Analysis And Optimization On Gas DeNO_x Control System Of 600MW Power Plant

In recent years,with the increasing of thermal power installation,thermal power plants have discharged more nitric oxides.Nitric oxides,which are discharged on the process of burning coals,are the mainly compositions of materials which can lead to secondary pollution like acid rain and photo-chemical pollution.Therefore,it is of vital importance to control the discharging of NO_X by thermal power plants.Selective Catalytic Reduction has superiority of high efficiency and the controllable stability,has become the most popular flue gas denox technology.In this paper,a denox system from a 600 MW thermal power plant is studied and he control strategy of the system is optimized.The generation mechanism of NO_X is analyzed based on the principle and mechanism of SCR,the practical situation of the power plant.In order to solve the lag of NO_X concentration measurement in gas,the primary variables are carried out by using principal component analysis based on analysis of the shortages of the previous control scheme,a mathematical model of the influence from burning to the NO_X concentration of the entry of SCR is built by using multiple linear regression(MLR),the measurements of the NO_X concentration of the entry of SCR is replaced by the dynamic pre-estimates.In order to make the gas denox control system satisfied with different situation,the parameters of the system are adjusted adaptively based on the test results which are got by building a dynamic mathematical model of the gas denox control system in different unit loads.Optimized SCR denox system has been put in operation for one year and acts well,has achieved considerable economic and social significance.Comparison of the control system effect before optimized and after shows that the optimized SCR denox control system has a good control quality.