Experimental study on heat transfer performance of neopentyl glycol/CuO composite solid-solid PCM in TES based heat sink

In this study, the thermal/chemical property and heat transfer performance of a solid-solid nano-enhanced PCM (SSPCM) comprising of neopentyl glycol (NPG) and copper oxide (CuO) nanoparticles is assessed for its possible usage in thermal energy storage (TES) based heat sink application. The SSPCM samples were prepared by mixing NPG with CuO nanoparticle in 0.5, 1 and 3% weight proportions. The thermal and chemical compatibility of the prepared samples were tested and confirmed by TGA and FTIR characterization methods. The effect of using CuO nano additives on solid-solid transition enthalpy of NPG was studied with the aid of DSC analysis. The results showed a decrease of enthalpy from 3.1 to 9.6% for the corresponding CuO weight fractions ranging from 0.5 to 3%. The thermal conductivity of the composite SSPCMs measured through laser flash technique, showed a maximum relative enhancement of about 4.08 to the value for pure NPG with 3 wt% CuO nanoparticle additions. The results of heat storage and release performance test showed a reduction of 14.1-33.8% in the storage time corresponding to 0.5 to 3 wt% of CuO nanoparticles loading. The heat transfer performance of the NPG/CuO SSPCM was experimentally investigated using a heat sink. The results indicated that the time taken by the heat sink to attain a temperature of 60 °C during heating was increased by 2.36 times the time taken without using any PCM by the addition of 3% weight fraction of CuO nanoparticles. This made the heat sink to be maintained at a lower temperature for a longer period of time. Also, addition of CuO nanoparticles in the NPG reduced the recovery time of the heat sink during cooling.