Improving the Ramp Rate of Thermal Power Units Based on Deep Utilization of Coal Powder in Milling Systems

Improving the ramp rate of thermal power units is an important way to solve the problem of large-scale consumption of new energy in China. The deep utilization of the coal powder in the milling system is one of the methods to accelerate the response rate of the boiler, thereby improving the ramp rate of thermal power units. Based on the analysis of the working principle and characteristics of a milling system, this paper considers the effect of primary air flow on the dynamics of the milling system, improves the simplest model of the milling system, and introduces the improved model into a drum boiler unit model. Based on the model, a new control strategy is designed based on the deep utilization of the coal powder in the milling system. This strategy is based on the predictive control algorithm and combines the traditional feedforward and decoupling control concept. More importantly, the dynamic compensation of the primary air flow is used to achieve the deep utilization of the coal powder in the milling system, thus rapidly changing the amount of coal powder entering the boiler. Simulation results show that the strategy can better ensure the rapidity and stability of the thermal power unit when the load is changed.