Melting of paraffin waxes embedded in a porous matrix made by additive manufacturing

The recent advances in additive manufacturing technology have widened the choice of materials that can be printed, opening new frontiers in the field of heat transfer devices. This paper explores the use of a solid porous matrix in which paraffin waxes, having different melting temperatures (42, 55, and 64◦C), were embedded. The solid matrix is made by additive manufacturing. The parent cell of the porous matrix occupies the volume of a cube with an edge of 5 mm. The entire 3D printed matrix has a square base with an edge of 100 mm, and it has a height of 20 mm. The solid matrix was printed between two plates, each one with a thickness of 10 mm, where thermocouples were inserted, and it was tested in an upright position, laterally heated applying three different heat fluxes (10, 15, and 20 kW m−2 ). The experimental results are given in terms of the temperature of the heated side, as well as of the phase change material, during the heating process. The temperature reached by the heated side and the time needed to completely melt the paraffin waxes are compared at the different working conditions. Furthermore, the thermal conductivities and diffusivities of the three paraffins and of the parent material of the porous matrix were experimentally evaluated.