Research And Design Of The Automatic Control System Of Circulating Fluidized Bed Boiler

Circulating Fluidized Bed Boiler(CFBB or CFB Boiler) is becoming the main coal combustion technique all over the world for its attractive advantages of high combustion efficiency,efficient sulfur removal, low NOx emission, fuel flexibility and good load-following capability. To meet the need of its commercial development, higher demand of CFBB automation is proposed.At first, the paper introduces the structure and process of CFBB, then analyzes the coupling relationship of parameters and problems of control system. Focusing on complex dynamic characteristic involved in combustion process of CFBB, here proposes a "thermal-oxygen" double-cross combustion control method for the 35T/h CFBB based on multivariable frequency decoupling control theory, which can effectively solve such problems as coupling relationship of key parameters, influence of inner disturbance, and burning efficency, thus enhance continuous automatic control of the boiler system. As to steam-water system, fuzzy control methods for main steam temperature control and water level control are introduced. The simulation results indicate that these methods can improve the control characteristic of steam-water system.In the end, the computer monitoring system on the basis of distributed control system scheme is put forward, which can improve the real-time control and management level of the CFBB.