Application of a spray desuperheating control strategy on 1000MW ultra supercritical thermal power unit

Boiler steam temperature controlled object has characteristic of full scope nonlinear and time-variable, taking more dificult to design of control systems. The paper takes time-variant, great-inertia and nonlinear controlled object as study backgroun. Combine with ultra supercritical boiler characteristics, analyze the change mechanism of main steam temperature of superheater outlet. Based on the improved Smith predictor, the spray desuperheating control system is presented. Combined with a 1000MW ultra supercritical boiler, the design points of the control strategy is given. Practice has proved, this system can effectively solve the ultra supercritical units of large delay and large inertia, improve the dynamic quality of control for main steam temperature, and reduce the difficulty of commissioning.