Transient hot strip measures thermal conductivity of organic foam thermal insulation materials

Hu, Rong; Ma, Aichun; Yang, Li

doi:10.1016/j.expthermflusci.2017.10.038

Cited by 9 publications

(5 citation statements)

References 18 publications

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“…A modification of the sample geometry configuration to extend the nominal measurement time when testing high-conductivity ceramic bars has been suggested by Gustavsson et al [101]. However, the THS method is not only suited for homogeneous solid materials, but also powdered materials [100], thermal insulation materials, such as organic foam [102] and aerogel [103], and liquids [104].…”

Section: Transient Hot Stripmentioning

confidence: 99%

Modeling and Measuring Thermodynamic and Transport Thermophysical Properties: A Review

et al. 2022

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The present review describes the up-to-date state of the evaluation of thermophysical properties (TP) of materials with three different procedures: modeling (also including inverse problems), measurements and analytical methods (e.g., through computing from other properties). Methods to measure specific heat and thermal conductivity are described in detail. Thermal diffusivity and thermal effusivity are a combination of the previously cited properties, but also for these properties, specific measurement and calculation methods are reported. Experiments can be carried out in steady-state, transient, and pulse regimes. For modeling, special focus is given to the inverse methods and parameter estimation procedures, because through them it is possible to evaluate the thermophysical property, assuring the best practices and supplying the measurement uncertainty. It is also cited when the most common data processing algorithms are used, e.g., the Gauss–Newton and Levenberg–Marquardt least squares minimization algorithms, and how it is possible to retrieve values of TP from other data. Optimization criteria for designing the experiments are also mentioned.

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Section: Transient Hot Stripmentioning

confidence: 99%

Modeling and Measuring Thermodynamic and Transport Thermophysical Properties: A Review

et al. 2022

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“…The molds were covered in order to avoid significant volume variation due to ice crystallization during freezing. They were kept inside three Styrofoam boxes (Figure S9) for 24 h in a standard freezer at −33 °C in order to promote isotropic cooling [39]. They were then freeze-dried under vacuum (~0.2 mbar) for 36 h (mold A) or 12 h (molds B-E).…”

Section: Preparation Of Hpmc Cryogelsmentioning

confidence: 99%

“…The thermal conductivity, k, of the cryogels (mold A) was measured using the Transient Hot Strip (THS) method [32,[39][40][41]. In this method, a constant linear electric power (P 0 ) is supplied to a resistive strip, which heats the sample.…”

Section: Characterization Of the Cryogelsmentioning

confidence: 99%

Tuning the Mechanical and Thermal Properties of Hydroxypropyl Methylcellulose Cryogels with the Aid of Surfactants

Dezotti

Furtado

Yee

et al. 2021

Gels

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The mechanical and thermal properties of cryogels depend on their microstructure. In this study, the microstructure of hydroxypropyl methylcellulose (HPMC) cryogels was modified by the addition of ionic (bis (2-ethylhexyl) sodium sulfosuccinate, AOT) and non-ionic (Kolliphor® EL) surfactants to the precursor hydrogels (30 g/L). The surfactant concentrations varied from 0.2 mmol/L to 3.0 mmol/L. All of the hydrogels presented viscous behavior (G″ > G′). Hydrogels containing AOT (c > 2.0 mmol/L) led to cryogels with the lowest compressive modulus (13 ± 1 kPa), the highest specific surface area (2.31 m2/g), the lowest thermal conductivity (0.030 W/(m·°C)), and less hygroscopic walls. The addition of Kolliphor® EL to the hydrogels yielded the stiffest cryogels (320 ± 32 kPa) with the lowest specific surface area (1.11 m2/g) and the highest thermal conductivity (0.055 W/(m·°C)). Density functional theory (DFT) calculations indicated an interaction energy of −31.8 kcal/mol due to the interaction between the AOT sulfonate group and the HPMC hydroxyl group and the hydrogen bond between the AOT carbonyl group and the HPMC hydroxyl group. The interaction energy between the HPMC hydroxyl group and the Kolliphor®EL hydroxyl group was calculated as −7.91 kcal/mol. A model was proposed to describe the effects of AOT or Kolliphor®EL on the microstructures and the mechanical/thermal properties of HPMC cryogels.

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“…The measurement of thermal conductivity [1] in building envelopes has been the subject of a multitude of studies, encompassing both steady-state [2] and dynamic ( refer to [2][3][4]) conditions. The investigations are classified according to whether they are performed in situ [5] on actual walls or in laboratory settings utilizing samples (see [6][7][8]).…”

Section: Introductionmentioning

confidence: 99%

“…Measurements of thermal conductivities hold significant importance across various applications. Indeed, this thermophysical parameter finds relevance in diverse research domains, including the identification and categorization of scrap materials within the recycling sector [36], the utilization of low thermal conductivity materials in construction [37], and the enhancement of indoor comfort and energy efficiency in buildings [38], among others. Boudenne et al [39], have devised an innovative method for measuring the conductivity of insulating materials.…”

Section: Introductionmentioning

confidence: 99%

Economical Experimental Device for Evaluating Thermal Conductivity in Construction Materials under Limited Research Funding

FAKRA,

RAKOTOSAONA,

RATSIMBA

et al. 2024

Preprint

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African scientific research faces formidable challenges, particularly with limited access to state-of-the-art measurement instruments. The high cost associated with these devices presents a significant barrier for regional research laboratories, impeding their ability to conduct sophisticated experiments and gather precise data. This predicament not only hampers the individual laboratories but also has broader implications for the African scientific community and the advancement of knowledge in developing nations—the financial cost barrier considerably impacts the research quality of these laboratories. Reflection on technical and economical solutions needs to be quickly found to help these countries advance their research. In civil Engineering, the thermal conductivity property is the most important measurement for characterising heat transfer in construction materials. Existing devices (i.e., conductometers) in a laboratory are expensive (approximately 30,000 euros) and unavailable for some African laboratories. The study proposes a new and affordable device to evaluate thermal conductivity in construction materials. The method involves establishing a thermal flux between a heat source ( from the Joule effect provided by steel wool where a current is circulating) and a cold source (generated by ice cube) under steady-state conditions. The development of the cylindrical prototype is based on the comparative flux-meter method outlined in the measuring protocol of the ASTM E1225 standard document. Experiments were conducted on four distinct materials (polystyrene, wood, agglomerated wood, and rigid foam). The results indicate a correct correlation between the experimental values obtained from the newly developed prototype and the reference values found in the literature. For example, concerning the experimental polystyrene study, the detailed case analysis reveals a good correlation, with a deviation of only 4%. The percent error found falls within the acceptable range indicated by the standards recommendations of the ASTM E1225 standard, i.e., within 5% acceptable error.

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Transient hot strip measures thermal conductivity of organic foam thermal insulation materials

Cited by 9 publications

References 18 publications

Modeling and Measuring Thermodynamic and Transport Thermophysical Properties: A Review

Modeling and Measuring Thermodynamic and Transport Thermophysical Properties: A Review

Tuning the Mechanical and Thermal Properties of Hydroxypropyl Methylcellulose Cryogels with the Aid of Surfactants

Economical Experimental Device for Evaluating Thermal Conductivity in Construction Materials under Limited Research Funding

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