Nano-enhanced Phase Change Materials Research Articles

Experimental investigation for thermal performance enhancement of various heat sinks using Al2O3 NePCM for cooling of electronic devices

Electronic devices are being used extensively for different applications, where the thermal management of these devices is still a critical challenge due to rapid miniaturization, high heat flux and constantly rising temperature. Phase change materials (PCMs) based thermal management is adopted, but the low thermal conductivity limits their use in temperature-controlled electronic devices. Nano-enhanced phase change materials (NePCMs) can advance the heat transfer rate (HTr), decrease the temperature, and increase the operating time of the electronic device. The present study compares the thermal performances (TP) of three different heat sinks (simple, circular pin finned and copper foam) with NePCM (RT54HC/Al2O3) and varying Al2O3 nanoparticles concentrations (0.15–0.25 wt%) and heat fluxes (0.98–2.94 kW/m2) to optimize the overall device performance. The results show that at a heat flux (HF) of 0.98 kW/m2 and 0.25 wt% of Al2O3 nanoparticles (NPs), the base temperature of simple, circular pin finned and Cu foam heat sink was reduced by 21.3%, 25.03%, and 36.2%, respectively. The Cu foam heat sink (HS) has exceptional TP than the HSs without Cu foam. Accordingly, NePCMs are highly recommended in electronic devices for an optimized thermal management system.

Experimental Analysis of Nano-Enhanced Phase-Change Material with Different Configurations of Heat Sinks.

The demand for high-performance and compact electronic devices has been increasing day by day. Due to their compactness, excessive heat is generated, causing a decrease in efficiency and life. Thermal management of electronic components is crucial for maintaining excessive heat within the limit. This experimental research focuses on the combined effect of nano-enhanced phase-change material (NePCM) with different configurations of heat sinks for cooling electronic devices. Multi-walled carbon nanotubes (MWCNTs) are used as nanoparticles with concentrations of 3 wt% and 6 wt%, RT-42 as the phase-change material (PCM), and aluminum as the pin fin heat sink material. Different configurations of the heat sink, such as circular, square, and triangular pin fins, are used against the fixed volume fraction of the fins. It is found that the square configuration has the highest heat transfer with and without PCM. A maximum base temperature reduction of 24.01% was observed in square pin fins with RT-42 as PCM. At 6 wt% of NePCM, the maximum base temperature lessened by 25.83% in the case of a circular pin fin. It is concluded from the results that a circular pin fin with NePCM is effective for base temperature reduction, and all fin configurations with NePCM collectively reduce the heat sink base temperature.

Thermal Performance Analysis of Various Heat Sinks Based on Alumina NePCM for Passive Cooling of Electronic Components: An Experimental Study

In the modern digital world, electronic devices are being widely employed for various applications where thermal performance represents a significant technical challenge due to continued miniaturization, high heat generated in the system, and non-uniform high-temperature causing failure. Phase change materials (PCMs) owing to the immense heat of fusion are primarily considered for thermal management, but their insulating properties hedge their applications in electronics cooling. Nano-enhanced phase change materials (NePCMs) have the ability to improve the thermal conductivity of PCM, decrease system temperature and escalate the operating time of devices. Accordingly, the current study focused on the experimental investigations for the thermal performance of three heat sinks (HS) with different configurations such as a simple heat sink (SHS), a square pin-fins heat sink (SpfHS), and Cu foam integrated heat sink (CufmHS) with various alumina nanoparticles mass concentrations (0.15, 0.20 and 0.25 wt%) incorporated in PCM (RT-54HC) and at heat flux (0.98–2.94 kW/m2). All HSs reduced the base temperature with the insertion of NePCM compared to the empty SHS. The experimental results identified that the thermal performance of CufmHS was found to be superior in reducing base temperature and enhancing working time at two different setpoint temperatures (SPTs). The maximum drop in base temperature was 36.95%, and a 288% maximum working time enhancement was observed for CufmHS. Therefore, NePCMs are highly recommended for the thermal management of the electronic cooling system.

