600MW超临界W火焰锅炉垂直水冷壁壁温分布特性及偏差控制
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摘要
在600MW超临界W火焰锅炉上进行了不同工况的燃烧试验,研究了主二次风(拱上C风、拱下F风)、乏气风配风方式对垂直管屏水冷壁壁温分布的影响。结果发现,W火焰锅炉炉膛水冷壁壁温分布受配风影响显著,尤其是沿炉宽度方向上壁温均匀性显著依赖于各燃烧器配风均匀性。通过对接近满负荷工况下水冷壁壁温偏差、壁温峰值以及壁温均值等关键参数分析,阐明了锅炉前、后墙水冷壁壁温偏差产生的原因以及壁温分布与配风内在关系,确定了调整水冷壁壁温分布及控制壁温偏差的优化配风方法,同时通过变负荷工况下壁温分布试验,验证了优化配风的适用性。研究显示:F风起到控制下炉膛主燃烧区域火焰形状的作用,前、后墙F风配风不一致会引起火焰偏斜,火焰偏斜一侧水冷壁出现显著壁温尖峰;C风有利于增大燃烧器煤粉气流下冲深度,但过大的C风易造成局部燃烧集中,水冷壁壁温均匀性变差;乏气风主要调整主燃烧器风煤比,乏气风开度过大,使得主燃烧器煤粉着火提前与火焰集中,易造成燃烧器周边水冷壁热负荷高,水冷壁壁温分布不均且出现壁温尖峰。在确保煤粉着火与稳燃的前提下,尽量关小乏气风,以保证煤粉气流有足够的下冲深度,提高下炉膛火焰充满度和水冷壁均匀吸热。
To investigate the temperature distribution characteristics of vertical membrane waterwall during combustion under various boiler conditions, the experiments of secondary air distribution in the upper and lower furnace including C-layer secondary-air on the arch and F-layer secondary-air in the lower furnace, fuel-lean air were carried out in a 600 MW subcritical down-fired boiler. The results indicate that the temperature distribution characteristics of vertical membrane waterwall, especially the uniformity of wall temperature distribution in width direction of boiler, are closely dependent on the secondary air distribution. To ensure the safety of water wall, through the analysis of the temperature deviation, the peak temperature and the average temperature of waterwall, the proper adjustment of the secondary air distribution could be determined and proved this relationship to be true under various loads. The research results show that the F-layer secondary-air could control the flame shape during combustion, and the inconformity of the secondary air distribution in the front and rear walls would lead to the flame deflection and the peak temperature of waterwall. The C-layer secondary-air on the arch could lengthen the fuel-rich coal/air downward distance. While the excessive C-layer secondary-air could easily cause the local combustion concentration and the nonuniformity of wall temperature distribution. Excessive fuel-lean air is favorable to ignite, but cause high heat load of water wall surrounding the burner. Shut down the fuel-lean air as much as possible on the basis of ensuring the ignition and steady combustion, which could be good for both the furnace flame fullness and the even waterwall heat absorption.
To investigate the temperature distribution characteristics of vertical membrane waterwall during combustion under various boiler conditions, the experiments of secondary air distribution in the upper and lower furnace including C-layer secondary-air on the arch and F-layer secondary-air in the lower furnace, fuel-lean air were carried out in a 600 MW subcritical down-fired boiler. The results indicate that the temperature distribution characteristics of vertical membrane waterwall, especially the uniformity of wall temperature distribution in width direction of boiler, are closely dependent on the secondary air distribution. To ensure the safety of water wall, through the analysis of the temperature deviation, the peak temperature and the average temperature of waterwall, the proper adjustment of the secondary air distribution could be determined and proved this relationship to be true under various loads. The research results show that the F-layer secondary-air could control the flame shape during combustion, and the inconformity of the secondary air distribution in the front and rear walls would lead to the flame deflection and the peak temperature of waterwall. The C-layer secondary-air on the arch could lengthen the fuel-rich coal/air downward distance. While the excessive C-layer secondary-air could easily cause the local combustion concentration and the nonuniformity of wall temperature distribution. Excessive fuel-lean air is favorable to ignite, but cause high heat load of water wall surrounding the burner. Shut down the fuel-lean air as much as possible on the basis of ensuring the ignition and steady combustion, which could be good for both the furnace flame fullness and the even waterwall heat absorption.
