Performance Analysis and Optimization of a Tower Solar Molten-Salt Thermal Storage Coupled sCO₂ Two-Stage Compression Recuperated Power Generation System

To improve the operational adaptability and power generation performance of solar power tower systems in arid regions of Northwest China, a solar power tower-sCOO₂ two-stage compression recuperated cycle coupled with molten-salt thermal storage was developed. Air cooling was adopted to cool the working fluid. Based on a thermodynamic model, the effects of ambient temperature, seasonal typical-day solar irradiance, and compression/expansion ratio allocation on system performance were analyzed. The results show that the net output power and efficiency decrease significantly when the ambient temperature exceeds 20 ℃. Seasonal differences in solar irradiance also lead to obvious fluctuations in the intraday output characteristics of the system. The optimization results show that the net output power reaches 36.33 MW and the solar-to-electric efficiency reaches 29.06% when the first-stage expansion ratio is 2.14 and the first-stage compression ratio is 1.12. The proposed system shows good power generation performance and operational adaptability. It can provide a reference for the design and operation optimization of solar power tower systems in Northwest China．