A swirl pulverized coal burner

Abstract

The invention relates to a swirl pulverized coal burner, which comprises a primary air channel, an axial-swirl internal secondary air channel and a tangential / axial-swirl external secondary air channel, wherein the external secondary air channel is positioned at the periphery of the internal secondary air channel. The swirl pulverized coal burner is characterized in that a center sleeve structure is arranged in the center of the primary air channel; the center sleeve structure comprises a center cylinder structure and an coaxial cylinder capable of moving back and forth in the axial direction, the conical cylinder is positioned at the front end of the center cylinder, and the sectional area of a primary air nozzle of the primary air channel is changed by the back-and-forth movement of the conical cylinder in the axial direction; an inlet of the internal secondary air channel is separated into a swirl air inlet channel and a direct flow air inlet channel; and a swirler is arranged in the external secondary air channel. The swirl pulverized coal burner disclosed by the invention is applied to an all-hearth air classifying low nitrogen oxide emission technology of a boiler, has the characteristics of good adjustability and strong ignition and burning stabilization properties and has the advantages of conveniently adjusting the coal-type-variable working conditions and improving the burning-out efficiency of a main burning area.

Description

technical field [0001] The invention relates to a swirl pulverized coal burner for a pulverized coal boiler of a power station. Background technique [0002] With the strict control of nitrogen oxide emissions from coal-fired power plant boilers in the country, in order to effectively reduce the nitrogen oxides produced by combustion in the furnace, the whole furnace staged combustion technology is generally adopted. Part of the oxygen fed from the main combustion area (the burner area where pulverized coal is fed into the furnace) is delayed into the furnace from the special tuyere on the upper part of the furnace to meet the burnout requirement, so that the air stoichiometric ratio of the main combustion area is less than 1. That is, an oxygen-deficient combustion atmosphere is formed, and a reducing atmosphere area is formed between the main combustion zone and the upper tuyere (burnout zone), so that the initial nitrogen oxides are fully reduced. At the same time, most ...

AI Technical Summary

Problems solved by technology

The reduction of the secondary air volume in the burner area reduces the adjustment ability of the secondary air, especially in the actual situation of the current power plant with variable coal consumption, it is easy to cause poor swirl intensity adjustment performance, and the diameter and length of the nozzle return area It often fails to meet the requirements, so that in the process of controlling nitrogen oxides, the initial ignition, stable combustion and burnout cannot meet the requirements, and problems such as reduced boiler efficiency and a sharp increase in the amount of cooling water will occur.

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