燃煤机组不同灵活性调节方案参与一次调频过程的经济性分析

提高燃煤发电机组运行高效灵活性是提高电网运行安全性的有效手段。采用GSE软件搭建了660 MW超临界燃煤机组动态仿真模型，研究了一次调频过程中4种热力系统调节方案下的主要热经济性参数和蓄热量的动态特性，定义了一次调频过程的热经济性指标，最终分析了一次调频作用时间和调节方案对平均标准煤耗率差值的影响规律。研究表明：一次调频升负荷过程，4种不同调节方案中的汽轮机输出功率和发电厂总效率均迅速升高，而发电标准煤耗率规律正好相反；锅炉和汽轮机系统蓄热量降低是4种方案可以参与一次调频的本质原因；平均标准煤耗率差值的最小值为-22.15 g/（kW·h），出现在高加抽汽节流方案下且一次调频作用时间为90 s。

Thermo-economic Analysis on Four Regulation Schemes with Different Flexibilities for Primary Frequency Regulation Control in a Coal-Fired Power Plant

Achieving high operational efficiency and flexibility of coal-fired power plants is an effective way to improve the security of power grids. In this study, the dynamic model of a 660 MW supercritical coal-fired power plant is developed via the GSE software, and then the dynamic characteristics of the main thermo-economic parameters and heat storage using four regulation schemes during the primary frequency regulation process are explored. After the thermo-economic index is defined for the primary frequency regulation, the deviations from average standard coal consumption rate with respect to different time durations of the four regulation schemes are analyzed. It turns out that during the primary frequency regulation load ramping up process, the output power of steam turbine and the total efficiency of power plant get boosted sharply with all the four regulation schemes, whereas the standard power generation coal consumption rate goes down in an opposite way. The basic reason for those four schemes eligible to participate in primary frequency regulation is explained as the heat storage reduction of both the boiler and steam turbine systems. The deviation from the average standard coal consumption rate hit the minimum value of -22.15 g/(kW·h), when the scheme of throttling extraction steam from high-pressure heaters is applied with the primary frequency regulation time duration set as 90 s.