Characteristic study of modified nano CuO powder-based paraffin composite and its experimental investigation of melting/solidification behavior for mobilized cold thermal storage systems
The low thermal conductivity of Phase Change Materials (PCM) reduces its performance and remains a challenging issue. In the present study, modified nano copper oxide powder (CuO) with various weight percentages is dispersed into paraffin wax to form Nano-PCM composites (NPCM). Transmission Electron Microscopy analysis showed the uniform dispersion of modified CuO and spherical in structure. Diffraction Scanning Calorimeter analysis (DSC) showed a trivial difference in the melting point of PCM and NPCM. The peak melting temperature of PCM was 18.56°C and for NPCM with 1% concentration was 17.14°C. The thermal conductivity of NPCM in solid and liquid states was high when compared to that of pure PCM. The thermal conductivity of NPCM with a 1% concentration is enhanced by 52% in a solid state and 20% in a liquid state. Solidification/Melting experiments conducted at different bath temperatures such as 15°C, 17°C, and 19°C for PCM and NPCM revealed that the solidification period and melting period reduced with an increase in concentrations of modified Nano CuO due to augmented heat transfer rates. The solidification time for NPCM with 1% concentration is reduced by 18.33% for discharging temperature 25°C, and melting time are reduced by 16.6% for charging temperature.