A METHOD OF REDUCING NITROGEN OXIDES OF A PULVERIZED COAL BOILER USING INNER COMBUSTION TYPE BURNERS

摘要

A method of reducing nitrogen oxides of a pulverized coal boiler using inner combustion type burners (2) includes that all or part of burners of the pulverized coal boiler are arranged as or changed into the inner combustion type burners (2), in which the ignition sources may be plasma generators (1) or ignition devices such as small oil guns etc., and the power thereof can be adjusted for controlling the ignition intensity in the burners (2). The inner sides of the burners (2) are divided into several stage combustion chambers (5), and are provided with pulverized coal concentrators (4) which do deep fuel classification in the burners (2). During the boiler operating, the ignition sources always keep working state, and the pulverized coal in the burners (2) is ignited step by step and burned in advance. The air capacity of the secondary wind in a primary combustion zone (22) is reduced, which makes the primary combustion zone (22) be in strong reducing atmosphere, and creates a high temperature and hypoxia condition for inhibiting the generation of NOx. The remain air is supplied from the upper furnace in the form of burn-out wind, and does deep air classification in the total furnace. Thus, the NOx generation of combustion can be effectively controlled on the premise of not reducing the boiler efficiency.