Development Of Denitrification Technology And Transformation Of NO_x Ultra-low Emission In Coal-fired Power Plants

At present,all sectors of our country pay more attention to environmental protection and strict treatment.The state has more stringent requirements for emission standards of coal-fired power plants.Nitrogen oxide is one of the main components of flue gas emission in coal-fired power plants,which has caused very important environmental protection problems.It is necessary to attach great importance to and limit the emission of nitrogen oxides.First,this paper describes the control of the emission of nitrogen oxides from coal fired power plants at home and abroad,and introduces two common technology of flue gas denitrification in coal-fired power plants:selective catalytic reduction and selective non catalytic reduction,which describe their working principles respectively,and illustrate the selective catalytic reduction technology by comparison.SCR,which is a simple,easy to control and efficient denitrification technology,is widely used in the flue gas denitrification system engineering of coal-fired power plants.The selective catalytic reduction process of high temperature and high dust is the best denitrification process in coal-fired power plants.Secondly,describes the operation status and start stop sequence of a denitration system in a plant,as well as its influence on the unit and its solutions.At the same time,in order to achieve ultra low emission,the denitrification system must be reformed.Three modification schemes are listed in this paper.In the end,the transformation scheme of the low nitrogen burner is determined by comparison,and the control process picture and the phase DCS data of the two secondary air control system and the denitrification system before and after the transformation are given,and the final transformation is verified.Successful。At the end,it is pointed out that the deoxidizing agent of the denitrification process is a major hazard.For the sustainable and coordinated development of the plant,the hidden danger must be eliminated.The feasibility of changing the ammonia process into a urea ammonia process is studied.It is feasible to use urea to produce ammonia instead of liquid ammonia.