Effect of PCM Selection on the Thermal Performance of a Coil-in-Shell Storage System

Abstract

The lack of design rules for the design and selection of phase change material-based thermal energy storage (PCM-TES) systems using heat exchangers is a major impediment to the development and general acceptance of such systems. To develop design rules, the thermal storage community must first determine and agree on PCM-TES performance comparison metrics. It appears logical that the properties of PCM could play a role in determining comparison metrics.

This research presents results of a study performed on a TES using a coil-in-shell heat exchanger using two different PCMs, dodecanoic acid and 1-octadecanol. Characterization of this TES was performed over a range of initial and final temperatures, both for charging and discharging, comparing results of each. An attempt is made to compare different experiments using Nusselt number, Fourier number, various Stefan number (Stem, Stes, Stet), average heat transfer rate (Qmean) and two normalized heat transfer rates (Qnorm) and (Qnorm,t).