The Circulating Fluidized Bed Boiler Combustion System Modeling And Predictive Control Simulation Study

Circulating fluidized bed boiler is a new type of boiler, and the application of fluidized bed combustion technology makes fuels burn more effectively. Compared with traditional coal-fired boiler, it has more advantages in environmental protection and energy saving. With the wider application of circulating fluidized bed boiler, there has been more and more study on modeling and controlling.This design is based on the analysis of practically running parameters data of circulating fluidized bed boiler in a factory in Yunnan. By taking the three-input three-output system in which coal feeder rotating speed and first air flow and secondary air flow are the input and principal steam pressure and bed layer temperature and temperature in combustion chamber are the output as the research object, modeling and controlling of it are formed.Modeling is based on partial least squares regression model. Partial least squares regression is a regression method that the statistician proposed through combining the thoughts of the principal component analysis and canonical correlation analysis with multiple linear regressions. It can overcome mutual negative influences between variables to a large extent and give the mathematics expressions of the model. The control algorithm of basic application is generalized predictive control direct algorithm. The predictive control has been developed in many process industries in the1970's. The general predictive control is one of the three classical algorithms and combined with the thought of the adaptive algorithm. Generalized predictive control direct algorithm avoids the equation solution of Diophantin and adaptively controls parameters and corresponds with result of real-time rendering.This paper briefly introduces the research background and gives the derivation of modeling and control algorithms and author's comprehension. The working in this paper is completed with matlab simulation. The system has been simulated and can meet the control requirements. Though there has been a certain gap while being compared with applying into practice, the author gives an attempt to the control of circulating fluidized bed boiler, hoping to guide and give some advice to the practice.