1000 MW超超临界锅炉折焰角斜坡积灰与塌灰计算分析
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摘要
超超临界燃煤发电技术是煤炭清洁利用的重要途径。超超临界锅炉中П型锅炉炉膛出口与水平烟道连接处的折焰角部位由于存在回流区极易形成积灰,严重影响锅炉安全运行。通过对超超临界燃煤锅炉折焰角积灰进行机理分析,包括灰粒与沉积层之间的黏结力和破坏灰粒沉积的力,建立折焰角积灰数学模型和塌灰预判模型,从而给出是否发生塌灰现象的预判结果,为电站安全运行及维护提供指导方案。该积灰与塌灰预判模型利用煤质相关参数、锅炉设计参数以及运行数据,得到烟气中煤灰颗粒的运动速度、深入沉积层深度和表面张力大小,从而定量计算出灰粒在折焰角斜面单位面积上的黏结力和灰粒对沉积层的冲击力,并根据单位面积上的黏结力、重力以及摩擦力之间的平衡关系得到折焰角部位理论最大积灰高度和实际最大积灰高度。当理论最大积灰高度大于实际最大积灰高度时,沉积层的摩擦力和黏结力大于重力沿折焰角斜面的分力,折焰角斜坡灰不会发生塌灰现象,反之,当理论最大积灰高度小于实际最大积灰高度时,则会发生塌灰现象。针对浙江浙能台州第二发电有限责任公司1 000 MW超超临界П型布置煤粉锅炉折焰角积灰与塌灰特性进行了计算分析,结果表明,当炉膛出口烟温为1 035℃,燃用设计煤种时,折焰角部位实际积灰高度为2. 48 m,小于重力平衡高度6. 69 m,该锅炉折焰角部位不会发生塌灰现象,折焰角设计及运行合理可行,超超临界锅炉折焰角斜坡积灰与塌灰预判模型对锅炉设计及优化运行具有参考价值。
Ultra-supercritical coal-fired power generation technology is an important way of coal clean utilization.Among the ultra-supercritical boilers,the furnace arch at the joint between the furnace outlet of the П type boiler and the horizontal flue is easy to form ash deposition due to the existence of the recirculation zone,which seriously affects the safe operation of the boiler.Through the mechanism analysis of the ash deposition of the furnace arch in the ultra-supercritical coal-fired boiler,including the adhesion force between the ash particle and the sediment and the force of destructing ash deposition the mathematical model of ash deposition of the furnace arch and the pre-judging model of ash collapse were established to give a prediction result of whether the ash collapse would occur,which could provide a guidance plan for the safe operation and maintenance of the power station.The ash deposition and ash collapse pre-judging model obtained the moving speed of the coal ash particles in the flue gas,the depth of the sediment layer and the surface tension based on adopting the coal quality parameters,boiler design parameters and operating data,so as to quantitatively calculate the adhesion force of ash particles in the per unit area of inclined plane of the furnace arch and the impact of the ash particles on sediments.The theoretical maximum ash deposition height and the actual maximum ash deposition height at the furnace arch position were obtained according to the equilibrium relationship among the adhesion force,gravity and frictional force in per unit area.When the theoretical maximum ash deposition height is greater than the actual maximum ash deposition height,the friction and adhesion force of the sediment layer are greater than the component force of gravity along the inclined plane of the furnace arch,and the ash deposition of the furnace arch does not collapse,otherwise,when the maximum ash deposition height is less than the actual maximum ash deposition height,ash collapse will occur.For the 1 000 MW ultra-supercritical П-type coal-fired boiler of Second Electric Power Generation Co.,Ltd. Taizhou Zhejiang province,the characteristics of the ash deposition and ash collapse at the furnace arch were calculated and analyzed.The results show that,the when the furnace outlet temperature is 1 035 ℃ and the design coal is burned,the actual ash height at furnace arch is 2.48 m,which is less than the gravity balance height of 6.69 m.The furnace arch of the boiler does not occur ash collapse,and the design and operation of the furnace arch is reasonable and feasible.The pre-judgment model of ash deposition and ash collapse at the furnace arch of the ultra-supercritical boiler has certain reference value for boiler design and optimization operation.
