外高桥1000MW超超临界机组闭环控制系统设计

外高桥1000MW超超临界机组是被控特性复杂多变且多变量相关的对象,协调控制系统采用负荷指令的静、动态前馈和汽轮机与锅炉间的解耦回路来保证控制品质;由于该机组锅炉为直流炉,燃水比既与负荷控制相关又与汽温控制密不可分,燃烧和给水控制系统采用以负荷指令为基础的比值控制加二者的解耦回路以基本保证燃水比;过热汽温控制采用以焓值调节器的指令修正给水流量指令来精确保证燃水比为主要手段,以喷水减温为辅助手段;Smith预估器被应用于过热、再热器喷水控制回路中,以解决汽温这种大迟延、大惯性对象的控制难题。

Closed loop control system design for Waigaoqiao 1 000 MW ultra-supercritical power unit

Waigaoqiao 1 000 MW ultra-supercritical unit is a controlled object with complex, changeable and multi-variable coupling characteristics, as a result, the static and dynamic feed forward of load command and the de-coupling loop between boiler and turbine are used in coordinated control system to ensure the control quality. For this once-through boiler, the fuel/water ratio depends on load and steam temperature control, besides, the ratio control strategy based on load demand and de-coupling loop are applied to the fuel and feed water control to ensure a fuel/water ratio basically. In the field of superheated steam temperature control, the command of enthalpy controller, associated with spray desuperheating, is used to modify that of feedwater, even to ensure the fuel/water ratio effectively. In addition, Smith predictor is also applied to the SH and RH spray water control system to improve the control quality of the variables with long delay.