Measurement of thermal diffusivity/thermal contact resistance using laser photothermal method at cryogenic temperatures

Heat to electricity energy conversion efficiency of a thermoelectric (TE) device is not only influenced by the TE materials properties, but it also depends on the temperature difference between both sides of the TE legs. Keeping this temperature difference as close as possible to the temperature difference between the heat sink and the heat source is crucial to maximize the TE device performance. However, achieving this is quite difficult, mainly due to the thermal contact resistance at the interfaces between the TE module and the heat sink/source. In this study, it is analyzed the effect of this thermal contact resistance on the impedance spectroscopy response of a TE module that is thermally contacted by two copper blocks, which act as heat exchangers. A new theoretical model (equivalent circuit) that takes into account the thermal contact resistance is developed, which includes two new elements that depend on this parameter. The equivalent circuit is validated with experimental impedance measurements where the thermal contact is varied. It is demonstrated that using this equivalent circuit the thermal contact resistance can be easily determined, which opens up the possibility of using impedance spectroscopy as a tool to quantify and monitor this crucial property for the TE device performance.

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“…Using R TE , R C , and R TC , the equivalent circuit elements of Eqs. (11), (12), (14) and (15), can be rewritten as,…”

Section: Theoretical Modelmentioning

confidence: 99%

“…Alternatively, thermal contact resistances can be also determined by fitting the temperature profile recorded in one solid when another solid in contact is heated by a laser beam [11,12].…”

Section: Introductionmentioning

confidence: 99%

Characterization of thermal contacts between heat exchangers and a thermoelectric module by impedance spectroscopy

Beltrán-Pitarch

Vidan

Garcı́a-Cañadas

2020

Applied Thermal Engineering

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“…The thermal contact resistance in various applications has been under intensive studies recently. (Dhuley, 2019;Liu, Ma, Wang, Wang, & Yang, 2019;Lorenzini et al, 2017;Ngo, Byon, & Lee, 2018;Xian, Zhang, Zhai, Yuan, & Yang, 2018;Dongmei, Huanxin, Shanjian, & Limei, 2017).…”

Section: Public Interest Statementmentioning

confidence: 99%

The thermal contact resistance of a steel-ceramic interface with oxide intermediates

2020

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Metal structures covered by refractories are widely employed in high temperature processes such as incineration and metal production. The thermal resistance in refractories used in high temperature processes is associated with different phases, phase boundaries and porosity in the refractory and with the thermal contact resistance between the refractory and the metal interface. Here, a light flash method was used to evaluate the thermal contact resistance of the ceramic/steel interface at temperatures of 25, 100, 200, 300 and 400°C. The material combinations studied were a commonly-used reference ceramic, Pyroceram 9606, and pressure vessel steel with oxidizing treatment at 450 and 650°C for 50 h. Thermal resistance at a ceramic/steel interface increased significantly when a porous oxide layer was formed on the steel surface. The thermal contact resistance of the interface varied from 0.1 to 0.4 × 10 −3 m 2 K/W, depending on the temperature and the oxidization of the steel sample.

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“…Before going on with the description of our investigation, it is relevant to mention popular techniques and technologies that have been employed for determining the thermal diffusivity of a given material. Some examples are laser flashes [9], laser interferometers [10] and photothermal techniques [11,12], which however require relatively complex and quite expensive instrumentation [13,14]. The hot wire technique [15][16][17] is a standard transient solution and was specifically devised for liquids [18,19].…”

Section: Introductionmentioning

confidence: 99%

Thermal diffusivity from Fourier’s inverse problem supervised by an optimization model: Theoretical analysis and experimental validation

Baccoli

Kumar

Concas

et al. 2022

Case Studies in Thermal Engineering

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Measurement of thermal diffusivity/thermal contact resistance using laser photothermal method at cryogenic temperatures

Cited by 27 publications

References 17 publications

Characterization of thermal contacts between heat exchangers and a thermoelectric module by impedance spectroscopy

Characterization of thermal contacts between heat exchangers and a thermoelectric module by impedance spectroscopy

The thermal contact resistance of a steel-ceramic interface with oxide intermediates

Thermal diffusivity from Fourier’s inverse problem supervised by an optimization model: Theoretical analysis and experimental validation

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