采用SNCR技术炉内燃烧及脱硝反应过程的数值模拟
摘要
选择性非催化还原法(Selective Non-Catalytic Reduction,简称SNCR)是目前发达国家普遍采用的烟气脱硝方法,是一种建设周期短、投资少、脱硝效率中等的烟气脱硝技术,它比较适合于对中小型电厂锅炉的改造,适合我国国情。
本文是在CRF(Combustion Research Facility)实验台热态实验的基础上,对炉内燃烧和SNCR脱硝反应过程进行数值模拟。首先对CRF实验台炉内燃烧过程进行数值模拟,得出适宜SNCR反应的温度区域。在合理模拟了炉内燃烧过程后,采用后置处理方法模拟计算了污染物NOx的生成过程,得出烟气中各组分浓度的分布并将其数值输出,作为SNCR脱硝反应过程模拟的入口条件。
本文在对燃烧模型简化的基础上,以燃烧及NOx生成模拟得出的结论作为入口条件,进行了SNCR过程的数值模拟。只考虑还原剂为NH3的情况,通过对SNCR过程的模拟得出了温度和氨氮摩尔比对脱硝效率的影响,并与实验结果进行对照。为SNCR烟气脱硝系统的优化设计提供了一定的帮助和指导。
Currently, the method of SNCR (Selective Non-Catalytic Reduction) is generally adopted by the developed countries for NOx removal. With its short period, low investment and average NOx removal efficiency, it is suitable for the retrofit of small and medium utility boilers, which fits China’s situation.
In this thesis, based on the experimental results obtained from CRF(combustion Research Facility), numerial simulation was done to investigate the process of in-furnace combustion and NOx removal. Firstly, the numerical simulation was done on the in-furnace combustion in order to find a suitable temperature region for SNCR. Then, with proper simulation of the temperature distribution, a method of post-simulation was done to simulate the NOx formation process. After that, the gas component concentration was output to be set as the entry parameters of SNCR.
Based on the simplified combustion model and making the results of combustion and NOx formation simulation as the entry parameters, numerical simulation of SNCR was done. With NH3 as the reducing material, the influence of the temperature and NH3/NO ratio on the NOx removal efficiency was attained by the simulation of SNCR process. The comparison between the simulation and the experimental results was also carried out. It lend support to the optimization design of SNCR system.
本文是在CRF(Combustion Research Facility)实验台热态实验的基础上,对炉内燃烧和SNCR脱硝反应过程进行数值模拟。首先对CRF实验台炉内燃烧过程进行数值模拟,得出适宜SNCR反应的温度区域。在合理模拟了炉内燃烧过程后,采用后置处理方法模拟计算了污染物NOx的生成过程,得出烟气中各组分浓度的分布并将其数值输出,作为SNCR脱硝反应过程模拟的入口条件。
本文在对燃烧模型简化的基础上,以燃烧及NOx生成模拟得出的结论作为入口条件,进行了SNCR过程的数值模拟。只考虑还原剂为NH3的情况,通过对SNCR过程的模拟得出了温度和氨氮摩尔比对脱硝效率的影响,并与实验结果进行对照。为SNCR烟气脱硝系统的优化设计提供了一定的帮助和指导。
Currently, the method of SNCR (Selective Non-Catalytic Reduction) is generally adopted by the developed countries for NOx removal. With its short period, low investment and average NOx removal efficiency, it is suitable for the retrofit of small and medium utility boilers, which fits China’s situation.
In this thesis, based on the experimental results obtained from CRF(combustion Research Facility), numerial simulation was done to investigate the process of in-furnace combustion and NOx removal. Firstly, the numerical simulation was done on the in-furnace combustion in order to find a suitable temperature region for SNCR. Then, with proper simulation of the temperature distribution, a method of post-simulation was done to simulate the NOx formation process. After that, the gas component concentration was output to be set as the entry parameters of SNCR.
