Numerical simulation of the combustion characteristics and NOx generation of a 660 MW pulverized coal boiler

Abstract

Coal-fired power plants play a vital role in China's power generation market, and the design, operation, and retrofitting of the boilers depend heavily on the deep insight into the multiphase flow, heat and mass transfer, and combustion. This study investigated the combustion characteristics and NOx generation of a realistic 660 MW four-corner tangential firing boiler by computational fluid dynamics. Specific sub-models were reasonably integrated into the simulation framework to represent the important sub-processes. By comparing with the experimental measurements, the simulation results were rationally validated. In detail, the gas temperature at specific sites (h = 52.4 m) and the NOx concentration at the boiler outlet were analyzed and compared. Subsequently, the distribution of the gas velocity and temperature and also some important species (O₂ and CO) was evaluated to assess the combustion characteristics. Finally, the NOx distribution was presented and its generation was analyzed based on the coal combustion process.