基于工质相变的变容储气A-CAES系统技术经济性分析

Technical and economic analysis of variable-volume gas storage A-CAES system based on working medium phase transition

绝热压缩空气储能(adiabatic compressed air energy storage,A-CAES)系统通常采用恒容储气的方式储存空气,导致空气不能完全从储气装置内释放,存在能量储存密度低、单位储气成本高的问题。为此提出了基于工质相变的变容储气A-CAES系统,通过借助外部工质的压力迫使空气完全从储气装置中释放。然而,采用变容储气的方式增加了储气装置复杂性和设备投资成本。因此,本文对基于工质CO_(2)相变的变容储气A-CAES系统进行了技术经济性分析,并与恒容储气A-CAES系统进行了对比。结果表明,基于工质相变的变容储气A-CAES系统的能量储存密度为28.30 MJ/m^(3),比恒容储气A-CAES系统的储能密度提高了83.65%。采用变容储气的方式可以使储气装置的单位储气成本从49.17元/kg降低至36.59元/kg。在整个系统运行周期内,基于工质相变的变容储气A-CAES系统的动态投资回收期和项目净现值分别为7.36 a和101427.85万元,比恒容储气A-CAES系统减少了1.45 a和增加了3831.74万元。基于工质相变的变容储气A-CAES系统具有较好的应用前景。

Adiabatic compressed air energy storage(A-CAES)systems commonly employ constant-volume gas storage,leading to incomplete air release from the storage vessel,resulting in challenges such as low energy storage density and high unit storage cost.To address this issue,a variable-volume gas storage A-CAES system based on working medium phase transition is proposed,which utilizes external working medium pressure to ensure complete air release from the storage device.However,adopting variable-volume gas storage increases the complexity of the storage system and equipment investment costs.Therefore,the technical and economic analysis of the variable volume gas storage A-CAES system based on the CO_(2)phase change of the working fluid is carried out in this paper,and compared with the constant volume gas storage A-CAES system.The results indicate that the energy storage density of the variable-volume gas storage A-CAES system based on working medium phase transition is 28.30 MJ/m^(3),which is 83.65%higher than that of the constant-volume gas storage A-CAES system.The variable volume gas storage method can reduce the unit gas storage cost from 49.17 yuan/kg to 36.59 yuan/kg.Over the entire operational period,the dynamic payback period and net present value of the variable-volume gas storage A-CAES system are 7.36 years and 1.01 billion yuan,respectively,which is 1.45 years less and 38.32 million yuan more than that of the constant-volume gas storage A-CAES system.