The stability and thermophysical properties of a thermal fluid containing surface-functionalized nanoencapsulated PCM

Karaipekli, Ali; Erdoğan, Taner; Barlak, Semahat

doi:10.1016/j.tca.2019.178406

Cited by 33 publications

(23 citation statements)

References 52 publications

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“…As shown, the vertical walls are maintained at hot and cold isothermal temperatures, while the horizontal walls are kept adiabatic. Based on the experimental study of Karaipekli et al 44 , such LFTFs are considered stable without any stabilizing agent or emulsifying and well dispersed with zeta potential of − 56.8 mV.…”

Section: Mathematical Modelmentioning

confidence: 99%

“…Thermophysical properties of the LFTF. The correlations for the specific heat capacity, dynamic viscosity, density and thermal of the LFTF and water are derived using the available experimental data of Karaipekli et al 44 . The correlations (Eqs.…”

Section: Mathematical Modelmentioning

confidence: 99%

“…2, the experimental data are in good accordance with the estimated values from the correlations. In Karaipekli et al 44 study, the NEPCMs were prepared using N-nonadecane as PCM and poly (styrene-co-methacrylic acid) as shell material for the encapsulation. The average size of the NEPCMs is equal to 212 nm, which is in the typical range of nanosized phase change particles (1-1000 nm) 44 .…”

Section: Mathematical Modelmentioning

confidence: 99%

“…In Karaipekli et al 44 study, the NEPCMs were prepared using N-nonadecane as PCM and poly (styrene-co-methacrylic acid) as shell material for the encapsulation. The average size of the NEPCMs is equal to 212 nm, which is in the typical range of nanosized phase change particles (1-1000 nm) 44 . The LFTFs were prepared at different volume fractions of 0.43, 0.85, 1.27 and 1.69%, and hence it can be considered as a dilute suspension.…”

Section: Mathematical Modelmentioning

confidence: 99%

“…Alay et al 43 used poly (methylmethacrylate-co-glycidyl methacrylate) shell to encapsulate n-hexadecane. Karaipekli et al 44 formulated the NEPCMs, using N-nonadecane as PCM and poly (styrene-co-methacrylic acid) as shell material for the encapsulation. A detailed review on the nanoencapsulation of inorganic and organic PCMs is presented in the literature 45 .…”

mentioning

confidence: 99%

See 4 more Smart Citations

Investigation of the novelty of latent functionally thermal fluids as alternative to nanofluids in natural convective flows

Haddad

Iachachene

Abu‐Nada

et al. 2020

Sci Rep

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This paper presents a detailed comparison between the latent functionally thermal fluids (LFTFs) and nanofluids in terms of heat transfer enhancement. The problem used to carry the comparison is natural convection in a differentially heated cavity where LFTFs and nanofluids are considered the working fluids. The nanofluid mixture consists of Al2O3 nanoparticles and water, whereas the LFTF mixture consists of a suspension of nanoencapsulated phase change material (NEPCMs) in water. The thermophysical properties of the LFTFs are derived from available experimental data in literature. The NEPCMs consist of n-nonadecane as PCM and poly(styrene-co-methacrylic acid) as shell material for the encapsulation. Finite volume method is used to solve the governing equations of the LFTFs and the nanofluid. The computations covered a wide range of Rayleigh number, 104 ≤ Ra ≤ 107, and nanoparticle volume fraction ranging between 0 and 1.69%. It was found that the LFTFs give substantial heat transfer enhancement compared to nanofluids, where the maximum heat transfer enhancement of 13% was observed over nanofluids. Though the thermal conductivity of LFTFs was 15 times smaller than that of the base fluid, a significant enhancement in thermal conductivity was observed. This enhancement was attributed to the high latent heat of fusion of the LFTFs which increased the energy transport within the cavity and accordingly the thermal conductivity of the LFTFs.