Based on the simplified combustion model and making the results of combustion and NOx formation simulation as the entry parameters, numerical simulation of SNCR was done. With NH3 as the reducing material, the influence of the temperature and NH3/NO ratio on the NOx removal efficiency was attained by the simulation of SNCR process. The comparison between the simulation and the experimental results was also carried out. It lend support to the optimization design of SNCR system.
引文
1中电联. 2004全国电力生产主要指标. http://www.ncpe.com.cn/tjzyw/tjgcscd/cd050102.htm, 2005-03-21
2郭永红.超细粉再燃低NOx燃烧技术的数值模拟与实验研究.博士学位论文.华北电力大学, 2006
3中华报告网. 2005中国煤炭行业投资于发展分析报告. http://www. Ccmnrt.com/B7/200507/B70201200507011456210000.asp
4田贺忠.中国氮氧化物排放现状、趋势及综合控制对策研究.博士学位论文:清华大学, 2003
5郑守忠.煤粉再燃技术中煤焦异相还原高温烟气中NO的实验和理论研究.博士学位论文.东南大学, 1999
6岑可法,姚强,骆仲泱.燃烧理论与污染控制.机械工业出版社,2004
7 L. L. Sloss. NOx emission from coal combustion. IEA Coal Research/36, 1991
8 C. Anderson, B. M. Brannstrom-Norberg, B. Hanell. Nitrous oxide emissions from different combustion sources. 1998, 23(3): 18~23
9 F. Kildsig, P. Morsig. N2O-Emission aus Kesselanlagen. In: VGB Kraftwerkstechnik 1991, 71(6): 592~593
10詹跃航.采用天然气再燃技术降低煤粉锅炉NOx生成的冷模实验研究.硕士学位论文.重庆大学, 2002: 10~20
11任俊清.工业锅炉氮氧化物的形成及降低措施.山西建筑. 2004, 30(70): 125~126
12朱法华,王圣,郑有飞.火电NOx排放现状与预测及控制对策.能源环境保护. 2004, 18(1): 1~5
13曾汉才,姚斌,程俊峰,王湘江.关于我国大型锅炉NOx排放评价及其排放标准修订的建议.锅炉制造. 2001(4): 1~4
14 Y. B. Zeldovich. The oxidation of nitrogen in combustion and explosions. Acta Physicochim, URSS, 1946, 21: 577~583
15 C. T. Bowman. Kinetics of nitric oxide formation in combustion processes. In: Proceedings of the Fourteenth Symposium (International) on combustion. Pittsburgh, PA, The combustion Institute, 1973: 270
16赵坚行.热动力装置的排气污染与噪声.科学出版社,1995
17氮氧化物排放控制技术经验总结.西安热工研究所, 1994
18 L. D. Smoot and P. J. Smith. NOx Pollutant Formation in a Turbulent Coal System. Coal Combustion and Gasification, Plenum, NY, 1985: 373
19 F. C. Lockwood and C. A. Romo-Millianes. Mathematical Modelling of Fuel-NO Emissions From PF Burners. J. Int. Energy, 1992, 65: 144~152
20 M. A. Leschziner. Practicals Evaluation of Three Finite Difference Schemes for the Computation of Steaty-State Recirculating Flow. Comput Mesheods Appl. Mech. Engrg, 1980, 23: 293~312
21 C. P. Fenimore. Formation of nitric oxide from fuel nitrogen in ethylent flames. Combustion and Flames. 1972, 19: 289~302
22 C. P. Fenimore. Reactions of fuel-nitrogen in rich flame gases. Combustion and Flames. 1976, 26: 249~256
23陈代宾.燃煤电厂选择性催化脱硝工艺的实践与探讨.电力环境保护. 2003, 19(3): 21~22
