新型电力系统建设对火电机组运行灵活性提出新要求,使得机组频繁和大幅度负荷调整成为运行新常态。在机组变负荷过程中,基于传统理想化稳态工况假设所计算得到的实时热耗率因受到动态过程复杂因素影响呈现出较大波动性,无法对机组运行经济性进行有效判断。针对该问题,本文以某600MW抽凝机组为研究对象,利用APROS仿真软件平台建立动态模型,进行升降负荷仿真实验。将不同升降负荷速率下机组动态过程的计算热耗率与稳态模型计算结果进行对比,分析机组变负荷过程热耗率动态特性,提出动态热耗率的修正方法,将实时热耗率分为稳态热耗率与动态热耗率偏差,并依据极端随机树(Extra Trees)算法建立动态热耗率偏差预测模型,将稳态热耗率作为机组热经济性评价指标,为火电机组动态过程经济性评价提供新方法。

. The construction of a novel electric power system imposes new requirements on the operational flexibility of thermal power units, necessitating frequent and significant load adjustments to become the new normal during operation. In the process of varying load in these units, the real-time thermal rate calculated based on traditional idealized steady-state conditions exhibits considerable fluctuation due to the complex factors inherent in dynamic processes, rendering it ineffective for making accurate judgments about unit operational economy. Addressing this issue, this paper focuses on a 600MW condensing extraction unit as the research subject, utilizing the APROS simulation software platform to establish a dynamic model for conducting load increase/decrease simulation experiments. By comparing the calculated thermal rates under different load change rates with the results from the steady-state model, the dynamic characteristics of the thermal rate during the unit"s load-changing process are analyzed. This paper proposes a method to correct the dynamic thermal rate, dividing the real-time thermal rate into steady-state thermal rate and dynamic thermal rate deviation. Furthermore, based on the Extra Trees algorithm, a predictive model for dynamic thermal rate deviation is established. With the steady-state thermal rate serving as the indicator for the thermal economic evaluation of the unit, this study offers a novel approach for assessing the economic performance of thermal power units during dynamic processes.