Research on the corrosion performance of SCR denitrification by-products on air preheaters in coal-fired power plants
In order to improve the operational efficiency of the SCR flue gas denitrification system in coal-fired power plants and reduce the corrosion and blockage effects of denitrification by-products on the air preheater,based on the analysis of the composition of SCR denitrification by-products in the target coal-fired power plant,a hanging plate weight loss corrosion experiment was conducted to focus on the effects of ammonium bisulfate concentration,ammonium sulfate concentration,corrosion temperature,corrosion time and steel type on the corrosion rate of the air preheater.The results show that the content of ammonium bisulfate in the by-products of SCR denitrification in the target coal-fired power plant is the highest,reaching 61.6％,and the content of ammonium sulfate also reaches 6.5％.The deposition of sulfate is prone to serious corrosion hazards on the air preheater.As the concentrations of ammonium bisulfate and ammonium sulfate gradually increase and the corrosion temperature gradually increases,the corrosion rate of the hanging pieces gradually increases;As the corrosion time gradually prolongs,the corrosion rate of the hanging pieces gradually decreases;In addition,under the same corrosion experimental conditions,the corrosion rate of weathering steel and stainless steel is significantly lower than that of ordinary carbon steel,with 316L stainless steel having the lowest corrosion rate.The research results suggest that the presence of ammonium bisulfate and ammonium sulfate in SCR denitrification by-products can cause severe corrosion to the air preheater,and the production of denitrification by-products should be minimized as much as possible.
万方数据
维普
