Heat transfer characteristics of phase change emulsions with solidification of phase change material particles in a circular tube

The heat transfer characteristics of phase change emulsions (PCEs) with solidification of phase change material (PCM) particles in a circular tube have been investigated. PCEs containing 10 wt% n-hexadecane were emulsified with the surfactants polyoxyethylene sorbitan monostearate (Tween 60) and polyoxyethylene sorbitan monooleate (Tween 80). The experiments were performed with a double-tube type heat exchanger. The PCE flowed inside the inner tube and was cooled from the outside. The supercooling phenomenon of the PCM particles inside the PCEs was confirmed, while the PCEs flowed inside the tube even though they were cooled below the melting point of the PCM. Furthermore, the solidification start temperatures of the PCM particles inside the flowing PCEs were almost the same when they were cooled under static conditions. The heat transfer performance of the PCEs improved when solidification of the PCM particles was in progress. The type of surfactant affected the solidification start temperature of the PCM particles, but it did not significantly affect the heat transfer performance. (C) 2020 Elsevier Ltd and IIR. All rights reserved.