Numerical investigation of thermal energy storage system loaded with nano-enhanced phase change material with Koch snowflake fractal cross-section

The melting of nano-enhanced phase change material (NEPCM) in a latent heat thermal storage system is investigated for PCM loaded within an annulus between an outer wavy cylinder and an inner Koch snowflake cylinder. The inner Koch snowflake cylinder is used in this study to increase the heating surface area and enhance the NEPCM melting process. The inner cylinder is hot, while the outer one is insulated. The system governing equations and the associated boundary conditions were numerically solved by employing the Galerkin weighted residual finite element method. The impacts of nanoparticle concentration, undulation number of the outer cylinder, annulus eccentricity, and inner cylinder geometry on the melting performance of the storage unit were examined and represented by the liquid fraction, isotherms, Bejan number, velocity, and Nusselt number. The usage of more blades and snowflake surfaces near the hot source's periphery portions disrupts the PCM surface's cohesiveness and increases heat penetration between the PCM layers. The nanoparticle concentration of 6 vol% enhances the melting time by about 32 %, and the undulation number of 8 participates in 25 % of performance enhancement. Putting the hot cylinder closer to the bottom of the storage unit expands the buoyancy effect and enhances the melting process by >3.2 times. The utilization of a Koch snowflake cylinder instead of a triangular one also shows an enhancement of >30 %.

Thermal radiation impact on bioconvection flow of nano-enhanced phase change materials and oxytactic microorganisms inside a vertical wavy porous cavity

This work examines the bioconvection of nano-enhanced phase change materials (NEPCMs) and oxytactic microorganisms in a vertical wavy cavity saturated by a porous medium. The novelty of this work is demonstrating the significance of wavy surface and thermal radiation on the bioconvection flow of NEPCMs and oxytactic microorganisms within a porous wavy cavity. Further, a novel attempt in achieving high-performance conductivity by combining the NEPCM and oxytactic microorganisms during the bioconvection flow in a complex wavy cavity is examined. The dimensionless governing partial differential equations are discretized using the finite element method and the discrete nonlinear systems are handled using the adaptive Newtons method. The results showed the contributions of thermal radiation to enhancing the strength of streamlines. The undulation number of a wavy wall affects the bioconvection flow and contours of streamlines and heat capacity inside a wavy cavity. The Rayleigh number strengthens the streamlines and bioconvection flow. Increasing the Darcy parameter improves the isotherms, oxygen isoconcentration, and microorganisms isoconcentration. Consequently, the PCM shifts towards the right side of a cavity along with a growth in the Darcy parameter. The mean Nusselt number Nuavg and Sherwood number Shavg are altered by the involved physical parameters. Increasing Rayleigh's number from 103 to 106 augments Nuavg by around 153.8% and declines Shavg by 33.3%.

Charging and discharging processes of low capacity nano-PCM based cool thermal energy storage system: An experimental study

The present study aims to investigate the performance of the low-capacity energy storage tank in different heat transfer fluid (HTF) conditions (at various flow rates) filled with spherical capsules containing nano-enhanced phase change material (nano-PCM). The nano-PCM is prepared by dispersing functionalized graphene nanoplatelets (f-GNP) with deionized (DI) water. The influence of HTF inlet temperature and volumetric flow rates on the total charging and discharging time of an energy storage tank filled with 35 spherical capsules are analyzed. The maximum reduction in total charging and discharging time of 18.26% and 22.81% is recorded for different HTF conditions. The amount of latent heat energy stored is nearly 5.5 times higher than the sensible heat stored at the HTF temperature of −4 °C. The cumulative energy recovery of 2637 kJ is recorded during the discharging process, which is 85.89% of the actual energy stored (3070 kJ) in the storage tank. In addition, the dispersion of f-GNP reduces the specific energy consumption (SEC) by around 28% for the nano-PCM at −4 °C HTF temperature. It is found that the required output temperature and average melting rate can be achieved in practical applications through the control of the flow rate of HTF and its inlet temperature.

Effect of Y-shaped fins on the performance of shell-and-tube thermal energy storage unit

Phase change materials (PCMs) are well known for their inherent poor thermal characteristics, which consequently results in limited thermal efficiency for thermal energy storage systems (TESS). The current work numerically attempts to improve the thermal efficiency of TESS by employing Y-shaped fins with nano-enhanced PCM (NePCM). The NePCM is contained inside the cylindrical TESS, while water, as heat transfer fluid (HTF), is pumped through inner pipes. Three different configurations of the TESS were studied and compared; case 1: the reference case (with no fins), case 2: with two Y-shaped fins attached to the tubes, and case 3: with four Y-shaped fins attached to the tubes. The finite element method is employed to discretize the system's governing equations. Besides the influence of the TESS configuration, the impact of HTF temperature (338 and 348 K) and the volume fraction of the nanoparticles (0–0.08) were also addressed. The evolution of temperature contours and liquid fraction of the three different configurations under the two different HTF temperatures are discussed and analyzed. The findings revealed that using nanoparticles with 8 vol% enhanced the thermal conductivity during melting by 19%. The melting process was accelerated by 87% when the HTF temperature was higher (348 K). Finally, TESS with four Y-shaped fins was found to be the most effective as it achieved a 48% melting time reduction compared to the base case (case 1).

