Experimental Study Of The Formation Characteristics From Typical Chinese Coal In A Sedimentation Furnace And Its Application On A 150MW Boiler

Coal-fired power plants,as one of the major sources of air pollution,discharge large amounts of atmospheric pollutants.The control of the emission of all major pollutants has become an important subject for the environmental governance of our country.In order to deal with the Severe environmental pollution problem,a new national standard had been issued stipulating a stricter emission limits.Thus,it is imperative toTransform Existing coal-fired boilers to low-nitrogen combustion model.In this paper,the basic characteristics of the four types of coal are analyzed.The combustion and pyrolysis experiment of eight representative samples are conducted on the subsidence furnace.The mechanism and conditions of the forming of NO_X are discussed,finding that the oxygen concentration of burning zone and the dwell time of coal powder burning in the high-temperature zone are the main factors inhibit NO_X generation.For further study of mode of occurrence of nitrogen in coal,X-Ray Photoelectron Spectra(XPS)research had been conducted on three kinds of coal and their corresponding char.It is found that the nitrogen in coal is mainly pyridine and pyrrole.They both possess strong thermal stability.Other nitrogen-containing functional groups tend to convert to pyridine and pyrrole during pyrolysis.The transformation of low nitrogen combustion was carried out on a 150MW coal-fire boiler aiming at reduce the exhaust fo pollutant.After the transformation project,the cold air power field experiment and operating experiment were carried out.The results showed that the project had achieved its goal.The Concentration of NOX had droped from700mg/m~3(dry state 6%oxygen)to 250mg/m~3(dry state 6%oxygen).According to the results of the experiments,the transformation project had effectively reduced the emission of NO_X.Besides,the project alleviated the problem of the furnace coking,reduced the amount of attemperation water of superheater and reheater.The boiler efficiency can reach above 91.85%as long as proper coal is used.The boiler had achieved excellent environmental and economic benefits.This paper studies the combustion characteristics and NO_X emission pattern of typical coal powder in China.A low-nitrogen combustion transformation project had been conducted.The boiler than experienced a few tests in order to examine the amount of NOX emission and operating parameter.The test showed that the boiler can realize low-nitrogen combustion and a stable and high effective operation.This study is useful for both reducing the NO_X emission of the power plant and improving the operating efficiency of the power plant.