The low load characteristic and energy-saving optimizing control of large capacity power plant

The variable load operation of the large capacity power plant and the variable working condition calculation of thermodynamic system are important subject for research in thermodynamic engineering field all the time. When the current operation point of the power plant is far away from the rated mode, it is very important to analyze the thermo-economy of thermodynamic system and offer appropriate operation guidance in engineering practices. Based on the steam turbine's variable working condition theory, this paper reveals the inherent characteristic of power plant under off-design condition. From the viewpoint of systematic engineering, according with thermodynamic system topological structure and system thermodynamic properties, the state model of thermo-economy has been studied and set up. Combining the optimization theory and the analytic equation of the heat consumption rate, the optimum operational main steam pressure setpoint has been offered to advanced control strategy. Thus the further intellectual optimum control can be put into practice, and the unit can meet the demand for safe and economical operation within the wider range of load.