Improvement of thermal conductivity of paraffin wax, a phase change material with graphite powder

Abstract

Phase-change materials (PCMs) are usually and at present applied as an energy storage application, because of their high latent heat and energy storage capability. Of various types of paraffin, the most commonly used as phase-change-material is paraffin wax. On the nuisance side, it has a bit low thermal conductivity of 0.2Wm−1K−1 due to which various methods are in use for its enhancements. In this present work graphite having thermal conductivity of 3000 Wm−1K−1, is used for improving thermal conductivity of paraffin. The paraffin graphite composite is formulated by the dispersion of graphite in paraffin wax above the melting temperature of the paraffin wax. So after dispersion in paraffin wax, thermal conductivity is measured. Further thermal conductivity of graphite is very high in certain plane therefore composite is heated to a molten state and composite paraffin graphite is aligned with strong magnetic field. SEM techniques are applied to determine the alignment of graphite in paraffin while thermal conductivity is measured by using Fourier's law. Results showed that graphite not only enhances thermal conductivity of paraffin graphite composites but also due to alignment of graphite thermal conductivity further improved.