Pulverized coal decoupling combustor with low nitrogen oxide discharge and pulverized coal decoupling combustion method with low nitrogen oxide discharge

Abstract

The invention relates to a pulverized coal decoupling combustor with low nitrogen oxide discharge and a pulverized coal decoupling combustion method with low nitrogen oxide discharge. The method is implemented through the following two stages: a) stage 1, firstly separating mixed airflow of pulverized coal and air into a concentrated part and a dilute part by virtue of the pulverized coal decoupling combustor provided by the invention, igniting the concentrated pulverized coal airflow, then feeding the concentrated pulverized coal airflow into a hearth, and performing combined combustion on the concentrated pulverized coal airflow and the dilute pulverized coal airflow; and b) stage 2, mixing the mixed airflow with secondary air in the hearth, and fully combusting the pulverized coal semicoke generated in the stage 1 under conditions of rich oxygen and high temperature which is insufficient to generate thermal NOx, wherein in the stage 1, the pulverized coal is pyrolyzed, gasified and gas-fired under reducing atmosphere, volatile components are fully separated out, products of pyrolysis and gasification are utilized to convert fuel-type NOx into more stable N2. According to the invention, an integration design of pulverized coal condensation, stable combustion and low nitrogen oxide discharge can be realized, the equipment structure is compact, the pulverized coal condensation effect is good, the stable combustion capability is strong, and the potential of inhibiting NOx from generating is high.

Description

technical field [0001] The invention belongs to the field of pulverized coal combustion equipment, and in particular relates to a pyrolysis gasification pulverized coal decoupling burner and a pulverized coal decoupling combustion method with low nitrogen oxide emissions. Background technique [0002] In the practical application of pulverized coal combustion, as the combustion temperature and oxygen concentration of the pulverized coal-air mixture in the combustion stage increase, the content of fly ash combustibles (unburned carbon and CO) in the flue gas decreases, and the pulverized coal is easier to burn quickly , fully burn out; at the same time, the high temperature and oxygen enrichment will make the NO generated in the combustion process x On the other hand, the lower the combustion temperature and oxygen concentration of the pulverized coal-air mixture in the combustion stage, the better the suppression of nitrogen oxides NO x Generated, but coal dust is less like...

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Problems solved by technology

However, these patents above are only suitable for layered combustion technology, and are only suitable for small and medium-sized decoupled combustion furnaces below 20 tons / h, and it is difficult to realize large-scale decoupled combustion furnaces for pulverized coal combustion.

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