Investigating the Performance Enhancement of Thermal Storage Using Nanoparticle‐Infused Phase Change Material With Triangular Fin Integration

ABSTRACT Thermal energy storage (TES) systems play a vital role in enhancing energy efficiency and reducing dependence on nonrenewable resources. This study investigates the synergistic integration of triangular fins and nanoparticle‐infused phase change materials (PCMs) to enhance heat transfer in a large triplex tube heat exchanger (TTHX). Numerical simulations, conducted using ANSYS Fluent 15 software, supported by experimental validation with an average deviation of around 2%, were used to evaluate fin placement, fin geometry, and the effect of 10 wt% Al 2 O 3 nanoparticles into the PCM. Results show that triangular fins significantly improve heat transfer, with external fins providing the fastest melting. The addition of nanoparticles increases thermal conductivity by nearly 25% and, when combined with optimized fins, reduces the melting time to 163 min. Energy‐performance analysis confirms that nano‐PCM accelerates charging due to enhanced conductivity, while pure PCM retains higher total stored energy. The optimal configuration, where eight external copper fins of 141 mm length and an 18% aspect ratio, delivered the best overall performance. These findings demonstrate that combining fin‐geometry optimization with nanoparticle enhancement substantially improves TES efficiency. The proposed approach is well‐suited for solar thermal systems, industrial waste‐heat recovery, and compact TES applications.