Volume 47

Performance Analysis of Isobaric Compressed CO2 Energy Storage System with Pumping Compensation Suzhen Yin, Junwei Liu, Xiaohu Yang, Zhan Liu

Abstract

Compared with the compressed air energy storage system, energy storage system with CO2 as working fluid has the advantages of high energy storage density and compactness. In this paper, a novel isobaric compressed CO2 energy storage system with a flexible gas holder is proposed. The thermodynamic modeling of the compressed CO2 energy storage system is established and the impact of some key parameters on system performance is studied. The results show that round-trip efficiency gradually increases from 67.86% to 77.00% as the compressor isentropic efficiency rises from 75% to 95%. As the relative pressure loss rate of the heat exchanger increases from 0.25% to 4.5%, the system round-trip efficiency experiences a decline from 73.12% to 71.49%.

Keywords Compressed CO2 energy storage, thermodynamic analysis, key parametric analysis, isobaric storage