600MW机组低氮燃烧器燃烧性能数值模拟
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摘要
以某600 MW四角切圆煤粉锅炉为研究对象,根据其结构参数、燃烧器改造设计参数,采用FLUENT软件数值建模研究不同负荷下低氮燃烧器的燃烧性能和脱硝系统的运行状态。对燃烧器区域的网格进行特殊处理,并根据冷态速度场进行模型验证,确立数值计算模型。采用Tecplot软件处理计算结果,获得低氮燃烧器改造后不同负荷下炉内的速度场、温度场和各组分浓度场分布。依据于炉内燃烧模拟结果,通过热力计算,获得不同负荷下脱硝系统的运行状态。结果显示:随着负荷的降低,炉内各场发生了较大的变化,当锅炉负荷降到65%ECR时,炉膛出口烟温920℃,脱硝入口烟温305℃,脱硝系统将自动退出。当锅炉在低负荷下运行时,须进行低氮燃烧器的正确调整,提高炉膛出口温度,获得良好的低氮燃烧器和脱硝系统联合运行特性。
According to the structural parameters and reformation design Parameters of burner, numerical studies of combustion properties of low NOx burner and operating status of denitration system for a 600 MW tangentially fired coal boiler were carried out under different loads on FLUENT software platform. The grid of burner zone was specially handled,and numerical model was validated and established based on cold velocity field test. By using Tecplot software to process the calculation results, velocity field, temperature field and component concentration field distribution for the low NOx burner were obtained under different loads. Based on the combustion simulation results,the operating status of denitration system under different loads was gained through thermodynamic calculation. The results showed that: With the decrease of the load, each field in furnace changed greatly,When the boiler load dropped to 65% ECR, the flue gas temperature of furnace outlet was 920℃,the flue gas temperature of denitration system inlet was 305℃, and the denigration system would be cut out automatically. To obtain a good co-operating characteristic of low NOx burner and denitration system, low NOx burner must be adjusted properly to increase the flue gas temperature of furnace outlet when the boiler is running at low load.
According to the structural parameters and reformation design Parameters of burner, numerical studies of combustion properties of low NOx burner and operating status of denitration system for a 600 MW tangentially fired coal boiler were carried out under different loads on FLUENT software platform. The grid of burner zone was specially handled,and numerical model was validated and established based on cold velocity field test. By using Tecplot software to process the calculation results, velocity field, temperature field and component concentration field distribution for the low NOx burner were obtained under different loads. Based on the combustion simulation results,the operating status of denitration system under different loads was gained through thermodynamic calculation. The results showed that: With the decrease of the load, each field in furnace changed greatly,When the boiler load dropped to 65% ECR, the flue gas temperature of furnace outlet was 920℃,the flue gas temperature of denitration system inlet was 305℃, and the denigration system would be cut out automatically. To obtain a good co-operating characteristic of low NOx burner and denitration system, low NOx burner must be adjusted properly to increase the flue gas temperature of furnace outlet when the boiler is running at low load.
引文
[1]中国能源统计年鉴2012[M].北京:中国统计出版社,2012.
[2]GB/T 13223-2011.火电厂大气污染物排放标准[S].
[3]王恩禄,张海燕,罗永浩,等.低NOx燃烧技术及其在我国燃煤电站锅炉中的应用[J].动力工程,2004,24(1):23~27.
[4]LIU Hu,LIU Yinhe,YI Guangzhou,et al.Effects of air staging conditions on the combustion and NOx emission characteristics in a600MW wall fired utility boiler using lean coal[J].Energy Fuels,2013,27(10):5831~5840.
[5]陈山.大型电站锅炉烟气脱硝选择性催化还原系统优化研究[D].杭州:浙江大学,2007.
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[9]HILL S C,L Douglas Smoot.Modeling of nitrogen oxides formation and destruction in combustion systems[J].Progress in Energy and Combustion Science,2000,26(4-6):239~247.
[10]CONSTENLA I,Ferrín J L,SAAVEDRA L.Numerical study of a 350MW tangentially fired pulverized coal furnace of the As Pontes Power Plant[J].Fuel Processing Technology,2013,116:189~200.
[11]Díez L I,Cortés C,Pallarés J.Numerical investigation of NOxemissions from a tangentially-fired utility boiler under conventional and overfire air operation[J].Fuels,2008,87(7):1259~1269.
[2]GB/T 13223-2011.火电厂大气污染物排放标准[S].
[3]王恩禄,张海燕,罗永浩,等.低NOx燃烧技术及其在我国燃煤电站锅炉中的应用[J].动力工程,2004,24(1):23~27.
[4]LIU Hu,LIU Yinhe,YI Guangzhou,et al.Effects of air staging conditions on the combustion and NOx emission characteristics in a600MW wall fired utility boiler using lean coal[J].Energy Fuels,2013,27(10):5831~5840.
[5]陈山.大型电站锅炉烟气脱硝选择性催化还原系统优化研究[D].杭州:浙江大学,2007.
[6]孙克勤,钟秦,于爱华.SCR催化剂的砷中毒研究[J].中国环保产业,2008,(1):40~42.
[7]KOEBEL M,MADIA G,ELSENER M.Selective catalytic reduction of NO and NO2 at low temperature[J].Catalysis Today,2002,73(3):239~247.
[8]Kang M,Park E D,Kim J M,et al.Manganese oxide catalysts for NOx reduction with NH3 at low temperatures[J].Appl Catal A,2007,327(2):261~269.
[9]HILL S C,L Douglas Smoot.Modeling of nitrogen oxides formation and destruction in combustion systems[J].Progress in Energy and Combustion Science,2000,26(4-6):239~247.
[10]CONSTENLA I,Ferrín J L,SAAVEDRA L.Numerical study of a 350MW tangentially fired pulverized coal furnace of the As Pontes Power Plant[J].Fuel Processing Technology,2013,116:189~200.
[11]Díez L I,Cortés C,Pallarés J.Numerical investigation of NOxemissions from a tangentially-fired utility boiler under conventional and overfire air operation[J].Fuels,2008,87(7):1259~1269.