混烧煤粉对循环流化床机组爬坡性能的影响

To address the technical difficulties of slow load response in circulating fluidized bed (CFB) power units due to the presence of large amounts of inert bed material on the fuel side of the boiler, a CFB power unit primarily fueled by coal gangue was focused on. A dynamic simulation model of the power unit's thermal system was established and validated, obtaining performance of key thermodynamic parameters such as output power, main steam temperature, main steam pressure, bed temperature, boiler evaporation rate and cycle efficiency during the load ramp-up process. To improve the power unit's load ramp-up capability, an optimization scheme involving dynamic co-firing of pulverized coal in the upper part of the CFB furnace was proposed to mitigate the inertial effects of coal gangue combustion. Results show that at the load ramp-up rate of 3%/min, the optimization scheme reduces the maximum deviations of output power, main steam pressure, main steam temperature, reheat steam temperature and bed temperature to 1.31%, 0.81%, 2.3 K, 3.5 K and 27.8 K respectively, all within the specified range of the DL/T 657—2015 Code for Acceptance Test of Modulating Control System in Fossil Fuel Power Plant standard. With the optimization scheme, the maximum allowable load ramp-up rate of the CFB power unit increases from 2%/min to 3%/min, while slightly improving the power unit's thermal economy.