Abstract:At present, in order to solve the problem of compressed air energy storage chamber, liquid air energy storage and liquid CO2 energy storage have been widely concerned and studied at home and abroad. In this paper, the thermodynamic physical model of the two energy storage systems is built with the help of Aspen Plus software, and the thermodynamics and key parameter sensitivity of the two energy storage systems are studied and analyzed with the help of energy analysis. The research shows that the loss of liquid air energy storage system mainly occurs in the compressor and heat and cold storage device, accounting for 45.02% and 37.61% respectively. The loss of liquid CO2 energy storage system mainly occurs in low-temperature expanders, compressors and cold and heat storage devices, accounting for 26.99%, 23.88% and 30.41% respectively. In terms of electric electric conversion efficiency: under adiabatic conditions, due to the large energy consumption in the charging and discharging process, the electric electric conversion efficiency of the two energy storage systems is less than 55%. Compared with the energy storage of liquid air, the energy storage efficiency of liquid CO2 is higher. In terms of system maturity: liquid air energy storage has been applied in engineering, while liquid CO2 energy storage is still in the research stage and has not been applied in engineering. From the aspect of investment cost; The investment cost per kilowatt of liquid CO2 energy storage is about 40% higher than that of liquid air energy storage.