Comprehensive performance evaluation and optimization of a liquid carbon dioxide energy storage system with heat source

The investigation of advanced large-scale energy storage systems is needed due to the installation and grid-connected generation of instability renewable energy. As the compression heat tends to low temperature, in this paper, a liquid carbon dioxide energy storage system with heat source and its modification are proposed, in which an ice storage carbon dioxide liquefaction scheme and a modified recuperator layout are specially designed. Firstly, thermodynamic and exergoeconomic models are developed to evaluate the proposed systems; Then, a comprehensive understanding of the proposed system is obtained by parametric analysis and multi-objective optimization; Finally, a comparative analysis shows the attractiveness of the proposed system. The results show that the modified recuperator configuration improves the system performance by recovering more turbine exhaust energy, and the relative cost difference is reduced by 6.86%. The efficiency and economy of the system are greatly influenced by the compressor and turbine performance. Multi-objective optimization obtained compromise results of total exergy efficiency and unit output cost of 68.79% and 34.04 $/GJ. The comparative analysis reflects that the proposed system has certain superiorities.