Improving the load ramp-up capacity and efficiency of coal-fired power plants by optimizing the pulverizing system control strategy

It is imperative to enhance the flexibility of coal-fired power plants (CFPP) to facilitate the integration of renewable energy. However, the pulverizing system, serving as the energy source, has become a dominant constraint on the load ramp-up capability of CFPP due to the inherent inertia and delay. In this paper, a dynamic simulation model of CFPP coupled with the pulverizing system was established. Through the implementation of the soft-sensing mechanism model for the pulverizer, real-time computation and accurate regulation of pulverized coal output are realized. A revised fuel control strategy, considering the evolution of the thermal system heat storage and the coordination between the main unit and auxiliaries to match the load, was conducted. The cumulative output deviation can be decreased by 216 kg, corresponding to a 16.2 % reduction. The load cycling rate was improved from 1.5 % to 2.5 % Pe min−1. The real-time and accumulation relative deviations of live steam temperature were reduced by up to 66.0 % and 56.7 %, respectively. Moreover, the performance of the pulverizing system with different operational modes was compared and analyzed. Maintaining four out of six mills in operation demonstrated superior performance, reducing the specific energy consumption of pulverizing by over 16.5 % and lowering the average standard coal consumption rate by 1.11 g kW−1 h−1.