Abstract: Aiming at the problems of high bed temper-ature and large concentration of NOx emission in a 200MW circulating fluidized bed boiler,the boiler is studied in this paper:the experimental analysis is carried out re-spectively from adjustment of fluidizing air volume, running oxygen rate, ratio of up and down secondary air and bed pressure.The experimental results show that with the in-crease of fluidizing air, the bed temperature and NOx emis-sion increased significantly;With the increase of running oxy-gen,bed temperature decreased significantly, NOx emissions increased significantly;Properly reducing the bed pressure and closing the opening of the lower secondary air register can effectively reduce the bed temperature and inhibit the formation of NOx.Through a variety of combustion adjust-ment means, the NOx emission concentration under three loads can be controlled below 240mg/m³.

Key words: CFB, bed temperature, reducing atmo? sphere, Nox