Thermodynamic analysis for a novel steam injection adiabatic compressed air energy storage hybrid system

This paper proposes a new steam injection adiabatic compressed air energy storage hybrid system (SI-ACAES) for the purpose of enhancing the installed capacity and output of ACAES systems. The proposed system preheats and humidifies the inlet working medium of the turbine by adding a saturator and recovering the heat of compression. For better evaluation of the performance of the system, this paper first performs an energy analysis and an advanced exergy analysis on the SI-ACAES system, followed by a parametric analysis. The results suggest that the SI-ACAES system has increased turbine power by 6.63 MW, round trip efficiency by 3.7%, compression heat utilization efficiency by 9.3%, and exergy round trip efficiency by 2.1% compared to the traditional ACAES system. The exergy efficiency increases with throttle valve outlet pressure, but when inlet water flowrate to the saturator (SAT) and external inlet air flowrate to heat exchanger 8 (HEX8) increase, the exergy efficiency begins to increase and then appropriately decreases.