Low-nitrogen combustion device for coal powder gasification combustion and combustion method

Abstract

The invention discloses a low-nitrogen combustion device for pulverized coal gasification combustion. The device comprises a multi-tangent-circle combustion hearth, wherein the multi-tangent-circle combustion hearth comprises a hearth angle wall and a hearth side wall, the furnace wall of the hearth is provided with one or more columns of nozzle groups which are arranged in the height direction, the nozzle groups comprise powder lower air nozzles, gasification nozzle groups, combustion-supporting air nozzles and top air nozzles, the gasification nozzle groups comprise first primary air nozzlegroups, second primary air nozzle groups and gasification air nozzle groups, and first primary air nozzles involved in the first primary air nozzle groups, second primary air nozzles involved in the second primary air nozzles groups and gasification air nozzles involved in the gasification air nozzle groups are sequentially arranged in the same direction or in the reverse directions according to the airflow horizontal rotating direction. The invention further discloses a method for performing low-nitrogen combustion based on the low-nitrogen combustion device for the pulverized coal gasification combustion. According to the low-nitrogen combustion device for the pulverized coal gasification combustion and the method, the generation of fuel type NOx and thermodynamic NOx can be fully inhibited; and the burnout stage is mainly the combustion of coal gas, and the amount of coke and the amount of fuel nitrogen in the coke are extremely low.

Description

technical field [0001] The invention relates to the field of pulverized coal combustion equipment. Specifically, the invention relates to a low-nitrogen combustion device and a combustion method for pulverized coal gasification combustion. Background technique [0002] The traditional air staged combustion technology mainly uses the increase of the burn-off air and the distance to the main combustion zone to control the reducing atmosphere and the area range of the reducing atmosphere in the furnace, but the oxygen-enriched burn-off stage is delayed and the coke with lower reactivity The combustion temperature is reduced and the combustion time is shortened, resulting in an increase in the content of fly ash combustibles and a decrease in boiler efficiency. At the same time, the large-scale reducing atmosphere in the furnace also increases the probability of coking in the furnace and high-temperature corrosion of the water wall. In addition, due to the influence of coke nit...

AI Technical Summary

Problems solved by technology

However, since the coke nitrogen conversion rate and the coal burnout rate increase almost simultaneously, the scheme of setting up a separate burnout zone will inevitably cause unburned coke to bring part of the coke nitrogen into the burnout zone, resulting in the conversion of part of the coke nitrogen in a high oxygen concentration environment , resulting in a step in the NOx concentration, and finally there is a limit to the further reduction of the NOx emission concentration

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