Thermal Analysis of Solidification in MWCNT and Hybrid Nanoparticle-Enhanced Eutectic PCMs Using T-History and DSC Methods

This study systematically evaluates the thermophysical properties of Nano-Enhanced PCM (NEPCM) and Hybrid Nano-Enhanced PCM (HNEPCM) using both the T-history method and Differential Scanning Calorimetry (DSC). Additionally, it examines and compares the Nusselt number and heat transfer coefficient in thermal energy storage (TES) systems incorporating NEPCM and HNEPCM. The findings reveal a strong correlation between latent heat, specific heat, and phase transition temperatures obtained from the T-history method and DSC analysis, confirming the accuracy and reliability of the custom T-history setup. The average heat capacity of NEPCM was 9.56% higher than that of HNEPCM. Thermal conductivity analysis reveals that NEPCM exhibits superior performance, with values of 0.2135 W/m K (solid) and 0.2018 W/m K (liquid), whereas HNEPCM records 0.197 and 0.1802 W/m K, respectively. Notably, 1% v/v MWCNT-based NEPCM enhances heat conduction efficiency by 8.37% compared to HNEPCM. The enthalpy of fusion for NEPCM was also 4.71% higher than that of 0.05% v/v CuO and 0.05% v/v Al₂O₃ hybrid nanoparticle-based HNEPCM, which exhibited a 24.21% lower heat transfer coefficient than NEPCM. DSC analysis reveals that HNEPCM begins melting at 41°C–42°C, whereas NEPCM exhibits its lowest endothermic peak at 45°C, with complete melting occurring within the 42°C–43°C range. These findings highlight the enhanced thermal performance of MWCNT-based NEPCM over hybrid CuO–Al₂O₃ HNEPCM, offering valuable insights into optimizing phase change materials (PCM) for efficient TES applications.