Thermal Energy Storage Characteristics Research Articles

Thermal energy storage characteristics of a latent heat storage vessel packed with surface cross-linked, form-stabilized, high-density polyethylene pellets by boiling phenomenon

This paper deals with an experimental investigation of latent thermal energy storage characteristics of surface cross-linked form-stabilized high-density polyethylene pellets as a phase change material (PCM), using pool boiling and condensation of an ethylene glycol–water solution. The polyethylene pellets and the heat transfer medium of ethylene glycol were mixed and poured into a cylindrical heat storage vessel. The heat transfer into the polyethylene pellets was mainly enhanced by the condensation of vapor bubbles of the ethylene glycol–water solution, which was heated by an electric heater set at the bottom of the vessel. The effects of heat input; amounts of PCM and ethylene glycol–water solution; and heater surface temperature on the heat storage characteristics were all investigated. As a result, a nondimensional correlation equation of the completion time of the heat storage process was derived as a function of nondimensional parameters. © 1999 Scripta Technica, Heat Trans Asian Res, 28(8): 649–663, 1999

Thermal energy storage characteristics of a latent heat storage vessel packed with surface cross‐linked, form‐stabilized, high‐density polyethylene pellets by boiling phenomenon

This paper deals with an experimental investigation of latent thermal energy storage characteristics of surface cross-linked form-stabilized high-density polyethylene pellets as a phase change material (PCM), using pool boiling and condensation of an ethylene glycol–water solution. The polyethylene pellets and the heat transfer medium of ethylene glycol were mixed and poured into a cylindrical heat storage vessel. The heat transfer into the polyethylene pellets was mainly enhanced by the condensation of vapor bubbles of the ethylene glycol–water solution, which was heated by an electric heater set at the bottom of the vessel. The effects of heat input; amounts of PCM and ethylene glycol–water solution; and heater surface temperature on the heat storage characteristics were all investigated. As a result, a nondimensional correlation equation of the completion time of the heat storage process was derived as a function of nondimensional parameters. © 1999 Scripta Technica, Heat Trans Asian Res, 28(8): 649–663, 1999

HIGH-PERFORMANCE PHASE-CHANGE THERMAL ENERGY STORAGE USING SPHERICAL CAPSULES

A theoretical and experimental investigation of the transient thermal characteristics of a phase-change thermal energy storage (TES) unit using spherical capsules is presented. A simulation program that considers rigorously transient aspects of both the surrounding heat transfer fluid and the phase change material (PCM) packed inside the spherical capsule is developed. The overall thermal response of this TES unit is described with variation of the capsule diameter, the flow rate, and the kind of PCMs, etc. The simulation results are then compared with experimental observations. Furthermore, a unique device employing a heat pump is presented to overcome the supercooling problem which has been one of the most serious problems (especially for inorganic hydrates) in the phase-change thermal energy storage.