EFEKTYWNOŚĆ ENERGETYCZNA ADIABATYCZNYCH ORAZ IZOTERMICZNYCH UKŁADÓW CAES

This article is devoted to the analysis of the impact of selected parameters on the thermodynamic efficiency of compressed air energy storage systems. Various structures of adiabatic CAES (Compressed Air Energy Storage) plant with thermal energy storage using thermal oil and a system with near isothermal compression and expansion process were analyzed. This paper presents the structures of the analyzed energy storage systems, adopted assumptions and results of the conducted analysis. Calculations were based on the real gas model and obtained results were further used to plot the energy efficiency characteristics. Among other things, the influence of the air storage pressure and the relative pressure loss within the heat exchangers on system efficiency were taken into account and determined. Analyzes have shown the possibility of achieving over 70% efficiency for adiabatic system and 65.6% for isothermal system while assuming that pressure losses are neglected. However, their significant impact on efficiency has been observed – in an extreme case, these losses can lead to reduction of the isothermal installation efficiency by almost 26.5 percentage points.