Journal of South China University of Technology(Natural Science) >

2023 , Vol. 51 >Issue 8: 62 - 70

DOI: https://doi.org/10.12141/j.issn.1000-565X.220446

Energy, Power & Electrical Engineering

Optimization Simulation of Ammonia Injection in SCR DeNO x System of Coal-Fired Power Plant

  • LU Zhimin ,
  • LI Bohang ,
  • TANG Wen ,
  • CHEN Yongcheng ,
  • WU Kangluo ,
  • YAO Shunchun
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  • 1.School of Electric Power Engineering, South China University of Technology, Guangzhou 510640, Guangdong, China
    2.Guangdong Red Bay Power Generation Co. , Ltd. , Shanwei 516623, Guangdong, China
卢志民（1979-），男，教授，博士生导师，主要从事固体燃料高效低污染利用研究。

Received date: 2022-07-13

  Online published: 2023-01-20

Supported by

the National Natural Science Foundation of China(51876068);Guangdong Provincial Science and Technology Plan Project(2020A0505140001);the Natural Science Foundation of Guangdong Province(2022A1515010741)

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Abstract

To improve the uniformity of NO x mass concentration distribution at the outlet of SCR (selective catalytic reduction) denitration reactor of a 660 MW unit, this paper proposed an optimal ammonia injection strategy based on the kinetic model with the objective of minimizing the relative standard deviation of NO x mass concentration distribution at the outlet of SCR. The on-site measured data was used as the inlet boundary condition, and CFD numerical simulation calculations were conducted by coupling turbulent flow, component transport, and chemical reactions in the reactor. The ammonia flow characteristics was visually analyzed, and the flow influence coefficient of the ammonia injection grid partition/nozzle was defined. The optimal controllable ammonia injection flow of different partitions or nozzles of the ammonia injection grid can be obtained by directly solving the optimization matrix equation, and combining the mathematical relationship between the outlet NO x concentration distribution and the inlet NH3 concentration, which is based on the SCR reaction kinetics model. The simulation results show that under the uniform ammonia injection mode, the mixing matching degree of ammonia nitrogen concentration in different zones is not high, the relative standard deviation of NO x mass concentration at the outlet of SCR reactor reaches 40.1%, and the uniformity of NO x mass concentration distribution at the outlet is poor. After the optimization of ammonia injection according to the method proposed in the paper, the relative standard deviation of NO x mass concentration at the outlet decreases to 6.8%, and the uniformity of the outlet is greatly improved. This can not only realize the pressure line emission of NO x to meet environmental requirements but also avoid areas with high and low denitrification efficiency. The flow field was visualized through numerical simulation in the article, and ammonia injection optimization was carried out by quantitatively solving the ammonia injection volume of each valve. This can provide theoretical reference for actual ammonia injection optimization debugging in power plants and reduce the blindness of adjustment.

Key words： SCR DeNO x reaction; numerical simulation; ammonia spraying optimization; NO x concentration field; kinetic model

Cite this article

LU Zhimin , LI Bohang , TANG Wen , CHEN Yongcheng , WU Kangluo , YAO Shunchun . Optimization Simulation of Ammonia Injection in SCR DeNO x System of Coal-Fired Power Plant[J]. Journal of South China University of Technology(Natural Science), 2023 , 51(8) : 62 -70 . DOI: 10.12141/j.issn.1000-565X.220446

