Based on the characteristics of supercritical carbon dioxide Brayton cycle

this paper proposes a new type of S-CO_2 Brayton cycle tower solar thermal power generation system with compressed CO_2 energy storage. The system uses excess solar energy to compress CO_2 near the critical point to a high-pressure state

and uses a gas boiler to burn natural gas at night to heat the high-pressure CO_2

which then enters the turbine to perform work and drives the generator to generate electricity. This paper uses the commercial software Ebsilon to establish tower solar thermal power generation system model with molten salt heat storage and compressed CO_2 energy storage respectively

and the bottom cycle working fluid is optimized to obtain the operating parameters under the best efficiency conditions. On this basis

the typical daily operating conditions are analyzed

and the thermal economy of the two systems is calculated. The results show that

when the heat storage time is 8 hours

compared with the daily average efficiency of the molten salt heat storage system

that of the new solar thermal power generation system using compressed CO_2 energy storage increases by 0.31% during the summer solstice and by 0.97% during the winter solstice. The new system has good application prospects.