Numerical Simulation Optimization And Experiment Research For The Flow Field Of Selective Catalytic Reduction System In200MW Thermal Power Plant

Now days，it becomes increasingly strict on the controlling of Nitrogen Oxide (NOx)emissions from thermal power plant in China. Selective Catalytic Reduction is widelyused for DeNOxof flue gas due to its mature and efficient technology. In SCR system, theNOxdesorption efficiency is decided by the flow fields of velocity and concentration ofthe reactor system. In this paper, CFD (Computational Fluid Dynamics) and Flow ModelTest are applied to study the flow field of200MW coal fired power plant, then theoptimization program is proposed.Firstly, this paper summarizes some essential design points for SCR reactor systemwith different structures and different characteristic. Then，The initial flow field of theSCR reactor was simulated to find the defect by the Fluent. Then, optimize the flow fieldsof velocity of SCR system by adding splitters.In order to improve the mixing degree offlue gas and ammonia, Ammonia Injector Grids (AIG) was designed on the basis of thestructure of SCR reactor. Considering the pressure loss and installation space were withinallowed limits, a new static mixer was designed to optimize the flow fields ofconcentration.Through the shift of size，angle and altitude of the static mixer, this papergot a best design project.According to principle of similitude, a physical model was built to test and verifythe result of numerical simulation.In this experiment, ammonia was substituted byCarbon dioxide; catalyst layers were substituted by porous plate; fly ash were replaced byflour. Then measure the distribution of velocity and concentration, incident angel and thepressure loss of the system. Based on these experiments, optimize the numericalmodeling result and proposed improvement program.