24 M. J. Rini, J. A. Nicholson, and M. B. Cohen. Evaluating the SNCR Process for Tangentially-Fired Boilers. Presented at the 1993 Joint Symposium on Stationary Combustion NOx Control, Bal Harbor, Florida., 1993: 24~27
25 Selective Non Catalytic Reduction for NOx Control on Coal-fired Boilers, Draft Report, prepared for the U.S. Environmental Protection Agency by The Cadmus Group, Inc., Bechtel Power Corporation, and Science Applications International Corporation. 1998: 7~9
26孙锦余.利用氮氧化物控制技术治理大气污染.节能. 2004, (5): 41~44
27马保国,李相国,胡贞武,张平均.煤燃烧过程中NOx的形成及控制技术.武汉理工大学学报. 2004, 26(4): 33~35
28陈杭君,赵华,丁经纬.火电厂烟气脱硝技术介绍.热力发电. 2005, (2): 15~19
29王斌. SCR脱硝技术及其在燃煤电厂中的应用.电力科学与工程. 2003, (3): 61~63
30赵华,丁经纬,毛继亮.选择性催化还原法烟气脱氮技术现状[J],中国电力Vol. 37, 2004, 12: 7~76
31路涛,贾双燕,李晓芸.关于烟气脱硝技术的SNCR工艺及其技术经济分析.现代电力. 2004,21(1): 17~22
32 M. J. Rini, J. A. Nicholson and M. B. Cohen. Evaluating the SNCR Process ForTangentially-Fired Boilers. Presented at the 1993 Joint Symposium on Stationary Combustion NOx Control, Bal Habor, Florida. 1993: 24~27
33钟秦.选择性非催化还原法脱除NOx的实验研究.南京理工大学学报. 2000, 24(1): 68~71
34钟秦.燃煤烟气脱硫脱硝技术及工程实例.化学工业出版社, 2002
35 J. R. Comparato. NOx Control Technologies: Focus SNCR. Western Coal Council Burning PRB Coal Seminar, Birmingham, Alabama, 1996: 24~26
36肖理生.大型贫煤锅炉高效低NOx分级燃烧技术的实验研究与数值模拟.华中理工大学博士论文,2000
37 Fluernt Inc. FLUENT user’s guide: release 6.0 [Z]. Lebanon, USA: Fluent Inc, 2001
38赵坚行.燃烧的数值模拟.科学出版社, 2002
39陶文铨.数值传热学.西安交通大学出版社, 1988
40帕坦卡S. V,张政译.传热与流体流动的数值计算.科学出版社, 1984
41傅维标.燃烧物理学基础.机械工业出版社, 1986
42王应时,范维澄,周力行,徐旭常.燃烧过程数值计算.科学出版社, 1986
43朱志强. W型火焰燃烧室燃烧过程及污染物生成的数值模拟.华北电力大学硕士论文, 2001
44李永华等. 800MW锅炉混煤燃烧数值模拟.中国电机工程学报. 2002, 22(6): 101~104
45张志刚.采用超细煤粉再燃锅炉降低NOx排放的数值模拟.华北电力大学硕士论文, 2005
46许言武.使用超细煤粉再燃技术的锅炉炉内过程的数值模拟.华北电力大学硕士论文, 2004
47 T. H. Shah, W. W. Liou, A. Shabbit and J. Zhu. A New k ?εEddy Viscosity Model for High Reynolds Number Turbulent Flows. Cmputers Fluilds, 1995, 24(3): 227~238
48 V. S. Krishnamurty, J. K. Clutter et al. Study of Two-Equation Based Modeling For Compressible Turbulent Flows, AIAA 96-0518, 1996
49 Fortsch, Dieter. Kluger, Frank, Schnell, Uwe, Spliethoit, Hartmut, Hein, R. G. Klaus. Kinetic modle for the prediction of NO emissions from staged combustion of pulverized coal. Symposium (International) on Combustion v 2, 1998: 3037~3044
50 D. B. Spalding, Concentration Fluctions in a Round Turbulent Free Jet, Chemical Engineering Scince, 1971, Vol. 26: 95~107
51 M. J. Rini, J. A. Nicholson, and M. B. Cohen. Evaluating the SNCR Process For Tangentially-Fired Boilers. Presented at the 1993 Joint Symposium on Stationary Combustion NOx Control, Bal Habor, Florida. 1993:24~27
