煤粉锅炉结焦机理和除焦方法探讨.doc

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  • 更新时间:2014-06-09
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摘 要:结焦是锅炉运行中比较普遍的问题,一般情况下,随着烟气一起运动的灰渣颗粒,由于炉膛水冷壁受热面的吸热而同烟气一起被冷却,如果液态的渣粒在接近水冷壁或炉墙前,已经因为温度降低而凝固,当附着在受热面管壁上时,将形成一层疏松的灰层,运行中通过吹灰很容易除掉。当炉膛内温度较高时,一部分灰颗粒已经达到熔融或半熔融状态,若这部分灰颗粒在达到受热面前未得到足够冷却达到凝固状态,具有较高的粘结能力,就容易粘附在受烟气冲刷受热面或炉墙上,甚至达到熔化状态,粘附熔融或半熔融状态的灰颗粒和未燃尽的焦炭使结焦不断发展。在燃烧过程中,煤粉颗粒中所含的易熔或易气化的物质迅速挥发,成气态进入烟气中,当温度降低时凝结,或者粘附在烟气冲刷的受热面或炉墙上。或者凝结在飞灰颗粒表面,成为熔融的碱化物膜,然后粘附在受热面上形成初始结焦层,成为结焦发展的条件。 

   针对电厂煤粉锅炉易结焦的现象,从燃煤灰分的化学性质、炉气的性质、空气动力场以及运行操作等方面分析了产生结焦的原因,并提出了加强燃煤灰分的监督、保证良好的炉内气氛、采用双通道燃烧器和提高管理人员预防结焦的意识等防止结焦的措施。

关键词:结焦,预防,现象分析,机理

 

Abstract:Coke is the boiler of the more common problem, in general, as the movement of smoke with ash particles, the furnace water wall heating surface of the heat-absorbing and with the same gas is cooled, if liquid water near the slag particles front wall or the furnace wall has been reduced because of the freezing temperature, when attached to the wall surface when heated, will form a layer of loose ash layer, the operation is easily removed by soot blowing. When the furnace temperature is higher, part of the ash particles have reached the semi-molten or molten state, if this part of the ash particles before reaching the heat did not get enough cooling to solidification state, has a high bonding capacity, it is easy to adhere to the subject heating surface erosion or furnace flue gas wall, even to the molten state, the adhesion of molten or semi-molten ash particles and unburned coke to continue to develop. In the combustion process, the coal particles contained in or easily fusible material gasification rapid evaporation into the gas into the flue gas, condensation when the temperature is lowered, or the erosion of adhesion in the flue gas wall furnace heating surface or . Or condensation in the surface of fly ash particles become molten alkaline material film, and then adhere to the heating surface to form the initial layer of coke, a coke conditions for development. 

    Pulverized coal power plant is easy for the phenomenon of coke from coal ash chemistry, the nature of furnace gas, the air force field and other aspects of the Operation have Coking and coal ash is proposed to strengthen the supervision to ensure Good furnace atmosphere, the use of dual-channel burner and improve management awareness of prevention of coke and other measures to prevent coking. 

Key words: coke, prevention, scene analysis mechanisms