In order to fully characterize the emission reduction performance of SO3 by low-low temperature electrostatic precipitator system (FGC+ESP), a method to test low-concentration SO3 was proposed, namely “two-stage controlled condensation + one-stage isopropanol absorption” sampling method, which can improve the accuracy of its test data. According to this method, in the pilot test, the SO3 removal efficiency of the low-low temperature electrostatic precipitator (LL-ESP) system (90 ℃ at ESP entrance) was 96.15%. In four groups of field measured data from three engineering projects, the SO3 removal efficiency of LL-ESP system was 69.1%-96.6%. The mechanism of SO3 adsorption and agglomeration by fly ash particles under low-low temperature conditions was verified. The study results can provide reference for the large-scale promotion and application of LL-ESP technology and SO3 emission reduction of coal-fired power plants.
