Cfb Boiler Superheated Steam Temperature Based On The Theory Of Fuzzy Decoupling Control Method Of Research

CFB boiler is a new product of environmental combustion in modern time, In modern large power plants, in order to improve fuel efficiency、thermal efficiency and adapt to the burning of kinds of coal, a part of them using circulating fluidized bed combustion. Increase in the length of the pipe caused by the large-scale, there are some difficulties about the design of control system of CFB boiler, conventional PID control system is difficult to complete the requirements of the nonlinear and coupled, multi-parameter, and achieve rapid, accuracy, stability results. In years of research and application, The new control system for the control of CFB boiler is imminent.Fuzzy decoupling control is an effective means of control for multi-parameter, nonlinear and coupling parameters, by eliminating the need to establish a precise mathematical model to implement the control, mainly for the fuzzy rules and the decoupling of coupling parameter, to lift the coupling under some kinds of disturbance. Because of nonlinear, strong coupling and multi-parameter characteristics of each object in the CFB boiler control system, fuzzy control applied to CFB boiler superheated steam temperature control can help to better enhance its quality, decoupling principle can help to format an independent input and output channels, the combination of fuzzy control theory and decoupling principle is an effective means of CFB boiler superheated steam temperature control.After fuzzification of CFB boiler superheated steam temperature control system, the decoupling method also must be fuzzified, another, using fuzzy controller as a decoupling compensator, fuzzy PID controller as the steam temperature controler, forming a double fuzzy control system of fuzzy decoupling-fuzzy PID control of the CFB boiler superheated steam temperature。 According the coupling of superheated steam temperature and primary air flow, solve the relative gain to determine the degree of coupling.This paper selected a300MW china-made circulating fluidized bed boiler superheated steam temperature control parameters as the simulation study, secondary air flow and the amount of fuel as disturbance, the superheated steam temperature and oxygen content in flue gas as outputing. Using fuzzy decoupling and fuzzy PID control can have a double fuzzy structure, analysising coupling relationship between superheated steam temperature and oxygen content in flue gas at the disturbance interference hereinafter, then giving a research about the control system, chosing the best CFB boile superheated steam temperature control system. By the simulation study, the double fuzzy control of fuzzy PID and fuzzy decoupling effectively solve the difficults to eliminate the shortcomings of the conventional PID, better reflects its superiority.