Regulation And Flow Field Optimal Design Of Flue Gas Velocity For Wet Flue Gas Desulfurization And Wet Electrostatic Precipitator System

Excessive emission of sulfur dioxide and fine particles in the atmosphere cause serious harm to human-beings and environment.In recent years,as the economy develops rapidly,acid rain and haze problem is becoming more and more serious.The main source of pollutant emissions is coal-fired power plant.With the strict execution of laws related to pollutant emission of the state,flue gas desulfurization and ultra low emission electrostatic precipitator technology has been widely noticed.In this thesis,the widely used wet flue gas desulfurization technology is studied focusing upon the velocity flow field distribution by using Computational Fluid Dynamic(CFD)simulation software.The simulation object is Flue Gas Desulfurization(FGD)device for a power plant 1240 MW unit.The research compares simulation results before and after the spray,and validates CFD results by operating data.The results show that the staggered spray layer arrangemente and Skirt at the entrance help improve flow field in the tower.The wet electrostatic precipitator technology(WESP)is good at removing tiny particles and aerosols,often deployed as the last ring of environmental protection island.The article applies flow field optimal design to WESP of a 1240 MW power plant unit for the purpose of ultra low emission.Firstly,the article conducts simulation for load equilibrium of wet electric precipitator,and the results show that current design can satisfy equilibrium index;The article proposes a optimal design for regulation of flow field,including installation site optimization,splitter design and hole spacing optimization for perforated plate;The article proposes a low-pressure optimal design for the purpose of improving profits and reducing costs.By comparing two designs,results show that the design can reduce system pressure loss on the premise of qualified velocity homogeneity at design stage.Finally,the article studies the dust collecting efficiency of WESP.The collecting efficiency model chooses voltage and current of six electric field,unit load,temperature and inlet dust concentration as model input,outlet dust concentration as output.The model is based on BP(Back Propagation)neural network and validated by historical data from WESP of a 350 MW power plant unit.The results show that the model is helpful to simulate the real collecting process.Furthermore,the article studies voltage optimization strategy based on the dust efficiency model,aiming at reducing energy consumption while satisfying the emission standard.