52 J. R. Howell, M. Perlmuffer, Monte Carlo. Solution of Radiative Heat Transfer in a Nongray. Nonsithermal Gas with Temperature Depandant Properties. Aner. Iust. Chem. Eng. J. V10, 1964
53 R. D. Boardman, L. D. Smoot. Pollutant formation and control. In: L. D. Smoot, editor. Fundamentals of coal combustion for clean and efficient use. Amsterdam: Elsevier, 1993: 433
54 R. K. Lyon. Method for the Reduction of the Concentration of NO in Combustion Effluents Using Ammonia. U.S. Patent 3900554, 1975
55 L. J. Muzio, J. K. Arand and D. P. Teixeira. Proc. Combust. Inst. 1976, 16: 199~208
56 M. A. Cremer, C. J. Montgomery. Development and Implementation of Reduced Chemistry For Computional Fluid Dynamics Modeling Of Selective Non-Catalytic Reduction. Proceedings of the Combustion Institute. 2000: 2427-2434
57 R. J. Kee, F. M. Rumpley and J. A. Miller. The Chemkin Thermodynamic database. Sandia National Laoratories. Sandia report, SAND87-9215B. 1997
58 R. J. Kee, F. M. Rumpley and J. A. Miller. Chemkin-II: A Fortran Chemical Kinetics Package for the Analysis of Gas Phase Chemical Kinetics. Sandia report, SAND89-9009B. 1998
59 J. Brouwer, M. P. Heap, D. W. Pershing and P. J. Smith. A Modle for prediction of Selective Non-Catalytic Reduction of nitrogen oxides by ammonia, urea, and cyanuric acid with mixing limitations in the presense of CO Proc. Combust. Inst. 1996, 26: 2117~2124
60 M. A. Cremer, C. J. Montgomery. Development and implementation of reduced chemistry for computional fluid dynamics modeling of Selective Non-Catalytic Reduction. Proceedings of the Combustion Institute, Volume 28, 2000: 2427~2434
2郭永红.超细粉再燃低NOx燃烧技术的数值模拟与实验研究.博士学位论文.华北电力大学, 2006
3中华报告网. 2005中国煤炭行业投资于发展分析报告. http://www. Ccmnrt.com/B7/200507/B70201200507011456210000.asp
4田贺忠.中国氮氧化物排放现状、趋势及综合控制对策研究.博士学位论文:清华大学, 2003
5郑守忠.煤粉再燃技术中煤焦异相还原高温烟气中NO的实验和理论研究.博士学位论文.东南大学, 1999
6岑可法,姚强,骆仲泱.燃烧理论与污染控制.机械工业出版社,2004
7 L. L. Sloss. NOx emission from coal combustion. IEA Coal Research/36, 1991
8 C. Anderson, B. M. Brannstrom-Norberg, B. Hanell. Nitrous oxide emissions from different combustion sources. 1998, 23(3): 18~23
9 F. Kildsig, P. Morsig. N2O-Emission aus Kesselanlagen. In: VGB Kraftwerkstechnik 1991, 71(6): 592~593
10詹跃航.采用天然气再燃技术降低煤粉锅炉NOx生成的冷模实验研究.硕士学位论文.重庆大学, 2002: 10~20
11任俊清.工业锅炉氮氧化物的形成及降低措施.山西建筑. 2004, 30(70): 125~126
12朱法华,王圣,郑有飞.火电NOx排放现状与预测及控制对策.能源环境保护. 2004, 18(1): 1~5
13曾汉才,姚斌,程俊峰,王湘江.关于我国大型锅炉NOx排放评价及其排放标准修订的建议.锅炉制造. 2001(4): 1~4
14 Y. B. Zeldovich. The oxidation of nitrogen in combustion and explosions. Acta Physicochim, URSS, 1946, 21: 577~583
