Evaluation of properties on paraffin oil-in-water emulsion as phase change slurry.

Paraffin is an easily available organic phase change material. Paraffin oil can be dispersed in the form of a small droplet in water as an oil-in-water emulsion. The binary fluid has a high heat capacity in the phase change temperature range of the used paraffin. The subject of this paper is the evaluation of the potential of paraffin oil-in-water emulsion for the cold energy storage application. The commercial paraffin blend (mixtures of different saturated alkanes) Rubitherm RT10 with a melting temperature of 10°C was used to make the emulsion. The following properties have been investigated of the emulsion: distribution of droplet size and the dependence between supercooling and droplet size; thermal properties as the latent heat of fusion, the phase change temperature range and optimal operation temperature rang in practical application and; rheological properties. A series of samples with weight percentages from 15 to 50% have been prepared. The properties of the emulsion in dependence of the paraffin concentration have been studied. The results show that an emulsion with a paraffin concentration up to 50 weight percent is an attractive candidate for cold storage application due to its high heat capacity.