Abstract :
A thermal energy storage system, consisting of a packed bed of rocks as storing material and air as high-temperature heat transfer
fluid, is analyzed for concentrated solar power (CSP) applications. A 6.5 MWhth pilot-scale thermal storage unit immersed in the ground
and of truncated conical shape is fabricated and experimentally demonstrated to generate thermoclines. A dynamic numerical heat transfer
model is formulated for separate fluid and solid phases and variable thermo-physical properties in the range of 20–650 C, and validated
with experimental results. The validated model is further applied to design and simulate an array of two industrial-scale thermal
storage units, each of 7.2 GWhth capacity, for a 26MWel round-the-clock concentrated solar power plant during multiple 8 h-charging/16
h-discharging cycles, yielding 95% overall thermal efficiency.
2012 Elsevier Ltd. All rights reserved.