Regulation mechanism of magnetic field on non-Newtonian melting and energy storage performance of metal foam composite nano-enhanced phase change materials

A numerical study is conduced to explore regulation mechanism of magnetic field on melting heat transfer and energy storage performance of nano-enhanced phase change material (NEPCM) composited with metal foam. The enthalpy-porosity method, Darcy-Forchheimer model and local thermal non-equilibrium model are used to describe melting process, flow in porous media and coupling heat transfer, respectively. The proposed model is then verified by experiments using thermochromic liquid crystal thermometry. Effects of nanoparticles mass fraction (0%≤Φwt≤5%), magnetic number (0≤Mn≤7×106), and Rayleigh number (104≤Ra≤106) on the non-Newtonian fluids flow, melting heat transfer and energy storage characteristics are illustrated and discussed. Results show that the addition of Fe3O4 nanoparticles can effectively promote melting and induce non-Newtonian effect of molten NEPCM, but Φwt has no significant influence on the heat transfer. With the increase of Mn, the suppression effect of magnetic field on the whole melting process of NEPCM enhances at moderate Ra = 105, and natural convection is fully developed with a “force bridge” phenomenon of Kelvin force. For lower Ra (=104), natural convection becomes weaker and magnetic field presents a “force loop” phenomenon. For larger Ra (=106), natural convective heat transfer has absolute predominance and the suppression effect of magnetic field can be ignored. Moreover, the increase of Φwt and Ra have obvious positive contributions to heat storage and heat storage efficiency. At low Ra, the suppression effect of magnetic field on heat storage and total melting time leads to decrease in energy storage efficiency.

Numerical investigation of a snowflake-shaped fin-assisted latent heat storage system using nanofluid

Latent heat thermal energy storage (LHTES) units can store important amounts of energy by employing phase change materials (PCMs). PCMs have a relatively inadequate thermal conductivity which hinders the thermal performance of LHTES. Thus, it is imperative to take measures to improve thermal conductivity or heat transfer within LHTES units. This article examines the heat diffusion improvement within wavy snowflake-shaped containers filled with nano-enhanced PCM (NEPCM). N-Octadecane enhanced with Al2O3 nanoparticles, respectively, are used as nanoparticles and PCM. A numerical model was developed using the standard Galerkin Finite Element Method to analyze the phase change phenomenon. The thermal performance of the LHTES is determined using thermodynamics' first and second laws. The effects of nanoparticle volume fractions (φ) and geometry parameters on the melting rate are investigated. The major findings revealed that the melting process could be well controlled using a lattice of heated fins. Also, the growth in waviness parameter and φ enhances the rates of the heat transfer and average liquid fraction.

Numerical study on n-octadecane PCM melting process inside a pear-shaped finned container

This work numerically explores the melting process of a nano-enhanced phase change material (NePCM) in thermal energy storage (TES) system. The TES unit is pear-shaped and filled with n-octadecane PCM loaded with Al 2 O 3 nanoparticles and fitted with copper fins. The heat transport governing equations are solved using the finite element method's enthalpy-porosity approach. The melting and heat transmission processes were investigated in terms of the impacts of a variety of factors, including the volume percentage of nanoparticles, the passage of time, the number and the dimensions of the fins. The findings show that the addition of nanoparticles improves the melting process of PCM. For example, adding 6% Al 2 O 3 into PCM decreases the melting time by 12.5%. Furthermore, longer and thinner fins are advised to increase melting rate due to decreased thermal resistance enhanced heat propagation in the deeper regions of the thermal storage unit.

