Cost Function Formulation and Realization Methods for Optimum Control of Fluidized Bed Combustors

The Fluidized Bed Combustion (FBC) technology differs basically from other combustor types, one example is the double role of air flow: combustion and fluidization. Because of such differences, the well proven classical combustion control methods can not be used effectively for FBCs. In this paper, the task of combustion control will be formulated by means of a cost function. A general form of this function will be proposed, the exponential terms of which define sufficiently the optimal operating point within the twodimensional space spanned by the two air flows. The parameters of these terms should be set according to the actual local circumstances such as supplier prescriptions and financial ambiance. Several ways of realization can be outlined for finding the minimum of the cost function, two of which will be discussed in detail. These structures were programmed and tested, throughout which tests, a verified programmed model of an industrial CFBC unit was used. The test runs of both control strategies pointed out their proper operations.