Research On Transformation Of Ultra-low Emission Denitration Of 4×220t/h Circulating Fluidized Bed(CFB) Boiler Of Thermal Power Plant

With the carrying out of ultra-low emissions,the emission standards of coal-fired boilers have become increasingly stringent,and the corresponding flue gas purification transformation of coal-fired boilers has become an inevitable trend.In view of the fact that the current SNCR denitrification equipment of circulating fluidized bed boilers in Thermal Power Plant cannot meet the requirements of ultra-low emission standards,this paper proposes a combined denitrification method of SNCR+SCR to meet the emission requirements.The main work of this paper is as follows:(1)According to the existing data,field test results and operation records of the Thermal Power Plant,the design parameters and operating parameters of the main equipments,and the operating status of the existing SNCR denitration equipment and the status of NO_x emissions are obtained.(2)In order to meet the requirements of ultra-low emission,the boiler needs to be reconstructed,and the economic and technical feasibility of the two transformation schemes are compared and analyzed.After the SNCR+SCR combined denitration method is determined,the types of reductant and catalyst are screened,and the corresponding equipments and facilities are modified to accommodate the changes caused by the operation of the unit after the transformation.(3)The software of Aspen plus was used to simulate the process of flue gas denitration,and the effects of ammonia nitrogen ratio,O2 concentration,temperature,the inlet NOx concentration,and flue gas flow rate on the denitration efficiency are analyzed.(4)The investment of the SCR denitrification transformation is estimated,and the operating cost of the SCR system,as well as the economic and social benefits after transformation are analysed.