Economic Analysis And Optimization Of Two-Stage Desulfurization For 300MW CFB Boiler

Circulating fluidized bed(CFB) boiler has been widely used in the wide combustion,high combustion efficiency,large load regulation and so on. Desulfurization of CFB boiler has the advantages of low investment cost, small floor area and simple system flow.But the disadvantage is large limestone consumption, low desulfurization efficiency and higher emissions.At present,most of the SO 2 emissions of CFB 300 MW boiler can not meet the 100mg/m3 emission limits of ?Emission Standard of Air Pollutants for Thermal Power Plants?.Therefore, an additional second stage desulfurization system is put forward to achieve the effect of deep desulphurization and ultra low emission.This paper analyzed the principle of the selection method of the desulfurization technology and studied the index system from the aspects of technology, economy and environment in detail. According to the principle of the technology of the desulfurization, the model of the second-stage desulfurization comprehensive fuzzy evaluation is established.Choosing membership degree formula of single target eigenvalue in fuzzy mathematics as membership function and using matrix analysis to determine the weight of each evaluation criteria layer by layer, the paper synthetically judges representative of domestic and international common project examples, which have used the technology above.Then the optimal desulfurization scheme is obtained by the maximum correlation degree., Using the comprehensive fuzzy evaluation,different regions and different power plants according to their own situation can be drawn the most suitable for flue gas desulfurization process.This paper has established the economic analysis and optimization model for the second-stage desulphurization.Through the investigation of 300 MW CFB unit with two-stage desulfurization system of Shanxi Jingyu Power Generation, analysis the impact of SO2 emission limits, sulfur content in coal, initial investment in desulfurization equipment and annual effective performance time on CFB-FGD twostage intensified desulfurization system's economy, finally get a scheme of reasonable desulfurization share. In the case of Sar=2.5%, Sar =2%, Sar =1.5%,the best share of the furnace desulfurization are: 68.7:31.3, 72.1:27.9, 76.8:23.2.Using this model which can provide a reference for the development and implementation of the CFB boiler desulfurization system from the selection to the economic optimization.