The effect of different enclosure materials and NePCMs on performance of battery thermal management system

A battery thermal management system (BTMS) with nano-enhanced phase change material (NePCM) is a favorable system because of its sustainable lifespan and high-latent heat in the absence of needing any external pumping power like air/liquid cooling in electric vehicles. However, some improvements and investigations are needed to improve the system. Hence, this current study has been conducted numerically to analyze the effect of different materials of the enclosure including copper (Cu), aluminum (Al), and acrylic (Acr) on thermal performance of a cylindrical lithium-ion BTMS by utilizing CuO nanoparticles and n-eicosane PCM. Additionally, the impact of various CuO nanoparticles volume fractions of NePCM (2 % and 4 %) on battery surface temperature and Nusselt number have been investigated. The battery is considered under the full discharge condition at a 3C current rate within 20 min. Furthermore, two different initial and ambient temperatures (300 K and 305 K) have been considered to study the thermal performance of BTMS in solid and solid/liquid phases of NePCM. The numerical results presented that using Cu enclosure in BTMS keeps the battery surface temperature at the lowest level and also causes to delay in melting the NePCM. Moreover, with the addition of CuO nanoparticles to pure n-eicosane and an increase in nanoparticles volume fraction, the battery surface temperature and onset melting time of NePCMs decreases and increases, respectively. Finally, the Nusselt number investigation illustrates that by adding nanoparticles to pure n-eicosane and increasing the nanoparticles volume fraction, the Nusselt number decreases slightly.

Evaluation of efficiency of double slope solar still and drinking water yield using silver nanoparticle mixed with phase change material

ABSTRACT This study shows the contribution of silver nanoparticles mixed with macro-encapsulated phase change material (PCM) in a double slope solar still. Experiments are carried out in three different depths and settings, first using simple double slope solar still, then by addition of PCM, and finally using PCM mixed with silver nanoparticles. Results obtained are compared during the sunshine period and also after sunset. The study shows that the silver nanoparticles in PCM results in reducing the yield and efficiency of the double slope solar still by 7.64% and 5.26% during the charging period. However, it continues to deliver potable water even after sunset due to the stored latent heat in the PCM. The higher thermal capacity of the PCM and the higher thermal conductivity of the silver nanoparticles resulted in a 16% increase in drinking water yield and a 62.53% rise in the thermal efficiency of the double slope solar still. The final cost per liter of the potable water generated using the double slope solar still was reduced to 3.80 INR and the payback time is 2 years which can be reduced further using PCM and nano-enhanced PCM inside the solar still.

Solidification of nano-enhanced PCM-porous composites in a cylindrical cold thermal energy storage enclosure

Latent thermal energy storage units are extensively used for compensating for the misalignment of energy production and demand. Regardless of the extensive applications of these appliances in the industries, they suffer from the slow progress of phase change, which restricts their great potential. The efforts of the current research are concentrated on using the combination of several enhancement techniques, including the implementation of porous foams, fins, and nanomaterials for pushing the phase change rate of one of these systems towards the desirable speed. For this purpose, first, the influence of container orientation is studied. Then, the freezing process of four different nano-enhanced phase change material (PCM)-porous composites, with porous materials of aluminum, copper, nickel, and graphite is examined. After selecting copper foam as the superior composite for the unit, different foam porosities are tested. It was found that while occupying 3%vol of the container capacity with CuO nanomaterials creates only 24.3% of improvement, spending the same volume on copper foam accelerates the process by 84.6%. The evaluations also indicated that by using copper foam with a porosity of 0.95 and CuO nanomaterials with a concentration of 0.03 at the same time, the phase change rate can be elevated by 92.5%.

Manufacturing of nano-enhanced shape stabilized phase change materials with montmorillonite by Banbury oval rotor mixer for buildings applications

