Research on High-Temperature Air Combustion of Pulverized Coal Boiler

The process of the combustion and heat transfer in the boiler body of 125 MW tangentially fired pulverized coal boiler is studied, and the flow field, temperature field and gas phase concentration distributions under different air temperature are predicted. The results show that, in every condition, the high-temperature region appears in the area where burners installed, and with the increase of furnace height, the temperature is gradually reduced. Compared with the low-temperature region, the concentration of CO is higher and the concentration of CO2 and O2 are both lower in the high-temperature region. The gas squirting from the burners flows around a tangent circle, the air velocity in the tangential diameter and close to the furnace wall is lower, conversely, in other regions. When the furnace temperature meets the industrial production requirement, the secondary air and the tertiary air using high temperature air, it could reduce the total amount of air and pulverized coal consumption, and also reduce the generation of pollutants and achieve the purpose of energy conservation and emissions reduction. With the increase of air temperature, the furnace temperature at the same section changes more even, so the water wall tube will be heated uniform, which is helpful for water cycle stability in boiler.