Thermophysical properties and thermal performance evaluation of multiwalled carbon nanotube-based organic phase change materials using T-History method

Abstract

Experimental studies have been carried out to evaluate the thermophysical properties and thermal performance of thermal energy storage (TES) systems. The TES system was filled with 0%-0.025% vol. fractions multiwalled carbon nanotubes (MWCNT)-based lauric acid (LA), paraffin wax (PW), and stearic acid (SA) nanoparticle-enhanced phase change materials (NEPCMs). The T-History method has been used to explore the thermophysical parameters, i.e., solid-liquid specific heat capacity, solid-liquid thermal conductivity, and heat of fusion. Results revealed that the solid thermal conductivity of the 0.02% MWCNT in lauric acid, paraffin wax, and stearic acid increased by 37.8%, 24.4%, and 13.5% than LA, PW, and SA phase change materials (PCMs), respectively. Also, an improvement in liquefying and solidification time has been observed for 0.02% vol. fraction MWCNT-based NEPCMs. However, the dimensionless numbers justified that the combined conduction and natural convection effect occurred in the PCMs/NEPCMs thermal energy storage. The coefficient and rate of heat transfer have been compared among 0%-0.025% vol. fraction of MWCNT-based pure lauric acid, paraffin wax, and stearic acid PCMs/NEPCMs. Also, the maximum heat transfer rate for 0.02% MWCNT in lauric acid, paraffin wax, and stearic acid NEPCMs has been increased by 61.16%, 87%, and 26.4%, respectively, compared to LA, PW, and SA phase change materials. Hence, the 0.02% MWCNT/PW-NEPCM-based TES system has higher performance than the mentioned TES systems.