Study Of The Performance,simplification And Characteristics Of SNCR De-NO_x In Cyclone Separator Of Circulating Fluidized Bed Boiler

With the more and more serious environmental pollution,circulating fluidized bed boiler(CFB)in which the temperature is low and the fuel can be recycled,which is concerned by the whole world.China put forward the goal of ultra low emissions to further contribute to the cause of environmental protection——under the condition of the reference oxygen content of 6%,the concentration of NOx emission is less than 50mg/Nm3.In order to achieve the goal of de NOx emissions required by the state,we must further improve the efficiency of denitrification by CFB.Selective non catalytic reduction(SNCR)has the advantages of less investment,simple equipment and so on.The SNCR reaction temperature window is located in the temperature range of the cyclone separator of the circulating fluidized bed boiler,and the flow time of the flue gas can reach to 1s in the cyclone separator to provide sufficient time for the SNCR denitrification reaction.Build a power plant 660 WM supercritical circulating fluidized bed unit ueing low calorific value coal(stone + washing coal gangue)in the cyclone separator with SNCR denitrification equipment to achieve the goal of ultra low emission.In this paper,the SNCR denitrification characteristics of a cyclone separator were simulated and analyzed.Provide significant guidance to the operation of supercritical circulating fluidized bed boiler.In this paper,CHMKIN software is used to analyze the mechanism of SNCR denitrification and the CHMKIN software is used to simplify the detailed SNCR reaction mechanism.The SNCR denitrification characteristics of a 660 WM supercritical circulating fluidized bed cyclone separator were studied by combining the simplified 18 basic elements and the CFD numerical simulation.The effects of temperature,ammonia nitrogen molar ratio and O2 content on the SNCR reaction were analyzed,and the optimal value was searched to provide meaningful guidance for the practical operation.At the same time,using the fluid dynamics simulation software to study the performance of the cyclone separator ——the pressure difference and separation efficiency.And presents new types of exhaust pipe——Inlet converging exhaust pipe and inlet diffuser exhaust pipe.Through the introduction of comprehensive factor analysis Y=?/?(? is the classification efficiency for the cyclone.? is the cyclone resistance coefficient)to compare the economic structure of the entrance of exhaust pipe,find that the exhaust pipe inlet to the gradual reduction of the most economical.