一种双工质气体压缩储能系统及其可行性分析

An Energy Storage System with Binary Cycle Gas Compression and Its Feasibility Analysis

[目的]压缩空气储能系统储气库容大、储气压力高,往往需要采用地下盐穴储气库,项目开发受制于盐穴资源的稀缺性。压缩二氧化碳储能系统采用常压柔性气膜储气仓储存二氧化碳气体,气膜仓体积巨大,占地面积过大,难以满足建设用地指标有要求的工业园区。为了实现气体压缩储能在工业园区的广泛应用,提出了一种双工质气体压缩储能系统。[方法]系统整合压缩空气储能与压缩二氧化碳储能两个系统,并共用储气库。储气库采用特殊设计的承压容器,由柔性隔膜分隔成等压且可缩放的空气腔和二氧化碳气腔。系统通过压缩空气回路和压缩二氧化碳回路的协同工作实现储能和释能,并保持储气库维持恒压运行。为了评估系统的储能效果及能量密度,对基于3 MPa储气压力地面储气库方式的100 MW/400 MWh储能系统进行初步的热力学计算,并对工程可行性进行分析。[结果]结果表明:系统的储能效率为70.20%;能量密度为3.85 kWh/m^(3)。系统适合工业园区配套储能,并可发挥其电、气、冷、热多联供的功能,相比电化学储能,具有显著的商业竞争力优势。[结论]针对工业园区储能场景,双工质气体压缩储能选址灵活、技术可行、设备成熟、成本可控,具有重大的潜在商业价值。

[Introduction]The compressed air energy storage system has a very large air storage volume and high pressure,and usually uses the underground salt cavern as the gas storehouse.Project development is constrained by scarce salt cavern resources.The compressed carbon dioxide energy storage system uses the storage tank with the atmospheric flexible gas film to store carbon dioxide gas.The gas film tank has a huge volume and occupies an excessive area,making it difficult to meet the requirements of construction land indicators of the industrial park.In order to achieve the widespread application of the energy storage with gas compression in industrial parks,an energy storage system with binary cycle gas compression is proposed.[Method]The system integrated the compressed air energy storage and compressed carbon dioxide energy storage systems,and utilized a shared gas storehouse.The gas storehouse adopted specially designed pressure vessels,which were divided into equal-pressure and scalable air chambers and carbon dioxide chambers using flexible membranes.The system could achieve the storage and release of energies through the collaborative work of compressed air circuits and compressed carbon dioxide circuits,while maintaining a constant-pressure operation in the gas storehouse.In order to evaluate the energy storage performance and energy storage density of the system,a preliminary thermodynamic calculation was conducted on the 100 MW/400 MWh energy storage system of the ground gas storehouse with a storage pressure of 3 MPa,followed by an analysis of the engineering feasibility.[Result]The results show that the energy storage efficiency of the system is 70.20%and energy density is 3.85 kWh/m3.The system is suitable for supporting energy storage in industrial parks and can provide the multi-generation function of electricity,gas,cooling and heating.Compared to electrochemical energy storage,it has significant commercial competitive advantages.[Conclusion]For energy storage scenarios in industrial parks,the energy storage with binary cycle gas compression has an important potential commercial value due to its flexible location selection,feasible technology,mature equipment,and controllable cost.