Nanocomposite Phase Change Materials Research Articles

Study of tree-shaped optimized fins in a heat sink filled by solid-solid nanocomposite phase change material

The aim of this work is to comprehensively study the effect of the material of the simple plate and tree-shaped optimized fins on the thermal behavior of an enclosed medium filled with a nanocomposite of neopentyl glycol/CuO solid-solid PCM. Increasing the heat transfer rate using a fixed amount of material is an important task that improves the fin performance. The tree-shaped fin is optimized based upon the density-based structure optimization method. A transient model based upon the enthalpy method is employed to numerically study the thermal behavior of the enclosed medium containing the SS-PCM. The thermal performance of the heat sink with the tree-shaped optimized and simple plate fins made of different materials are explored. Results show that the aluminum and copper fins have the highest melting rate compared to the examined materials. Their melting rate is 50% higher than steel 302 in the case of flat plates, and 25% in the case of a tree structure. Also, the tree-shaped optimized fins outperform the plate structure fins by reaching the lowest temperature of the concentrated heat source and temperature non-uniformity under the condition that the two strucutures have the same height. When the two heights are different, the temperature distribution was optimized for materials with the lowest thermal conductivity. For steel materials, a 10% decrease in the maximum temperature was observed in the tree structure compared to the flat plates. Finally, it was shown that the nanoparticle fraction played a negligible role in heat transfer, as less than 1% change in melting rate and temperature parameters was obtained.

Two-dimensional lamellar phosphogypsum/polyethylene glycol composite PCM: Fabrication and characterization

In this work, a nanocomposite phase change material (PCM) has been designed by combining two-dimensional lamellar anhydrous calcium sulfate with polyethylene glycol (PEG). We report a facile strategy to controllably fabricate two-dimensional lamellar anhydrous calcium sulfate (LAH) with the average thickness of 28.63 nm from phosphogypsum (PG) through ethylenediamine tetraacetic acid disodium (Na2EDTA) induction in glycerol and ethylene glycol solutions at 98 °C. The obtained 2D lamellar CaSO4 was a slit-type mesoporous material stacked by the nanosheet of calcium sulfate. It has a specific surface area of 70.02 m2/g, which is 10 times larger than phosphogypsum. Na2EDTA acts as a crystal habit-directing agent to regulate crystal morphology through nonclassical nanoparticle-mediated crystallization processes, resulting in the crystalline morphology tending to be lamellar. Lamellar anhydrous calcium sulfate phase change composites (LAHPCMs) were prepared with 2D lamellar anhydrous nano-CaSO4 and polyethylene glycol (PEG). The LAHPCMs had a high latent heat storage capacity (92.99 J/g). Lamellar anhydrous calcium sulfate phase change composites have good thermal stability and durability, structure stability, and good liquid leakage resistance. These results provide the possibility for phosphogypsum to be used for energy storage and thermal insulation.

Activated carbon nanotube/polyacrylic acid/stearyl alcohol nanocomposites as thermal energy storage effective shape-stabilized phase change materials

Stearyl alcohol (SA) as one of organic phase change materials (PCMs) has promising thermal energy storage prospective. However, the leakage issue during solid-liquid phase change period and low heat harvesting and releasing rate significantly attenuates its TES potential. Towards to overcome these drawbacks, the SA was shape-stabilized using the cross-linked poly acrylic acid (PAA) and activated single walled carbon nanotubes (a-SWCNTs) at three different weigh ratio of 1:1:2, 1:3:4 and 1:5:6 (a-SWCNTs:PAA:SA). The chemical/crystalline and morphologic structures of the produced shape stabilized-nano composite PCMs (SS-NCPCMs) were investigated by FT-IR, XRD and SEM analyses. The latent heat storage (LHS) features and thermal stability of the SS-NCPCMs were measured by DSC and TGA techniques. The thermal cycling effect on the LHS properties and chemical structures of the SS-NCPCMs was also estimated. The DSC findings indicated that the SS-NCPCMs had melting temperature of around 55–56 °C and latent heat capacity of about 135 J/g. TGA measurements disclosed that the thermal degradation temperatures of the nano composite PCMs were prolonged somewhat compared to the SA. A 500 heating-cooling cycling test revealed that the SS-NCPCMs had great chemical and LHS stability. The heat harvesting and releasing performance of the NCPCMs were considerably shortened compared to those of pure SA. The obtained results exposed that the synthesized SWCNTs/PAA/SA composites can be evaluated as promising LHS materials for thermal management of electronic systems, automobile modules, food carriers, solar PV panels etc.

