燃煤电厂不同超低排放控制措施颗粒物排放浓度研究

Study on the particulate emission level after ultra-low emission retrofit of coal-fired power plant

为研究燃煤电厂超低排放后颗粒物排放控制规律,以当前装备两种主流超净颗粒物控制技术电除尘器+石灰石-石膏湿法脱硫+旋汇耦合除尘装置和电除尘器+石灰石-石膏湿法脱硫装置+湿式静电除尘器的3家燃煤电厂为研究对象,通过总排口颗粒物浓度在线监测仪的监测结果与颗粒物脱除有关的环保设施进行颗粒物控制效果、稳定控制能力、最大峰值荷载的分析,结果显示装备有湿式电除尘器的两个电厂,99.9%的颗粒物排放浓度低于5 mg/m^(3),好于采用石灰石-石膏湿法脱硫+旋汇耦合除尘装置的电厂,其仅有91.6%的颗粒物排放浓度低于5 mg/m^(3);其中装备有湿式电除尘器的两个电厂其99.5%的数据低于3 mg/m^(3),这是因为湿式电除尘可以有效控制电除尘器振打导致二次扬尘带来的排放口颗粒物浓度变化,提高整个除尘系统的峰值荷载能力;此外,研究采用的抽取式颗粒物监测仪能准确捕捉电除尘振打产生的二次扬尘峰值,及时跟踪电除尘器运行的趋势规律,因湿法脱硫系统协同电除尘器及湿式电除尘器的作用,电除尘振打产生的二次扬尘浓度显著被抑制,测得的最小二次扬尘浓度值为0.5 mg/m^(3)。

In order to study the emission control law of particulate matter after ultra-low emission of coal-fired power plant,taking the three coal-fired power plants currently equipped with two mainstream ultra-clean particulate control technologies as the research object,which are electrostatic precipitator+limestone-gypsum wet desulfurization+rotary coupler and electrostatic precipitator+limestone-gypsum wet desulfurization+wet electrostatic precipitator.Analyze the particle control effects,the stability control ability,and the maximum peak load through results of the particulate monitor installed at the chimney outlet and environmental protection facilities related to particulate matter removal.The results show two power plants equipped with wet electrostatic precipitator,99.9%of particulate emission concentration is less than 5 mg/m^(3),it is better than the power plant that adopts limestone-gypsum wet desulfurization+rotary coupler device,and its only 91.6%of the particulate matter emission concentration is less than 5 mg/m^(3).Among them,the two power plants equipped with wet electrostatic precipitator have 99.5%of data below 3 mg/m^(3),this is because the wet electrostatic precipitator can effectively control the change in the concentration of particulate at the chimney outlet caused by the dust re-entrainment of the electrostatic precipitator rapping,improve the peak load capacity of the entire dust removal system.In addition,the particulate monitor used in this study can accurately measure the changes in concentration caused by the dust re-entrainment generated by the electrostatic precipitator rapping,timely follow the trend of the operation of the electrostatic precipitator.Because the wet desulfurization system cooperates with the electrostatic precipitator and the wet electrostatic precipitator,the concentration of the dust re-entrainment generated by the electrostatic precipitator rapping is significantly suppressed,and the measured minimum dust re-entrainment value is 0.5 mg/m^(3).