Over fire air nozzle structure

Abstract

The invention discloses an over fire air nozzle structure. According to the main technical scheme, the over fire air nozzle structure comprises a boiler body; the main combustion area combustor comprises a plurality of pulverized coal combustors, and the pulverized coal combustors are all installed on the front wall and the rear wall of the boiler body; the plurality of separated over-fire air nozzles are mounted above the main combustion area combustors and are arranged on four walls with the same elevation, the plurality of separated over-fire air nozzles on the front wall and the rear wall correspond to the plurality of pulverized coal combustors one by one up and down, and the plurality of separated over-fire air nozzles are of square structures; the airflow inlet direction of the multiple separated type over fire air nozzles is of a straight section structure, the airflow outlet direction of the multiple separated type over fire air nozzles is of an inclined section structure, and the inclined section structure is divided into an upper inclined section, a middle inclined section and a lower inclined section. The upper deflection section and the lower deflection section are offset by 20 degrees to 35 degrees in the clockwise direction, and the middle deflection section is offset by 20 degrees to 35 degrees in the anticlockwise direction.

Description

technical field [0001] The invention relates to the technical field of wall-type opposing pulverized coal boilers, in particular to a structure of an overburning air nozzle. Background technique [0002] At present, the large-scale swirling flow hedge boilers in thermal power plants have been modified with low-nitrogen burners. Among them, the separated burn-off air is one of the standard configurations. However, during operation, it is found that the CO concentration is high, often reaching several thousand ppm or even tens of thousands of ppm has seriously affected the economic operation of power plant boilers. [0003] In order to reduce NOx emissions, the air excess coefficient of the burner in the main combustion zone is generally less than 1, and the remaining part of the secondary air enters the furnace from the overfired air. Most of the design of the pulverized coal burner in the main combustion area is that the primary air enters the furnace directly, and the inne...

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Problems solved by technology

[0006] In view of this, the present invention provides an overfired air nozzle structure, the main purpose of which is to solve the problem of high CO concentration at the outlet of the air preheater and large deviations of flue gas temperature and steam temperature on both sides of the horizontal flue after the low-nitrogen transformation of the swirl-flux boiler. The problem

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