Thermal conductivity, reliability, and stability assessment of phase change material (PCM) doped with functionalized multi-wall carbon nanotubes (FMWCNTs)

The thermal properties of Phase Change Material (PCM) can be altered by introducing nanoparticles, and composite formed from the addition of nanoparticles are termed Nano-Enhanced Phase Change Materials (NEPCM). In the present study, the enhancement of thermal conductivity and feasibility study of dispersing multi-walled carbon nano tubes (MWCNTs) and functionalized MWCNT (FMWCNTs) in various mass fractions (AFMW-0.1, AFMW-0.3, AFMW-0.5, AFMW-0.7, AFMW-1.0) into the Plusice A70 PCM were examined. Differential scanning calorimetry (DSC) and TEMPOS thermal analyzer measured the latent heat storage, melting temperature, and thermal conductivity of the nano PCM composite. The thermal conductivity measured for the prepared nanocomposite showed a 109.5% enhancement for 1.0 wt% of non-functionalized MWCNT and 150.7% enhancement for 1.0 wt% of functionalized MWCNT compared to pristine PCM's thermal conductivity. This statement concluded that 50% enhancement for a 1.0 wt% of functionalized MWCNT compared to non-functionalize MWCNT immersed in A70 PCM. The nano composite PCM was thermally stable up to 200 °C and no chemical reaction takes place between the base PCM and nanoparticles. The result shows that the microscopic structure remained stable for the nanocomposite while the optical transmittance reduced noticeably for the nanocomposite relative to pristine A70 PCM. It can be concluded, the prepared nano composite PCM may be useful for solar thermal, photovoltaic thermal system, and low concentrated photovoltaic thermal system applications.

Evaluation of Rutting and Fatigue Behavior of Modified Asphalt Binders with Nanocomposite Phase Change Materials

Evaluation of Rutting and Fatigue Behavior of Modified Asphalt Binders with Nanocomposite Phase Change Materials

Experimental investigations on the thermal performance and phase change hysteresis of low-temperature paraffin/MWCNTs/SDBS nanocomposite via dynamic DSC method

Benefitting from high storage density, phase change material (PCM) has been widely utilized in cold chain logistics. However, the phase change process of composites is normally non-isothermal, which will lead to phase change hysteresis (PCH). The exploration of the mechanism and influence factors of PCH remains a huge challenge. In this paper, a nanocomposite PCM (NCPCM) based on paraffin (PA) was prepared to address this issue via the two-step method. Here, the applications of multi-walled carbon nanotubes (MWCNTs) and sodium dodecylbenzene sulfonate (SDBS) were contributed to the enhancement of thermal conductivity and suspension stability. Subsequently, after various characterization techniques, the results showed that thermal conductivity of the NCPCM with 1.0 wt% MWCNTs and a 2:1 mass ratio of MWCNTs and SDBS increased by 1.86 times. Moreover, the NCPCM exhibited high thermal charging-discharging efficiency, thermal stability, and cyclic stability. More importantly, the PCH has been studied via the dynamic differential scanning calorimetry (DSC) method. The effects of temperature range, temperature changing rate, and sample mass on the hysteresis degree were investigated. Furthermore, the PCH was interpreted in terms of energy storage, temperature delay, internal thermal resistance, crystallinity, and interfacial free energy. It was proved that the NCPCM possesses a smaller hysteresis degree when the temperature range was −40–50 °C, temperature changing rate was 10 K min−1, and sample mass was within 10 mg.

