对燃煤电厂传统的静电除尘技术进行改造是满足我国日益严格的污染物排放标准的必要前提。针对燃煤细颗粒物的生成机理、气体污染物脱除技术对细颗粒物排放影响及高效除尘技术进行了较全面的总结，其中高效除尘技术部分主要包括对强化尾部除尘技术原理、优点和局限性及投运情况和源头控制技术机理，发展趋势等方面的介绍。煤中无机矿物的气化凝结、异相作用和破碎是PM_2.5的主要形成机理。电厂NO_x和SO_x等污染物控制技术对PM_2.5的排放有复杂的影响作用。燃煤电厂可从强化尾部除尘、烟气预处理和燃烧源控制3个方面对PM_2.5排放加以控制。强化尾部除尘技术通过对传统除尘设备进行技术改造，从而改善其对细颗粒物的脱除效果，如高频电源除尘技术、湿电除尘技术、电袋复合除尘技术等。烟气预处理技术通过外加条件对进入除尘器之前的烟气进行处理，使烟气中的细颗粒物发生团聚长大或降低烟温以提高除尘效率，目前常用的有团聚技术和低低温电除尘技术。团聚技术又主要包括化学团聚、湍流团聚、蒸汽相变团聚、声波团聚等。燃烧源头控制细颗粒物生成技术可解决传统除尘设备存在的穿透窗口问题，且无需增加额外设备，经济型较高，主要包括混煤燃烧技术和添加剂技术。深入理解气体污染物脱除技术对细颗粒物排放的影响的将为燃煤细颗粒物排放控制提供一种新思路。

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 PM_2.5 are gasification,condensation,heterogeneity and fragmentation of inorganic minerals.Pollutant control technologies such as NO_x and SO_x in power plants have a complex impact on PM_2.5 emissions.There are mainly three technical routes for PM_2.5 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.

1 燃煤PM_2.5生成机理

2 气态污染物脱除技术对PM_2.5排放的影响

   2.1 脱硝技术对PM_2.5排放的影响

   2.2 脱硫技术对PM_2.5排放的影响

3 高效PM_2.5减排技术发展

   3.1 尾部除尘强化技术

   3.2 烟气预处理技术

   3.3 燃烧源头控制技术

4 结语