Experimental Evaluation of a High-Temperature Radial-Flow Packed Bed Thermal Energy Storage under Dynamic Boundary Conditions

• High-temperature thermal energy storage is recognized to be a key technology to ensure a future fossil-free energy scenario. Packed bed thermal energy storage is an economically viable high-temperature and large-scale energy storage solution. The present work introduces the experimental investigation of an innovative 49.7 kWhth radial-flow type high-temperature packed bed thermal energy storage under dynamic boundary conditions. Various quasi-dynamic air flow rate profiles, representative of different potential applications, have been tested during the charge process to investigate their influence on the thermodynamic performance of the storage. The outlet thermal power during the discharge has been controlled by managing the air flow rate. Short operational cycles have also been performed. The results show that dynamic boundary conditions can lead to a thermal efficiency reduction between 0.5 and 5 % with respect to static conditions. A control of the air mass flow rate could be an efficient strategy to stabilize the thermal power output during the discharge while minimizing peaks in the pressure drop. This work testifies that specific dynamic boundary conditions should be included during the thermal storage design process since they could largely affect the unit thermodynamic performance and potential scale-up. If no specific dynamic profiles are available during the packed bed storage design stage, it is suggested to consider average air mass flow rate to guarantee limited efficiency reduction.

Subject headings

TEKNIK OCH TEKNOLOGIER  -- Maskinteknik -- Energiteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Mechanical Engineering -- Energy Engineering (hsv//eng)

Keyword

Energiteknik

Energy Technology

Publication and Content Type

vet (subject category)

ovr (subject category)