隨著國內新環保標準的推出和執行,電廠作為低氮燃燒改造的重要項目,積極響應號召進行低氮整改。電廠低氮燃燒改造活動,在一定程度上對電廠運行效率有很大的提升,同時對電廠電力生產活動的環保性也有積極作用。電廠低氮燃燒器結構復雜,各部分匹配要求標準高,對此,我們需準確掌握電廠電廠低氮燃燒器的結構,為后續的整改工作打下堅實的基礎。
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、主風箱外部設備情況
1, the main bellows external equipment
風箱外部設備由點火器控制柜、油點火器、火檢裝置主要組成。風箱設備中的所有風噴嘴和燃料噴嘴利用風箱外部的連接桿連接到電動傾斜驅動單元上,并能夠在垂直方向進行傾斜角度進行調整。風箱中爐膛四個角的傾斜驅動調節是同步的,保證了所有的噴嘴在傾斜角度方面都是相同的。而爐膛中火球的相對位置通過使所有噴嘴傾斜程度同步來實現上下移動。風門的開合程度是根據預先設定的程序來控制的,而所有的風門都是由電動驅動裝置驅動的。
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、改造前的內部風箱結構
2. inner bellows structure before renovation
在電廠
低氮燃燒器改造進行之前,位于爐膛的四個角分別有4個風箱,這些風箱內的設備將燃料和風送到爐膛內,以確保對爐膛內燃料和風量的控制。每個風箱內部都被分割成9個小風室,這9個小風室內分別安裝有二次風噴口或煤粉燃燒器。每個風箱內都有自己獨立的行動控制系統,利用翻板門的形式對進入到爐膛內的風量和燃料量進行控制,同一層的4個角的翻板門行動是同步的,因此進入這4個小風室的風量是一致的并保證爐膛內的燃料能充分燃燒。翻板門在不同層可以被調節到不同的開合度,這樣給風箱輸送的燃料量和風量就會不同。不同層小風室內產生的二次風風速可以根據一些運行參數來控制,如給煤量和風箱與爐膛內差壓。
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、風室內部配風情況
3. air distribution inside the air chamber
燃料風又稱周界風或3次風,風源來自二次風大風箱引出。位置靠近煤粉噴嘴,起到加速和混和煤粉氣流以及冷卻煤粉噴嘴的作用,每個煤粉噴嘴都配備一個燃料風室,一般由本層的給煤量控制。輔助風主要是通過兩層煤粉燃燒器噴口層之間的小風室進入爐膛的二次風,它是對爐膛內的燃燒效率進行調節的風項??梢酝ㄟ^調整這些“燃燒控制風門”(控制輔助風的翻板門)的開合程度對爐膛內部的燃燒壓力與風量之間的差壓進行控制。通過調節風門開度和爐膛進風量來保證其他燃料和氧氣的進入。
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.