Packed bed thermal energy storage: A simplified experimentally validated model. (December 2015)

• Record Type: Journal Article
• Authors: Anderson, Ryan; Bates, Liana; Johnson, Erick; Morris, Jeffrey F.
• Is Part Of: Journal of energy storage. Volume 4(2015)
• Page Start: 14
• Page End: 23
• Publication Date: 2015-12
• Subjects: Packed beds -- Thermal energy storage -- Sensible heat -- Concentrating solar power; Energy storage -- Periodicals; Energy storage -- Research -- Periodicals; 621.3126
• DOI: 10.1016/j.est.2015.08.007
• Languages: English
• ISSNs: 2352-152X

Abstract

Highlights: Packed bed thermal energy storage with air as HTF and alumina as storage material. A one-equation thermal model matches the experimental results well. The thermal model includes the packed bed, storage vessel, and heat losses. Varying thermophysical properties effects are presented at low and high temperature. The assumption of fluid/solid thermal equilibrium in the model is analyzed. Abstract: Thermal energy storage in packed beds is receiving increased attention as a necessary component for efficient implementation of concentrated solar power plants. A simplified, one-equation thermal model for the behavior of a packed bed is presented for α-alumina as solid storage material and air as the heat transfer fluid. The model successfully predicts the thermocline behavior over time. Two flow rates during storage are presented for alumina in a cylindrical packed bed. Temperature-dependent thermophysical properties are utilized to accurately model the systems. An additional study of air and alumina at high temperature (700 °C) is presented to further highlight the importance of variable thermophysical properties in real models. Explicit consideration is given to explain situations where the modeling approach is valid based on a Biot number analysis and the thermal capacities of the solid and fluid.