Effect of expanded graphite surface modification on phase change materials nanocomposites thermal protection efficiency

AbstractIn order to investigate phase change materials (PCMs) thermal energy storage capacity as well as shape stability, PCM nanocomposites were fabricated by employing modified expanded graphite (EG) as a conductive filler and polyethylene glycol (PEG) PCM. To improve PCM composite shape stability, EG surface has been modified by utilizing Toluene 2 and 4 diisocyanate (TDI), ethylene glycol and PEG 600, respectively. Findings have illustrated that for PEG PCM/modified EG nanocomposites, shape stability was achieved at 5 wt.% of modified EG filler with less than 10% of melt leakage for all prepared samples as a consequence of surface adsorption capacity increment as well as adequate compatibility. Furthermore, phase change efficiency was calculated as 98% and in addition, thermal diffusion at PCM melting temperature range was negligible and approximately equal to zero. To conclude, it could be declared that, fabricated phase change material composite had desirable characteristics along with adequate shape stability for thermal energy storage applications.

Thermophysical investigation of metallic nanocomposite phase change materials for indoor thermal management

This experimental work discusses the thermophysical investigation of metallic nanocomposite PCMs having a potential application in indoor thermal management. Organic fatty alcohol (lauryl alcohol) was used as a phase change material (PCM). Four metallic nanoparticles, namely Al2O3, CuO, Fe3O4, and SiC at the concentrations of 1 wt%, 3 wt%, 5 wt%, were used to prepare nanocomposite PCMs, and their phase change properties were investigated. The results showed a minor change in the phase change temperatures, and the latent heat values varied between 6.56% and 18.5%. Besides, the degree of supercooling was reduced for nanocomposite PCMs. Fourier transform infrared spectroscopy, and thermogravimetric analysis showed no chemical reaction between the nanoparticles and the base PCM. The nanocomposite PCMs decomposed above 110°C, higher than the proposed application temperature range. In addition, the maximum enhancement in thermal conductivity of PCM at 10°C with 5 wt% of Al2O3, CuO, Fe3O4, and SiC nanoparticles were about 29.1%, 52.2%, 9.2%, and 17.9%, respectively. The endothermic freezing process was carried out, and lower phase change duration was recorded for nanocomposite PCMs compared to pure PCM. Based on various experimental studies, Al2O3 and CuO nanocomposite PCMs exhibits significantly improved thermal and physical properties than the Fe3O4 and SiC nanocomposite PCMs and can be used as a potential thermal energy storage material for indoor thermal comfort applications.

Thermal performance of a phase change material-based heat sink in presence of nanoparticles and metal-foam to enhance cooling performance of electronics

The present study explores the parametric investigation of a heat sink filled with composite of pure phase change material (PCM), nanocomposite phase change material (NCPCM), metal-foam (MF) by employing the numerical approach for effective passive thermal management of electronics. The combinations of heat sink are varied by filling PCM, NCPCM, MF+PCM and NCPCM+MF. Different parameters such as MF materials, porosities, pore densities (PPI-pores per inch), volume fractions of nanoparticles in NCPCM, power levels and combination of MF+NCPCM by varying different porosities and nanoparticles volume fractions. Copper (Cu) nanoparticles of 1%, 3% and 5% volume fraction were dispersed in RT-35HC, used as a PCM, and copper, aluminium (Al) and nickel (Ni) MFs were embedded inside the heat sink. Transient simulations with conjugate heat transfer and melting/solidification schemes were formulated using finite-volume-method (FVM). The thermal performance and melting process of the NCPCM filled heat sink were evaluated through melting time, heat storage capacity, heat storage density, rate of heat transfer and rate of heat transfer density. The results showed that with the addition of Cu nanoparticles and MF, the rate of heat transfer was increased and melting time was reduced. The melting time was reduced by −1.25%, −1.87% and −2.34%; and rate of heat storage is enhanced by 1.35%, 0.76%, and 0.19% with the addition of 1%, 3% and 5% volume fraction of Cu nanoparticles, respectively. The composite of MF+NCPCM showed the lower heat sink temperature and higher liquid-fraction were obtained. The latent-heating phase duration was decreased with the increase of Cu nanoparticles volume fraction. Additionally, the lower reduction in melting time of −18.10% and higher rate of heat transfer of 8.12% were obtained with 1% Cu nanoparticles, 95% porosity and 10 PPI Cu MF based heat sink.

