[关键词]
[摘要]
针对燃煤机组SCR脱硝系统出口NOx浓度大时延、大惯性导致常规PID控制效果不佳的问题,提出了串级IMC-PID的出口NOx浓度控制方案。对SCR脱硝系统出口NOx浓度进行扰动试验,根据试验数据并基于单纯形(Nelder-mead)法实现了对出口NOx浓度动态特性的系统辨识,构建出口NOx浓度的被控对象模型,基于所得模型参数实现对串级IMC-PID控制系统的参数整定。将重新设计的控制系统用于某300 MW亚临界燃煤机组的SCR脱硝系统,实际应用效果表明,与原始控制方案相比,采用串级IMC-PID控制方案的SCR脱硝系统的出口NOx浓度控制平稳,波动范围明显减小,控制效果显著改善。
[Key word]
[Abstract]
Since the outlet NOx concentration control of the SCR system based on conventional PID is usually poor,a cascade IMC-PID controller was proposed to improve the control performance.Based on the data acquired by step change test and Nelder-Mead algorithm,the model for the dynamic characteristic of outlet NOx concentration was established and the model parameters were determined.Through the established model and its parameters,the cascade IMC-PID controller could be tuned properly.Finally,the improved controller was applied to the outlet NOx concentration control of an actual 300 MW subcritical unit.The actual application indicated that the control performance based on cascade IMC-PID controller was satisfactory in comparison with conventional PID controller.
[中图分类号]
X705
[基金项目]
国家自然科学基金(51676131);上海市科委项目资助(13DZ2260900)