Study On Retroffting And Operation Management Of SCR Denitrification System For 600mw Coal-fired Power Plants

The environmental protection department has been claimed that they will take some punishment on the power plant which can not control the emissions of major air pollutants（such as NOx、SOx and dust）.It’s very impotant to install SCR denitrification system in the coal-fired power plants.We must make sure that the SCR denitrification system run safely and stably.In the paper,the equipment modification of SCR denitrification system in Shanghai Wujing second power plant is investigated.If we want to start retrofitting the SCR denitrification system,we must choose urea or ammonia as a reducing agent for Selective Catalytic Reduction（SCR）technology.By comparing the cost of urea or ammonia as reducing agent,we choose urea as SCR reducing agent in our power plants.For guiding the operation of the technicians in the power plant,we have conducted boiler performance test before and after SCR retrofitting.It will reduce NOx emissions if we increase the opening degree of the upper overfire air,reduce the total air flow rate and the boiler air damper.Besides,we also need change low NOx burners,air prehearter and induced draft fan when a SCR denitrification system is installed in the power plant.Afte the denitrification system performance test,it is obtained that the urea consumption rate is about 205kg/h,the denitration efficiency is above 80%,the ammonia slip is less than 3μL/L,at full load,and SO₂/SO₃ conversion rate is no more than 0.48%.By analyzing the operating parameters,we can know how to solve the operation problems occurred in the SCR denitrification system（such as the control of NOx emissions and the pyrolysis system of urea）,and we can improve the operation availability of the SCR denitrification system.