摘要
火电机组实现灵活性转型是构建新型电力系统、实现“碳达峰”“碳中和”目标的关键。为提升火电机组的灵活性,提出了小汽轮机驱动和电动机驱动液态压缩二氧化碳储能系统与火电机组耦合的方案,并建立了其热力学系统模型,采用热耗率和能量利用系数对系统进行评价,开展系统热力学性能对比分析,确立了最佳储能耦合方案。研究表明:储能阶段从凝结水泵出口抽取凝结水,吸收压缩热后返回7号低压加热器出口,释能阶段从中压缸排汽抽取蒸汽,加热膨胀后的CO_(2)后返回5号低压加热器疏水冷却器时,耦合系统性能最佳,热耗率比原系统降低了48.308 k J/(k W·h),能量利用系数提升了0.52百分点;改变CO_(2)膨胀机入口温度和质量流量可实现快速变负荷,耦合储能系统后,机组调峰能力增加了17.1%;配置热水罐并最大放热时,机组调峰能力增加了37.4%,提升了火电机组灵活性。
Flexible transformation of thermal power units is the key to build a new power system and achieve the goal of “carbon peak” and “carbon neutrality”. In order to promote the flexibility of thermal power units, the coupling scheme for small steam turbine drive and motor drive liquid compressed carbon dioxide energy storage system and thermal power unit is put forward, and the thermodynamic system model is established. Moreover, the heat consumption rate and energy utilization coefficient are used to evaluate the system, the thermodynamic performance of the system is compared and analyzed, and the optimal coupling scheme of energy storage is established. The researches show that, in the energy storage stage, condensate water is extracted from the outlet of the condensate pump, and the compressed heat is absorbed and returned to the outlet of No.7 low-pressure heater. In the energy release stage, steam is extracted from the exhaust of the middle pressure cylinder, and the expanded CO_(2)is heated and returned to the No.5 low-added hydrophobic cooler, the coupling system has the best performance. The heat consumption rate is 48.308 k J/(k W·h) lower than that of the original system, and the energy utilization coefficient increases by 0.52 percentage point. Changing the inlet temperature and the mass flow rate of CO_(2)expander can quickly change the load. After coupling with the energy storage system, the peak regulation capacity of thermal power unit increases by 17.1%, when the hot water tank is configured and the maximum heat is released, the peak regulation capacity of the unit increases by 37.4%, indicating the flexibility of thermal power unit is improved.
作者
严晓生
王小东
韩旭
韩中合
YAN Xiaosheng;WANG Xiaodong;HAN Xu;HAN Zhonghe(School of Energy,Power and Mechanical Engineering,North China Electric Power University,Baoding 071003,China;CHN Energy Lianjiang Port&Power Co.,Ltd.,Fuzhou 350500,China)
出处
《热力发电》
CAS
CSCD
北大核心
2023年第2期90-100,共11页
Thermal Power Generation
基金
河北省自然科学基金项目(E2020502001)
国家科技支撑计划项目(2014BAA06B01)。
关键词
压缩二氧化碳储能
热耗率
热力系统优化
灵活性改造
调峰深度
compressed carbon dioxide energy storage
heat loss rate
thermodynamic system optimization
flexibility transformation
peak regulation depth
