Research For The Superheated Steam Temperatuer Control System Of The Subcritical Pressure Boiler

Power plant boiler superheated steam temperature of power plant operation is a very important parameter, Temperature will directly affect the safety and economy of the turbine. As a result of superheater not only has large time lag, nonlinear, time-varying, multi-variable characters, it also has the characteristics of self balance ability, decided to raise the superheat steam temperature control of thermal process control quality, is an important research topic in the field of thermal process control. In this paper, the controlled object the characteristic analysis of superheater,a more detailed description of the superheated steam system of static and dynamic characteristics.In addition, joined in the flue gas, steam disturbance and increase the feedforward signal, on the superheated steam temperature cascade control system simulation, points out that the control process of the mathematical model of the object change, so it has some limitations. In order to solve the problem, put forward to superheated steam temperature of thermal power station,using the cascade PID control and fuzzy control strategy. Its main purpose is to make the cascade PID control and fuzzy control, the advantages of combination of complementary, exploration to further improve the temperature control is an effective way of quality. The fuzzy control is introduced to normal PID control scheme. According to the L.A.Zaden fuzzy reasoning algorithm and data above to derive fuzzy control table, after the completion of the above work offline, putting the fuzzy control table into DCS system, and in the operation unit to be debugged, the ideal effected. The simulation results show that the controlled object, as a superheater, joined in the flue gas, steam disturbance and change the object’s mathematical model of heat exchanger, the superheated steam temperature cascade fuzzy control system is not dependent on the mathematical model of controlled object, control over the quality of the cascade PID control system, which is conducive to the power plant safety, economy, reliability, optimization and environmental protection requirements, has a broad application prospec...