Under the background of dual⁃carbon target，the circulating fluidized bed combustion technology，as an im⁃ portant part of coal⁃fired power generation，realizes an efficient and clean utilization of inferior fuel and is also a main force to participate in deep peak regulation of power grid in the future. However，CFB boilers still have a lot of room for improvement in load regulation rate，NOx emission control at deep low and low loads，and heating surface wear. Therefore，the powdered coal circulating fluidized bed (PC-CFB) combustion technology is proposed. By reducing the fuel particle size from the wide sieve distribution of 0 - 10 mm to a narrow sieve distribution of 0 - 1 mm， a sufficiently high circulating flow rate can be achieved at a low bed stock. Regulating chemical reactions through flow regimes，the reducing atmosphere needed for low⁃NOx combustion is strengthened，and the residence time of fine lime⁃ stone in the furnace is extended，the combustion performance of the boiler can also be improved. More importantly，the rate of change in chemical reaction，i.e. heat release，increases due to the decrease of fuel particle size. Supplemented by cyclic interventions that can increase the rate of change in heat transfer rate，the combination of which can im⁃ prove the rate of load regulation. The change of fuel particle size inevitably leads to the reduction of bed particle size， and significantly improves the deep low load capability and the in⁃furnace control of NOx emissions at low loads. This idea is confirmed by the modelling prediction， which shows that when the range of fuel particle size is reduced from the conventional size distribution to 0-1 mm，the average bed particle size decreases greatly and the material con⁃ centration in the dilute phase zone increases，and the circulating flow rate increases by about 27%. The reducing at⁃ mosphere in the furnace is enhanced，and the original emission concentration of NOx is reduced by about 35%. The im⁃ proved performance of the circulation system can prolong the residence time of fine limestone in the furnace，im⁃ prove the efficiency of desulfurization reaction，and reduce the original SO2 emission concentration under the same con⁃ ditions of calcium⁃sulfur ratio and NOx emission. Meanwhile， the combustion efficiency is significantly improved，the carbon content of bottom slag is reduced by 89%，and the heat loss of incomplete solid combustion is re⁃ duced by 52%，indicating that PC-CFB combustion technology has more advantages in enhancing the operational flexi⁃ bility of CFB boilers，strengthening the low⁃NOx combustion，and improving the combustion performance.

1 CFB燃烧技术现状分析

   1.1 运行灵活性

   1.2 深度低负荷NOx排放控制

   1.3 可靠性问题

2 PC-CFB燃烧技术

   2.1 定态设计理论

   2.2 PC-CFB燃烧技术原理

3 PC-CFB锅炉运行性能模型预测

   3.1 CFB模型及验证

   3.2 燃料粒度对锅炉物料循环特性的影响

   3.3 燃料粒度对污染物排放的影响

   3.4 燃料粒度对锅炉燃烧特性的影响

4 结论