【作者】 程蛟；

【导师】 刘勇；

【作者基本信息】 武汉大学 ， 热能动力工程， 2004， 硕士

【摘要】 国华盘山发电公司两台引进前苏联的500WM超临界直流锅炉，原设计燃用晋北烟煤，后改烧神华煤。改烧后一直存在锅炉大面积结渣和掉渣问题，而且锅炉结的渣非常硬，出现了砸伤冷灰斗斜坡水冷壁、影响除渣系统运行和锅炉灭火造成机组非停的问题。 通过燃煤结渣特性的分析，确定国华盘山500MW锅炉试验燃用的神华补连塔煤具有严重的结渣和沾污倾向，属于具有严重结渣和高度沾污倾向的煤种。 通过对单只燃烧器出口空气动力场试验和锅炉热态燃烧调整试验，可以得出以下结论： (1)二次风旋流挡板位置对燃烧器出口流场的影响非常显著； (2)二次风旋流挡板位置在0°～+15°范围内，燃烧器出口流场的回流区和扩散角都比较合适，流场比较合理； (3)本锅炉燃烧器旋流特性较强，通常情况下，本锅炉燃烧器二次风旋流挡板不宜在0°以下运行； (4)对于燃用优质易燃煤质，可选择较弱的二次风旋流强度运行，如将二次风旋流挡板角度置在+10°～+15°范围内，并在热态时对各燃烧器运行情况进行检查和合理的调整； (5)为改善炉内气氛、降低水冷壁表面附近温度和炉膛出口温度，控制和改善锅炉结渣状况，锅炉不宜采用低氧燃烧方式，机组负荷在300～500MW负荷范围内，炉膛出口烟气含氧量宜控制在原设计值5.5％，不得低于5％； (6)机组在60％额定负荷以下运行时，为了降低厂用电和保证燃烧稳定，锅炉宜采用四台磨煤机运行，机组在60％～80％额定负荷运行时，宜采用五台磨煤机运行，在80％额定负荷以上运行时，应该采用六台磨煤机运行，一次风压应控制在10kPa；磨煤机通风量应控制在75～90km~3／h范围，过高和过低的通风量都是有害的； (7)由于锅炉特性和煤质特性的限制，燃烧调整和运行调整的作用是有限的，必须重视机组的运行方式和定期工作，机组的调峰运行方式、严格按照定期切换制度切换磨煤机、按照锅炉运行状况进行吹灰，也是控制锅炉结渣的重要手段； 按照试验结果进行合理的运行调整，加上严格的定期工作，盘电500MW锅炉在100％燃用神华煤的情况下，可以保证安全稳定和经济运行。更多还原

【Abstract】 There are two 500MW supercritical pressure boilers in Pan Shan power station, which are designed to use bituminous in North Shan Xi, but really used coal is Shen Hua coal. The serious slagging is appeared after Shen Hua coal is used, which causes the TBF in bottom of boiler, problem in dust removal system, and flameout leading to outage.Analysis of ash slagging performance shows that Shen Hua coal used in the boiler has the serious slagging and fouling characteristic.Through the testing of cold air model of single burner and hot combustion regulation the conclusion is as below:(1)The position of secondary air baffle has obvious influence on outside flow field of burner;(2) When position of secondary air baffle is at 0~+15 the backing flow area and diffusing angle of outside flow field is good;(1) As the swirling intensity of the burner is strong the position of secondary air swirling baffle is not fit in 0;(2) If the coal is easy to be ignited the swirling intensity of secondary air can be weak, the position of secondary air swirling baffle is better in +10~+15, and the burner’s operating situation will be checked and correctly regulated;(3) In order to get a good atmosphere and lower temperature near the waterwall and outlet of furnace, which is favorable to slagging controlling in boiler, the low oxygen operation model is not good. When the load is at 300-500MW the gas flow oxygen rate in furnace outlet, will be controlled in 5.5%, not below 5%;(4) When the load is below 60%MCR the better operation model is four pulverizers in operating; when the load is at 60%~80%MCR the better operation model is five pulverizers in operating; when the load is above 80%MCR the better operation model is six pulverizers in operating, the pressure of primary air should be controlled in 10kPa, air flow of pulverizer is at 75~90km3/h;(5) The effect of combution regulation .is limited other measures must be used.If the boiler is operated in correct way the stable and economic operation can be achieved at 500MW load and 100% Shen Hua coal.更多还原