Enhancing melting of nanoparticle-enriched phase change materials in thermal energy storage systems

The enhancement of melting performance in phase change materials (PCMs) has become a critical challenge in the development of advanced thermal energy storage systems (TESS). Efficient melting and solidification are essential for maximizing energy utilization, yet conventional PCMs often suffer from low thermal conductivity, which restricts their heat transfer rates. To overcome this limitation, structural and material modifications are widely explored. Among these, the integration of fins within storage systems has proven highly effective. In particular, T-shaped fins are advantageous because their extended surface area significantly improves heat distribution during the melting process. In addition to structural modifications, the incorporation of nanoparticles into PCMs has emerged as a practical strategy to enhance thermal conductivity. By embedding high-conductivity nanoparticles into the base PCM, the overall energy absorption, conservation, and storage capabilities are improved. This investigation examines the combined effect of fin geometry and nanoparticle addition on the melting behavior in a horizontal shell-and-tube storage system. Specifically, PCMs integrated with nanoparticles are analyzed using T-shaped and V-shaped fins, and their performance is compared with that of eight longitudinal fins at an equal fin volume fraction. Both experimental and numerical validations are conducted to confirm accuracy. Results indicate that T-shaped fins coupled with nano-enhanced PCMs accelerate melting, reduce overall melting time, and improve uniformity, independent of heat transfer fluid (HTF) temperature.