Research For SCR NO_x Project Transformation In Wangqu Power Plant

NO_x is one of the main pollutants released from coal combustion process for coal-fired power plants,and coal-fired boilers are the main control objects of NO_x emissions as main coal users.13th Five-Year"period,the control of NO_X pollution is the focus of air pollution control in China,so it is imperative to research on denitration of coal-fired boiler.Selective Catalytic Reduction(Selective catalytic,Reduction,SCR)technology has become the main choice of NO_x emission control of boiler coal fired power plantbecause of its high rate of removal of flue gas denitrification(more than90%).In this paper,the denitration retrofit project of 2*600MW unit in phase 1 project of Wangqu power plant was studied.According to the present status of the unit,a low nitrogen combustion reactor was adopted in the furnace and SCR denitrification was carried out in the flue at the end of the furnace.SCR DeNO_x reactor(composed of one layer plate,and two layers of honeycomb)are arranged between the boiler economizer and air preheater for high dust disposal,and the flue gas velocity in the reactor is about4~6m/s.After the denitration transformation,we meet the design requirements:denitrification efficiency is not less than 88%,the ammonia escape rate is less than 3ppm,NO_x emission concentration is from 27 to 38 ppm.the denitrification system body pressure drop is less than or equal to 1100Pa.The SCR denitrification system of 2×600MW boiler in Wangqu power plant is studied in this paper.Through the analysis of the influence factors of SCR denitration efficiency,combined with the analysis of a large amount of data recorded by the DCS plant in SCR denitrification system,the main factors affecting denitrification efficiency,this paper provide guidance for operating personnel adjustment and a reference for optimizing operation and denitration system for other domestic power plant SCR.This is of great significance for reducing the operation cost of SCR technology and saving energy and reducing consumption in power plants.According to the low characteristics of the original catalyst efficiency,the structure of the catalysts was modified by three layer plate catalysts instead of original catalyst layers(one layer plate,two layers of honeycomb),enhancing the performance of the catalyst.For the problem that the catalyst is easy to block up,the traditional steam blowing method has been improved in Wang Qu power plant,and a loud sonic soot blower with adjustable frequency is adopted.The high frequency acoustic wave catalyst with adjustable amplitude modulation can effectively dredge the channel of catalyst and remove the dust scale in the fine hole of catalyst surface,so as to maintain the activity of catalyst.In view of the installation of SCR analysis of its economic benefit and social benefit,the results indicate,the NO_X reduction of construction and operation of the power plant is very large,but also improved the power plant area of the environment,promote the integration of the relationship between enterprises.