Performance Analysis of a High Temperature Hybrid Compressed Air Energy Storage System

In this paper, based on the consideration of the turbomachinery's off-design condition, such as the characteristic maps, the performance analysis of a high temperature hybrid compressed air energy storage (HTH-CAES) system is carried out. The performance comparison between the HTH-CAES and the advanced adiabatic CAES (AA-CAES) is also implemented. In the first cycle, the round trip efficiency of the HTH-CAES system is 63.9% and the largest exergy loss component is the electric heaters. In the consecutive cycles, the round trip efficiency increases with the raised cycle numbers till a stable condition. Comparing with the AA-CAES, it can be found that the addition of electrical heaters can improve the energy/power capacity of energy storage system. Meanwhile, the electric heating temperature has a negative effect on system round trip efficiency.