与燃煤机组耦合的液化空气储能系统技术经济分析

Techno-Economic Analysis of a Liquefied Air Energy Storage System Coupled with Coal-fired Power Unit

液化空气储能(liquefied air energy storage, LAES)因其存储规模大和不受地理条件限制的独特优势,可参与现有燃煤机组的调峰改造,以推进新型电力系统的建设发展。为此提出一种与燃煤机组耦合的新型LAES系统,并且建立耦合系统的热力学模型和经济性模型,分析储能容量变化对耦合系统的影响。结果表明:与某670 MW燃煤机组耦合时,可以综合考虑选择44.2 MW/176.8 MW·h的液化空气储能系统。在燃煤机组的3种低负荷(30%THA、40%THA和50%THA)工况下,耦合运行的LAES系统的往返效率在51%左右,比单独运行的LAES系统高出大约9个百分点。耦合运行的LAES系统的投资收益率接近10%,14 a之内可实现投资回收。敏感性分析显示增大峰谷电价差有利于提升系统的经济性能。

Due to its unique advantages of large storage scale and without limitation by geographical conditions,liquefied air energy storage(LAES)can participate in peak-regulation transformation of existing coal-fired power units to promote the construction and development of new power systems.Therefore,a novel LAES system coupled with coal-fired power unit was proposed,and the thermodynamic and economic models of the coupling system were established to analyze the influence of the change of energy storage capacity on the coupling system.Results show that a 44.2 MW/176.8 MW·h LAES system can be selected for comprehensive considerations when coupling with a 670 MW coal-fired unit.Considering three low-load(30%THA,40%THA,and 50%THA)conditions for the coal-fired power unit,the round-trip efficiency of the coupling liquefied air energy storage system is about 51%,which is about 9 percentage points higher than that of the independent LAES system.The rate of return on investment of the coupling LAES system is close to 10%,and the investment can be recovered within 14 years.The sensitivity analysis results show that it is beneficial to improve the economic performance of the system through enlarging the difference between peak and valley electricity prices.