Author:

Keywords:

energy and environment

Abstract:

A fluid mechanical analysis of a hydraulic air compression system for Compressed Air Energy Storage application is presented. With this compression concept, air is charged into an underground reservoir, for later use in power generation, by entraining bubbles into a downward flow of water from a surface reservoir. Upon releasing the air in the underground reservoir, the water is pumped back to the surface. The analytical model delineated in the paper is used to predict the hydraulic compressor performance characteristics (pumping power, pump head, compression efficiency) as a function of water flowrate and system geometrical parameters. The results indicate that, although large water pumps are needed, efficiencies as high as 90% (relative to ideal isothermal compression) can be expected. This should result in lower compression power than for conventional compressor systems, while eliminating the need for the usual intercoolers and aftercooler. (A)