Thermal Conductivity of High-Temperature Multicomponent Materials with Phase Change

Aktay, K.S. do Couto; Tamme, Rainer; Müller‐Steinhagen, Hans

doi:10.1007/s10765-007-0315-7

Cited by 64 publications

(17 citation statements)

References 11 publications

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“…However, as indicated by Couto Aktay et al [20], thermal conductivity of inorganic salts/EG composites dropped nearly 50% after melting, which might show it is inappropriate to neglect the contribution of inorganic salts to thermal conductivity of composites, as salts have higher thermal conductivity and more sensitive to changes in physical structure.…”

Section: Temperature-dependent Thermal Conductivitymentioning

confidence: 99%

“…Lyeo et al [19] studied the thermal conductivity of Ge 2 Sb 2 Te 5 from 25°C to 400°C, and found an increase with temperature after a solid-solid phase change at 130°C. Couto Aktay et al [20] observed the effective thermal conductivity of the eutectic alkali nitrate salts/EG composites dropped by 11-30% after melting. Thermal conductivity of mixtures of organic PCMs and thermal conductive nanoparticles, were nearly temperature-independent out of the phase change temperature range; but slightly increased near the phase change temperature [21][22][23].…”

Section: Introductionmentioning

confidence: 99%

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Thermal conductivity of an organic phase change material/expanded graphite composite across the phase change temperature range and a novel thermal conductivity model

Ling

Chen

et al. 2015

Energy Conversion and Management

264

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a b s t r a c tThis work studies factors that affect the thermal conductivity of an organic phase change material (PCM), RT44HC/expanded graphite (EG) composite, which include: EG mass fraction, composite PCM density and temperature. The increase of EG mass fraction and bulk density will both enhance thermal conductivity of composite PCMs, by up to 60 times. Thermal conductivity of RT44HC/EG composites remains independent on temperature outside the phase change range (40-45°C), but nearly doubles during the phase change. The narrow temperature change during the phase change allows the maximum heat flux or minimum temperature for heat source if attaching PCMs to a first (constant temperature) or second (constant heat flux) thermal boundary. At last, a simple thermal conductivity model for EG-based composites is put forward, based on only two parameters: mass fraction of EG and bulk density of the composite. This model is validated with experiment data presented in this paper and in literature, showing this model has general applicability to any composite of EG and poor thermal conductive materials.

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Section: Temperature-dependent Thermal Conductivitymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Thermal conductivity of an organic phase change material/expanded graphite composite across the phase change temperature range and a novel thermal conductivity model

Ling

Chen

et al. 2015

Energy Conversion and Management

264

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“…However, due to the limitations of current technology, PCM is difficult to achieve large-scale production, which restricts its application in large constructions. In addition, PCM itself has shortcomings of not-high heat conductivity coefficient and the value directly relates to the heat storage and release rate of PCM [8]. Adding excellent heat conductivity additives (such as copper, nickel, aluminum, etc.)…”

mentioning

confidence: 99%

Phase Change Energy Storage with Composite Plates Optimized Structure for Maximizing Energy Storage Potentials

Yao¹,

Kong²,

Qi³

et al. 2017

Proceedings of the 2016 International Conference on Architectural Engineering and Civil Engineering

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Abstract-The vacuum absorption method was used to fabricate the phase change material particle (PCMP) in a vacuum heating roller box, and then PCMPs were pressed to form the composite phase change energy storage plate (CPCESP) through a mould. Tests about the thermal conductivity and the heat storage and release capacity of CPCESP with different aluminum (Al) mass fractions were conducted; meanwhile, their fitting curves were obtained. According to the linear optimization principle and different actual situations, Al mass fractions, thermal conductivity and heat storing and discharge capacity per unit mass for CPCESP can be achieved, in order to optimize CPCESP heat storage and release performance.

