Improved thermo-physical properties and energy efficiency of hybrid PCM/graphene-silver nanocomposite in a hybrid CPV/thermal solar system

Abstract

In this research work, novel hybrid Graphene-Silver (Gr-Ag) nanomaterial has been used for first time with paraffin wax as a phase change material (PCM) to improve its thermo-physical properties. Thermal and electrical energy efficiencies of the novel synthesized nanocomposite (PCM/Graphene-Silver) has been investigated in solar thermal collector systems (CPV/T). This paper focuses on preparation, characterization, thermo-physical properties and energy efficiency in concentrated photovoltaic/thermal (CPV/T) system of new class of nanocomposites induced with hybrid Gr-Ag nanomaterial in three different concentrations. The specific heat capacity (cp) of hybrid PCM/Graphene-Silver nanocomposite increased by introducing hybrid Gr-Ag nanomaterial. Electrical and thermal energy performance of the hybrid PCM/Graphene-Silver is investigated in a CPV/T system using Matlab 2017b program. The improvement of cp is found to be ~40% with 0.3 mass% of hybrid Gr-Ag nanomaterial loaded in PCM. The highest thermal conductivity increment is found to be ~11% at 0.3 mass% concentration of hybrid Gr-Ag nanomaterial in PCM. The endothermic enthalpy value of the hybrid PCM/Graphene-Silver nanocomposite is found to be ~75.6 J g-1 at 0.1 mass% loading concentration of hybrid Gr-Ag nanomaterial. Melting point of hybrid PCM/Graphene-Silver nanocomposite with loading concentration of 0.3 mass% is measured to be 73.2 °C. The highest thermal efficiency using the hybrid Graphene-silver nanoparticles reached the value of 39.62% which represents 4.16% increment in comparison with the pure PCM. The equivalent electrical efficiency is improved by 2.8% at the loading concentration of 0.3 mass% of the hybrid Gr-Ag nanomaterial. These new class of nanocomposites represented the capability of enhancement in the performance of the CPV/T system consisting of lower PV temperatures, higher temperature gains across the cooling fluid and higher electrical and thermal efficiencies.

A mini review on paraffin‐graphene and related hybrid phase change materials for building energy applications

“…The melting temperature of the graphene added beeswax decreased to 61.57°C from 62.28°C and two times higher thermal conductivity has been observed for graphene‐based PCM. Other studies also proved that the thermophysical properties of the paraffin or PCM improved by adding the graphene or GO, such as latent heat, thermal conductivity, phase change duration, phase change temperatures and sub‐cooling, density, and viscosity of the PCM 62‐66 …”

Heat transfer analysis in thermal energy storage—A comprehensive review‐based latent heat storage system

“…The specific heat capacity was found to increase by this method of infusion. Thermal and electrical performance of the hybrid PCM/Gr‐Ag is calculated using MATLAB 2017b 31 . Also the thermal conductivity of the hybrid model showed an increase by approximately 11% for 0.3% mass fraction.…”

Thermodynamic and Energy Efficiency Analysis of a Domestic Refrigerator Using Al2O3 Nano-Refrigerant

“…The main objective has been to create a new type of coolant with higher heat transfer capability, which has been used in variety of products such as computers, power electronics, car engines, heat exchangers, and high-powered lasers. Enhancement in thermal properties such as thermal conductivity due to the presence of nanoparticles has attracted great interest of researchers, but instability of nano-size solid particles in the basefluid, especially at high concentrations, Sustainability 2021, 13, 5659 2 of 15 still remains a challenge in its application [12][13][14][15]. Many studies have been conducted on the fundamental properties, application, and characterization of different types of nanoparticles dispersed in different base fluids [16][17][18][19].…”