为了分析某660 MW超超临界二次再热燃煤机组快速响应动态特性，基于Modelica/Dymola平台建立了高精度二次再热机组动态仿真模型。为了验证模型的可靠性和精确性，将仿真结果与不同负荷下设计数据进行比较发现，模型在不同负荷下的静态误差均在±5%以内。针对目前灵活性运行对电网负荷快速响应要求，模拟机组在分别切除4个高压加热器后负荷的瞬态响应特性，并具体分析了切除1号高压加热器对汽轮机抽汽以及锅炉主要受热面烟气侧与蒸汽侧动态特性的影响，获得了切除高压加热器后汽轮机抽汽变化动态过程和发电功率快速响应情况，以及锅炉烟气侧与蒸汽侧的参数变化动态过程。模拟结果表明：切除4个高压加热器均可以有效增加机组瞬时电负荷，分别可以达到29.8，15.6，8和6 MW，快速发电功率增加持续时间达到1 100,100,130和250 s，说明切除高压加热器可以改善二次再热燃煤机组对电网自动发电控制（AGC）的快速响应特性。
In order to analyze the rapid response dynamic characteristics of a 660 MW ultrasupercritical double reheat coalfired unit,a highprecision double reheat unit dynamic simulation model was established based on Modelica/Dymola platform. In order to verify the reliability and accuracy of the simulating model,the static simulating results were compared with the design data under different working loads. It was found that the static error of the simulating model under different working loads was within ±5%. Under the requirements of the flexible operation for the rapid response of the power grid currently,the transient response characteristics of the power unit loads after the bypass of four highpressure(HP)heaters were simulated,and the influence of the bypass at No.1 highpressure heater on the dynamic characteristics of the steam turbine extraction and the flue gas and steam sides of the main heating surfaces of the boiler was analyzed in detail. The dynamic process of the steam turbine extraction change and the rapid response situation of the power generation after the bypass of four highpressure heaters as well as the dynamic process of parameter changes on the flue gas and steam sides of the boiler were obtained respectively. The simulation results show that the bypass of four highpressure heaters can effectively increase the instantaneous power load of the unit to 29.8 MW,15.6 MW,8 MW and 6 MW respectively,and the duration of rapid power generation increment can reach 1 100 s,100 s,130 s and 250 s,indicating that the bypass of four highpressure heaters can improve the rapid response characteristics of double reheat coalfired units to automatic generation control(AGC) requirement from power grid.