摘要
分析了管式空气预热器严重腐蚀及其漏风率偏高的原因,认为发生腐蚀是由烟气中存在SO3以及受热面金属壁温低于烟气露点而使硫凝结附着所致。对此,提出了减少烟气中的SO3,降低烟气的露点和减少硫酸的凝结量,以及提高空气预热器冷端的壁温,使之在高于烟气露点下运行等措施。实施后,锅炉的平均漏风率降至3%左右,提高了锅炉的运行效率。
Severe corrosion and high air leakage occurred on the tubular air preheater,condensation and the subsequent adhering of sulphocompound caused by SO3 appearing in flue gas and the low wall temperature of heating surface which is below the flue gas dew point was considered as the major reason.To solve the problems,several measurements were proposed:blocking the leaked tube;enhancing both frequency and quality of soot blowing;adopting proper excess air coefficient;strictly controlling hot air temperature in the earlier stage of boiler start;maintaining the air preheater after the unit shutdown;changing the entire tube box when the number of invalid tubes occupied more than 10% of the total.After these improvements,the average air leakage rate of the retrofitted boiler decreased to about 3%.
出处
《热力发电》
CAS
北大核心
2012年第9期115-117,共3页
Thermal Power Generation
关键词
管式空气预热器
积灰
腐蚀
漏风率
烟气露点
tubular air preheater
ash deposition
corrosion
air leakage rate
dew point
sulphur
condensation
