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

Zhao, C.Y.; Tao, Y.B.; Yu, Yinsheng

doi:10.1016/j.energy.2021.123033

Cited by 36 publications

(9 citation statements)

References 33 publications

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“…[34,35] More importantly, nanomaterials are prone to aggregation or sedimentation and cause deterioration of the heat transfer pathway during the long-term energy charging and discharging process. [36] The reason for the low thermal conduction efficiency of nanomaterials enhanced PCM composite resulting from the uneven dispersing of nanomaterials can be divided into two: the poor dispersing ability of nanomaterials in PCMs owing to unsatisfactory compatibility and density difference, and the aggregation of nanomaterials during long-term use. [37,38] In this work, it is envisioned that TBT and PW can form a completely homogeneous solution before the generation of a porous TiO 2 skeleton.…”

Section: Nanomaterials Enhanced Thermal Conductivity Analysismentioning

confidence: 99%

Phase Change Thermal Energy Storage Enabled by an In Situ Formed Porous TiO₂

Liu

Xiao

Zhao

et al. 2022

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leakage during the phase transition process; [8] c) fabrication shape stabilization via a chemical grafting strategy on some functional group active materials; [9,10] and d) electrospinning strategy. [11] Among the numerous reports on the shape stabilization of PCMs, the physical blending method stands out because of its practical operation technique and almost no waste emissions. [12][13][14] However, the capillary force, which plays a critical role in the adsorption of liquid-state PCMs, results in challenges for the complete adsorption of liquid PCMs owing to the inherent surface tension between the liquid and solid interfaces. Herein, for the first time, we use the practical operation and no-emission advantages of the physical blending method, avoiding the energy storage density shrinkage resulting from the uneven adsorption caused by capillary force.Capillary force, which dominates the adsorption capacity of supporting materials toward LSPCMs, can be calculated via the Young-Laplace equation: [15] ρ θ = 2 cos / p r (1)where p, ρ, θ, and r are the capillary force, the surface tension of melted PCMs, the wetting angle between PCMs and supporting material, and the radius of the supporting material pore, respectively. If the pore size of the supporting material is small, the capillary force may be sufficient to maintain the liquid PCMs in the phase transition cycles, leading to better thermal reliability and stability. Therefore, micro/nanoscale pores are good choices for the shape-stabilization of PCMs and for enhancing the thermal reliability of PCMs because of the strong capillary force. [7,16] In contrast, surface tension inhibits complete contacting or entry between supporting materials and PCMs, resulting in an air chamber, which decreases the energy storage density and thermal interfaces, making the physical blending method less desirable (Figure 1). [17,18] Manipulating surface characteristics on porous materials is a common way to enhance the compatibility between supporting materials and PCMs. [17] For example, Wang et al. found that dopamine can be adopted to modify the surface of expanded vermiculite (EVM) to promote the phase change behavior and improve the heat storage characteristics of polyethylene glycol (PEG)/ EVM-dopamine (EVMX) form-stable composite. [19] Zhang et al. realized that modifying the surface polarity of copper foam with superhydrophobic/superhydrophilic properties would be Uneven and insufficient encapsulation caused by surface tension between supporting and phase change materials (PCMs) can be theoretically avoided if the encapsulation process co-occurs with the formation of supporting materials in the same environment. Herein, for the first time, a one-pot one-step (OPOS) protocol is developed for synthesizing TiO 2 -supported PCM composite, in which porous TiO 2 is formed in situ in the solvent of melted PCMs and directly produces the desired thermal energy storage materials with the completion of the reaction. The preparation features straightforward operation and high environ...

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Section: Nanomaterials Enhanced Thermal Conductivity Analysismentioning

confidence: 99%

Phase Change Thermal Energy Storage Enabled by an In Situ Formed Porous TiO₂

Liu

Xiao

Zhao

et al. 2022

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“…The first part of this work is devoted to the characterization of molecular organization of the studied n-hexadecane samples considered in MD simulations used to evaluate thermophysical properties. As mentioned above, crystalline structure of n-hexadecane [17] are scarcely achievable with the simulation parameters used here. Instead, we suggest that amorphous state, characterized by amorphous molecules organization is more probably reached when the calculations are performed below the liquid-solid transition temperature.…”

