关键词: 燃煤电厂, 选择性催化还原, 烟气, 脱硝, 氨, V型扰流板, 气流速度

Abstract: The mixture evenness of ammonia and flue gas has great impacts on both the denitrification efficiency and the ammonia slip. By taking the example of the selective catalytic reduction (SCR) flue gas denitrification system of a 600-MW coal-fired power plant as the study case, the Fluent software is used to calculate the air mixture flow rate at various flue gas velocities with no spoiler and the ammonia-air mixture flow rate at 0.5 and 0.8 m/s respectively. The optimal flow rate combination is obtained as flue gas velocity of 3.7 m/s and ammonia-air mixture flow rate of 0.5 m/s. Then, the V-shaped spoiler(horizontally or vertically arranged) is installed behind the ammonia injection grid to make the ammonia mixed evenly with the flue gas. Numerical simulation is conducted on velocity, flow field uniformity, pressure and pressure drop. From the simulation results the horizontal V-shaped spoiler exhibits satisfactory performance in mixing the ammonia evenly with the flue gas so as to meet the designed requirements of system pressure drop.

Key words: coal-fired power plant, selective catalytic reduction, flue gas, denitrification, ammonia, V-shaped spoiler, airflow velocity