两种多等级运行的压缩二氧化碳储能系统综合性能对比

To expand the charge/discharge power range of energy storage systems to adapt to different levels of renewable energy accommodation capacity,two-series and three-series systems are proposed in this study based on Multi-Level compressed carbon dioxide energy storage systems and a comparative study of their comprehensive performance is conducted.First,the operating mode of the systems under three charge/discharge levels and a model for thermal analysis of the components are introduced.Then,the safe operation ranges of both the turbine and compressor are investigated.Thereafter,the charge and discharge power ranges of the systems at different levels are obtained.Finally,performance indicators of the two systems at each level are compared. According to the results,the optimal pressure of the medium-pressure storage tank is 4.178 MPa for the three-series system and 5.088 MPa for the two-series system,as derived from the models and the design parameters；the charge power range of the two-series system is 2 2.78% higher than that of the three-series system；the charge power gap of the three-series system is 2 2.80% lower than that of the two-series system；compared to the three-series system,the two-series system has a higher charge power range,discharge power range,round-trip efficiency,and energy density at all the three levels.Therefore,the two-series system has better system performance.The study demonstrates that the two-series system delivers superior operational performance,with these findings holding significant practical implications for promoting rural low-carbon transition and enhancing efficiency in large-scale renewable energy utilization.