Study on control optimization of steel-ball mill coal pulverization system for flexible operation of thermal power plant
In order to solve the problems of the large fluctuation of the outlet air-powder temperature and the considerable deviation of the instantaneous coal mill output during the process of load cycling of the double-inlet and double-outlet steel ball mill system,several control strategies of considering the feedforward of hot primary air temperature and the optimization of coal level differential pressure setting value were proposed.The mechanism modeling and transient disturbance experiment research were carried out for one BBD4360 steel ball mill,and the models of the critical parameters,such as the coal level differential pressure and the outlet air-powder temperature,were established and verified.Based on the study of the dynamic model of the coal mill,the influence of the original and the optimized control strategies on the outlet air-powder temperature,the output of the coal mill,and the power consumption of the coal pulverizing system were obtained.The results show that the proposed control strategy can reduce the temperature deviation of the pulverized coal at the outlet by more than 2℃,reduce the cumulative deviation of the pulverized coal output of the pulverizing system by more than 50%,and reduce the average energy consumption of the pulverizing system by more than 5%,comprehensively improving the control effect of the critical parameters of the pulverizing system.The optimal control strategy of the ball mill pulverized system can effectively reduce the steam temperature and pressure deviations caused by the fuel supply during the peak shaving process and ensure the operational flexibility and efficiency of coal-fired generating units.
ball millcoal level controlfixed value optimizationoutput of pulverizing systemtransient energy saving