3D numerical analysis of thermal performance in PV system integrated with pyramid-shaped nano-PCM dispersed with Single-Walled Carbon Nanotubes

This paper studies the use of nano-improved phase change materials (NPCM) as an approach for thermal energy storage in PV systems. A computational fluid dynamics (CFD) numerical model is developed to simulate a PV-NPCM system in which the PCM has a geometry of a pyramid with a square base. The thermal analysis is carried out using the ANSYS Fluent software which applies the enthalpy-porosity approach to simulate the liquefaction process of PCM. The nanoparticles utilized are Single-Walled Carbon Nanotubes (SWCNTs) with a volume fraction of 6% which were dispersed in RT-42 paraffin wax. The simulation is carried out over a period of 7 hours. The study is transient-based to account for real-world conditions. Accordingly, a regression model is created for the incident solar irradiance to consider its variation along the day. Results revealed that the PV-NPCM system had a faster liquefaction rate because it has higher thermal conductivity due to the existence of nanoparticles. On the other hand, the system with pure PCM showed a higher thermal storage capacity of 199.6 kJ/kg because pure PCM has higher latent heat than NPCM. The percentage difference between thermal energy stored in the pure and NPCM is 15.9%