Enhancing latent heat thermal energy storage efficiency: thermal performance analysis of phase change material enriched with TiO₂ nanoparticles

Abstract This work examines the capacity of titanium dioxide (TiO 2 ) nanoparticles to improve the thermal efficiency and characteristics of phase change materials (PCMs) in latent heat thermal energy storage (LHTES) systems. The TiO 2 nanoparticles were introduced in varying concentrations of 0.5%, 1.0%, 1.5% and 2.0%. The effect of varying concentrations of TiO 2 nanoparticles on thermal conductivity (TC), melting and solidification time, and charging and discharging efficiency was studied and compared with paraffin wax at different flow rates (0.5 LPM, 1.0 LPM and 1.5 LPM). A total of 4 samples were prepared using a magnetic stirrer. Fourier Transform Infrared Spectroscopy (FTIR) is employed to analyze chemical interactions, while Field Emission Scanning Electron Microscopy (FESEM) is used to analyze the distribution of nanoparticles in the PCM matrix. The tests demonstrate that the TiO 2 nanoparticles are evenly distributed inside the PCM matrix and have no harmful chemical interactions. In addition, Thermogravimetric Analysis (TGA) is utilized to assess the thermal stability of the nano-enhanced PCM (NEPCM). The TGA results demonstrate the improved resistance to heat degradation of the NEPCM, which is crucial for the long-term operation of the LHTES system. Each sample’s thermal conductivity and pure paraffin wax were also checked using a hot disk TPS 500 instrument. The findings demonstrate that the addition of TiO 2 nanoparticles enhances the thermal conductivity of the PCM by 35%, 53%, 69.5%, and 88% at 0.5, 1.0, 1.5, and 2.0% when compared with pristine PCM. The improved thermal conductivity resulted in faster heat transfer rates during the charging and discharging. Compared with paraffin wax, at an HTF flow rate of 0.01 Kg s −1 , the NEPCM containing 0.5% TiO 2 improved the charging, discharging, and overall efficiencies around 2.89%, 5.21%, and 2.25%, respectively. This research offers vital knowledge on the advantages of using TiO 2 nanoparticles to enhance the thermal efficiency and behaviour of PCMs in LHTES systems. This opens up possibilities for more effective and environmentally friendly energy storage solutions in applications like batteries, food storage, buildings, HVAC, etc.