Experimental investigation on heat transfer behavior of the novel ternary eutectic PCM embedded with MWCNT for thermal energy storage systems

Abstract

In this paper, the variation of thermophysical properties such as the thermal conductivity, thermal energy storage capacity, viscosity, and phase change temperature of the novel ternary eutectic phase change material (PCM) with respect to multi-walled carbon nanotubes (MWCNTs) concentration are investigated. The novel ternary eutectic PCM was formed by the permutation of oleic acid, isopropyl palmitate, butyl stearate in a eutectic mole fraction of 0.44–0.33–0.23. The heat transfer analysis of the materials encapsulated in spherical ball was experimentally investigated. The results concluded that the ternary eutectic PCM with 0.10 mass percentage of MWCNT enhances the heat transfer rate by 34.45% with respect to the pure PCM. Furthermore, the thermal conductivity of the MWCNT dispersed ternary eutectic PCM shows an increasing trend and reaches the maximum enhancement of 67.28% for 0.10 mass percentage of MWCNT concentration. The crystallinity decrement of the composite PCM was increased linearly from 0.19 to 3.2% for the increasing MWCNT concentration along with the convergence of melting and solidification enthalpy at the maximum dispersion of MWCNT concentration. New correlations governing the variation of thermal conductivity, viscosity and thermal expandability of the ternary eutectic PCM with respect to MWCNT concentrations have also been developed and presented in this study. The novel ternary eutectic PCM with 0.10 mass percentage of MWCNT with good thermal reliability after 500 thermal cycles and compatibility with the spherical encapsulated high-density polyethylene ball could be an eminent candidate for low-temperature cold storage applications.