Cooperative-control CFB (Circulating Fluidized Bed) boiler in-furnace desulphurization and denitration burning system and cooperative-control CFB boiler in-furnace desulphurization and denitration burning method

Abstract

The invention discloses a cooperative control CFB (Circulating Fluidized Bed) boiler in-furnace desulphurization and denitration burning system and a cooperative-control CFB boiler in-furnace desulphurization and denitration burning method. The burning system comprises a hearth, a coal feeding port, a primary air chamber, a secondary air box, a secondary air pipe, a cyclone separator, a material returning mechanism and a material returning pipe for connecting the material returning mechanism with the hearth. The burning system is characterized in that the material returning pipe comprises an upper-layer material returning pipe and a lower-layer material returning pipe, the tail end of the upper-layer material returning pipe is higher than that of the lower-layer material returning pipe, and the upper-layer material returning pipe is connected with the material returning mechanism and the dilute phase zone of the hearth; the lower-layer material returning pipe is connected with the material returning mechanism and the dense phase zone of the hearth, and a charging hole is formed in the upper layer material returning pipe. The burning system is capable of effectively solving the contradiction between in-furnace desulphurization and denitration in a fluidized bed boiler, emission of sulfur dioxide and oxynitride is greatly reduced, and the fluidized bed boiler can meet the energy-efficient and environment-friendly demands.

Description

technical field [0001] The invention relates to a combustion system and method for coordinated control of desulfurization and denitrification in a CFB boiler. Background technique [0002] With the country's emphasis on environmental protection, the standards for flue gas emissions from coal-fired boilers are becoming more and more stringent. The National Development and Reform Commission, the Ministry of Environmental Protection, and the National Energy Administration jointly issued a notice on printing and distributing the "Coal Power Energy Conservation and Emission Reduction Upgrading and Transformation Action Plan (2014-2020)", pointing out that air pollutants from newly built coal-fired power generation units in eastern my country The emission concentration basically reaches the emission limit of gas turbine units (that is, under the condition of the reference oxygen content of 6%, the emission concentration of soot, sulfur dioxide, and nitrogen oxides is not higher tha...

AI Technical Summary

Problems solved by technology

Fuel type NO X It is mainly generated in the dense-phase area of ​​the fluidized bed furnace, and the furnace return pipe is arranged in the dense-phase area of ​​the furnace, so that more nitrogen oxides will be formed in the dense-phase area, and it is difficult to achieve simultaneous reduction of SO emissions 2 and NO X requirements, unable to meet the increasing environmental protection needs, the use is restricted

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