Cascade and deep coal-fired flue gas SO<3> removal system and method

Abstract

The invention relates to a cascade and deep coal-fired flue gas SO<3> removal system and method. The system includes an SCR denitration device, an alkaline absorber spraying device, an air preheater, a temperature regulating and effect improving device, an electrostatic precipitator, a desulfurization tower and a wet electrostatic precipitator, wherein the temperature regulating and effect improving device comprises a cooling section and a heating section, the SCR denitration device, the air preheater, the cooling section of the temperature regulating and effect improving device, the electrostatic precipitator, the desulfurization tower and the wet electrostatic precipitator are sequentially arranged in the flue gas removal direction. The alkaline absorber spraying device is arranged in front of the SCR denitration device, behind the SCR denitration device, in front of the air preheater, behind the air preheater or in front of the cooling section of the temperature regulating and effect improving device. The cascade and deep coal-fired flue gas SO<3> removal system conducts cascade and deep removal on flue gas SO<3> through various pollutant control devices and achieves that the SO<3>emission concentration is less than 5 mg / Nm<3>.

Description

Technical field [0001] The invention belongs to the technical field of coal-fired flue gas pollutant removal, and specifically relates to a coal-fired flue gas SO 3 Step depth removal system and method. Background technique [0002] Coal-fired thermal power generation is currently the main form of electricity production in my country. my country’s thermal power generation is as high as 80% of the total power generation, of which coal-fired electricity installed capacity accounts for 75% of the total capacity. In 2014, my country's total energy consumption was 3.61 billion tons of standard coal, and coal consumption accounted for 66% of total energy consumption. China's coal-based energy supply pattern will not change in the future. [0003] In coal-fired power plants, SO 3 There are two main sources of sulphur: One is in the combustion process, the combustible sulfur contained in coal burns to generate SO 2 After part of SO 2 Is further oxidized to form SO 3 ; Second, in the selec...

AI Technical Summary

Problems solved by technology

[0005] Among the existing coal-fired pollutant control equipment, there is no specific environmental protection equipment to control SO in flue gas. 3 With the increasingly stringent environmental protection requirements, it is urgent to develop a coal-fired flue gas SO 3 The removal system and control method give full play to the effect of each pollutant control equipment on SO 3 removal potential to reduce SO in flue gas 3 hazards to power plants

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