Abstract: In recent years, to realize ultra-low emission of air pollutants from coal-fired power plants, the application of low-low temperature ESP technique has just stepped onto the stage. Taking the low-low temperature ESP of 660 MW unit in Zhejiang Wenzhou Power Plant as the research object, the PM and SO₃ simultaneous removal effects of low-low temperature ESP are tested, and the resistivity of fly ash and its impact on dust removal efficiency at low-low and regular temperatures are studied. The results show that since the flue gas cooler is put into operation, the working condition resistivity of fly ash under low-low temperature has been lowered by ten times compared with the regular working conditions. The emission mass concentration of dust has been decreased from 6.94 mg/m³ to 3.25 mg/m³, which meets the ultra-low emissions requirements, and the SO₃ removal rate reaches 96.6%.

Key words: low-low temperature ESP, multiple pollutants simultaneous removal, ultra-low emissions, dust, SO₃, working condition resistivity