空气预热器二次燃烧的成因及预防

Formation and Prevention of Secondary Fire in an Air Preheater

空气预热器能起到降低机组排烟温度,提高锅炉效率的作用,大型电站锅炉常采用回转式空气预热器。若锅炉本体运行不当,容易使处于尾部受热面的空预器发生二次燃烧事故。现以一起回转式空气预热器发生二次燃烧的过程,分析空气预热器发生二次燃烧的成因,当锅炉燃料燃烧不完全或空预器吹灰不正常,是导致空预器发生二次燃烧的主要原因,进而从控制锅炉燃烧及规范运行制度方面,提出预防空预器发生二次燃烧的措施。

Air preheater is applied to temperature reduction of exhausted gas from power unit and increment of boiler efficiency. Rotary air preheater is common used in large power plant boiler. The accident of secondary fire will easily happen in the preheater at the end heating surface of a boiler if the boiler is operating improperly. The formation of secondary fire in preheater has been analyzed in the paper taking an example of the process of a secondary fire occurred in a rotary air preheater. It is the major reason to lead a secondary fire that an incomplete burning in the boiler or improper ash blowing in the preheater are taken. It is necessary to control the burning in the boiler and to abide by the operating system and put forward the countermeasures for preventing the secondary fire.