Optimization experiments of the SNCR denitrification system in circulating fluidized bed boiler after ultra-low emission transformation

Abstract

The current work firstly aims to improve denitrification efficiency of the selective non-catalytic reduction (SNCR) denitrification system in a circulating fluidized bed (CFB) boiler after ultra-low emission transformation, to reduce the operating pressure of the subsequent selective catalytic reduction (SCR) denitrification system, and to extend the service life of the boiler. Secondly, it attempts to ensure that the concentration of nitrogen oxides (NOx) does not exceed the emission standard, to drop the consumption of the reducing agent, and to save operating costs. Therefore, some key factors, such as the number of spray guns affect denitrification efficiency and the amount of ammonia escape, were chosen as the operating parameters to be optimized. Meanwhile, a 150 MW CFB boiler in the Inner Mongolia Autonomous Region of China was employed for the experimentation. We then designed and implemented the optimization experiments of the SNCR denitrification system, including optimizing the operating parameters and deeply optimizing the SNCR denitrification process. The denitrification efficiency can reach 76.6% when there are four spray guns with valve opening of 50, 100, 100, and 50% respectively from top to bottom. The current work can be used as a frame of reference for carrying out relevant experiments on similar units.