Performance Study Of Wear-Resisting Grilles Of SCR Denitrification System In The Power Plant Boilers

With the increase of the installed capacity in power plants and the severity of today's environmental problems, we should strictly control the Nitrogen Oxide(NOx) emission.Based on no by-product, high removal efficiency, high stability and simple device, etc,SCR flue gas DeNOx technology has been widely used in power plants. SCR flue gas DeNOx technology arranged in the high dust environment is now widely used in coal-fired power plants, but because of the SCR reactor working in the high dust environment for long time, catalysts are easily blocked, worn and poisoned by solid particles. So we need to install wear-resisting grilles in the flue to intercept larger particles, which can improve the activity of catalysts and service life.Based on the test bed of cold erosion wear and the analysis of experimental data, the article analyzed erosion wear resistance of four kinds of common stainless steel wear-resisting grilles(including 316 stainless steel, 316 L stainless steel, 2Cr13 stainless steel and 2Cr13 + SiC material) in the power plant boilers. It mainly analyzed the influence of different factors(including fly ash erosion velocity, particle size, erosion angle and concentration of fly ash). Based on fluent simulation software, the article analyzed the influence of the gas-solid two-phase flow field to the wear-resisting grilles.At the same time based on the experimental research, the article calculated and checked the experience parameters of the wear equation.This study showed that the erosion speed of fly ash particles had a pronounced influence on the wear-resisting properties of grilles. The relative quality of wear and tear of grilles increased with the increasing of erosion speed, which increased in exponential speed. At the same time the study defined the coefficient of the erosion wear resistance which showed the erosion wear resistance of four kinds of materials, and the results showed that the wear resistance of materials was 2Cr13+SiC>2Cr13>316>316L. Particle size was also one of the important influencing factors, the relative quality of wear and tear of grilles increased with the increasing of particle size in the range of45.81~101.58?m.The relative quality of wear and tear of grilles increased firstly and then decreased with the increasing of erosive angle, and the biggest erosive angle rangedfrom 30°~35°, at the same time the study defined the dimensionless coefficient of angle which showed the influence of angle to the grilles. The wear rate of grilles rised with the increase of the fly ash concentration, which increased basically in exponential speed(index=1). The article analyzed the influence of the continuous phase flow field, moving tracks of particles, and fly ash particle residence time to the grilles through the numerical simulation, and calculated the parameters of the wear equation of grilles through the combination of experiments and numerical analysis, which would bring great significance to the design and engineering application of the wear-resisting grilles.