Improvement of thermal conductivity of paraffin by adding expanded graphite

Abstract

This paper investigated the use of graphite with different configuration designs to improve the thermal energy storage of phase change material systems. Two types of graphite have been combined with paraffin in order to improve thermal conductivity of phase change material: synthetic graphite (Timrex SFG75) and graphite waste obtained from damaged tubular graphite heat exchangers. Paraffin/graphite phase change material composites have been prepared by the cold uniaxial compression technique. Their morphologies have been observed and analyzed by scanning electron microscope, and their thermophysical properties have been estimated using new experimental tools. Results show that the thermal conductivity and thermal diffusivity can be accurately measured by these new experimental tools. Moreover, results highlight the fact that the phase change material thermal properties are greatly influenced by the graphite addition. 2016 The Author(s).