Highly stable n-hexacosane loaded exfoliated graphite nanosheets for enhanced thermal energy storage application

In the present work, we demonstrate an in-situ synthesis of phase-change material (n-hexacosane) loaded exfoliated-graphite nanosheets (EGPCM) by modified hydrothermal method, exhibiting high thermal stability over extended thermal cycling. During the hydrothermal method, the exfoliation of graphite enables more surface area to absorb n-hexacosane leading to better interaction between the carbon and phase change material (PCM). The morphological and structural results confirm the PCM loading in porous dendritic structures without any chemical reactions of n-hexacosane. Further, the latent heat, thermal conductivity, and stability of as-prepared EGPCM composites were established by differential scanning calorimetry (DSC), thermo-gravimetric analysis (TGA), and infrared thermography (IR). The charging of EGPCM nanocomposite was observed at 58.07 °C with a latent heat of 167.70 J/g and discharging at 48.51 °C with a latent heat of 149.52 J/g. The EGPCM composites exhibit high thermal conductivity (10.47 W/m K compared to pure n-hexacosane 0.26 W/m K) and a highly stable nature against thermal degradation after 200 charging/discharging cycles. A detailed comparison of the as-prepared EGPCM material with previously reported PCM nanocomposites is also provided, showing the proposed mechanism's enhanced thermal stability and storage capability. The presented work demonstrates a scalable, custom-built latent-heat reservoir using inner-linings of as-prepared nanocomposite material. Infrared thermography and COMSOL simulations pertaining to thermal performance showed significant improvement in the thermal conductivity of the composite compared to n-hexacosane, attributed to the 3D network of exfoliated graphite.

Thermal properties of the three-dimensional graphene/paraffin nanocomposite phase change materials

The excellent properties of graphene phase change nanocomposite made it have potential application value in the field of heat storage materials, which was expected to achieve the integration of heat transfer and storage. In order to enhance the thermal performance of paraffin in energy storage, the structure models of n-octadecane and three kinds of graphene/n-octadecane composites were established. Molecular dynamics method was used to study the variation of thermophysical properties. It is found that the strong interaction between graphene and noctadecane restricts the diffusion intensity of n-octadecane molecules, which reflects in the decreasing trend of the self-diffusion coefficient. In addition, the thermal conductivity of each system in the solid state is higher than that of liquid, and abruptly drops near the melting point. The thermal conductivity of the composite PCM always higher than the pure noctadecane and increases with the amount of graphene.

Effect and mechanism of doped graphene nanosheets on phase transition properties of sodium nitrate