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“…The most common CFms are types of aluminum alloys, copper and diamond. However, the mechanical properties of metal-based heat sink materials are difficult to control at temperatures over 550°C [2,3]. Thus, CFms are actively investigated as heat sink materials because of their good properties, such as high thermal stability, high thermal/electrical conductivity, low density, high porosity and high specific surface area [4,5].…”

mentioning

confidence: 99%

“…As a reference material, CFm had a thermal conductivity of 2.35 ± 0.00 W/mK with an apparent density of 0.67 g/cm 3 . CFm-C0.5G, CFm-C1.0G, CFm-C2.0G, and CFm-C3.0G had thermal conductivities of 2.00 ± 0.01, 3.40 ± 0.02, 3.37 ± 0.00, and 2.12 ± 0.01 W/mK, respectively, and their apparent densities were 0.40, 0.58, 0.47 and 0.50 g/cm 3 , respectively.…”

mentioning

confidence: 99%

The effects of carbon coating onto graphite filler on the structure and properties of carbon foams

Kim¹,

Kim²,

Lee³

2017

Carbon letters

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Carbon foams (CFms) are of crucial importance in electrical and mechanical devices due to their high thermal conductivity used for eliminating high heat flow and maintaining low temperatures [1]. The most common CFms are types of aluminum alloys, copper and diamond. However, the mechanical properties of metal-based heat sink materials are difficult to control at temperatures over 550°C [2,3]. Thus, CFms are actively investigated as heat sink materials because of their good properties, such as high thermal stability, high thermal/electrical conductivity, low density, high porosity and high specific surface area [4,5]. CFms are suitable materials for applications in phase-change materials, such as in latent heat thermal energy storage and lithium-ion batteries [6][7][8][9].CFms are prepared from thermoplastic graphitizable precursors, such as petroleum-derived, coal-derived and mesophase pitch (MP). In particular, MP has been widely used as an appropriate precursor for high-performance carbon materials due to its attractive properties, i.e., high coke yield, low softening point, and high fluidity [10]. Previous processes used a blowing technique, or pressure release, to produce foam from MP. These manufacturing techniques have many disadvantages: the volume fraction of generated cells cannot be precisely controlled, and controlling the shape and distribution of cells is difficult, if not impossible [11]. To better control and tailor the structure of such foams, polymer template methods are actively being researched. Hydrogel template methods are suitable for preparing high-strength CFms due to their large quantities of carbon precursors and the pressure generated through hydrogel shrinkage via heat treatment [10,12]. However, their mechanical strengths are low because of their high porosities.One method for improving the mechanical strength of CFms is adding fillers with a high mechanical strength. Several additives have been used as fillers, including carbon nanofibers, short carbon fibers, graphite and graphene nanosheets [13][14][15][16][17][18][19][20][21][22]. In particular, graphite has beneficial properties that include high lubricating ability, heat resistance, corrosion resistance and thermal/electrical conductivity. It has been widely applied in various fields as a highly functional component with efficient properties. Additionally, the theoretical thermal conductivity of graphite is high, with values ranging from 3000 to 5000 W/mK, and its mechanical strength is 1100 GPa [23,24]. The thermal/mechanical properties of CFms could be improved by the addition of carbon nanofillers with good thermal/mechanical properties through the formation of network structures comprising CFms and carbon nanofillers. Furthermore, carbon nanofillers can be carbon-coated (C-coated) to improve the interfacial bonding with metal. For example, Katzman [25] showed that carbon fibers could be C-coated using amorphous pitch to improve the interfacial bonding with metal oxide and prepare a carbon-fiber-reinforced metal-matrix compo...

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Thermal Conductivity of High-Temperature Multicomponent Materials with Phase Change

Cited by 64 publications

References 11 publications

Thermal conductivity of an organic phase change material/expanded graphite composite across the phase change temperature range and a novel thermal conductivity model

Thermal conductivity of an organic phase change material/expanded graphite composite across the phase change temperature range and a novel thermal conductivity model

Phase Change Energy Storage with Composite Plates Optimized Structure for Maximizing Energy Storage Potentials

The effects of carbon coating onto graphite filler on the structure and properties of carbon foams

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