%0 Journal Article %A Barbour, Edward %A Mignard, Dimitri %A Ding, Yulong %A Li, Yongliang %D 2019 %T Adiabatic Compressed Air Energy Storage with packed bed thermal energy storage %U https://repository.lboro.ac.uk/articles/journal_contribution/Adiabatic_Compressed_Air_Energy_Storage_with_packed_bed_thermal_energy_storage/9563843 %2 https://repository.lboro.ac.uk/ndownloader/files/17196173 %K Adiabatic Compressed Air Energy Storage %K Packed beds %K Thermal energy storage %K Thermodynamic analysis %K Mechanical Engineering not elsewhere classified %K Economics %X The majority of articles on Adiabatic Compressed Air Energy Storage (A-CAES) so far have focussed on the use of indirect-contact heat exchangers and a thermal fluid in which to store the compression heat. While packed beds have been suggested, a detailed analysis of A-CAES with packed beds is lacking in the available literature. This paper presents such an analysis. We develop a numerical model of an A-CAES system with packed beds and validate it against analytical solutions. Our results suggest that an efficiency in excess of 70% should be achievable, which is higher than many of the previous estimates for A-CAES systems using indirect-contact heat exchangers. We carry out an exergy analysis for a single charge-storage-discharge cycle to see where the main losses are likely to transpire and we find that the main losses occur in the compressors and expanders (accounting for nearly 20% of the work input) rather than in the packed beds. The system is then simulated for continuous cycling and it is found that the build-up of leftover heat from previous cycles in the packed beds results in higher steady state temperature profiles of the packed beds. This leads to a small reduction (<0.5%) in efficiency for continuous operation. %I Loughborough University