Research On Combustion Control System Of Circulating Fluidized Bed Boiler

Circulating fluidized bed boiler(CFBB)is a rapid development of new coal-fired boilers in recent years,because of its high efficiency,low pollution,the benefits are more and more popular,the application development prospects are better.On the basis of modeling,this paper discusses the application of intelligent control theory in circulating fluidized bed boiler.Firstly,the combustion system is decoupled,and then the fuzzy PID adaptive Smith control method is used to optimize the decoupled system to solve the coupling and control problem of the combustion system.The experimental results show that the method has important theoretical significance and good Practical value.In this paper,the coupling of the combustion system is analyzed and studied,and the transfer function of the system is deduced according to the response curve of bed temperature and main steam pressure.The coupling degree of coal supply and primary air flow is calculated and analyzed,and the one-to-one correspondence relationship of each variable is established to realize single-input-to-single-output control.The cascade decoupling and feedforward decoupling algorithms are used to decouple the combustion system.The simulation results show that the feedforward decoupling effect is better than cascade decoupling.Then,according to the fuzzy controller,it has a precise mathematical model which does not need to be controlled.It is suitable for large time-delay nonlinear time-varying systems.The algorithm is simple and practical,and it meets the control requirements of the combustion system.And the adaptive Smith controller can be used Smith predictor to compensate the delay characteristics of the system,on the other hand can use the adaptive control in the control process to adjust the Smith predictor model parameters and the control object model to match,to improve the system control accuracy.The simulation results show that the fuzzy PID adaptive Smith control method satisfies the stability,real-time and fastness of the control.According to the characteristics of the circulating fluidized bed boiler,the hardware and software of ABB's distributed control system are used to form the real-time and efficient boiler control system,and the corresponding control strategy is given.At the same time,the communication network topology and the underlying data acquisition Circuit program,complete the control algorithm programming and host computer monitoring configuration programming.In this paper,the CFBB control technology has made some additions to the CFBB combustion control automation,and has made a useful exploration for the realization of CFBB automation.