Numerical comparison and sizing of sensible and latent thermal energy storage for compressed air energy storage

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2015
Kaya, Mine
Intermittent and variable characteristics of renewable energy systems can be compensated by energy storage systems (ESS). There is a wide range of ESS specialized for different applications. Compressed Air Energy Storage (CAES) is often used for wind power plants due to high power rating at the discharge and long discharge duration. CAES takes ambient air and pressurizes through a compressor and stores compressed air in a volume when supplied energy is greater than demand. If demand exceeds supply, CAES is discharged by drawing compressed air from storage, running turbine after heating compressed air by external heat source (fuel). Thermal Energy Storage (TES) is another ESS, which is generally coupled with solar thermal energy systems. TES systems can store sensible or latent heat in a storage medium. A feature of TES is capability of being used with CAES. External heat source can be eliminated by TES by storing thermal energy of air at the compressor exhaust to be used to heat air before turbine. CAES with TES systems are named as Adiabatic CAES (A-CAES) and comprise of a compressor, TES, air storage and a turbine. In this study, TES of an A-CAES system is modeled and effect of TES on CAES is investigated. Performance of individual TES is analyzed for different heat storage mediums - latent and sensible -, tank and heat storage medium dimensions. Aim of the present study is to model a TES, which is capable of storing maximum heat in a minimum volume and shortest duration and implement the promising designs to CAES and investigate the performance of overall system by means of efficiency and total work output using MATLAB.
Citation Formats
M. Kaya, “Numerical comparison and sizing of sensible and latent thermal energy storage for compressed air energy storage,” M.S. - Master of Science, Middle East Technical University, 2015.