引文
[1]石践,陈玉忠,侯玉波,等.W火焰锅炉燃烧优化与改造技术研究和工程应用[J].中国电机工程学报,2016,36(22):6187-6192.Shi Jian,Chen Yuzhong,Hou Yubo,et al.Investigations on the combustion optimization&modification of W-flame boilers and engineering applications[J].Proceedings of the CSEE,2016,36(22):6187-6192(in Chinese).
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[3]罗小鹏,石践,黄锡兵,等.超临界W型火焰锅炉垂直水冷壁水动力特性研究[J].锅炉技术,2016,47(1):9-14,44.Luo Xiaopeng,Shi Jian,Huang Xibing,et al.Study on hydrodynamic characteristics of vertical membrane water wall in supercritical pressure w shaped flame boiler[J].Boiler Technology,2016,47(1):9-14,44(in Chinese).
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[5]商显耀,张忠孝,范浩杰,等.700℃超超临界锅炉热偏差与流量偏差对壁温特性影响的研究[J].锅炉技术,2016,47(5):1-5,63.Shang Xianyao,Zhang Zhongxiao,Fan Haojie,et al.Study on the effect of hydrodynamic and thermal deviation on wall temperature of 700℃ultra supercritical boiler[J].Boiler Technology,2016,47(5):1-5,63(in Chinese).
[6]高正阳,孙小柱,宋玮,等.W火焰锅炉结构效应对火焰影响的数值模拟[J].中国电机工程学报,2009,29(29):13-18.Gao Zhengyang,Sun Xiaozhu,Song Wei,et al.Numerical simulation on the effect of structure on flame for W flame boiler[J].Proceedings of the CSEE,2009,29(29):13-18(in Chinese).
[7]樊泉桂,樊晋元.超超临界锅炉的汽温偏差探析[J].锅炉技术,2010,41(2):1-4,17.Fan Quangui,Fan Jinyuan.Research on the steam temperature deviation in the ultra-supercritical boilers[J].Boiler Technology,2010,41(2):1-4,17(in Chinese).
[8]唐斌,顾君苹,张缦,等.350MW超临界循环流化床锅炉水冷壁流量分配及壁温计算[J].煤炭学报,2016,41(10):2560-2567.Tang Bin,Gu Junping,Zhang Man,et al.Calculation on distribution of flow rate and temperature in water wall of350MW supercritical circulating fluidized bed boiler[J].Journal of China Coal Society,2016,41(10):2560-2567(in Chinese).
[9]杨冬,于辉,华洪渊,等.超(超)临界垂直管圈锅炉水冷壁流量分配及壁温计算[J].中国电机工程学报,2008,28(17):32-38.Yang Dong,Yu Hui,Hua Hongyuan,et al.Numerical computation on the mass flow rate profile and metal temperature in vertical water wall of an ultra supercritical boiler[J].Proceedings of the CSEE,2008,28(17):32-38(in Chinese).
[10]朱亚清,张曦.超超临界1000MW机组锅炉水冷壁管超温控制策略[J].热力发电,2015,44(8):99-103.Zhu Yaqing,Zhang Xi.Control strategy for water wall overheat in a 1000MW ultra supercritical unit[J].Thermal Power Generation,2015,44(8):99-103(in Chinese).
[11]高花妮,左霖,罗建平.超临界锅炉螺旋管圈与内螺纹垂直管圈水冷壁特性比较[J].热力发电,2012,41(6):1-5,10.Gao Huani,Zuo Lin,Luo Jianping.Property comparison of water-walls with spiral pipe-rings and with vertical pipe-rings boasting inner threads[J].Thermal Power Generation,2012,41(6):1-5,10(in Chinese).
