A SIMULATOR-BASED TUNING OF SMITH-PREDICTOR IN A PILOT CFB BOILER

摘要

A simulator of the combustion process of a pilot-scale circulating fluidized bed (CFB) boiler has been utilized for control design purposes. The simulator was used to tune a delay-compensating controller, Smith-predictor, which was installed in an oxygen-content control system of the boiler. The Smith-predictor was extended with a filter, which improves the stability of the system against modeling errors. The tuning resulted in smaller fluctuation of the oxygen-content around the oxygen setpoint. Thus, it became possible to decrease excess air, and thereby to decrease the flue-gas emissions and increase the thermal efficiency of the boiler. Both simulation and experimental results of the pilot boiler are presented in this paper.