超临界机组锅炉给水控制系统的研究

Research and analysis of feedwater control system of supercritical concurrent boiler

针对超临界火力发电机组运行过程中燃料量、给水流量与负荷指令变化呈现不同的时间特性,从而对水煤比和汽温控制产生较大影响的实际问题。在对前馈-反馈控制原理、闭环回路工作周期、水煤比的动态与静态分析等方法进行详细阐述的基础上,采用超前滞后模块、测量值滤波、调整控制参数以及优化运行方式等手段,提高了直流锅炉控制系统的稳定性和准确性。同时,该方法在辅助调峰时段可以完全满足直流锅炉低负荷条件下的给水控制要求。试验结果表明,所提出的控制过程时间同步和测量值滤波策略具有便于实现和整定计算的优点,相比文献[1]中相位和工作周期的解析方法,给水控制系统的稳态指标提高约5 t/h。

In view of the fact that the fuel flow,feed water flow and load instructions change in different time characteristics during the operation of supercritical thermal power units,which has a greater impact on water-coal ratio and steam temperature control.On the basis of detailed description of feed-forward-feedback control principle,closed-loop working cycle,dynamic and static analysis of water-coal ratio,the stability and accuracy of once-through boiler control system are improved by means of Leading-Lag module,measurement filtering,adjusting control parameters and optimizing operation mode.At the same time,the method can fully meet the requirements of feed water control of once-through boiler under low load conditions during the auxiliary peak regulation period.The experimental results show that the proposed strategy of time synchronization and measurement filtering for the control process in this paper has the advantages of easy implementation and tuning calculation.Compared with the analysis method of phase and duty cycle in Document[1],the steady state index of the feed water control system is increased by 5 t/h.