Performance analysis of a compressed liquid carbon dioxide energy storage system

Compressed air energy storage (CAES) is one of the most promising technologies to alleviate the conflict of electricity supply and demand and it is very important for improving stability of the grid. In this paper, a compressed liquid carbon dioxide energy storage system is proposed to overcome the drawbacks of traditional CAES systems. With liquid carbon dioxide as new working medium instead of compressed air, the dependence of system on large cavern and fossil fuel is reduced. The system efficiency and exergy efficiency are calculated to analyze the performance of system. The parametric analysis is conducted to examine the effect of some parameters. The results show that system efficiency and exergy efficiency first rise then fall with the increasing of outlet pressure of compressor, turbine and pump. But the changes of system efficiency and exergy efficiency caused by pump outlet pressure are far less severe than that caused by turbine outlet pressure and compressor outlet pressure.