An experimental investigation on thermal energy storage characteristics of nanocomposite particles dispersed phase change material for solar photovoltaic module cooling

Abstract

Electrical conversion efficiency of a solar photovoltaic (SPV) module suffers due to increase in its temperature. An integration of thermal energy storage system with phase change material (PCM) in a SPV module will improve its overall efficiency by maintaining its temperature. Though, Paraffin is the most common PCM for SPV cooling application, its low thermal conductivity limits its performance. Thermal performance of the Paraffin can be enhanced by utilizing high conductive nanocomposite particles. In the present research work, the enhancement in thermal characteristics of Paraffin by dispersing titanium dioxide - silver nanocomposite particles are examined. Titanium dioxide - silver nanocomposite particles (NP) are synthesized using sol-gel process and characterized using standard techniques. The effect of dispersing titanium dioxide - silver nanocomposite particles (NP) in 0.5, 1, and 1.5 % mass concentrations with thermal cycling on thermal conductivity and hence the storage performance of Paraffin are investigated. Further, the chemical, physical and thermal stabilities of nanocomposite particles dispersed Paraffin (NCDPWX) are examined. When compared to the base Paraffin, the cycled NCDPWX with 1 wt% NP exhibits a better thermal conductivity (0.384 W/mK), melting heat capacity (128 kJ/kg), freezing heat capacity (119.46 kJ/kg), melting time (6.07 min), freezing time (10.11 min), thermal stability up to 352 °C, substantial reduction in degree of super cooling (3.96 °C), impregnation ratio (102.64 %), impregnation efficiency (100.92 %), thermal storage capability (98.31 %) and better chemical stability. Overall, the synthesized NCDPWX is a suitable thermal energy storage material for cooling of SPV modules.