空气预热器密封片失效原因分析及建议

通过宏观分析、理化检验、扫描电镜观察及能谱成分分析,对燃油电厂空气预热器密封片的失效原因进行分析。结果表明:空气预热器密封片出现规律性破损,是由低温硫酸露点腐蚀、密封片刮擦及吹灰蒸汽带水共同作用导致,其中又以吹灰蒸汽带水作用为甚。建议通过提高吹灰蒸汽过热度以及延长疏水时间,来提高吹灰蒸汽品质,进而达到减缓密封片损坏的目的。

Failure Analysis and Suggestions for Air Preheater Seal

By means of macroscopic analysis, physical and chemical testing, SEM and EDS analysis, the failure cause of the air preheater seal of a fuel power plant was analyzed. The analysis results show that the air preheater seal was regularly damaged, which was caused by low-temperature sulfuric acid dew point corrosion, seal scraping, and soot-blowing steam with water. Among them, the soot-blowing steam with water was the primary cause for the failure. It is suggested to improve the quality of soot-blowing steam by increasing its superheat degree and prolonging its hydrophobic time. In this way, the damage of the seals can be slowed down.