Investigation of a High-Temperature Packed-Bed Sensible Heat Thermal Energy Storage System With Large-Sized Elements

Abstract

A high-temperature, sensible heat thermal energy storage (TES) system is designed for use in a central receiver concentrating solar power plant. Air is used as the heat transfer fluid and solid bricks made out of a high storage density material are used for storage. Experiments were performed using a laboratory-scale TES prototype system, and the results are presented. The air inlet temperature was varied between 300 °C to 600 °C, and the flow rate was varied from 50 cubic feet per minute (CFM) to 90 CFM. It was found that the charging time decreases with increase in mass flow rate. A 1D packed-bed model was used to simulate the thermal performance of the system and was validated with the experimental results. Unsteady 1D energy conservation equations were formulated for combined convection and conduction heat transfer and solved numerically for charging/discharging cycles. Appropriate heat transfer and pressure drop correlations from prior literature were identified. A parametric study was done by varying the bed dimensions, fluid flow rate, particle diameter, and porosity to evaluate the charging/discharging characteristics, overall thermal efficiency, and capacity ratio of the system.

Experimental study and numerical modelling of high temperature gas/solid packed-bed heat storage systems

“…Thanks to a validated one-dimensional three-phase model taking account of intra-particle conduction, they show that the first-and the second-law efficiencies of the storage are not always maximized by the same operating conditions. Kuravi et al, 2013, investigated a 32-kWh packed bed consisting of large bricks forming ducts and running up to 530°C. The storage exhibits thermal stratification despite the large size (and hence the potentially large Biot number) of the bricks.…”

Using demolition wastes from urban regeneration as sensible thermal energy storage material

“…The specific heats of samples in this study are higher than the rocks (gneiss, rhyolite, marble, limestone) and inertized waste materials characterized as potential sensible heat TES materials in previous studies. [9][10][11][12][16][17][18][20][21][22]…”

“…[6][7][8] Among the sensible heat storage materials for high temperature are aluminum silicate composite materials, silica rocks, quartz and basalt gravels, alumina beads, desert sands, and inertized products reported in previous solar power plant studies. [9][10][11][12] These materials can be costly and deplete the natural resources considering the large amounts needed for such applications in industry. Using cheap storage materials is essential for economical solutions that will boost the competitiveness of industries while reducing energy costs.…”

Thermal Energy Processes in Direct Steam Generation Solar Systems: Boiling, Condensation and Energy Storage – A Review

“…Sensible TES using solids often utilise packed beds (Kuravi et al, 2013;Bruch et al, 2014) which can be modelled as porous media (Andreozzi et al, 2012) or flow channel passages within volumes containing the storage medium (Buscemi et al, 2018), or combinations with thermocline liquid storage tanks (Mostafavi Tehrani et al, 2017). During charging, the temperature of the storage media is increased by heat transfer from the interfacing fluid, while during discharging heat is transfered back into the interfacing fluid.…”