Numerical Simulation of Combustion Characteristics Analysis in a 660 MW W-Boiler Based on CFD-DPM

Numerical simulations of internal flow and combustion for 660 MW W‑boilers are performed using CFD‑DPM in this study to optimize combustion efficiency and reduce pollutant emissions. The k-ε model and discrete phase model are employed to characterize the gas-solid flow and pulverized coal combustion. The effects of different operating loads and secondary air incident angles on the flow and temperature fields, and NOx emission characteristics are analyzed. Results indicate that the boiler’s symmetric flow and temperature distributions are exhibited under design load. Stable combustion is ensured through a high-temperature zone in the lower furnace. The 30° incident angle achieves optimal air-coal mixing, maximizing combustion efficiency and minimizing CO emissions, while the 40° angle shows advantages in NOx reduction. NOx emissions are positively correlated with load. The emission of NO is 85.4% lower in the lower-load condition. This study provides a reliable theoretical basis for the operational optimization and low-nitrogen transformation of 660 MW W-boiler.