Research Of Intelligent Control For Thermal Process Of Circulating Fluidized Bed Boiler

Circulating fluidized bed boiler is recognized as a most potential for development of clean coal combustion technology and is widely used in many countries for its advantages which traditional coal-fired boilers have not, such as strong coal adaptability, high combustion efficiency, good load regulation. However, the CFB combustion process is very complex which have non-linear, time-varying, big-lag, multi-variable and strong-coupled characteristics. it's difficult for the traditional control method to ensure the control of CFB boiler target requirements. This thesis propose an adaptive fuzzy control method based on BP neural network decoupling for typical thermodynamic processes and study the control system.Firstly, this thesis analyzes the working principle of CFB boiler, structure and characteristics. Base on the basis of identification at the scene, the CFB boiler thermal process mathematical model are given. According the parameters schematic diagram of CFB boiler, the CFB boiler combustion control system is divided into steam pressure control system, bed temperature control system, air feeding control system and furnace pressure control system. Then study the working principle of every control system and the working principle of stream temperature control system.Secondly, this thesis propose decoupling system based on BP neural network for the multi-variable and strong-coupled characteristics of CFB boiler combustion control system. This thesis design CFB boiler combustion process adaptive fuzzy control system base on the basic knowledge of fuzzy control and CFB control requirements. To give the coal amount cluster fusion control system as an example, we study the design of the adaptive fuzzy control system.Finally, from the research of CFB boiler stream temperature control system's simulation, demonstrate the good performance of the fuzzy controller. The main steam pressure and bed temperature are expected as the research object, simulation curves showed that the controller was proposed in this paper effectively overcome the boiler load change on the steam pressure and the effects of bed temperature, so that steam pressure and bed temperature maintained at comparatively steady state.