600MW Sub-critical Steam Turbine Brush Seal Transformatio Nand Application Research

Rotary air preheater is one of indispensable auxiliary equipment in the large power plant boiler. Air leakage rate is an important preheater performance indicator, to improve the reliability of preheater, reducing the air leakage rate has always been a hot problem in the study of the current preheater. Recently, a lot of research work for the air preheater leakage problem was carried out by many domestic and foreign experts, and a lot of technical solutions were proposed.This paper researched the 600 MW subcritical boiler air preheater. The air leakage problem of two boiler air preheaters wasstudied. A reconstruction scheme was proposed through research and data collection. After a variety of technical and economic comparison of the seal rehabilitation program, the flexible contact sealing technology combined with rigid sealing technology was used to deal with the air preheater sealing problems. The air preheater leakage ratereduced effectively, and the technology was economic and reliable.Finally this solution was implemented. Through the air preheater seal systematic optimization process, the actual operating data and performance test results show that, after the flexible contact sealing technology was used, the air preheater leakage rate of two boiler reduced effectively, the air preheater leakage rate reduced to 4%, the pressure of the air preheater flue gas side turned significantly, the dry flue gas heat lossreduced because of the reduction of the air preheater leakage rate, and the boiler efficiency increase 0.2%, the coal consumption decreased 0.4g/kWh and it saved2031.6 T standard coal every year. The desired effect of reconstruction was achieved,it also has better economic benefits.Through the research and implementation of the project, it can provide an appropriate technical reference for the same type of units,it has a strong engineering significance.