Study On Reducing NOx Emission Technologies Of Coal Fired Boiler

Nitrogen oxide is one of the main pollutants emitted by coal fired power plants. In this paper, the 1025t/h and 2209t/h capacity of Huaneng Dezhou power plant is made up of sub critical coal-fired units, this paper compares and analyses the emission of nitrogen oxides and the improvement of NOx reduction.This paper introduces the formation and harm of NOx, expounds the development status of the technology of denitrification at home and abroad. In this paper, the combustion adjustment test before the reform of the unit is introduced. The relationship between the NOx emission concentration, the boiler efficiency and the unit load is analyzed, and the influence of the operation mode and the parameter change on the NOx emission is investigated. On the basis of this, a new scheme of low NOx combustion for two capacity boilers is put forward.In this paper, the process technology and design parameters of SCR system of two kinds of capacity boiler are analyzed. The same points and different points of SCR transformation technology of two capacity boilers are summarized, and the requirement of SCR denitrification system for boiler system transformation is discussed, and the transformation of 1025t/h and 2209t/h of the same type and SCR boiler is used for reference. The contrast analysis of the two boiler capacity of SCR de denitrification system under 90%,80%,70% load performance test, carried out the SCR DeNOx flow test, results show that the SCR system the performance index and the flow field distribution meet design requirements, and give the best operating conditions.In view of the SCR operation, the optimization of the SCR system is analyzed, and the influence factors of the denitrification efficiency and ammonia escape are analyzed, and the optimization scheme for the power plant is put forward. This paper expounds the influence of SCR modification on the blockage of air preheater, and puts forward a concrete solution to change the combustion mode according to the experiment of NOx distribution in the flue gas of the power plant.