Thermal Efficiency of Paraffin Nano Container in Presence of Porous Walls Structures

This study investigates the thermal performance of paraffin-based nanocontainers within porous wall environments, with a focus on optimizing energy storage and transfer efficiency in building applications. Phase change materials (PCMs) such as paraffin offer significant potential in thermal management due to their ability to store and release latent heat during phase transitions. In this study, paraffin nanocontainers with two specific dimensions, 200 nm and 700 nm, were simulated under varying volume fractions (0%, 10%, 20%, 40%, 60%, and 80%) to assess their melting and solidification characteristics. Two types of encapsulating shells, silicon dioxide (SiO₂) and copper oxide (CuO), were applied to analyze the effect of shell material on thermal behavior. The RANS approach in a laminar formulation and the volume of fluid (VOF) method were utilized to simulate interfacial behavior between the paraffin and air within the nanocontainers. Boundary conditions were set at an external temperature of 50°C and an initial temperature of 20°C, while the enthalpy-porosity model was used to simulate phase transitions. The type of shell material significantly influences the heat transfer rate and phase transition times. SiO₂ and CuO shells displayed differences in melting and solidification times, with CuO shells exhibiting faster phase change dynamics. For both dimensions of nanocontainers, the presence of porous walls facilitated a higher heat flux compared to solid walls, improving thermal efficiency. These findings underscore the potential of paraffin-based PCMs in energy-efficient building design, especially in applications requiring precise thermal control. This research contributes to advancing PCM integration in building materials.