【摘要】 新型电力系统建设背景下，燃煤机组的灵活性对消纳波动性新能源至关重要。凝结水节流方法通过充分利用汽轮机蓄热，在提升机组灵活性方面发挥着关键作用。该文基于Modelica语言，利用Dymola仿真平台建立600 MW超临界纯凝式汽轮机系统模型，并与设计值进行对比验证。通过分析汽轮机系统在不同节流量下功率调节的动态响应特性，进一步探讨不同工况下机组变负荷的响应能力。最后，分析回热系统的动态(火用)流及(火用)损的变化规律。结果表明，机组输出功率变化量及最大响应速度与节流量呈正相关关系，且在不同工况下，功率增量与凝结水流量均满足指数拟合关系。相较于50%汽轮机额定热耗工况(turbine heat acceptance,THA),75%和100%THA工况最大功率增量分别提升64.5%和105.4%。动态(火用)分析表明，回热系统蓄能沿凝结水流动方向逐级释放并重构热力平衡。其中，除氧器和1#低加的总(火用)损及动态(火用)响应系数均高于其余低加，总(火用)损由高到低依次为除氧器、1#、4#、3#和2#低加。因此，凝结水节流显著增强机组快速调节能力，其非线性负荷响应特性源于回热系统蓄能的动态释放机制。更多还原

【Abstract】 In the context of constructing a new power system, the flexibility of coal-fired units is crucial for accommodating fluctuating renewable energy. The condensate throttling method plays a key role in enhancing unit flexibility by fully utilizing the thermal storage of the steam turbine. This paper establishes a 600 MW supercritical condensing steam turbine system model based on the Modelica language. The model is simulated using Dymola simulation platform and validated against the design values. By analyzing the transient response characteristics of the power regulation under different throttle flow rates, the study further explores the unit’s responsiveness to variable loads under different operating conditions. Additionally, dynamic exergy flow and exergy loss are analyzed for reheat system. The results indicate that both the change in unit power and the maximum response speed are positively correlated with the throttling flow rate. Under different working conditions, the power increment exhibits an exponential relationship with the condensate flow rate. Compared with the 50% turbine heat acceptance(THA), the maximum power increment increases by 64.5% and 105.4% under 75% and 100% THA. Dynamic exergy analysis reveals that the stored thermal energy in the regenerative heating system is progressively released along the condensate flow path, leading to a new thermodynamic equilibrium. The total exergy loss and dynamic exergy response coefficient of the deaerator and 1# low-pressure heater are higher than those of the remaining low-pressure heaters. The total exergy loss is distributed across the deaerator, 1#, 4#, 3# and 2# low-pressure heater in descending order. Therefore, condensate throttling enhances rapid load regulation, with its load-dependent nonlinear response driven by the dynamic release and redistribution of stored energy in the regenerative heating system.更多还原