摘要
为解决无烟煤锅炉燃烧中存在的着火性能差、燃尽率低、锅炉设备燃烧不稳、效率下降、受热面结渣严重等问题,对某220 t/h燃烧无烟煤锅炉进行燃烧系统灵活性改造优化研究。通过热态试验,研究煤粉细度、锅炉负荷、磨煤机启停、三次风、二次风、瓦斯等因素对煤粉着火的影响;通过冷态试验,计算冷态下一、二、三次风风速,试验包括飘带试验、炉膛速度场的测量、贴壁速度场的测量。220 t/h无烟煤锅炉灵活性改造方案为:假想切圆直径为700 mm,对应的实际切圆直径为4 000 mm;下一次风喷口的V型由垂直方向改为水平方向;将原上一次风百叶窗水平浓淡燃烧器喷口V型稳燃体去除,改为直板型;卫燃带面积由80.64 m^2调整为63.36 m^2;加装4台瓦斯流量表。通过优化研究,提出了修正后的冷态实际切圆大小的计算公式,确定修正系数K_(xs)=1.132,并做出实际切圆与一次风速、二次风速的关系曲线。改造后试验机组最大限度地减轻锅炉受热面结焦,掺烧劣质煤的运行特性明显改善,飞灰含碳量平均控制在3.29%,优化方案可在无烟煤燃烧锅炉灵活性改造中推广。
In order to solve problems in the anthracite boiler combustion,such as poor ignition performance,low burnout rate,unstable combustion of boiler,efficiency decline,large area of heating surface and so on.Optimize flexibility of combustion system in a 220 t/h anthracite boiler was researched.Influence of coal powder fineness,boiler load,coal mill start and stop,tertiary air,secondary air,gas and other factors on coal fire was studied in thermal test.Tertiary air,secondary air and primary air were obtained,and tie-floating test,hearth and wall velocity were studied in cold test.Scheme of optimize flexibility in a 220 t/h anthracite boiler is confirmed.Imaginary cut circle size and actual cut circle size are 700 mm and 4 000 mm,respectively.V type of lower primary air is changed from vertical to level,and V-gutter of upper primary air horizontal bias burner is replaced by straight plate.Refractory belt area is adjusted from 80.64 m^2 to 63.36 m^2,and four mashgas flow neter are installed.According to experimental results,calculation formula of actual cut circle size is obtained,and correction factor Kxs is determined to 1.132,moreover,the relationship between actual cut circle and primary air speed,secondary air speed is made.After transforming,test unit reduces boiler heating surface coking maximally,improves operation properties of mixed burning inferior coal,and unburned carbon content is controled to 3.29%.The optimization scheme can be popularized in the flexible transformation of anthracite combustion boiler.
作者
熊英莹
谭厚章
XIONG Yingying1,2, TAN Houzhang2(1. Department of Power Engineering, Shanxi University, Taiyuan 030006, China ;2. Laboratory of Thermo-Fluid Scienee and Engineering,Ministry of Education,Xi＇nn Jiaotong University ,Xi＇an 710049,Chin)
出处
《洁净煤技术》
CAS
2018年第1期108-114,共7页
Clean Coal Technology
基金
国家自然科学基金资助项目(91544108
51306142)
关键词
四角切圆
无烟煤锅炉
灵活性改造
热态试验
冷态试验
four-angle cut round
anthracite boiler
flexible transformation
thermal test
cold test
