Research On The Main Steam Control System Of Once-through Boiler

Thermoelectricity power generation is the main force in the development of modern society.With the continuous progress of modern science and technology,the capacity and parameter of power unit has increased,and the system becomes more complex.Moreover under the background of building a harmonious society and developing circular economy,there are some new requirements has been put forword to improve the level of automation of thermal power plants and the economic operation of the unit.Boiler steam control system is one of the important systems in the process of thermal power plant production.Steam parameters directly affects the safe,reliable production and economic operation of the whole system.And the main steam temperature is the main control parameters.So it is particularly urgent to improve the level of its automation control and optimize its control strategy.Taking the main steam temperature as the research object and according to the large delay,large inertia,time-varying and nonlinear properties of main steam temperature,the main steam temperature control system is designed and the simulation experiments is completed in this article.The main research work is as follows:(1)The influence of main steam temperature on system and the dynamic characteristics and static characteristics of the main steam temperature is analyzed in this paper.In addition the main steam temperature control strategy based on the cascade of water spray cooling control is expounded in detail.(2)Based on the study of fuzzy control and PID algorithm and according to that the fuzzy control system does not depend on the characteristics of the precise mathematical model of the controlled system,the fuzzy PID control system of main steam temperature is designed,which replace the conventional PID controller withfuzzy PID controller as the main regulator of cascade control system.And its working principle and realization process is studied.(3)Combining fuzzy system with neural network,the fuzzy logic technology is put into the neural network.So that the control system reflect the expert knowledge of the language rules and neural network self-learning ability at the same time.The main steam temperature control system which based on the fuzzy-neural network is designed.And its working principle and realization process is studied.(4)Simulation experiment.The results turned out that replace PID control with fuzzy PID control can improve adjustment quality of the main steam temperature.While the main steam temperature control system based on fuzzy neural network is more efficient.