15 C. T. Bowman. Kinetics of nitric oxide formation in combustion processes. In: Proceedings of the Fourteenth Symposium (International) on combustion. Pittsburgh, PA, The combustion Institute, 1973: 270
16赵坚行.热动力装置的排气污染与噪声.科学出版社,1995
17氮氧化物排放控制技术经验总结.西安热工研究所, 1994
18 L. D. Smoot and P. J. Smith. NOx Pollutant Formation in a Turbulent Coal System. Coal Combustion and Gasification, Plenum, NY, 1985: 373
19 F. C. Lockwood and C. A. Romo-Millianes. Mathematical Modelling of Fuel-NO Emissions From PF Burners. J. Int. Energy, 1992, 65: 144~152
20 M. A. Leschziner. Practicals Evaluation of Three Finite Difference Schemes for the Computation of Steaty-State Recirculating Flow. Comput Mesheods Appl. Mech. Engrg, 1980, 23: 293~312
21 C. P. Fenimore. Formation of nitric oxide from fuel nitrogen in ethylent flames. Combustion and Flames. 1972, 19: 289~302
22 C. P. Fenimore. Reactions of fuel-nitrogen in rich flame gases. Combustion and Flames. 1976, 26: 249~256
23陈代宾.燃煤电厂选择性催化脱硝工艺的实践与探讨.电力环境保护. 2003, 19(3): 21~22
24 M. J. Rini, J. A. Nicholson, and M. B. Cohen. Evaluating the SNCR Process for Tangentially-Fired Boilers. Presented at the 1993 Joint Symposium on Stationary Combustion NOx Control, Bal Harbor, Florida., 1993: 24~27
25 Selective Non Catalytic Reduction for NOx Control on Coal-fired Boilers, Draft Report, prepared for the U.S. Environmental Protection Agency by The Cadmus Group, Inc., Bechtel Power Corporation, and Science Applications International Corporation. 1998: 7~9
26孙锦余.利用氮氧化物控制技术治理大气污染.节能. 2004, (5): 41~44
27马保国,李相国,胡贞武,张平均.煤燃烧过程中NOx的形成及控制技术.武汉理工大学学报. 2004, 26(4): 33~35
28陈杭君,赵华,丁经纬.火电厂烟气脱硝技术介绍.热力发电. 2005, (2): 15~19
29王斌. SCR脱硝技术及其在燃煤电厂中的应用.电力科学与工程. 2003, (3): 61~63
30赵华,丁经纬,毛继亮.选择性催化还原法烟气脱氮技术现状[J],中国电力Vol. 37, 2004, 12: 7~76
31路涛,贾双燕,李晓芸.关于烟气脱硝技术的SNCR工艺及其技术经济分析.现代电力. 2004,21(1): 17~22
32 M. J. Rini, J. A. Nicholson and M. B. Cohen. Evaluating the SNCR Process ForTangentially-Fired Boilers. Presented at the 1993 Joint Symposium on Stationary Combustion NOx Control, Bal Habor, Florida. 1993: 24~27
33钟秦.选择性非催化还原法脱除NOx的实验研究.南京理工大学学报. 2000, 24(1): 68~71
34钟秦.燃煤烟气脱硫脱硝技术及工程实例.化学工业出版社, 2002
35 J. R. Comparato. NOx Control Technologies: Focus SNCR. Western Coal Council Burning PRB Coal Seminar, Birmingham, Alabama, 1996: 24~26
36肖理生.大型贫煤锅炉高效低NOx分级燃烧技术的实验研究与数值模拟.华中理工大学博士论文,2000
37 Fluernt Inc. FLUENT user’s guide: release 6.0 [Z]. Lebanon, USA: Fluent Inc, 2001
38赵坚行.燃烧的数值模拟.科学出版社, 2002
39陶文铨.数值传热学.西安交通大学出版社, 1988
40帕坦卡S. V,张政译.传热与流体流动的数值计算.科学出版社, 1984
41傅维标.燃烧物理学基础.机械工业出版社, 1986
42王应时,范维澄,周力行,徐旭常.燃烧过程数值计算.科学出版社, 1986
43朱志强. W型火焰燃烧室燃烧过程及污染物生成的数值模拟.华北电力大学硕士论文, 2001
44李永华等. 800MW锅炉混煤燃烧数值模拟.中国电机工程学报. 2002, 22(6): 101~104