[12]郭岸龙,方庆艳,赵斯楠,等.660MW超临界墙式切圆煤粉锅炉烟温偏差优化控制[J].动力工程学报,2017,37(5):341-348.Guo Anlong,Fang Qingyan,Zhao Sinan,et al.Optimal control of gas temperature deviation in a 660MWsupercritical tangentially-fired boiler[J].Journal of Chinese Society of Power Engineering,2017,37(5):341-348(in Chinese).
[13]刘鹏远,张大龙,张海,等.缝隙式喷口600MW超临界W火焰锅炉改造前后燃烧特性的试验与数值计算研究[J].中国电机工程学报,2017,37(2):606-613.Liu Pengyuan,Zhang Dalong,Zhang Hai,et al.Experimental and numerical studies on combustion characteristics of a 600MW supercritical arch-fired boiler equipped with slot burners before and after retrofit[J].Proceedings of the CSEE,2017,37(2):606-613(in Chinese).
[14]杨勇,俞谷颖,陈端雨,等.超临界压力W火焰锅炉炉膛水冷壁热负荷分布的试验研究[J].动力工程学报,2015,35(6):429-436.Yang Yong,Yu Guying,Chen Duanyu,et al.Experimental study on water wall heat load distribution of supercritical pressure W-flame boile[J].Journal of Chinese Society of Power Engineering,2015,35(6):429-436(in Chinese).
[15]周文台,杨勇.超临界压力W火焰锅炉运行方式对炉内热负荷影响的试验研究[J].动力工程学报,2016,36(4):253-257.Zhou Wentai,Yang Yong.Effects of operation mode on heat load distribution in a supercritical pressure W-flame boiler[J].Journal of Chinese Society of Power Engineering,2016,36(4):253-257(in Chinese).
[16]张大龙,蒙晨玮,朱余乐,等.燃烧无烟煤的W火焰锅炉热流密度分布的数值模拟[J].煤炭学报,2016,41(10):2495-2502.Zhang Dalong,Meng Chenwei,Zhu Yule,et al.Numerical simulation of the heat flux distribution of water wall of an anthracite coal fired arch-fired boiler[J].Journal of China Coal Society,2016,41(10):2495-2502(in Chinese).
[2]王刚,蔡宏.降低超临界W火焰直流锅炉水冷壁温差措施的探讨[J].锅炉技术,2015,46(3):22-25.Wang Gang,Cai Hong.Discussion on measures for reducing waterwall temperature difference of supercritical arch fired boiler[J].Boiler Technology,2015,46(3):22-25(in Chinese).
[3]罗小鹏,石践,黄锡兵,等.超临界W型火焰锅炉垂直水冷壁水动力特性研究[J].锅炉技术,2016,47(1):9-14,44.Luo Xiaopeng,Shi Jian,Huang Xibing,et al.Study on hydrodynamic characteristics of vertical membrane water wall in supercritical pressure w shaped flame boiler[J].Boiler Technology,2016,47(1):9-14,44(in Chinese).
[4]何洪浩,李文军,曾俊,等.超超临界直流锅炉垂直管屏水冷壁壁温分布特性[J].动力工程学报,2017,37(4):257-260,292.He Honghao,Li Wenjun,Zeng Jun,et al.Temperature distribution of vertical tube water wall in an ultra-supercritical once-through boiler[J].Journal of Chinese Society of Power Engineering,2017,37(4):257-260,292(in Chinese).
[5]商显耀,张忠孝,范浩杰,等.700℃超超临界锅炉热偏差与流量偏差对壁温特性影响的研究[J].锅炉技术,2016,47(5):1-5,63.Shang Xianyao,Zhang Zhongxiao,Fan Haojie,et al.Study on the effect of hydrodynamic and thermal deviation on wall temperature of 700℃ultra supercritical boiler[J].Boiler Technology,2016,47(5):1-5,63(in Chinese).
[6]高正阳,孙小柱,宋玮,等.W火焰锅炉结构效应对火焰影响的数值模拟[J].中国电机工程学报,2009,29(29):13-18.Gao Zhengyang,Sun Xiaozhu,Song Wei,et al.Numerical simulation on the effect of structure on flame for W flame boiler[J].Proceedings of the CSEE,2009,29(29):13-18(in Chinese).
