Effects of moisture in coal on pulverized coal combustion characteristics

Effects of moisture in coal on pulverized coal combustion characteristics are investigated by means of a three-dimensional numerical simulation. The results show that as the moisture increases, flame temperature and NOx mole fraction decrease, while O2 mole fraction increases in the region near the burner, and the peaks of the flame temperature and NOx mole fraction shift downstream. Also, the increase in the moisture increases the unburned carbon fraction and decreases the NOx conversion at the outlet of the furnace. These trends agree well with the previous experimental results. It is found that the contribution of thermal NOx to the total NOx drastically decreases with an increasing moisture content, whereas the emission of fuel NOx increases.