45张志刚.采用超细煤粉再燃锅炉降低NOx排放的数值模拟.华北电力大学硕士论文, 2005
46许言武.使用超细煤粉再燃技术的锅炉炉内过程的数值模拟.华北电力大学硕士论文, 2004
47 T. H. Shah, W. W. Liou, A. Shabbit and J. Zhu. A New k ?εEddy Viscosity Model for High Reynolds Number Turbulent Flows. Cmputers Fluilds, 1995, 24(3): 227~238
48 V. S. Krishnamurty, J. K. Clutter et al. Study of Two-Equation Based Modeling For Compressible Turbulent Flows, AIAA 96-0518, 1996
49 Fortsch, Dieter. Kluger, Frank, Schnell, Uwe, Spliethoit, Hartmut, Hein, R. G. Klaus. Kinetic modle for the prediction of NO emissions from staged combustion of pulverized coal. Symposium (International) on Combustion v 2, 1998: 3037~3044
50 D. B. Spalding, Concentration Fluctions in a Round Turbulent Free Jet, Chemical Engineering Scince, 1971, Vol. 26: 95~107
51 M. J. Rini, J. A. Nicholson, and M. B. Cohen. Evaluating the SNCR Process For Tangentially-Fired Boilers. Presented at the 1993 Joint Symposium on Stationary Combustion NOx Control, Bal Habor, Florida. 1993:24~27
52 J. R. Howell, M. Perlmuffer, Monte Carlo. Solution of Radiative Heat Transfer in a Nongray. Nonsithermal Gas with Temperature Depandant Properties. Aner. Iust. Chem. Eng. J. V10, 1964
53 R. D. Boardman, L. D. Smoot. Pollutant formation and control. In: L. D. Smoot, editor. Fundamentals of coal combustion for clean and efficient use. Amsterdam: Elsevier, 1993: 433
54 R. K. Lyon. Method for the Reduction of the Concentration of NO in Combustion Effluents Using Ammonia. U.S. Patent 3900554, 1975
55 L. J. Muzio, J. K. Arand and D. P. Teixeira. Proc. Combust. Inst. 1976, 16: 199~208
56 M. A. Cremer, C. J. Montgomery. Development and Implementation of Reduced Chemistry For Computional Fluid Dynamics Modeling Of Selective Non-Catalytic Reduction. Proceedings of the Combustion Institute. 2000: 2427-2434
57 R. J. Kee, F. M. Rumpley and J. A. Miller. The Chemkin Thermodynamic database. Sandia National Laoratories. Sandia report, SAND87-9215B. 1997
58 R. J. Kee, F. M. Rumpley and J. A. Miller. Chemkin-II: A Fortran Chemical Kinetics Package for the Analysis of Gas Phase Chemical Kinetics. Sandia report, SAND89-9009B. 1998
59 J. Brouwer, M. P. Heap, D. W. Pershing and P. J. Smith. A Modle for prediction of Selective Non-Catalytic Reduction of nitrogen oxides by ammonia, urea, and cyanuric acid with mixing limitations in the presense of CO Proc. Combust. Inst. 1996, 26: 2117~2124
60 M. A. Cremer, C. J. Montgomery. Development and implementation of reduced chemistry for computional fluid dynamics modeling of Selective Non-Catalytic Reduction. Proceedings of the Combustion Institute, Volume 28, 2000: 2427~2434