DeNOx Technology Selection and Optimal Design of SNCR System for a 300MWe CFB Boiler

With the increasing pressure on NOx removal in China, a part of CFB boilers have to install the deNOx devices to meet the updated emission regulation. Aiming to the large-scale 300MWe CFB boilers, the existing SCR and SNCR technologies are compared and the SNCR technology using urea as reductant is recommended based on the technical, economic and safety concerns. The design of the SNCR system is also presented. By employing the CFD method, the different urea distributions inside the cyclone are illustrated and the layout of 10 nozzles for each cyclone is optimized to the outer side of cyclone inlet. The technological flow chart of the SNCR system is given to show the whole process of urea storage, transport and injection.