Abstract: With the tightening of environmental protection policies,the requirements for flue gas emissions are becoming more and more strict,and the removal of industrial exhaust pollutants faces a serious situation.Compared with the traditional flue gas purification process,the activated coke flue gas purification process has the technical characteristics of water saving,energy saving and no secondary pollution.As the core of the process,the research of the reactor has become the key to restrict the development of this technology.Taking the active desulfurization and denitration reactor of a certain project as the research object,a numerical analysis model was established and the pressure drop values between the model and the field device under different working conditions were compared.The average deviation between the two is 5.9%.The model can reflect the actual operation of the device to a certain extent.On this basis,CFD software was used to simulate and analyze the flow field inside the reactor and the concentration field of key components. According to the simulation results,the flue gas flow in the inlet chamber of the reactor is turbulent,and eddy currents and cavities appear,which leads to a difference in the residence time of flue gas in the active coke layer.In addition,according to the distribution map of ammonia mass fraction in the ammonia injection area,it can be seen that the uneven distribution of ammonia gas has a negative impact on the removal efficiency of system pollutants.In view of the above problems,the method of adding internal components in the reactor is adopted to improve the removal efficiency of the system pollutants.In order to improve the uniformity of flue gas at the inlet of the reactor,a deflector was installed at the flue gas inlet of the reactor and the optimization effects of three different types of deflector were compared and analyzed.The results show that the equidistant stepped curved deflector is installed at the flue gas inlet,the effect of uniform distribution of flue gas is the best.The uniformity of air flow in the system is increased by 11% and the pressure drop is reduced by 267 Pa compared with that before adding deflector.As the ammonia selective catalytic reduction method is adopted for flue gas denitrification of activated coke,ammonia gas needs to be injected as a reducing agent during the denitration process.Under a certain amount of ammonia injection,whether the ammonia gas concentration distribution in the denitration zone of the reactor is uniform directly affects the final denitration efficiency of the system.In order to improve the uniformity of ammonia concentration distribution,a porous plate is added on the basis of the original ammonia spray grid,and the porous plate is used to split and distribute the ammonia gas to achieve the purpose of mixing ammonia gas and flue gas in a short distance.Compared with the traditional method of reducing the diameter of the ammonia injection hole and increasing the number of ammonia injection tubes,the installation of perforated plate can reduce the risk of grid blockage during operation of the device and improve the stability of the device.The simulation results show that addition of porous plates above the ammonia spray grid improves the uniformity of ammonia spray by 21%.After optimization,the system's pollutant removal efficiency has reached more than 85%,meeting pollutant discharge requirements and improving system's operating stability,reducing risk of ash and pipe plugging. The correlation between simulation results and actual field operation data is good,indicating that simulation results are highly reliable and have some reference significance for actual production.