The use of adequate thermal energy storage (TES) systems has shown the potential to increase energy efficiency in many fields, such as the building sector. Shape-stabilized phase change materials (SS-PCMs) have attracted attention to address one of the key barriers of phase change materials (PCMs), the leakage during the liquid state, that nowadays limits its applicability. However, SS-PCMs still have drawbacks to overcome, such as poor fire reaction and thermal stability. In the present study, polymeric SS-PCMs are nano-enhanced with layered silicates to overcome these drawbacks. The new shape-stabilized nano-enhanced phase change material (SS-NEPCM) is based on ethylene propylene diene monomer (EPDM) as a polymeric matrix, palmitic acid (PA) as PCM and montmorillonite (MMT) as the layered silicate. An innovative method based on a Banbury mixer was used to prepare it, which is an industrially scalable fabrication method. To evaluate the effect of each component, eight different formulations were prepared: pure EPDM, EPDM with MMT additions (1 wt%, 3 wt% and 5 wt%), EPDM with PA additions (5 wt% and 10 wt%) and EPDM with MMT (3 wt%) and PA additions (5 wt% and 10 wt%). The composite materials obtained were not degraded by processing as FT-IR results show. The results obtained by X-ray diffraction showed that an ordered intercalated morphology is formed between EPDM chains and MMT. Thermogravimetric experimental results revealed an increase in the thermal stability of SS-NEPCM as a result of the barrier effect provided by MMT. Moreover, SS-NEPCM fire resistance was improved with a great reduction or avoidance of the dripping phenomenon.

Investigation of thermal performance of a shell and tube latent heat thermal energy storage tank in the presence of different nano-enhanced PCMs

Thermal energy storage is crucial for the sustainability of an energy supply system. One of the best thermal energy storage systems is latent heat thermal energy storage tanks. In the present study, a shell and tube heat storage tank is simulated based on computational fluid dynamics. The tank consists of 18 hot and cold tubes and the space between them is filled with paraffin as a phase change material (PCM). The effects of adding SWCNT and GNP nanoparticles are evaluated on the PCM in different heat fluxes. The simulation is implemented by developing the C++ code in OpenFOAM software, and the solution is performed with the PIMPLE algorithm and finite volume method. Results reveal that the melting volume ratio of the PCMs is independent of the inlet heat flux, and increasing the inlet heat flux only accelerates the melting process. Adding SWCNT to the paraffin reduced the melting time by 43% and stored 147% more latent heat energy in comparison to pure paraffin.

Charging process of a partially heated trapezoidal thermal energy storage filled by nano-enhanced PCM using controlable uniform magnetic field

This paper presents a computational analysis of the flow and thermal behaviors of a nano-enhanced Phase Change Material (PCM) exposed to a magnetic field. One of the applications of PCM is to use for thermal charging of heat storage devices, which can be used in renewable energy management. The PCM is placed in a trapezoidal enclosure with a partially heated bottom wall, while the other walls are insulated. The equations governing the flow and heat transfer in the PCM are first defined and converted into the non-dimensional form. The finite element method is then employed to solve these equations. The impacts of various parameters on the PCM melting time and Nusselt number, are studied. In particular, the results showed that raising Rayleigh number enhances PCM melting due to increased buoyancy effects but only for low values of Hartmann number. Increasing the latter decreases the resistive magnetic effects which limits the convective flow and reduces melting. The volume fraction also had a slight impact on the PCM behavior. Raising the fraction improved the thermal conductivity of the working fluid and consequently increased the amount of melted PCM in the cavity.

Natural Convection within Inversed T-Shaped Enclosure Filled by Nano-Enhanced Phase Change Material: Numerical Investigation.

Energy saving has always been a topic of great interest. The usage of nano-enhanced phase change material NePCM is one of the energy-saving methods that has gained increasing interest. In the current report, we intend to simulate the natural convection flow of NePCM inside an inverse T-shaped enclosure. The complex nature of the flow results from the following factors: the enclosure contains a hot trapezoidal fin on the bottom wall, the enclosure is saturated with pours media, and it is exposed to a magnetic field. The governing equations of the studied system are numerically addressed by the higher order Galerkin finite element method (GFEM). The impacts of the Darcy number (Da = 10−2–10−5), Rayleigh number (Ra = 103–106), nanoparticle volume fraction (φ = 0–0.08), and Hartmann number (Ha = 0–100) are analyzed. The results indicate that both local and average Nusselt numbers were considerably affected by Ra and Da values, while the influence of other parameters was negligible. Increasing Ra (increasing buoyancy force) from 103 to 106 enhanced the maximum average Nusselt number by 740%, while increasing Da (increasing the permeability) from 10−5 to 10−2 enhanced both the maximum average Nusselt number and the maximum local Nusselt number by the same rate (360%).

