Modeling and simulation for boiler combustion control system of 1000MW ultra-supercritical unit

Abstract

Taking the 1000MW ultra-supercritical once-through boiler as a research object, the combustion process of boiler is analyzed through principles of energy transferring, heat exchange, and mass flow balances. Since the complete and accurate model of boiler combustion is the basis of performance study and optimizing control, a mechanism mathematical model of boiler combustion control system is built up in this paper. It is the first time that boiler combustion control system has successfully covered the coal mill pulverizing system, and this model consists of the other three controlled variables subsystems: main steam pressure control system, furnace pressure control system and flue gas oxygen content control system. Furthermore, this paper gives the simulation of the mechanism mathematical model and analyzes the response curves of the outputs after giving each input a step disturbance respectively at two different load conditions. The results of the simulation show that the mathematical model is reasonable and effective.