Analysis and Optimization of CAES Systems Coupled with a Double Reheat Power Plant

Driven by carbon neutrality targets, improving the flexibility of thermal power units is crucial for low-carbon power systems. This paper proposes a compressed air energy storage (CAES) system coupled with a 1,000 MW double reheat power plant (DRPP), in which condensate absorbs compression heat and extraction steam heats the air turbine inlet, eliminating the need for separate hot and cold storage tanks. An Ebsilon-based DRPP model is used to compare steam extraction–water return schemes in charging and discharging modes, select the schemes with minimum thermal consumption, and perform parametric studies on compressor pressure ratio, air turbine inlet temperature, and storage capacity. A genetic algorithm optimization targeting the minimum levelized cost of energy (LCOE) yields an optimal design with LCOE of 0.081 $/kWh, coupled-system efficiency of 46.68%, round trip efficiency of 54.48%, and energy storage density of 4.49 kWh/m3, providing a reference for efficient integration of reheat units with CAES.