Modeling And Simulation Of Selective Catalytic Reduction System

By force of the increasingly stringent regulations of NOx emissions, selective catalytic reduction (SCR) technology as a mature post-combustion removal of NOx technology has been introduced into and increasingly widely applied in our country. Numerical simulation and optimize analysis for SCR system can help us to know the factors of de-NOx reduction, understand the basic physics phenomenon of catalytic reduction and transfer coupling and characteristic within the catalytic reduction. It can make us known the basic rule of physics phenomenon and apply the academic gist to design catalyzer, optimize flue path and strengthen reduction It also helps us to digest and absorb the indraught technic, untie the core technic and empolder the technic with own property right.The main study content in this paper divides into two parts: first part is to numerical modeling for design optimization of SCR applications by compute fluid dynamics method. Numerical modeling for design optimization of SCR applications is the core content of the paper. On the basis of combination of abroad research result, the development to the project, the equipment design, the construction effort, and the commissioning and optimization effort. At first the CFD model is created and flow filed inside the SCR system on BMCR load is analyzed. Based on the characteristic of the flow status, a guide device is designed to optimize the flow and improve the efficiency of the system. Secondly species transport equation is used to model the status of the molar ratio of reagents in rector for the three different sizes of nozzle. And the reason is analyzed.Second part based on the established dynamic mathematical model, a dynamic simulation model has developed by using MATLAB. Firstly, the steady calculation for model is carried on. The flow field of flue gas and concentration field of the components computed by FLUENT software in five different loads are imported as the boundary condition of the model. Then based on the established dynamic simulation model, a series of dynamic simulation experiment have been done by using this simulation model,which include the simulation experiment of step disturbance about NOx concentration,NH3 concentration,temperature,flue gas flux and so on.The simulation results current is correct. The analyzed results indicate that the established dynamic mathematical model for SCR reactor in this paper is credible,and prove that the simulation model is practical.Based on the work mentioned above, in this paper the guide device and ammonia injection grid is designed to make sure the system can run nuturally. And dynamic mathematical model of the selective catalytic reduction is established. This model is applicable to the basic study for SCR reactor technique,and to steady and dynamic performance study for SCR reactor,and can provide a academic reference for the design,operation,technics and parameter optimization study for a SCR reactor.