Analysis and Commissioning of SCR Denitration Control System in Coal-Fired Power Plant

T88 denitration system of a power plant is equipped with a set of urea pyrolysis and its corresponding process equipment. The process of the denitration system and its control logic is detailed introduced in this paper. According to the characteristics of hysteresis of the denitration system, three control strategies were formulated during the commissioning process. Finally, combined with the actual situation, the large spray gun automatic and the small guns manual were determined to make the control effect reach the optimum. Through modifying the control logic and adjusting the control logic parameters of the three loops, the concentration of nitrogen and oxygen compounds at the outlet of SCR(selective catalytic reduction) could be maintained around the set value, which meets the requirements of the ultra-low emission.