Advances in the study of the effects of pollutant removal equipmenton PM2.5 emissions in coal-fired power plants

The transformation of the traditional electrostatic dust removal technology of coal-fired power plants is a necessary prerequisite for meeting increasingly stringent pollutant emission standards.The particle formation mechanisms during coal combustion,the influence of gas pollutant removal technology on the emission of fine particles and high-efficiency dust removal technology were reviewed.For the high-efficiency dust removal technology,it mainly includes the principle,advantages and limitations of enhanced tail dust removal technology,and the introduction to the operational situation,the mechanism of source control technology,and development trends.The main formation mechanisms of PM2.5 are gasification,condensation,heterogeneity and fragmentation of inorganic minerals.Pollutant control technologies such as NOx and SOx in power plants have a complex impact on PM2.5 emissions.There are mainly three technical routes for PM2.5 emission reduction,i.e.enhanced tail dust removal,flue gas pretreatment,and combustion source control.The reform of traditional dust devices can improve the removal efficiency,such as high-frequency power precipitator,wet electrostatic precipitator and ultraclean electrostatic-fabric integrated precipitator.The flue gas pretreatment technology treats the flue gas before entering the dust collector through additional conditions,so that the fine particles will agglomerate and grow or reduce the flue gas temperature to improve the removal efficiency.At present,common technologies mainly include agglomeration technology and low-temperature electric dust removal.For particle agglomeration technology,it mainly consists of chemical agglomeration,turbulent agglomeration,heterogeneous condensation agglomeration,acoustic agglomeration.Combustion source control technology can solve the problem of penetration window,and does not need to add additional equipment,which is more economical.Combustion source control technology mainly includes mixed coal combustion technology and additive technology.An in-depth understanding of the impact of gaseous pollutant removal technology will provide a new idea for the control of fine particulate emissions from coal combustion.