Phase change characterization of eco-friendly isopropyl palmitate-based graphene nanoplatelet nanofluid for thermal energy applications

• Design of stable isopropyl palmitate-based nanoenhanced phase change materials. • Analysis of solid–liquid transition and enthalpy-temperature curves. • Reductions in sub-cooling higher than 2 K, increases in the latent heat up to 5.9%. • The IPP polymorphism was not significantly altered due to the GnPs dispersions. • Reductions up to 12% in the isobaric heat capacities compared to the base material. Thermal energy storage (TES) facilitates the integration of renewable energy by decoupling production and consumption, mitigating intermittence issues. However, current TES systems use fossil fuel-based products as storage media, so the development of sustainable and efficient materials should be investigated. This work aims to the design and characterization of new eco-friendly nanoenhanced phase change materials (NePCMs) based on dispersions of graphene nanoplatelets of two different lateral sizes (7.2 and 40 μm) in isopropyl palmitate for cold storage applications. The stability of the NePCMs was analysed by dynamic light scattering, selecting Span® 80 as surfactant to improve the stabilization of both nanomaterials within the base material. The influence of the nanoadditive concentration on the temperature transitions and on the solid–liquid phase change were comprehensively studied by differential scanning calorimetry, finding out that the dispersed nanoadditives do not alter the polymorphism of the isopropyl palmitate. Additionally, reductions in the sub-cooling effect higher than 2 K for both nanoplatelets were found, with increases in the latent heat up to 5.9 and 3.9% for the shorter and the longer nanoplatelets, respectively. Isobaric heat capacities were also determined by temperature-modulated differential scanning calorimetry, reporting maximum reductions of 12% compared to the base material.

Turbulent melting characteristics of hybrid nano-enhanced molten salt phase change material in rectangular enclosure

The turbulent melting characteristics of hybrid nano-enhanced phase change material (HNEPCM) in a three-dimensional rectangular enclosure has been numerically investigated. The lower and upper walls are partially heated and cooled using constant surface temperature boundary condition and the other surfaces are specified with adiabatic boundary condition. The rectangular enclosure is filled with molten salt phase change material (PCM) of potassium nitrate (KNO3) with melting temperature of 334 °C. The transient melting rates of PCM are investigated by dispersing hybrid mono-dispersed spherical nanoparticles of Aluminum oxide (Al2O3) combined with Silicon dioxide (SiO2), Titanium dioxide (TiO2) and Multi-walled carbon nanotubes (MWCNT). The Rayleigh number (Ra) and particle volume fraction (ϕ) are varied in the range of 106≤Ra≤1010 and 2%≤ϕ≤5%. The turbulent phase change process of PCM is modeled using enthalpy–porosity approach with Lam–Bremhorst k−ϵ turbulence model. The three-dimensional governing equations are discretized using Finite difference technique and computations are carried out using Fortran 90 in-house code. The stronger thermal buoyancy force accelerates the melting rate and the melting pattern indicates the accumulation of large quantity of molten metal in the upper regions of the rectangular enclosure. The average melting velocity and turbulent kinetic energy of pure KNO3 PCM is increased by 51.17% and 77.84% by the addition of Al2O3−MWCNT hybrid nanoparticles. The impact of hybrid nanoparticles on the melting rate and thermal performance of PCM is significant in higher Rayleigh number flows than transitional flows. The present results are validated and are in close agreement with the benchmark experimental results.

A Numerical Investigation of a Melting Rate Enhancement inside a Thermal Energy Storage System of Finned Heat Pipe with Nano-Enhanced Phase Change Material.

Thermal energy storage via the use of latent heat and phase transition materials is a popular technology in energy storage systems. It is vital to research different thermal enhancement techniques to further improve phase transition materials’ weak thermal conductivity in these systems. This work addresses the creation of a basic shell and a tube thermal storage device with wavy outer walls. Then, two key methods for thermal augmentation are discussed: fins and the use of a nano-enhanced phase change material (NePCM). Using the enthalpy–porosity methodology, a numerical model is developed to highlight the viability of designing such a model utilizing reduced assumptions, both for engineering considerations and real-time predictive control methods. Different concentrations of copper nanoparticles (0, 2, and 4 vol%) and wavenumbers (4,6 and 8) are investigated in order to obtain the best heat transmission and acceleration of the melting process. The time required to reach total melting in the studied TES system is reduced by 14% and 31% in the examined TES system, respectively, when NePCM (4 vol% nanoparticles) and N = 8 are used instead of pure PCM and N = 4. The finding from this investigation could be used to design a shell-and-tube base thermal energy storage unit.