Ultra-supercritical coal-fired power generation technology is an important way of coal clean utilization.Among the ultra-supercritical boilers,the furnace arch at the joint between the furnace outlet of the П type boiler and the horizontal flue is easy to form ash deposition due to the existence of the recirculation zone,which seriously affects the safe operation of the boiler.Through the mechanism analysis of the ash deposition of the furnace arch in the ultra-supercritical coal-fired boiler,including the adhesion force between the ash particle and the sediment and the force of destructing ash deposition the mathematical model of ash deposition of the furnace arch and the pre-judging model of ash collapse were established to give a prediction result of whether the ash collapse would occur,which could provide a guidance plan for the safe operation and maintenance of the power station.The ash deposition and ash collapse pre-judging model obtained the moving speed of the coal ash particles in the flue gas,the depth of the sediment layer and the surface tension based on adopting the coal quality parameters,boiler design parameters and operating data,so as to quantitatively calculate the adhesion force of ash particles in the per unit area of inclined plane of the furnace arch and the impact of the ash particles on sediments.The theoretical maximum ash deposition height and the actual maximum ash deposition height at the furnace arch position were obtained according to the equilibrium relationship among the adhesion force,gravity and frictional force in per unit area.When the theoretical maximum ash deposition height is greater than the actual maximum ash deposition height,the friction and adhesion force of the sediment layer are greater than the component force of gravity along the inclined plane of the furnace arch,and the ash deposition of the furnace arch does not collapse,otherwise,when the maximum ash deposition height is less than the actual maximum ash deposition height,ash collapse will occur.For the 1 000 MW ultra-supercritical П-type coal-fired boiler of Second Electric Power Generation Co.,Ltd. Taizhou Zhejiang province,the characteristics of the ash deposition and ash collapse at the furnace arch were calculated and analyzed.The results show that,the when the furnace outlet temperature is 1 035 ℃ and the design coal is burned,the actual ash height at furnace arch is 2.48 m,which is less than the gravity balance height of 6.69 m.The furnace arch of the boiler does not occur ash collapse,and the design and operation of the furnace arch is reasonable and feasible.The pre-judgment model of ash deposition and ash collapse at the furnace arch of the ultra-supercritical boiler has certain reference value for boiler design and optimization operation.
引文
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[9]卢红书.锅炉折焰角塌灰对燃烧的影响及防范措施[J].东北电力技术,2016,37(6):47-48,52.LU Hongshu.Analysis on impact and countermeasures of ash fouling for boiler furnace arch[J].Northeast Electric Power Technology,2016,37(6):47-48,52.
[10]麦勇军,徐立力,李军安,等.折焰角型锅炉频繁灭火原因分析与处理[J].广西电力,2014,37(3):47-50.MAI Yongjun,XU Lili,LI Jun'an,et al.Analysis and treatment of frequent outfire of furnace arch type boiler[J].Guangxi Electric Power,2014,37(3):47-50.
[11]兰建辉.670 MW“W”火焰锅炉折焰角积灰治理[J].广西电力,2013,36(6):50-52.LAN Jianhui.Treatment of ash deposition of furnace arch in670 MW“W”falme boiler[J].Guangxi Electric Power,2013,36(6):50-52.
[12]陆雪强.锅炉折焰角塌灰原因分析及处理[J].发电设备,2011,25(6):444-446.LU Xueqiang.Cause analysis on ash collapsing at furnace arch in a boiler and the countermeasures[J].Power Equipment,2011,25(6):444-446.
[13]许继芳,李建朝,翁文凭,等.Mg O-B2O3-SiO2-CaO-Al2O3体系富硼渣表面张力的计算[J].中国有色金属学报,2017,27(1):206-214.XU Jifang,LI Jianchao,WENG Wenping,et al.Calculationof surface tension for Mg O-B2O3-Si O2-CaO-Al2O3molten boronrich slag system[J].The Chinese Journal of Nonferrous Metals,2017,27(1):206-214.
[14]岑可法,樊建人,池作和,等.锅炉和热交换器的积灰、结渣、磨损和腐蚀的防止原理与计算[M].北京:科学出版社,1998.
[15]许洁.典型煤灰与混合灰熔融特性及粘温特性研究[D].上海:华东理工大学,2015.
[16]陈一平,陈耀华,杨剑锋,等.国产首台2 030 t/h“W”火焰锅炉技术改造[J].中国电力,2009,42(2):40-44.CHEN Yiping,CHEN Yaohua,YANG Jianfeng,et al.Technical retrofit on the first domestic 2 030 t/h W-flame boiler[J].Electric Power,2009,42(2):40-44.
