Cryogenic Energy Storage (CES) system is currently gaining significant attention in the field of large-scale energy storage systems. This is because this system can provide high energy-density during storage and uses air or nitrogen that are available at no or a low cost. Moreover, the technology has matured and can be used on-site in a decoupled manner. The CES system has three sub-processes, namely, charging or liquefaction, storage, discharging or power cycle. To investigate the improvement potential of such systems, state-of-the-art configurations for each sub-processes have been analyzed in this paper. A configuration consisting of a multi-stage turbine expansion, a turbine and a JT-valve connected in series at the liquefaction stage, Organic Rankine cycle for utilization of heat of compression, and a four-stage reheat Rankine cycle with thermal energy storage at cryogenic temperature has been proposed. The study suggests that a high turnaround efficiency (about 90%) of the process may be achieved by an appropriate external source of thermal energy.

低温储能（CES）系统目前在大规模储能系统领域中引起了极大的关注。这是因为该系统可在存储过程中提供高能量密度，并使用免费或低成本获得的空气或氮气。而且，该技术已经成熟并且可以以分离的方式在现场使用。CES系统具有三个子过程，即充电或液化，存储，放电或电源循环。为了研究这种系统的改进潜力，本文分析了每个子过程的最新配置。由液化阶段串联连接的多级涡轮膨胀机，涡轮和JT阀组成的配置，有机朗肯循环以利用压缩热，提出了一种在低温下具有热能储存的四阶段再加热朗肯循环。研究表明，通过适当的外部热能来源可以实现较高的周转效率（约90％）。