References

1 冯前伟，张杨，王丰吉，等 ．燃煤机组SCR脱硝超低排放改造前后性能对比分析［J］．中国电机工程学报，2020，40（20）：6644-6652.
  FENG Qianwei， ZHANG Yang， WANG Fengji，et al ．Performance comparison and analysis before and after SCR ultra-low emission transformation of coal-fired units ［J］．Proceedings of the CSEE，2020，40（20）：6644-6652.
2 杨婷婷，白杨，吕游，等 ．SCR脱硝系统多目标优化控制研究［J］．中国电机工程学报，2021，41（14）：4905-4911.
  YANG Tingting， BAI Yang， You Lü，et al ．Study on multi-objective optimal control of SCR denitrification system ［J］．Proceedings of the CSEE，2021，41（14）：4905-4911.
3 于玉真，李伟亮，王绍龙，等 ．SCR脱硝系统流道均流装置数值模拟与优化［J］．中国电机工程学报，2018，38（24）：7304-7313，7457.
  YU Yuzhen， LI Weiliang， WANG Shaolong，et al ．Numerical simulation and optimization of SCR DeNO x system flow channel flow-equalizing equipment ［J］．Proceedings of the CSEE，2018，38（24）：7304-7313，7457.
4 李军状，杨勇平，朱法华，等 ．SCR高脱硝效率燃煤发电机组逃逸氨分布特性实测研究［J］．中国电机工程学报，2021，41（10）：3447-3453.
  LI Junzhuang， YANG Yongping， ZHU Fahua，et al ．Actual measurement study on escaped ammonia distribution with SCR high denitration efficiency of coal-fired unit ［J］．Proceedings of the CSEE，2021，41（10）：3447-3453.
5 王乐乐，孔凡海，何金亮，等 ．超低排放形势下SCR脱硝系统运行存在问题与对策［J］．热力发电，2016，45（12）：19-24.
  WANG Lele， KONG Fanhai， HE Jinliang，et al ．Difficulties and countermeasures of SCR denitration system operation in ultra low emission situation ［J］．Thermal Power Generation，2016，45（12）：19-24.
6 刘国富，沈德魁，肖睿 ．基于流场诊断的燃煤电站SCR系统喷氨优化及试验验证［J］．东南大学学报（自然科学版），2017，47（1）：98-106.
  LIU Guofu， SHEN Dekui， XIAO Rui ．Optimization and experimental verification of AIG tuning for SCR system of coal-fired power station based on diagnose of flow field ［J］．Journal of Southeast University （Natural Science Edition），2017，47（1）：98-106.
7 CHO J M， CHOI J W， HONG S H，et al ．Application of computational fluid dynamics analysis for improving performance of commercial scale selective catalytic reduction ［J］．Korean Journal of Chemical Engineering，2006，23（1）：43-56.
8 LIU G F， BAO W Y， ZHANG W，et al ．An intelligent control of NH3 injection for optimizing the NO x /NH3 ratio in SCR system ［J］．Journal of the Energy Institute，2019，92（5）：1262-1269.
9 郅勇 ．燃煤机组SCR系统流场设计与喷氨优化研究［D］．武汉：华中科技大学，2016.
10 卢志民，李文庆，廖永进，等 ．基于影响因子的SCR脱硝系统喷氨量优化模拟［J］．中国电机工程学报，2021，41（14）：4923-4930.
  LU Zhimin， LI Wenqing， LIAO Yongjin，et al ．Influential factors-based optimization simulation of ammonia injection in SCR DeNO x system ［J］．Proceedings of the CSEE，2021，41（14）：4923-4930.
11 孙虹，华伟，黄治军，等 ．基于CFD建模的1 000 MW电站锅炉SCR脱硝系统喷氨策略优化［J］．动力工程学报，2016，36（10）：810-815，821.
  SUN Hong， HUA Wei， HUANG Zhijun，et al ．CFD-based numerical simulations on optimization of the ammonia spraying strategy in a 1 000 MW SCR denitrification system ［J］．Journal of Chinese Society of Power Engineering，2016，36（10）：810-815，821.
12 计佳青，王琦，沈德魁，等 ．660 MW燃煤机组SCR系统流场及喷氨优化［J］．中国计量大学学报，2020，31（2）：257-265.
  JI Jiaqing， WANG Qi， SHEN Dekui，et al ．Optimization of flow field and ammonia injection of SCR systems for 660 MW coal-fired units ［J］．Journal of China Jiliang University，2020，31（2）：257-265.
13 李文庆 ．燃煤电厂SCR脱硝系统分区喷氨优化模拟研究［D］．广州：华南理工大学，2021.
14 成明涛，钟俊，廖永进，等 ．基于流场多变的SCR脱硝系统喷氨优化调整试验［J］．热力发电，2016，45（12）：130-136.
  CHENG Mingtao， ZHONG Jun， LIAO Yongjin，et al ．Optimization experiments of ammonia-injection in SCR denitrification system based on changeable flow field ［J］．Thermal Power Generation，2016，45（12）：130-136.
15 NGU Y T，LIM Y， EOM W H，et al ．Experiment and CFD simulation of hybrid SNCR-SCR using urea solution in a pilot-scale reactor ［J］．Computers and Chemical，2010，34（10）：1580-1589.
16 孙桐，卢平，蔡杰，等 ．SCR脱硝反应器流场的数值模拟及结构优化［J］．电站系统工程，2015，31（4）：6-8，12.
  SUN Tong， LU Ping， CAI Jie，et al ．Simulation and structure optimization of a SCR reactor ［J］．Power System Engineering，2015，31（4）：6-8，12.
17 周智健，王信，常剑，等 ．660 MW燃煤电厂SCR脱硝系统CFD模拟优化研究［J］．中国电机工程学报，2021，41（19）：6688-6699.
  ZHOU Zhijian， WANG Xin， CHANG Jian，et al ．CFD simulation and optimization of SCR DeNO x system in a 660 MW coal-fired power plant ［J］．Proceedings of the CSEE，2021，41（19）：6688-6699.
18 余廷芳，李俊，曾过房，等 ．火电厂SCR烟气脱硝装置的模拟优化［J］．南昌大学学报（工科版），2014，36（2）：113-117，132.
  YU Tingfang， LI Jun， ZENG Guofang，et al ．Simulation and optimization for flue gas SCR reactor of thermal power units ［J］．Journal of Nanchang University （Engineering Science Edition），2014，36（2）：113-117，132.
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