Mathematical Model of Biomass Boiler for Control Purposes

This paper focuses on building dynamic mathematical model of biomass boiler of medium energy output (in units of MW) as a controlled system and the use of this model in practice. Model of controlled system will serve especially for research of new ways of industrial biomass boilers control and will provide a device for the optimisation of existing control systems. At first, area of automatic control of biomass boilers with medium energy output is described. Control of these boilers is with regard to their lowered dynamical properties considered problematic. Construction of the model is based on the heat and mass balance calculations made according to experimental data. These balance calculations serve to precise static properties of experimental unit for biomass combustion. Central part of the paper presents development of the final model that resulted from balance calculations and from analysis of step responses of the system obtained by measuring. Built dynamic model is compared with experimental data through simulations in Matlab/Simulink and verified. For validation of its applicability, the model of controlled system is completed with control system and closed-loop control circuit is validated by simulation. Then the design of new controller configuration, which improves the quality of control considerably, is presented. At the final part of the paper, possibilities of other use of the model are given, both in control theory and in industrial practice.