压气机抽气调控的燃气轮机电站系统动态特性分析

Dynamic performance analysis on power-duty gas turbine system controlled by compressor air extraction

为进一步提高电站燃气轮机负荷爬坡速率,缩短电网负荷响应时间,增强燃气轮机电站系统调频服务市场竞争力,基于集总参数法和能量、动量、连续性方程,采用模块化建模方法,在MATLAB/Simulink仿真平台上建立了压气机抽气调控的燃气轮机系统动态模型。利用ThermoFlex和电厂运行数据分别验证了模型的稳态特性和动态特性,证明了模型的可靠性。功率-流量、温度-阀门开度采用PID控制器,通过试凑整定参数,保证了系统参数变化更加平滑稳定。分别模拟了20%、40%阶跃降负荷和20%斜坡降负荷指令下系统动态响应,并与传统燃气轮机调峰机组进行对比。结果表明:暂不考虑抽气系统储能利用,虽然抽气系统在效率方面劣于基准系统,但阶跃降负荷下抽气系统表现出更快的负荷调节速率。研究可为压气机抽气储能提升电站燃气轮机调峰调频潜力提供理论参考。

In orderto further improve theloadclimbing ability of heavy duty gas turbines,reduce grid load response time and enhance the market competitiveness in frequency regulation service,a dynamic model for gas turbines controlled by compressor bypass air extraction was established on MATLAB/Simulink platform,based on the lumped-parameter method,the modular modeling method and energy,momentum,continuity equations.Thermo Flexand plant field data were used to validate the steady-state and dynamic performance,and the reliability of the proposed model was demonstrated.PID controller was adopted for controlling power-air mass flowrate and temperature-valve opening.The controller parameters were adjusted by trial to ensure that the power system parameters change smooth and stably.Finally,the dynamic response of the compressor bypass air extraction system was simulated and compared with that of the conventional peak shaving gas turbine,under 20%,40% step load decrease and 20% ramp load decrease,respectively.The results indicate that,although compressor bypass air extraction system is inferior to the benchmark system in power efficiency without consideration of extraction air energy utilization,it shows faster load regulation rate in dynamic analysis under step load decrease.The research demonstrates the potential application of compressor bypass extraction air energy storage in gas turbines for power peak shaving and frequency regulation.