基于焓值控制的超临界机组给水控制策略优化与仿真研究

超临界机组中的控制技术是超临界发电技术中的重要一环,纯直流阶段的给水控制是超临界机组整个控制系统的核心之一。在传统给水控制系统的基础上,设计了以燃水比为基础,以控制住汽水分离器出口微过热蒸汽焓为目的的控制策略,进而达到控制给水量至合适值的目的,保证整个系统的平衡稳定。在机组变负荷工况下,将二者作为主控对象进行动态校正。仿真结果表明,优化控制策略之后的系统能将主蒸汽温度控制在可调范围之内,同时也保证了燃水比的精确性和快速性。

Optimization and Simulation for Feedwater Control Strategy of Supercritical Unit Based on Enthalpy Control

The control technology in supercritical units is an important part of the supercritical power generation technology.The feedwater control in once-through stage means great to supercritical units.Based on the traditional water control strategy and watercoal ratio,the control strategy is designed for controlling the slightly-superheated steam enthalpy at the separator exit for the purpose of appropriate value and the stability guarantee of whole system.As the mainly-controlled objects,both slightly-superheated steam enthalpy and water-coal ratio are dynamically corrected.The simulation indicates that the improved control strategy can give dual attention to the accuracy and rapidity of the water-coal ratio and can keep the main superheated steam temperature within an adjustable range.