Gas Turbine-Based Binary Working Fluid Gas Compression Energy Storage System

Objective The efficiency of existing compressed air energy storage is insufficient, and site selection is restricted by gas storage conditions, which hinders large-scale deployment of compressed air energy storage. To improve the efficiency of compressed air energy storage, a gas turbine-based binary working fluid gas compression energy storage system is proposed.

Method The compression and expansion processes of the gas turbine are decoupled, and a dual-working fluid gas storage system with constant-pressure and variable-volume operation in the gas storage chamber is employed. Energy storage and power generation are realized through the coordinated operation of the air working fluid energy storage loop and CO₂ working fluid energy storage loop. Preliminary thermodynamic calculations and engineering feasibility analysis were conducted on the binary working fluid gas compression energy storage system based on a 50 MW industrial gas turbine.

Result The results show that the system's energy storage efficiency reaches approximately 80%, on par with pumped hydro energy storage, higher than that of conventional gas compression energy storage, but lower than that of lithium-ion battery energy storage. The system cost is between that of pumped hydro energy storage and lithium-ion battery energy storage, and slightly lower than that of salt cavern compressed air energy storage.

Conclusion In regions rich in fuel resources such as natural gas and hydrogen, the gas turbine-based binary working fluid gas compression energy storage system can be applied to scenarios including high-energy-consuming industries, new energy bases, and power grids, with good engineering feasibility and commercial competitiveness.