Experimental analysis of a low cost phase change material emulsion for its use as thermal storage system

A 46 1 commercial tank with a helical coil heat exchanger and containing a low cost phase change material emulsion has been experimentally analyzed as a thermal energy storage system in terms of volumetric energy density and heat transfer rate, for its subsequent comparison with other thermal energy storage systems. This phase change material emulsion shows a phase change temperature range between 30 and 50 degrees C, its solids content is about 60% with an average particle size of 1 mu m. The low cost phase change material emulsion shows a thermal storage capacity by mass 50% higher than water and an increase in viscosity up to 2-5 orders of magnitude. The results have shown that the global heat transfer coefficient of the phase change material emulsion tank is around 2-6 times higher than for conventional latent systems previously analyzed in literature, although 5 times lower than if it contains water. The phase change material emulsion tank presents an energy density 34% higher than the water tank, which makes it a promising solution. Measures to improve its performance are also studied in this work. (C) 2015 Elsevier Ltd. All rights reserved.