Comparison of Thermal Characteristics of Sensible and Latent Heat Storage Materials Encapsulated in Different Capsule Configurations
This paper presents the thermal modeling and performance comparison of sensible and latent heat based thermal energy storage (TES) systems using concrete and phase change materials (PCMs) encapsulated in containers of different geometrical configurations. The sensible heat storage (SHS) and latent heat storage (LHS) module considered here is a capsule containing concrete or sodium nitrate which exchanges heat with the source material. SHS capsule is modeled using the energy conservation equation. Effective heat capacity method is employed to account the latent heat of the PCM. Boussinesq approximation and Darcy law’s source term are added in the momentum equation to incorporate the natural convection of molten PCM and nullify the velocities of solid PCM. The equations of the 2D axisymmetric model are solved using COMSOL Multiphysics. Charging time of capsules in four different configurations viz., spherical, cylindrical (H = D, H = 4D) and novel cylindrical configurations are compared. The thermal characteristics are compared using isothermal contour plots and temperature–time curves.
KeywordsEncapsulation Performance prediction Solar thermal Energy storage
The authors sincerely thank the Department of Science and Technology (DST), Government of India, for the financial support (Project No: DST/TM/SERI/2K10/53(G)).
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