Molten salt is regarded as one of most promising candidates for solar energy storage due to possessing stable properties and large energy storage densities. However, the intrinsically low thermal conductivity of molten salt has become a bottleneck for rapid heat storage and transport. The addition of nanoparticles is generally considered to be a most effective way to improve the thermal conductivity of molten salt phase change materials (PCMs), while the phase change enthalpies of the nanocomposite phase change materials usually show two opposite trends of enhancement or decrement. Furthermore, the reason for the abnormal change of phase change enthalpy has not been clear in the literature so far, so the mechanism of change needs to be further explored. In this work, graphene nanosheets (GNS)@NaNO<sub>3</sub> (sodium nitrate) nanocomposite phase change materials are prepared by the hydration ultrasonic method. The materials are characterized by scanning electron microscope, and the phase change characteristics are measured using differential scanning calorimeter. Molecular dynamics simulation is carried out to explain the mechanism for the formation of the NaNO<sub>3</sub> dense layer and the non-collateral decrease of the enthalpy from the microscopic level. With the increase of GNS mass fraction, the melting point of the GNS@NaNO<sub>3</sub> composite phase change material decreases slightly while the phase change enthalpy decreases significantly with a non-colligative trend. A 13.81% decrease of the theoretical phase change enthalpy is observed with a GNS doping ratio of 1.5%. The NaNO<sub>3</sub> clusters observed on the surface of GNS are considered to have not melted, thereby resulting in a reduction in the phase change enthalpy. The mechanism is further investigated by molecular dynamics simulation, showing that the strong van der Waals attraction between GNS and NaNO<sub>3</sub> leads the 2–4 Å-thick NaNO<sub>3</sub> dense layer to form in the vicinity of GNS. With the increase of GNS mass fraction, the centroid equivalent distance between the dense layer and GNS gradually increases, which leads their mutual attraction to first increase and then weaken. When GNS mass fraction is 1.5%, the centroid equivalent distance reaches the position closest to the potential well, leading to a strongest mutual attraction. In other words, the phase change enthalpy decreases most obviously at this mass fraction. Thus, some conclusions can be drawn as follows. The type of interaction between molten salt and nano-enhancers and the position of the potential well are the fundamental reasons for the thickness of molten salt dense layer and the reduction of phase change enthalpy. The calculation of the interaction energy can be used to guide the selection of the mass fraction of the nano-enhancers, so as to avoid the loss of core material cluster and phase change enthalpy caused by the introduction of the nano-enhancers to a greatest extent. The preparation cost of the composite phase change material can also be reduced to a certain extent.

Thermal conductivity enhancement of phase change material with charged nanoparticle: A molecular dynamics simulation

The present work investigates the effects of charged nanoparticles on thermal properties of phase change material (PCM). Nanoparticles (CuO) with different electrical charges were dispersed into paraffin (octadecane) to prepare nanocomposite phase change material (NPCM). Molecular dynamics method was used to study the thermal conductivity of NPCM and reveal the effect of the charged nanoparticle. The results show that the thermal conductivity of NPCM is promoted with increasing nanoparticle charges. Coulomb energy is nonlinearly increased with the increasing charge. Furthermore, the local density of atoms is also affected by the charged nanoparticle. The peak value of local density increases with increasing nanoparticle charges. Phonon density of state (PDOS) is calculated to study the phonon transport in NPCM. Phonon scattering is weakened around the nanoparticle due to the existence of nanolayer. Moreover, the thickness of nanolayer is increased with the increasing charge, resulting in weaker phonon scattering and contributing to more thermal conductivity enhancement of NPCM. It can be a good way to control the thermal properties of NPCM by adjusting the nanoparticle charge.

A comprehensive review on thermophysical properties and solar thermal applications of organic nano composite phase change materials

The recent advancements in phase change materials (PCM) have made them emerge as a novel class of materials to be deployed in thermal energy storage. An effective strategy to enhance the thermal conductivity of PCM is to disperse highly conductive nano additives. A comprehensive summary of the recent advances over the previous decade in synthesis routes that effectively enhances the thermal conductivity of PCM based on different dimensional nano additives is highlighted. Fundamental mechanisms for thermal conductivity rise, like phonon interaction, interfacial thermal resistance, Vander Waals forces, construction of thermally conductive pathways, were considered. Furthermore, the effect of factors like; aspect ratio, temperature, type of nano additives, and surfactant on thermophysical properties are also studied. An in-depth analysis of various solar thermal applications of Nano-enhanced PCMs (NePCM) integrated systems delivering improved performance is also done. Finally, an outline of economic impact, challenges, and future outlooks in the context of NePCMs are also presented.

