辅助燃煤机组AGC调节的熔盐电加热器动态性能研究

Dynamic performance of molten salt electric heater with AGC regulation for auxiliary coal-fired units

燃煤机组耦合熔盐电加热器系统可大幅提升其调频调峰能力。基于Modelica语言建立了熔盐电加热器的动态模型并完成了试验验证,揭示了熔盐电加热器在熔盐流量扰动和机组自动发电控制(AGC)负荷扰动下的动态特性。基于其动态特性提出了“前馈+PID”调节的温度控制方法,计算分析了熔盐电加热器辅助燃煤机组AGC调节时的电负荷变化特性和热力参数变化特性。研究结果表明,配置10 MW熔盐电加热器可使660 MW燃煤机组AGC变负荷速率提升340%,且所提控制方法能够维持电加热器热力参数的稳定。

The coupling of coal-fired units with molten salt electric heater systems can significantly improve their frequency regulation and peak shaving capabilities.On the basis of Modelica language,a dynamic model of the molten salt electric heater is established and the experimental verification is completed,it reveals the dynamic characteristics of the molten salt electric heater under the disturbance of molten salt flow rate and unit AGC load.A temperature control method of“feedforward+PID”regulation is proposed based on its dynamic characteristics,and the characteristics of electrical load and thermal parameter changes during AGC regulation of coal-fired units assisted by molten salt electric heaters are calculated and analyzed.The results indicate that,configuring a 10 MW molten salt electric heater can increase the AGC variable load rate of a 660 MW coal-fired unit by 340%,and the proposed control method can maintain the stability of thermal parameters of the electric heater.