Heat transfer enhancement in nano-enhanced phase change materials (NePCM): an experimental study for latent heat thermal energy storage
摘要
The low thermal conductivity of organic PCMs affects the fast absorption of latent heat in TES applications; however, there is a lack of systematic investigations using a variety of nanoparticle-based NePCMs on a bench scale at equivalent experimental setups. This work experimentally investigates the melting process, energy storage rate, and convective heat transfer of paraffin-wax-based NePCMs with CuO, Al2O3, and Fe3O4 nanoparticles at mass fractions of φ = 0.01, 0.1, and 0.5 mass% subjected to a constant heat flux boundary condition of 860 W m−2 on the top wall. The experiments were performed in a rectangular cross-sectional enclosure (80 × 40 × 40 mm) with a copper heater plate at the top; the progression of solid–liquid interface, temperature sensors measurements of temperature distribution, and gravimetric phase change tracking were considered as primary measurement techniques. The investigation revealed that, NePCM containing 0.5 mass% CuO nanoparticles had 30–40% faster melting times compared to the control PCM (P-58), with an energy storage rate of 92.86 J min−1 vs. 53.51 J min−1 of the base PCM, with the maximum average Nusselt number of around 21 for the initial melting period. Nanoparticle loading above 0.5 mass% induced measurable sedimentation, establishing a practical concentration ceiling; CuO NePCM at the optimal loading emerges as a viable candidate for solar thermal storage, battery thermal management, and electronic cooling applications.