大型电站燃煤锅炉多环芳烃排放特性

采用烟气等速取样方法在浙江某电厂2座蒸汽容量为1000t/h和2000t/h的燃煤电站锅炉进行电除尘器前后烟气和飞灰中多环芳烃分布的研究，给出了多环芳烃的浓度和排放因子，并对烟气净化装置对多环芳烃的脱除效率进行了观察。结果显示：电除尘出口处多环芳烃的排放因子在2.93~ 18.2mg/kg煤之间；电除尘器入口处的烟气中多环芳烃总生成量随着锅炉负荷量的增加而呈减少趋势，产物中以四环和五环的多环芳烃居多；电除尘器飞灰中多环芳烃的总生成量随着锅炉负荷量的增加呈增加的趋势，在电除尘器各个电场中的分布量有明显的差异。电除尘器出口处烟气的多环芳烃分布较除尘器入口的分布更为不均匀，电除尘器对多环芳烃的脱除作用是有选择性的。

The Polycyclic Aromatic Hydrocarbons Emission Character in the Large-scale Power Plant Boiler

The polycyclic aromatic hydrocarbons(PAHs)distribution character of the flue gas and fly ash emitted from electrostatic precipitator in two coal-firing boilers with the steam capacity 1000t/h and 2000t/h have been studied in a power plant of PR.Zhejiang based on isoknetic sampling method.PAHs concentrations and PAHs emission factors were determined.In addition,the PAHs removal efficiencies of air pollution control devices were also included.The result show that measured total PAHs emission factors are between 2.93 and 18.2 ug/kg feedstock;The total PAHs content in the flue gas of electrostatic precipitator inlet decrease with the boiler charge increasing;The forming PAHs is mainly the 4-ring and 5-ring species;The total-PAHs content in the fly ash of electrostatic precipitator inlet increases with the boiler charge increasing and the PAHs content of fly ash varies widely in every electric field.The PAHs distribution character in the flue gas of the electrostatic precipitator outlet sharply contrasts with the inlet,which shows the removed effect of electrostatic precipitator to PAHs is selective.