保定热电厂450 t/h CFB锅炉床温控制系统改造

针对保定热电厂450t/h循环流化床(CFB)锅炉原床温控制系统难以投入运行的问题,提出采用负荷分段控制,用串级控制替换原有的单回路控制,引入床温变化率作为速度反馈量,设计前馈控制,并用主汽流量对床温设定值进行修正。改造效果表明,有效改善了系统的动态品质,超调量减小,上升时间、峰值时间、调节时间都缩短,控制速度加快,对工况改变时模型变化的鲁棒性有较大提高,调节机构的稳定性提高,自动投运率提高。此项改造为提高CFB锅炉运行的稳定性提供参考。

Reconstruction of bed temperature control system of 450 t/h CFB boiler in Baoding Cogeneration Power Plant

In view of difficulties to put the bed temperature control system into operation on 450 t/h CFB boiler in Baoding Cogeneration Power Plant, several measures were presented, such as the load piecewise control was proposed, previous single loop control was replaced by cascade control, change rate of bed temperature was led in as rate feedback, feed -forward control was designed, and the set point of bed temperature was corrected by steam flow. The results show that the reconstruction is effective to improve the dynamic performance in overshoot and control speed, in addition, the robustness of models is enhanced in case of conditions variation, the stability of control mechanism and automatic in-operation rate are improved. This takes great reference for ensuring the stable operation of CFB boilers.