Coal powder partial gasification cooperative denitration system and method

Abstract

The invention provides a coal powder partial gasification cooperative denitration system and method. The structure is simple, design is reasonable, reformation is convenient, ultra-low emission of nitrogen oxides of a power station boiler can be realized without ammonia injection, and technical economy is high. The coal powder partial gasification cooperative denitration system comprises a coal bin, a coal mill, a boiler, a cyclone separator, a gasification furnace and a filter; a coal outlet of the coal bin is connected with an inlet of the coal mill, a coal powder outlet of the coal mill isrespectively connected with an inlet of the cyclone separator and a burner nozzle arranged in the main combustion area of the boiler, and the coal powder outlet of the coal mill is connected with a primary air pipe; a fine coal powder outlet of the cyclone separator is connected with the burner nozzle, and a coarse coal powder outlet of the cyclone separator is connected with an inlet of the gasification furnace; a coal gas outlet of the gasification furnace is divided into two paths, one path is connected into a flame folding angle area of the boiler through a reburning nozzle, the other pathis connected into a tail flue after passing through the filter, and the tail flue connects the coal gas into the tail flue at the tail of an air preheater through a spray gun; and a catalyst layer isarranged on the downstream part of a spray gun in the tail flue.

Description

technical field [0001] The invention relates to flue gas denitrification technology in thermal power plants, in particular to a coal powder partial gasification cooperative denitrification system and method. Background technique [0002] Nitrogen oxide emissions from coal-fired power plants are one of the main causes of environmental problems such as acid rain and photochemical pollution. In recent years, the emission standards of nitrogen oxides have become more and more stringent, and some require that the emission concentration of nitrogen oxides should not exceed 30mg / m 3 . [0003] Commonly used NOx emission reduction technologies in coal-fired power plants include low-NOx combustion technology, non-selective catalytic reduction technology (SNCR) and selective catalytic reduction technology (SCR). Both SNCR and SCR technologies use ammonia as the denitrification reducing agent. In order to ensure higher denitrification efficiency, a higher ammonia nitrogen molar ratio...

AI Technical Summary

Problems solved by technology

However, the pyrolysis or gasification of pulverized coal requires large pyrolysis or gasification equipment, and the initial investment is large, which is not suitable for the transformation of existing coal-fired units; and CO is burned and gasified in the main combustion zone, and the other The generation of CO in the main combustion zone is easy to form high-temperature corrosion and reduce the service life of equipment

Images