Latent Heat Release Characteristics of Solid-liquid Phase Change Heat Storage Microcapsule Slurry by Condensation Heat of Vapor under a Vacuum Condition

Recently, studies have begun on a functional heat transfer medium using fine spherical microcapsules encapsulated with phase-change material and dispersed in water. This enables the medium to maintain fluidity whether the phase-change material is solid or liquid. The present study has clarified the laten-heat storage characteristics of microcapsule slurry by increasing its heat transfer coefficient with the help of evolved heat condensing of vapor from the slurry in heat storage. Paraffin wax with the melting point of 62°C was encapsulated into the fine microcapsules and used as a phase-change material. The cooling coil surface temperature and concentration of paraffin in the microcapsule slurry were selected as the experimental parameters. As a result, the non-dimensional correlation equations of the heat release completion time and heat transfer coefficient were derived in terms of non-dimensional parameters.