改造前的电厂低氮燃烧器概况

随着国内新环保标准的推出和执行，电厂作为低氮燃烧改造的重要项目，积极响应号召进行低氮整改。电厂低氮燃烧改造活动，在一定程度上对电厂运行效率有很大的提升，同时对电厂电力生产活动的环保性也有积极作用。电厂低氮燃烧器结构复杂，各部分匹配要求标准高，对此，我们需准确掌握电厂电厂低氮燃烧器的结构，为后续的整改工作打下坚实的基础。

With the introduction and implementation of new domestic environmental protection standards, power plants, as an important project of low nitrogen combustion renovation, have responded positively to calls for low nitrogen rectification. The low nitrogen combustion retrofit activities of the power plant have greatly improved the operation efficiency of the power plant to a certain extent, and also have a positive effect on the environmental protection of the power production activities of the power plant. The structure of low-nitrogen burners in power plants is complex and the matching requirements of various parts are high. therefore, we need to accurately grasp the structure of low-nitrogen burners in power plants and lay a solid foundation for subsequent rectification work.

1、主风箱外部设备情况
1, the main bellows external equipment

风箱外部设备由点火器控制柜、油点火器、火检装置主要组成。风箱设备中的所有风喷嘴和燃料喷嘴利用风箱外部的连接杆连接到电动倾斜驱动单元上，并能够在垂直方向进行倾斜角度进行调整。风箱中炉膛四个角的倾斜驱动调节是同步的，保证了所有的喷嘴在倾斜角度方面都是相同的。而炉膛中火球的相对位置通过使所有喷嘴倾斜程度同步来实现上下移动。风门的开合程度是根据预先设定的程序来控制的，而所有的风门都是由电动驱动装置驱动的。
The external equipment of bellows is mainly composed of igniter control cabinet, oil igniter and fire detector. All air nozzles and fuel nozzles in the bellows device are connected to the electric tilt drive unit by connecting rods outside the bellows and can adjust the tilt angle in the vertical direction. The tilt drive adjustment of the four corners of the hearth in the bellows is synchronous, ensuring that all nozzles are the same in terms of tilt angle. While the relative position of fireball in the hearth can move up and down by synchronizing the inclination of all nozzles. The degree of opening and closing of the air door is controlled according to a preset program, and all the air doors are driven by an electric drive device.

2、改造前的内部风箱结构
2. inner bellows structure before renovation

在电厂低氮燃烧器改造进行之前，位于炉膛的四个角分别有4个风箱，这些风箱内的设备将燃料和风送到炉膛内，以确保对炉膛内燃料和风量的控制。每个风箱内部都被分割成9个小风室，这9个小风室内分别安装有二次风喷口或煤粉燃烧器。每个风箱内都有自己独立的行动控制系统，利用翻板门的形式对进入到炉膛内的风量和燃料量进行控制，同一层的4个角的翻板门行动是同步的，因此进入这4个小风室的风量是一致的并保证炉膛内的燃料能充分燃烧。翻板门在不同层可以被调节到不同的开合度，这样给风箱输送的燃料量和风量就会不同。不同层小风室内产生的二次风风速可以根据一些运行参数来控制，如给煤量和风箱与炉膛内差压。
Before the reformation of the low nitrogen burners in the power plant, there were four air boxes at each of the four corners of the furnace. the equipment in these air boxes sent fuel and wind to the furnace to ensure the control of the fuel and air volume in the furnace. The inside of each air box is divided into nine small air chambers, which are respectively provided with secondary air nozzles or pulverized coal burners. Each air box has its own independent action control system, which uses flap doors to control the air volume and fuel volume entering the furnace. the flap doors of the four corners on the same floor are synchronized, so the air volume entering the four small air chambers is consistent and the fuel in the furnace can be fully combusted. The flap door can be adjusted to different opening and closing degrees in different layers, so that the amount of fuel and air delivered to the bellows will be different. The wind speed of the secondary air generated in different small wind chambers can be controlled according to some operating parameters, such as the amount of coal supplied and the differential pressure between the bellows and the furnace.

3、风室内部配风情况
3. air distribution inside the air chamber

燃料风又称周界风或3次风，风源来自二次风大风箱引出。位置靠近煤粉喷嘴，起到加速和混和煤粉气流以及冷却煤粉喷嘴的作用，每个煤粉喷嘴都配备一个燃料风室，一般由本层的给煤量控制。辅助风主要是通过两层煤粉燃烧器喷口层之间的小风室进入炉膛的二次风，它是对炉膛内的燃烧效率进行调节的风项。可以通过调整这些“燃烧控制风门”(控制辅助风的翻板门)的开合程度对炉膛内部的燃烧压力与风量之间的差压进行控制。通过调节风门开度和炉膛进风量来保证其他燃料和氧气的进入。
The fuel wind is also called perimeter wind or tertiary wind, and the wind source comes from the large secondary wind bellows. It is located close to the pulverized coal nozzles and plays a role in accelerating and mixing the pulverized coal flow and cooling the pulverized coal nozzles. each pulverized coal nozzle is equipped with a fuel plenum, which is generally controlled by the coal supply quantity of this floor. The auxiliary air is mainly the secondary air entering the hearth through the small air chamber between the nozzle layers of the two-layer pulverized coal burner. it is the air term that regulates the combustion efficiency in the hearth. The differential pressure between combustion pressure and air volume in the furnace can be controlled by adjusting the opening and closing degree of these " combustion control dampers" ( flap doors controlling auxiliary air ). Other fuels and oxygen can be ensured to enter through adjusting the opening of the air door and the air inlet quantity of the hearth.