The opportunities offered by the coupling of Stirling engine with fluidized bed combustion, by placing the heater of the SE directly immerged in the fluidized bed, are discussed in this work. It is illustrated as the resulting system could represent a possible way to raise the application of Stirling engines for micro-CHP generators based on biomass. Some experimental evidences are firstly illustrated, then, with the help of simple models, the main effects on the SE configuration and performances are described. The increase of heat transfer coefficients between the heat source and the hot side working fluid is found to be of primary importance. The homogeneous distribution of the heat flux, the temperature of the heat source, the potential for the reduction of dead volumes are some beneficial consequences with several implications on the design of the engine. All these properties can be exploited to increase the overall efficiency of the coupled system. Expectance gained from experimental investigations, technological experiences and modeling results will be confronted.