Comparison of phase change slurries: Physicochemical and thermal properties

Abstract

Phase change slurries (PCS) consist on a carrier fluid binary system, where water is mostly used as continuous phase and micro-encapsulated phase change materials (MPCM) are used as dispersed phase. PCS are used in Thermal Energy Storage (TES) for building applications, combining the latent heat capacity of the MPCM with the sensible heat capacity of the carrier fluid, and at the same time giving the PCM pumpable properties. In this study, two PCS samples are compared and characterized, the commercial Micronal® DS 5007 X from BASF and a laboratory made PCS28. Thereby, in this paper thermal stability is studied by using thermogravimetrical analysis (TGA) and the main components of the MPCM have been studied using Fourier transformed infrared spectroscopy (FT-IR). Moreover, TGA coupled with FT-IR is used to study deeply the thermal decompositions of the PCS microcapsules and products derived thereof. Finally, differential scanning calorimetry (DSC) is performed to study the melting enthalpy and the melting temperature range of the phase change material (PCM). This paper concludes that both types of PCS have good potential from thermal energy storage purposes such as solar space heating applications.

The work is partially funded by the Spanish government (ENE2011-28269-C03-02 and ENE2011-22722). The authors would like to thank the Catalan Government for the quality accreditation given to their research group GREA (2014 SGR 123) and research group DIOPMA (2014 SGR 1543). The research leading to these results has received funding from the European Union's Seventh Framework Programme (FP7/2007-2013) under grant agreement n° PIRSES-GA-2013-610692 (INNOSTORAGE).