[2]沙龙.1 000 MW超超临界褐煤锅炉燃烧技术研究[D].哈尔滨:哈尔滨工业大学,2014.
[3]王旋.煤粉工业锅炉节能增效技术改造研究[J].洁净煤技术,2016,22(1):82-85.WANG Xuan.Technical innovation research on energy saving and efficiency improvement of industrial pulverized coal boiler[J].Clean Coal Technology,2016,22(1):82-85.
[4]廖运波.某600 MW锅炉折焰角斜坡积灰分析及解决措施[J].环境与发展,2017,29(10):231-232.LIAO Yunbo.Analysis of ash filling in a flaring angle slope of a600 MW boiler and its solution[J].Environment and Development,2017,29(10):231-232.
[5]陈一平,于鹏峰,邹自敏,等.火电厂锅炉折焰角斜坡积灰原因及对策[J].中国电力,2011,44(2):46-48.CHEN Yiping,YU Pengfeng,ZOU Zimin,et al.Study on ash fouling of boiler furnace arch and its countermeasures in coal fired power plant[J].Electric Power,2011,44(2):46-48.
[6]姚英俊.燃煤电站锅炉折焰角积灰的原因分析及对策研究[J].中国标准化,2016(15):241,243.YAO Yingjun.Coal-fired power plant boiler flame angle analysis of the causes of formation and countermeasures research[J].China Standardization,2016(15):241,243.
[7]周保中.基于支持向量机的超超临界锅炉受热面污染监测模型研究[J].发电与空调,2016,37(6):36-38,35.ZHOU Baozhong.Research on fouling monitoring model for heating surface of ultra-supercritical boiler based on the support vector machine[J].Power Generation Technology,2016,37(6):36-38,35.
[8]胡洪伟.灰分沉积特性的理论和实验研究[D].合肥:中国科学技术大学,2017.
[9]卢红书.锅炉折焰角塌灰对燃烧的影响及防范措施[J].东北电力技术,2016,37(6):47-48,52.LU Hongshu.Analysis on impact and countermeasures of ash fouling for boiler furnace arch[J].Northeast Electric Power Technology,2016,37(6):47-48,52.
[10]麦勇军,徐立力,李军安,等.折焰角型锅炉频繁灭火原因分析与处理[J].广西电力,2014,37(3):47-50.MAI Yongjun,XU Lili,LI Jun'an,et al.Analysis and treatment of frequent outfire of furnace arch type boiler[J].Guangxi Electric Power,2014,37(3):47-50.
[11]兰建辉.670 MW“W”火焰锅炉折焰角积灰治理[J].广西电力,2013,36(6):50-52.LAN Jianhui.Treatment of ash deposition of furnace arch in670 MW“W”falme boiler[J].Guangxi Electric Power,2013,36(6):50-52.
[12]陆雪强.锅炉折焰角塌灰原因分析及处理[J].发电设备,2011,25(6):444-446.LU Xueqiang.Cause analysis on ash collapsing at furnace arch in a boiler and the countermeasures[J].Power Equipment,2011,25(6):444-446.
[13]许继芳,李建朝,翁文凭,等.Mg O-B2O3-SiO2-CaO-Al2O3体系富硼渣表面张力的计算[J].中国有色金属学报,2017,27(1):206-214.XU Jifang,LI Jianchao,WENG Wenping,et al.Calculationof surface tension for Mg O-B2O3-Si O2-CaO-Al2O3molten boronrich slag system[J].The Chinese Journal of Nonferrous Metals,2017,27(1):206-214.
[14]岑可法,樊建人,池作和,等.锅炉和热交换器的积灰、结渣、磨损和腐蚀的防止原理与计算[M].北京:科学出版社,1998.
[15]许洁.典型煤灰与混合灰熔融特性及粘温特性研究[D].上海:华东理工大学,2015.
[16]陈一平,陈耀华,杨剑锋,等.国产首台2 030 t/h“W”火焰锅炉技术改造[J].中国电力,2009,42(2):40-44.CHEN Yiping,CHEN Yaohua,YANG Jianfeng,et al.Technical retrofit on the first domestic 2 030 t/h W-flame boiler[J].Electric Power,2009,42(2):40-44.