中国电力 ›› 2017, Vol. 50 ›› Issue (11): 175-179.DOI: 10.11930/j.issn.1004-9649.201703052

• 节能与环保 • 上一篇    下一篇

SCR Control+脱硝控制系统研究及其在660 MW机组的应用

武宝会, 李刚, 薛大禹, 贾晓静   

  1. 西安热工研究院有限公司,陕西 西安 710032
  • 收稿日期:2017-03-20 出版日期:2017-11-25 发布日期:2017-11-29
  • 作者简介:武宝会(1961—),男,陕西蒲城人,研究员,从事电站自动化控制、电站锅炉燃烧监测及锅炉环保等技术研究。E-mail: wubaohui@tpri.com.cn

Study on SCR Control+ Denitrification Injection Control System and Its Application in a 660 MW Unit

WU Baohui, LI Gang, XUE Dayu, JIA Xiaojing   

  1. Xi'an Thermal Power Research Institute Co., Ltd., Xi'an 710032, China
  • Received:2017-03-20 Online:2017-11-25 Published:2017-11-29

摘要: 针对SCR脱硝系统大扰动、大惯性、大延迟的特点,以及SCR喷氨控制系统在超低排放改造后运行中普遍存在的问题,结合多个脱硝优化项目的数据积累,提出了带有状态预估控制算法的SCR Control+系统模型。其依据主导因素的分析方法,选取影响NOx浓度的状态变量,通过设计状态变量预估控制模块,可准确、快速预测NOx浓度的变化。也即采用状态变量预估,克服时滞与输入波动影响;应用串级反馈控制,保证控制系统的稳态指标。该喷氨控制系统在660 MW机组的应用结果表明,机组负荷发生较大变化导致SRC反应器入口NOx浓度大幅波动时,SCR反应器出口NOx浓度仍能保持良好的控制状态,与设定值始终偏差很小,且在各种工况下均能实现脱硝控制的快速、有效和稳定,因而可适应超低排放对NOx排放浓度和氨逃逸的控制要求。

关键词: 超低排放, SCR脱硝, 控制模型, 喷氨量控制, 状态预估

Abstract: Regarding the delayed response of SCR DeNOx system due to the high inertia under large perturbations, and other problems in the operation of SCR ammonia injection control system after ultra-low emission retrofit, the SCR Control+ system model with state prediction algorithm is proposed based on the data accumulation of multiple denitrification optimization projects. Through the analysis of dominant factors, the state variables influencing the NOx concentration are selected, and the change of the NOx concentration is accurately and quickly predicted by designing the state variable predictive control module. The state variable predictive control is used to overcome the influence of delay and input perturbation, and the cascade feedback control is applied to ensure the steady state index of the control system. The practical application in a 660 MW unit shows that the DeNOx control system based on SCR Control+ model can effectively maintain the control performance of SCR DeNOx system during large fluctuations of SCR inlet NOx concentrations under substantial load variations and only little deviations are observed from the setting values. The system can realize fast, effective and stable control over the denitrification under all loading conditions, which meets the control requirements for ultra low emissions of NOx and ammonia escape.

Key words: ultra low emission, SCR De-NOx, control model, ammonia injection control, state estimation

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