精品毕业论文--循环流化床锅炉燃烧控制系统设计.doc

摘要
近年来,国际上发展起来新一代高效、低污染的清洁燃烧锅炉----,平均容量小,且以燃煤为主。锅炉容量小于 35 t/h的约占工业锅炉总量的 98 . 9 %, 其中2~ 10 t /h的占 75 % ,锅炉平均容量不到3 t /h。燃煤工业锅炉占工业锅炉总量的 80 %以上, 燃油气锅炉约占 15%, 电加热锅炉占 1 %左右,其余的以沼气、黑液、生物质等为燃料的锅炉。
可见在我国循环流化床的重要性,但是在此发展中,循环流化床还存在着很多问题,在循环流化床的控制,和结构上,在不断的创新。循环流化床锅炉是在鼓泡流化床锅炉技术的基础上发展起来的新炉型,它与鼓泡床锅炉的最大区别在于炉内流化风速较高(一般为4~8m/s),在炉膛出口加装了气固物料分离器。被烟气携带排出炉膛的细小固体颗粒,经分离器分离后,再送回炉内循环燃烧。循环流化床锅炉可分为两个部分:第一部分由炉膛(快速流化床)、气固物料分离器、固体物料再循环设备和外置热交换器(有些循环流化床锅炉没有该设备)等组成,上述部件形成了一个固体物料循环回路。第二部分为对流烟道,布置有过热器、再热器、省煤器和空气预热器等,与其它常规锅炉相近。
关键词:循环流化床循环流化床控制燃烧系统旋风分离器 DCS操作
Abstract
Circulating fluid bed boilers have been deveoped, which are specific of the high effeciency and minor  boilers in china mainly work by burning coal , with a large quantity and covering range , but a low average volume less than 3t/h . % industrial boilers among the whole are of a volume less than 35t/h , 75% of which vary from 2 to 19t/h . coal heating industrial boilers about 15% , whereas electricall heated boilers about 1% , and the rest of them are mainly motivated by methane , black liquor , biomass , the development of boiler technology , problems concerning circulating fluid bed(CFB) still exist . In the field of structure and control of CFB , there are continuous innovations . Circulating fluid bed boilers , a new type of boilers that evolves with the help of bubble fluid bed and fluid bed boiler technoloy , are distinguished with the bubble fluid bed in that the new type works with a higher fluidized windspeed (normally 4-8m/s) , and it applies a ges-solid material separator . Tiny solid particles carried out of the boiler by the fume are sent back to the boiler after being separated . Circulating fluid bed boilers consists of two parts . The first part is made up of the hearth , gas-fluid material separator , solid material recycling device , as well as outlaid heatexchanger (absent in some boilers ) , all of pose a solid material circulation loop . The second part is t