基于中间点焓值校正的超超临界机组给水控制策略仿真

Simulation Study on Water-feeding Control Strategy for Ultra-supercritical Units Based on Intermediate Point Enthalpy Correction

纯直流阶段的给水自动控制是超超临界直流发电机组控制系统的核心部分,在传统给水自动控制系统的基础上,以燃水比为基础,选取分离器出口微过热蒸汽焓值作为燃水比的反馈信号,在机组变负荷情况下,将二者作为主控对象进行动态校正。DCS和AnySimu平台的仿真结果表明:优化后的直流给水自控策略将主蒸汽温度控制在可调范围内,并且兼顾了燃水比的快速性和精确性。

The water-feeding control in once-through stage means great to uhra-supercritical units. Basing on the traditional water control strategy and the water-coal ratio, a control strategy which having slightly-superhea- ted steam enthalpy at the separator exit chosen as the feedback signal of water-coal ratio was presented ;and as the mainly-controlled objects,both slightly-superheated steam enthalpy and water-coal ratio were dynamically corrected. The simulation with the AnySimu software indicates that the improved control strategy can give dual attention to the rapidity and accuracy of the water-coal ratio and can have the main superheated steam tempera- ture kept within an adjustable range