Thermal Behaviour of Nanocomposite Phase Change Material for Solar Thermal Applications

The use of solar thermal technologies has shown great prospects towards solar energy conversion into more useful forms of energy and has increasingly expanded solar thermal technology applications. However, the inability to properly store the excess solar energies during peak hours and demands have limited many of their applications. The integration of thermal energy storage (TES) systems with thermal technologies have increased the solar thermal technology performance but the poor thermal characteristics exhibited by phase change materials (PCM) limited the system overall performance. The enhancement of PCM properties by nonadditive have shown increased material performance in TES application and thereby extending the use of solar thermal technology application. Given this narrative and identifies literature gaps, the present study investigated experimentally the enhancement of paraffin PCM using nonadditive metallic of different types and concentrations and analysed their thermal behaviours. The results showed that Cu/paraffin PCM nanocomposites had good thermal reliability in proposed applications even after 150 thermal cycles under different temperatures. Moreover, thermal conductivity was improved significantly as an enhancement of 39% was reported when adding 2.5% of Cu nanoparticles. While specific heat and thermal diffusivity has been enhanced by 16% and 9%, respectively compared to pure paraffin. The obtained results were compared with different theoretical models such as Maxwell mode, Hamilton Crossover model, Jeffery model, and Bruggeman model. The calculated values show a good agreement with experimental ones. As a result, the prepared Cu/Paraffin nanocomposite PCM shows significant promise in thermal energy storage application due to its favourable phase change temperature, comparatively large latent heat, enhanced thermal conductivity and high thermal reliability and conversion. The proposed nanocomposite PCM can be used in many applications such as building materials to reduce interior temperature swings, enhance thermal comfort, and conserve electricity consumption.

Molecular dynamics simulation on thermal enhancement for carbon nano tubes (CNTs) based phase change materials (PCMs)

In the study, CNTs based nanocomposite phase change materials (NPCMs) is considered for breaking through the constraint of the low thermal conductivity of conventional PCMs for thermal energy storage. A molecular dynamics simulation method is newly established to predict the structural, diffusive and thermal properties of composite PCMs based on CNTs. It is found that the PCMs is preferentially distributed as either one or two ring-shaped layers that discretely separated from the CNTs wall with a distance of 3.8 Å and 8.0 Å, respectively. The mean square displacement (MSD) and the self diffusion coefficient are characterized for featuring the molecule mobility and predicting the melting temperature of the composite PCMs. Interestingly, the dense phase existing between the CNTs wall and the PCMs is proven to be the dominant factor that negates the phase change enthalpy of the composite system. In realistic experiments using the CNTs with a radius of 10∼15 Å, the thermal conductivity is highly potential to be improved to 5∼15 W/m·K, indicating an augmentation of the thermal conductivity by approximate 32∼100 times compared to pure PCMs. The formation of efficient heat conduction paths explains for the intrinsic mechanism of the tremendous improvement in the CNTs based NPCMs, which could be achieved in the premise of strong binding effect of materials and reduced contact thermal resistance among CNTs in macroscopic PCM modules.

Multi-Scale Numerical Modelling for Predicting Thermo-Physical Properties of Phase-Change Nanocomposites for Cooling Energy Storage

One major limitation of phase-change materials (PCM) for thermal energy storage comes from their poor thermal conductivity hindering heat transfer process and power density. Nanocomposites PCMs, where highly conductive nanofillers are dispersed into PCM matrices, have been exploited in the past decades as novel latent heat storage materials with enhanced thermal conductivity. A computational model based on continuum simulations capable to link microscopic characteristics of nanofillers and the bulk PCM with the macroscopic effective thermal conductivity of the resulting nanocomposite is the aim of this work. After preliminary mean-field simulations investigating the impact of the nanofiller aspect ratio on the thermal conductivity of the nanocomposite, finite element simulations at reduced aspect ratios have been performed with corrected thermal conductivity values of the filler, to take into account the thermal interface resistances between fillers and matrix. Finally, the thermal conductivity at the actual aspect ratios has been extrapolated by the results obtained at reduced aspect ratios thus saving computational time and meshing efforts. This method has been validated through comparison against previous literature evidence and new experimental characterizations of nanocomposite PCMs.

