摘要
燃煤机组与大规模储能系统协调运行能够有效提高电力系统的灵活性,平滑可再生能源电力输出。提出一种与燃煤机组耦合的气液互转二氧化碳储能系统,利用燃煤机组凝结水和给水回收压缩热,通过疏水预热透平入口CO_(2),实现了储/释能过程的热力解耦,无需配备储热装置。基于耦合系统数学模型,优化设计了系统耦合方案,并与独立CO_(2)储能系统进行了性能对比分析。结果表明:压缩热梯级回收将末级间冷器(火用)效率从73.3%提升至89.6%,疏水梯级预热代替抽汽预热使一级预热器(火用)效率从53.1%提升至89.7%;在最佳耦合方案下,系统电-电效率相比于独立系统从63.6%提高至76.8%,度电成本从0.13美元/(kW·h)降低至0.093美元/(kW·h),往返效率略降至63.2%;叶轮机械与换热器是系统总(火用)损和投资成本的主要来源,是提升系统热力性能和经济性的关键部件;提升释能功率至90MW后,系统度电成本降低至0.089美元/(kW·h),机组调峰范围扩大至86.4%~107.6%。
The coordinated operation of coal-fired power plant(CFPP)with large-scale energy storage systems can effectively regulate the flexibility of power system and smooth the renewable power output.A gas-liquid interconversion carbon dioxide energy storage system coupled with a CFPP was proposed,which recovers compression heat using condensate and feedwater of CFPP and preheats turbine inlet CO_(2)through drain water,realizing thermal decoupling of charge and discharge processes without heat storage devices.Based on the mathematical models of the coupling system,the system coupling schemes were designed and optimized,and a comparative performance analysis with stand-alone system was conducted.The results show that,the compression heat cascade recovery boosts the exergy efficiency of last-stage intercooler from 73.3%to 89.6%,and the exergy efficiency of the first-stage preheater improves from 53.1%to 89.7%by replacing extraction preheating with drain water cascade preheating.In the optimal coupling scheme,the system energy storage efficiency improves from 63.6%to 76.8%compared to the stand-alone system,and the levelized cost of electricity reduces from 0.130 dollar/(kW·h)to 0.093 dollar/(kW·h),with a slight reduction in round-trip efficiency to 63.2%.The turbomachinery and heat exchangers,representing the main contributors to the total system exergy destruction and investment cost,are key components in improving thermodynamic and economic performance.Increasing the discharge power to 90 MW reduces the levelized cost of electricity to 0.089 dollar/(kW·h)and expands the peak regulating range to 86.4%~107.6%.
作者
侯坤
刘向阳
何茂刚
HOU Kun;LIU Xiangyang;HE Maogang(Key Laboratory of Thermal-Fluid Science and Engineering of MOE,Xi’an Jiaotong University,Xi’an 710049,China)
出处
《热力发电》
北大核心
2025年第10期1-10,共10页
Thermal Power Generation
基金
国家自然科学基金项目(51936009)。
关键词
燃煤机组
二氧化碳储能
耦合方案
性能分析
coal-fired power unit
carbon dioxide energy storage
coupling schemes
performance analysis
