回转式空气预热器的冷段堵灰分析与进口风温计算

根据文献1]推出的回转式空气预热器的冷段受热面的平均金属壁温计算式,分析了最低壁温计算中存在的问题,建议了合理的最低壁温,对某燃煤电厂的220 MW机组锅炉的回转式空气预热器的冷段最低壁温、酸露点温度与冷风温度进行了计算与比较,空气预热器发生堵灰的根本原因在于烟气中存在SO3以及受热面金属壁温低于烟气露点。对此,提出了提高受热面壁温在烟气以上的控制措施。所得结论对合理选取回转式空气预热器的最低进口风温,避免冷段堵灰、电站锅炉的安全运行具有重要的工程参考价值。

Analysis of cold sector ash fouling and caculating of inlet air temperature of regenerative air heater

Based on the calculate formula of regenerative air heater's averge tube temperature of cold section introduced by the document 1],the existence problem of the minimum surface temperature's calculating is analyzed in this paper,the rational minimum temperature is suggested.Taking the air heaters of 220 MW utility boilers as a case study,the minimum of cold metal temperature,the acid dew point temperature and the inlet air temperature are calculated and compared.The basic causes leading to ash-clogging in the said air heaters were: SO3 existing in the flue gas and the wall temperature of heating surface was lower than dew point of the flue gas.For these reasons,some control measures for enhancing wall temperature of the heating surface are put forward,so as to ensure the normal operation of the said air heaters.The proposed method and results can be a reference in choosing the reasonable inlet air temperature.