Preparation and thermophysical property analysis of nanocomposite phase change materials for energy storage

Paraffin wax and various nanoparticles (CuO, Al2O3 and Fe3O4) were used as matrix and heat conduction enhancer of phase change materials (PCMs), respectively. The dispersant Span 80 was added into the nanocomposite to provide stable PCMs. Based on analyses of melting and freezing curves and infrared thermal imaging tests, the phase change latent heat, viscosity, and thermal conductivity of the nanocomposite PCMs were measured. This article also analyzes the effects of heating power and fan power on heat transfer characteristics of the heat pipe with PCMs as the cooling system. Temperature of evaporator is investigated by applying PCMs energy storage. It is found that temperature fluctuations in the evaporator is alleviated by filling an adiabatic section covered with PCMs for energy storage in the cooling system. The results show that compared to pure paraffin wax, the thermal conductivity of 1.2 wt% CuO/paraffin composite PCMs increases by 24.9 % at 25 °C, whereas the thermal conductivity at 70 °C increases by 20.6 %. Compared to pure paraffin wax, the latent heat of the nanocomposite PCMs decreases by 1.5 %, the viscosity increases by 10.1 % at the melting temperature 70 °C. With an integrated cooling scheme, the temperature of the evaporator with 1.2 wt% nano-CuO/paraffin composites at a 2 V fan voltage is 22.0 % less than that without PCMs at a 0 V fan voltage.

Thermal investigation of a solar box-type cooker with nanocomposite phase change materials using flexible thermography

In this study, three SBCs are developed as (i) SBC with phase change material (PCM: waste cooking oil and C4H4O3), (ii) a novel SBC with nanocomposite PCM (NPCM), and (iii) a SBC without NPCM. The novel proposed cooker integrated with NPCM (MgAl2O4/Ni/Fe2O3-PCM) was experimentally developed and its performance was evaluated using fuzzy logic and Cramer's rules, and image processing techniques. The results indicated that the implementation of a bar plate absorber coated with MgAl2O4/Ni-doped, Fe2O3 nanoparticles, and integrated with PCM increases the cooker's internal temperature up to 164.12 °C. The used nanocomposite materials were in the average particle size of 20 μm. The cooking materials were verified with the temperature in the segmentation process. The NPCM indicated the SBC's thermal performance enhancement of 11% in comparison with the SBC with PCM and without NPCM. Additionally, the overall thermal performance of SBCs without NPCM, with PCM, and with NPCM was obtained as 24.90–33.90%, 24.77–45.20%, and 31.77–56.21%, respectively. Moreover, the temperature of the bar plate absorber was achieved as 163.74 °C, 147 °C, and 113.34 °C for the SBC with NPCM, PCM, and without NPCM, respectively, under the solar radiation of 1,037 W/m2.

Thermal process enhancement of HNCPCM filled heat sink: Effect of hybrid nanoparticles ratio and shape

The present study based on the numerical investigation of a hybrid nanocomposite phase change material (HNCPCM) filled heat sink for passive cooling of electronic devices. The combination of graphene oxide (GO) and silver (Ag) hybrid nanoparticles are added inside the RT-28HC to enhance thermal performance. The volume fraction ratios of Ag:GO are varied from 0:0, 0:4, 1:3, 2:2, 3:1 and 4:0. Four different shape factor values of 3.7, 4.9, 5.7 and 16.1 of Ag-GO are varied. The transient simulations are carried out to solve the governing equations using the finite volume method scheme. The results depicted that employing HNCPCM has better heat transfer enhancement compared to the pure PCM because of the addition of nanoparticles. The results showed that adding the Ag-GO inside the RT-28HC improved the thermal conductivity and uniformity in the melting process compared to the RT-28HC based heat sink. With the addition of Ag-GO, melting time of HNCPCM filled heat sink is reduced and heat transfer rate in increased. The optimum ratio of 1:3 of Ag:GO nanoparticles and shape factor value of 16.1 show the higher thermal conductivity of 0.348 W/m.K, 12.93% reduction in melting time, 8.65% enhancement in heat storage capacity and rate of heat transfer.