Heat Storage Characteristics of Latent-Heat Microcapsule Slurry Using Hot Air Bubbles by Direct-Contact Heat Exchange

Abstract

This study deals with the heat storage characteristics of latent-heat microcapsule slurry consisting of a mixture of fine microcapsules packed with latent-heat storage material and water. The heat storage operation for the latent-heat microcapsules was carried out by the direct-contact heat exchange method using hot air bubbles. The latent-heat microcapsule consisted of n-paraffin as a core latent-heat storage material and melamine resin as a coating substance. The relationship between the completion time of latent-heat storage and some parameters was examined experimentally. The nondimensional correlation equations for temperature efficiency, the completion time period of the latent-heat storage process and variation in the enthalpy of air through the microcapsule slurry layer were derived in terms of the ratio of microcapsule slurry layer height to microcapsule diameter, Reynolds number for airflow, Stefan number and modified Stefan number for absolute humidity of flowing air.