[7]樊泉桂,樊晋元.超超临界锅炉的汽温偏差探析[J].锅炉技术,2010,41(2):1-4,17.Fan Quangui,Fan Jinyuan.Research on the steam temperature deviation in the ultra-supercritical boilers[J].Boiler Technology,2010,41(2):1-4,17(in Chinese).
[8]唐斌,顾君苹,张缦,等.350MW超临界循环流化床锅炉水冷壁流量分配及壁温计算[J].煤炭学报,2016,41(10):2560-2567.Tang Bin,Gu Junping,Zhang Man,et al.Calculation on distribution of flow rate and temperature in water wall of350MW supercritical circulating fluidized bed boiler[J].Journal of China Coal Society,2016,41(10):2560-2567(in Chinese).
[9]杨冬,于辉,华洪渊,等.超(超)临界垂直管圈锅炉水冷壁流量分配及壁温计算[J].中国电机工程学报,2008,28(17):32-38.Yang Dong,Yu Hui,Hua Hongyuan,et al.Numerical computation on the mass flow rate profile and metal temperature in vertical water wall of an ultra supercritical boiler[J].Proceedings of the CSEE,2008,28(17):32-38(in Chinese).
[10]朱亚清,张曦.超超临界1000MW机组锅炉水冷壁管超温控制策略[J].热力发电,2015,44(8):99-103.Zhu Yaqing,Zhang Xi.Control strategy for water wall overheat in a 1000MW ultra supercritical unit[J].Thermal Power Generation,2015,44(8):99-103(in Chinese).
[11]高花妮,左霖,罗建平.超临界锅炉螺旋管圈与内螺纹垂直管圈水冷壁特性比较[J].热力发电,2012,41(6):1-5,10.Gao Huani,Zuo Lin,Luo Jianping.Property comparison of water-walls with spiral pipe-rings and with vertical pipe-rings boasting inner threads[J].Thermal Power Generation,2012,41(6):1-5,10(in Chinese).
[12]郭岸龙,方庆艳,赵斯楠,等.660MW超临界墙式切圆煤粉锅炉烟温偏差优化控制[J].动力工程学报,2017,37(5):341-348.Guo Anlong,Fang Qingyan,Zhao Sinan,et al.Optimal control of gas temperature deviation in a 660MWsupercritical tangentially-fired boiler[J].Journal of Chinese Society of Power Engineering,2017,37(5):341-348(in Chinese).
[13]刘鹏远,张大龙,张海,等.缝隙式喷口600MW超临界W火焰锅炉改造前后燃烧特性的试验与数值计算研究[J].中国电机工程学报,2017,37(2):606-613.Liu Pengyuan,Zhang Dalong,Zhang Hai,et al.Experimental and numerical studies on combustion characteristics of a 600MW supercritical arch-fired boiler equipped with slot burners before and after retrofit[J].Proceedings of the CSEE,2017,37(2):606-613(in Chinese).
[14]杨勇,俞谷颖,陈端雨,等.超临界压力W火焰锅炉炉膛水冷壁热负荷分布的试验研究[J].动力工程学报,2015,35(6):429-436.Yang Yong,Yu Guying,Chen Duanyu,et al.Experimental study on water wall heat load distribution of supercritical pressure W-flame boile[J].Journal of Chinese Society of Power Engineering,2015,35(6):429-436(in Chinese).
[15]周文台,杨勇.超临界压力W火焰锅炉运行方式对炉内热负荷影响的试验研究[J].动力工程学报,2016,36(4):253-257.Zhou Wentai,Yang Yong.Effects of operation mode on heat load distribution in a supercritical pressure W-flame boiler[J].Journal of Chinese Society of Power Engineering,2016,36(4):253-257(in Chinese).
[16]张大龙,蒙晨玮,朱余乐,等.燃烧无烟煤的W火焰锅炉热流密度分布的数值模拟[J].煤炭学报,2016,41(10):2495-2502.Zhang Dalong,Meng Chenwei,Zhu Yule,et al.Numerical simulation of the heat flux distribution of water wall of an anthracite coal fired arch-fired boiler[J].Journal of China Coal Society,2016,41(10):2495-2502(in Chinese).