Numerical Simulation And Experiment Research For A SCR System In Coal-fired Boiler Plant

The efficient operation of SCR system is the key to the reduction of nitrogen oxides(NOx)in coal-fired power plants.During the long-term operation of SCR system,problems such as blocking of catalyst,high ammonia slip,and catalyst deactivation have emerged in the power plant in Guangdong,due to the change of operating conditions such as coal quality and combustion conditions,In order to solve the problems existing in the operation of the system,this paper combines the relevant research results,then use the numerical simulation and experimental analysis to optimize the denitrification system,completed the following work:1?Use the chemical kinetics Chemkin software and the application of SCR denitrification reaction mechanism to simulate the SCR ddenitrification system.The effects of flue gas atmosphere,ammonia injection rate and temperature rise on denitrification efficiency were simulated and analyzed.At the same time,based on the regeneration experiment,the influence of the above factors on the denitrification experiments was analyzed and verified.2?Based on a comprehensive study of the internal structure and the characteristics of the flue gas of the SCR system.the numerical simulation of the velocity field in the flow field of the system was carried out by Fluent,the distribution of the flow field under different flow path conditions was studied and corresponding flow path optimization schemes were proposed.At the same time,adding the ash model based on the flow field analysis,analyzing the distribution of ash and the deposition area of the ash,which provides a theoretical basis for the arrangement and operation of the soot blowing device in the actual operation.3?Based on the simulation and the experimental analysis,analyse the factor such as the flue gas quantity,the denitrification rate,the inlet/outlet NOx concentration,the ammonia escape rate,the SO2 / SO3 conversion rate,the flue gas temperature drop,the NH3 / NOx mole ratio,then the adjust the ammonia spray grid to ensure uniform reactor outlet NOx concentration and lower ammonia slip.This paper focuses on the practical application of SCR denitrification technology,the works consist of numerical simulation,experiment research and field test.Above mentioned results of simulation and analysis is significant to the design of flue structure,baffle arrangement and optimal design of ammonia injection for the SCR denitrification system of coal-fired boiler.