Study on Thermal Properties of Bio-PCM Candidates in Comparison with Propylene Glycol and Salt Based PCM for sub-Zero Energy Storage Applications

Abstract

Phase Change Materials (PCMs) provide a greater density of energy storage with a smaller temperature difference between storing and releasing heat compared to sensible heat storage methods. This paper reports results of study on bio-PCM made of vegetable oil ester and water mixtures. T-history thermal analysis method was implemented in determining thermal properties of the bio-PCM candidates. Comparison analysis was also performed in order to evaluate how favorable the investigated bio-PCM compared with conventional salt based PCM and propylene glycol. The study results showed that with right amount vegetable oil ester, the bio-PCMs can reduce freezing point and reduce or even eliminate super-cooling of water. On the other hand, salt based PCMs and propylene glycol showed high super-cooling and lower latent heat storage. This study has shown that the investigated water based bio-PCMs are strong PCM candidates for sub-zero energy storage applications.