Numerical Simulation-Based Flow Field Optimization of SCR Denitrification System for Iron Ore Sintering Flue Gas

A selective catalytic reduction (SCR) technology can effectively solve the problem of NOx non-compliance in iron ore sintering flue gas emissions and achieve ultra-low emissions of exhaust gases. The arrangement of the inflow structure in its denitrification reactor is the key to ensure the denitrification efficiency, so that the physical fields such as flue gas flow rate, temperature, pressure and ammonia–nitrogen concentration in the reactor are uniformly distributed. Therefore, based on the problems occurring in a steel plant, numerical simulations were conducted using FLUENT software to compare and analyze the distribution of the flow field in the reactor before and after the installation of the deflector structure, and to conduct a study on the effect of the number of deflectors on the uniformity of the physical field in the reactor. The results show that the addition of the deflector structure greatly improves the uniformity of the physical field, increases the denitrification efficiency, and makes the measurement indexes meet the design requirements. Moreover, with the increase of the number of deflectors at the elbow on the flue, the deviation of the non-uniformity of the flue gas flow rate upstream of the first catalyst layer was gradually reduced, which effectively improved the uniformity of the airflow distribution in the reactor.