Thermo-dynamic and economic analysis of a novel pumped hydro-compressed air energy storage system combined with compressed air energy storage system as a spray system

The efficiency of adiabatic compressed air energy storage technology is limited by the low utilization of thermal energy in the energy storage room. Therefore, a pumped hydro-compressed air energy storage system combined with a compressed air energy storage system as a spray system is introduced in the present research and analyzed by thermodynamic and economic analysis to verify the feasibility of system. For the performance analysis of the system, the main components and the whole system are precisely analyzed from the thermodynamic point. The results show that the round-trip efficiency and total exergy efficiency of the system are 52.45% and 77.8%. The system can significantly improve the air temperature in the air storage room, reduce the pressure energy loss of the system, and increase the energy storage capacity. Moreover, achieving high system round-trip efficiency is dependent on components of the system with high efficiencies. By optimization of the system operation mode, the round-trip efficiency of the system can reach 56%.