四角切圆无烟煤燃烧系统灵活性改造优化研究
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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.
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.
引文
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[13]陈冬林,李慧勇,周臻.确定燃煤锅炉卫燃带敷设面积的一种代数计算方法[J].动力工程,2006,26(5):638-640,675.CHEN Donglin,LI Huiyong,ZHOU Zhen.An algebraic method for determ ining the refractory belt area of coa I fired boilers[J].Journal of Power Engineering,2006,26(5):638-640,675.
[14]陈冬林.准恒的燃烧理论与试验研究[D].武汉:华中科技大学,2003.
[15]赵铁军,曹际恒.火电厂锅炉卫燃带的改造[J].中国电力,1997,30(12):68-69.
[2]崔永忠,高苑辉,王力,等.燃烧无烟煤锅炉稳定燃烧的治理[J].电力建设,2002,23(8):25-27.CUI Yongzhong,GAO Yuanhui,WANG Li,et al.Control on stability of combustion of anthracite coal fired boiler[J].Electric Power Construction,2002,23(8):25-27.
[3]魏博,文彪,谭厚章,等.准东煤掺混焦炭燃烧特性研究[J].热力发电,2017,46(6):51-55.WEI Bo,WEN Biao,TAN Houzhang,et al.Co-combustion characteristics of Zhundong coal mixed with coke powder[J].Electric Power Construction,2017,46(6):51-55.
[4]周志军,黄镇宇,朱自力,等.射流偏转及实际炉膛切圆的分析计算方法[J].浙江大学学报(工学版),2000,34(6):642-646.ZHOU Zhijun,HUANG Zhenyu,ZHU Zili,et al.Jet deflection and analytic calculation of the actual furnace tangential circle[J].Journal of Zhejiang University(Engineering Science),2000,34(6):642-646.
[5]岑可法.锅炉燃烧试验研究方法及测量技术[M].北京:水利电力出版社,1987.
[6]陈学俊,陈听宽.锅炉原理[M].2版.北京:机械工业出版社,1991.
[7]陈刚,丘纪华,张志国,等.稳燃腔煤粉燃烧器的试验研究及应用[J].动力工程,1994(6):37-41,63.CHEN Gang,QIU Jihua,ZHANG Zhiguo,et al.Experimental research on tubular pulverized coal burenrs[J].Power Engineering,1994(6):37-41,63.
[8]陈刚.四角切向燃煤锅炉炉内实际切圆的计算[J].电站系统工程,2002,18(4):17-18.CHEN Gang.Calculation of actual tangential circle diameter in tangential PC-fired boiler furnace[J].Power System Engineering,2002,18(4):17-18.
[9]胡光,金正淑.四角切圆锅炉浓淡燃烧器的应用研究[J].华东电力,2003,31(1):32-33.
[10]刘福国,潘风国.切向燃烧炉内实际切圆直径的回归分析[J].锅炉技术,1999,30(2):7-9.LIU Fuguo,PAN Fengguo.Regression analysis of the actual tangential circle diameter in furnace for tangential-firing boiler[J].Boiler Technology,1999,30(2):7-9.
[11]何佩繁,赵仲虎,秦裕馄.煤粉燃烧器的设计和运行[M].北京:机械工业出版社,1987.
[12]岑可法,焚建人.燃烧流体力学[M].北京:水力电力出版社,1991.
[13]陈冬林,李慧勇,周臻.确定燃煤锅炉卫燃带敷设面积的一种代数计算方法[J].动力工程,2006,26(5):638-640,675.CHEN Donglin,LI Huiyong,ZHOU Zhen.An algebraic method for determ ining the refractory belt area of coa I fired boilers[J].Journal of Power Engineering,2006,26(5):638-640,675.
[14]陈冬林.准恒的燃烧理论与试验研究[D].武汉:华中科技大学,2003.
[15]赵铁军,曹际恒.火电厂锅炉卫燃带的改造[J].中国电力,1997,30(12):68-69.