The Design And Application Of Adaptive Fuel Caloricity Calibration

The coordinated control system is the link between the power grid and the thermal power unit.It is also the core control system for the nor mal operation of the thermal power unit,and directly affects the safety and economy of the unit and the power grid.But the growing shortage of primary energy has a great impact on the power generation industry.The coal quality of the burning coal in man y power plants can not be guaranteed owing to the tension of electric coal and the rise of coal price.The core of real time change of coal quality is the change of fuel caloricity,which will directly lead to the change of control system gain and control quality.Therefore,the correction of fuel caloricity is one of the urgent problems to be solved in power plants.The conventional correction method of fuel caloricity is based on the static model of the unit.When the load changes,the correction circuit of caloricity is in the state of tracking,and it is difficult to achieve the real-time correction of the fuel caloricity.In this paper,according to the characteristics of the coordinated control system,the actual time correction method of fuel caloricity is studied.The main research contents include:(1)Based on the characteristics of the coordinated control system,the CARMA model of the unit load with the amount of coal supply and the change of the opening degree of the steam turbine valve is given.The CARMA model of the unit load is identified by using the least square method of fading memory.The caloricity coefficient of the unit is obtained by using the identified parameters through the function of caloricity calculation of the fuel.(2)The basic principle and characteristics of BP neural network are analyzed in depth,and the improved algorithm of BP network based on reducing network sensitivity is selected.and the neural network model of correction coefficient of fuel value is established.The simulation results show that the model has a good fitting effect and provides a basis for the design of subsequent fuel caloricity correction.(3)Based on the fuel caloricity coefficient,a coordinated control system optimization scheme is designed.The fuel caloricity correction part is added to the coordinated control system in order to correct the combustion rate control instruction of the power plant boiler turbine coordination system in time.