With the implementation of ultra-low emission standards,Selective Catalytic Reduction Denitrifica-tion(SCR)has high denitrification efficiency and relatively low price,and has been widely used in major thermal power plants,becoming the main technology applied for flue gas denitrification at present.During the operation of SCR denitrification equipment,some ammonia escape may occur,leading to frequent clogging of the air preheater,which has seriously threatened the safety and economy of thermal power unit.Regarding the dust blockage phenomenon in the Ljungstrom Trisector four-compartment air preheater for a 2×660 MW power plant unit,the analysis indicates that the causes are low-temperature corrosion at the cold end,NH4 HSO4 adhesive ash,and incomplete ash blowing.To address these issues,measures such as setting up a circulating air compartment,adding sector plates and arc doors,and installing a circulating air duct have been implemented to carry out the air quantity segmentation and ash-blockage modification.After the unit was modified,the operating resistance of the air preheater decreased to around 1.7 kPa,the air leakage rate dropped to 5.5％,the power consumption of the induced draft fan decreased by 6％,and the exhaust gas tem-perature decreased by 8℃.The boiler′s operational efficiency improved,and there was an increase in both safety and economic benefits.
关键词
空预器/硫酸氢铵/防堵灰/氨逃逸
Key words
Air preheater/ammonium bisulfate/anti-ash blockage/ammonia escape
维普
万方数据