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Section: Mathematical Modelmentioning

confidence: 99%

Section: Mathematical Modelmentioning

confidence: 99%

Section: Mathematical Modelmentioning

confidence: 99%

Section: Mathematical Modelmentioning

confidence: 99%

mentioning

confidence: 99%

See 3 more Smart Citations

Investigation of the novelty of latent functionally thermal fluids as alternative to nanofluids in natural convective flows

Haddad

Iachachene

Abu‐Nada

et al. 2020

Sci Rep

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Microencapsulation of Molten Salt in Titanium Shell for High‐Temperature Latent Functional Thermal Fluid

Wang

et al. 2020

Energy Tech

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Herein, a water‐limited sol–gel method is applied to fabricate microencapsulated phase change materials (MEPCMs) which have a sodium nitrate (NaNO3) core and a titanium dioxide (TiO2) shell. The MEPCM has a high melting temperature of 306.5 °C and a solidification temperature of 296.7 °C, which shows a potential usage as a high‐temperature compatible thermal storage medium for industrial waste heat recovery and concentrated solar power (CSP). The MEPCM is demonstrated to be thermally stable for 200 thermal cycles with a high latent heat of 135.3 J g−1. The high‐temperature latent functional thermal fluid (HT‐LFTF) is prepared by dispersing the NaNO3@TiO2 MEPCMs into thermal oil. The test results show that MEPCMs provide an 18.4% effective thermal conductivity enhancement and 131.7% effective specific heat enhancement compared with base thermal oil. The rheological test indicates that the MEPCMs added in the thermal oil enhance the viscosity of the suspension and it increases with the MEPCM concentration. This work provides a new type of thermal oil–based functional thermal fluid containing high‐temperature MEPCM and paves the way for the application of LFTF in high‐temperature heat storage and transfer.

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Characterisation of commercial phase change materials with potential application in gypsum boards for buildings

Marín

Ushak

Gracia

et al. 2021

Intl J of Energy Research

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Summary Currently, there is an expanded utilisation of lightweight construction structures in buildings, which results in a low structure's thermal storage capacity of the envelope due to the application of thermally unsuitable materials. PCMs incorporated into building structures components are potential alternatives to manage the inadequate thermal energy storage capacity of lightweight structures. To provide a guide for selecting and applying commercial PCMs in construction, nine organic and inorganic bulk materials were selected, and their thermophysical properties were characterised. Thus, the enthalpy of melting/crystallisation, the melting/crystallisation temperature, the stability of 50 cycles, and the verification of the presence of the subcooling phenomenon by DSC and the T‐history method were evaluated. Since the adequate methods to incorporate the PCMs in gypsum are suspension and vacuum impregnation, their thermal properties, together with density and viscosity, need to be considered, properties that are not typically reported in the datasheets of commercial PCMs. Furthermore, the temperature dependence of the viscosity and density of the solid/liquid PCMs were measured by a rheometer and densimeter/pycnometer, respectively. Based on liquid and solid density values, the volumetric expansion of PCMs during the melting process was calculated. Finally, the characterisation parameters were compared with those provided by the suppliers of the different companies. The characterisation's results indicate that for both organic and inorganic PCMs, the fusion temperature (21°C‐26°C) and the density values (0.777‐1.515 g/cm3 for liquid state and 0.895‐1.860 g/cm3 for solid state) were consistent with the values provided in the datasheet from the suppliers'. Viscosity values were found to be higher than expected, and the enthalpy was found to be lower (19%‐30%) when compared with the technical datasheets from manufacturers'. The cycling stability study results were consistent only for the organic samples, without displaying phase segregation or subcooling problems. Based on the thermophysical characterisation, it was possible to establish that three organic RT‐21, RT‐21(TA), RT‐25, and three inorganic SP‐21E, PCM 21C, HS‐24P PCMs would be suitable products for their inclusion into gypsum boards under the conditions analysed. These findings provide new insights regarding the applicability and development of new strategies and materials for passive or active heating/cooling applications in buildings.

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The stability and thermophysical properties of a thermal fluid containing surface-functionalized nanoencapsulated PCM

Cited by 33 publications

References 52 publications

Investigation of the novelty of latent functionally thermal fluids as alternative to nanofluids in natural convective flows

Investigation of the novelty of latent functionally thermal fluids as alternative to nanofluids in natural convective flows

Microencapsulation of Molten Salt in Titanium Shell for High‐Temperature Latent Functional Thermal Fluid

Characterisation of commercial phase change materials with potential application in gypsum boards for buildings

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