Section: Liquid/amorphous State a Molecular Investigationmentioning

confidence: 99%

“…Specifically, molecular dynamics (MD) techniques are effective tools for investigating the behavior of various systems based on interactions between individual atoms. As a result, it allow us the investigation of the thermophysical [15,16,17], rheological [18,19,15], and structural [13,20] characteristics of PCMs and PCM-based nanocomposites. Howewer, MD simulations require the specification of the suitable interaction potential and its subsequent parametrization.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Thermophysical properties of $n$-hexadecane: Combined Molecular Dynamics and experimental investigations

Klochko,

Noel,

Sgreva

et al. 2022

Preprint

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Investigating properties of phase change materials (PCMs) is an important issue due to their extensive use in heat storage systems and thermal regulation devices. Improvement of the efficiency of such systems should be based on a better knowledge of the microscopic mechanisms governing the thermal and rheological characteristics of PCMs. This may be accomplished by the use of molecular simulations of the aforementioned quantities and their linkage with macroscale investigations. In this work, we studied thermophysical properties of n-hexadecane for different temperatures regimes using molecular dynamics (MD) and carry out several experimental measurements. Particularly, we focused on the evaluation of various rheological and thermal properties such as thermal conductivity, κ, viscosity, η, diffusion coefficient, D, and heat capacities Cp and Cv. Special attention was paid to the comparison of the results of simulations with experimental ones.

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“…This has promoted various applications of nanofluids in a wide range of fields, such as cooling fluids for nuclear reactors [ 7 ] and for thermal management of electronics [ 8 – 9 ]. As mentioned above, nanofluids have also proved to be very effective as working ﬂuids [ 10 – 11 ] in solar thermal systems and for enhancing the thermal characteristics of phase-change materials (PCM) that are used for latent thermal storage media [ 12 ] in solar thermal systems.…”

Section: Introductionmentioning

confidence: 99%

Comparative molecular dynamics simulations of thermal conductivities of aqueous and hydrocarbon nanofluids

Loya¹,

Najib²,

Aziz³

et al. 2022

Beilstein J. Nanotechnol.

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The addition of metal oxide nanoparticles to fluids has been used as a means of enhancing the thermal conductive properties of base fluids. This method formulates a heterogeneous fluid conferred by nanoparticles and can be used for high-end fluid heat-transfer applications, such as phase-change materials and fluids for internal combustion engines. These nanoparticles can enhance the properties of both polar and nonpolar fluids. In the current paper, dispersions of nanoparticles were carried out in hydrocarbon and aqueous-based fluids using molecular dynamic simulations (MDS). The MDS results have been validated using the autocorrelation function and previous experimental data. Highly concurrent trends were achieved for the obtained results. According to the obtained results of MDS, adding CuO nanoparticles increased the thermal conductivity of water by 25% (from 0.6 to 0.75 W·m−1·K−1). However, by adding these nanoparticles to hydrocarbon-based fluids (i.e., alkane) the thermal conductivity was increased three times (from 0.1 to 0.4 W·m−1·K−1). This approach to determine the thermal conductivity of metal oxide nanoparticles in aqueous and nonaqueous fluids using visual molecular dynamics and interactive autocorrelations demonstrate a great tool to quantify thermophysical properties of nanofluids using a simulation environment. Moreover, this comparison introduces data on aqueous and nonaqueous suspensions in one study.

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

Cited by 36 publications

References 33 publications

Phase Change Thermal Energy Storage Enabled by an In Situ Formed Porous TiO₂

Phase Change Thermal Energy Storage Enabled by an In Situ Formed Porous TiO₂

Thermophysical properties of $n$-hexadecane: Combined Molecular Dynamics and experimental investigations

Comparative molecular dynamics simulations of thermal conductivities of aqueous and hydrocarbon nanofluids

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

Cited by 36 publications

References 33 publications

Phase Change Thermal Energy Storage Enabled by an In Situ Formed Porous TiO2

Phase Change Thermal Energy Storage Enabled by an In Situ Formed Porous TiO2

Thermophysical properties of $n$-hexadecane: Combined Molecular Dynamics and experimental investigations

Comparative molecular dynamics simulations of thermal conductivities of aqueous and hydrocarbon nanofluids

Contact Info

Product

Resources

About

Phase Change Thermal Energy Storage Enabled by an In Situ Formed Porous TiO₂

Phase Change Thermal Energy Storage Enabled by an In Situ Formed Porous TiO₂