Optimization Analysis And Optimization Research On Wide Load Denitrification In Coal-Fired Power Plants

Nitrogen oxides(NOx)are one of the main sources of atmospheric pollution.In the past few years,most of the domestic coal-fired power plants had been installed SCR(Selective Catalytic Reduction)denitrification device,to meet the country's increasingly stringent environmental requirements.Through the process analysis of SCR reactor,this paper studies the influence of coal variety,ambient temperature,unit load,and oxygen content of running smoke on the efficiency of SCR denitration.According to the above results,when the flue gas temperature is lower than the minimum temperature that the catalyst allows for continuous operation under low load conditions,the SCR denitration device will not be used.In order to realize the wide load denitration,the flue gas temperature must be increased to meet the temperature requirement of the catalyst in the SCR plant.In this paper,the performance test of SGRS(flue gas reheating system)was carried out in combination with a wide load denitrification project of a coal-fired unit in a power plant.It show that the device can make the flue gas temperature increases 10?30 ? under low load condition,satisfies the requirements of the wide load denitration.However,raising the temperature of the flue gas has an effect on the efficiency of the unit.This paper analyzes and compares the operation parameters of boiler before and after modification,such as the exergy efficiency of boiler,the exhaust temperature,the power generation coal consumption and the amount of denitrification reducer,etc.The calculation results show that,the boiler efficiency will decrease by 3%and the average coal consumption will increase by 13g/kW after the low load of SGRS device.In order to optimize the operation economy of the boiler,it puts forward the operation optimization scheme based on the characteristics of the unit efficiency rising with the increase of unit load,by reducing the number of operating units,the unit load rate is increased to improve the economy of the unit,and the feasibility is proved through theoretical calculation.