Research on Performance Optimization of Denitration Control System for Coal-Fired Units Under Deep Peak Regulation Mode

As the penetration rate of green energies like wind and solar power continues to rise, grid stability faces growing challenges. Coal-fired units are required to perform deep peak shaving to stabilize grid operations; however, this practice leads to unstable boiler combustion and degraded flue gas conditions, resulting in significant fluctuations in NO_x emissions and high ammonia slip rates. To address these issues, this paper proposes an advanced control strategy coupled with intelligent feedforward technology to enhance the performance of the boiler′s denitration control system. Taking the 2×700 MW subcritical coal-fired units at Zhuhai power plant as the research subject, an advanced control system based on an externally mounted PLC was designed. It employs a cascade control structure and incorporates algorithms such as engineering fast control (EFC) and intelligent feedforward control to optimize ammonia injection dosage. Field tests demonstrate that the upgraded denitration system effectively improves the SCR system′s performance under deep peak shaving conditions, providing robust technical support for safe, economical, and environmentally friendly unit operation.