Thermal Energy Storage Characteristics of a Latent Heat Storage Vessel Packed with Surface Cross-Linked, Form-Stabilized, High-Density Polyethylene PelletS by Boiling Phenomenon

摘要

This paper deals with an experimental investigation of latent thermal energy storage characteristics of surface cross-linked form-stabilized high-density polyethyl- ene 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.