Thermally induced vibration and strength failure analysis of thermoelectric generators

The performance of the thermoelectric module highly depends on the geometry of the legs, the module area, and implicitly on the number of the pairs, besides the properties of the materials. The geometry of the legs consists of the shape, the dimensions on three axes, and whether the legs are filled or are hollow. The legs can have one hollow or more, the hole can be from the top to bottom or not. This paper studies and compares the performance of different thermoelectric modules in function of the shape: square, triangular, trapezoid, reverse trapezoid, hourglass, inverse hourglass (filled and with the hollow from the top to the bottom or not), and with different dimensions of the length and width. The simulations are performed using the COMSOL Multiphysics software, where 3D numerical models are developed and solved using the finite element method. The results are compared with others from the specialized literature for a one pair square shape. The current-voltage and power-voltage characteristics have a good matching, which proves the simulations are good and the model can be used for other shapes. A steady-state heating condition is applied to the hot side of the thermoelectric generators, while the cold side is subjected to steady state, natural convection, and forced convection heating conditions. The square shape with an internal hollow is studied first. The best performance when the length and width are 1 mm × 1 mm, 1.5 mm × 1.5 mm, and 2 mm × 2 mm is obtained for the thermoelectric generator with filled square legs. The highest maximum power is obtained for thermoelectric generator with the sizes 2 mm × 2 mm. The gain in power for the square shape in comparison with the worst value of the TEG (Inverse Hourglass for filled and Triangular for hollow) for the three dimensions considered is for those filled 199%, 202%, and 204%, respectively, and for those that are hollow 198%, 232%, and 243%, respectively. The reduction in maximum power is 5%, for the thermoelectric generator with square legs (2 mm × 2 mm) and with hollow legs, in comparison with one filled. The maximum power increases for the thermoelectric generator with square legs which have a hollow interior, in this case 2 mm × 2 mm, with 0.2% and 1% for the thermoelectric generator with sizes of 1 mm × 1 mm. Additionally, the results obtained for the square filled shape are compared with the real ones obtained for a thermoelectric generator with sizes 40 mm × 40 mm × 4 mm. The matching is very good, which confirms that the model can be used for different geometry of the thermoelectric generators in order to help the manufacturers improve their performance.

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“…The lattice thermal conductivity and the bandgap are the same. The Seebeck coefficient for both n-and p-type materials is almost isotropic [16].…”

Section: Introductionmentioning

confidence: 99%

Legs Geometry Influence on the Performance of the Thermoelectric Module

Rjafallah

Cotfas

2022

Sustainability

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“…Mathematical modeling of the heat conduction is an important stage in the design of systems subjected to thermal loads, because it allows the appropriate selection of materials to avoid adverse phenomena related to the occurrence of thermal stresses. For example, the temperature distribution in the tested system may lead to the formation of thermal stresses, which may cause micro-cracks in the components of this system [ 1 , 2 , 3 ], and cyclical changes in the thermal load of the device may cause undesirable vibrations of the components of this device [ 4 , 5 , 6 ]. On the other hand, the heat source causing high temperature of biological tissue may destroy diseased tissue, but it may also damage healthy tissue [ 7 , 8 ].…”

Section: Introductionmentioning

confidence: 99%

Fractional Order Dual-Phase-Lag Model of Heat Conduction in a Composite Spherical Medium

2022

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In the paper, a solution of the fractional dual-phase-lag heat conduction problem is presented. The considerations are related to the heat conduction in a multi-layered spherical medium with azimuthal symmetry. The final form of the analytical solution is given in a form of the double series of spherical Bessel functions and Legendre functions. Numerical calculations concern the study of the effect of the order of the Caputo derivative on the temperature distribution in a composite solid sphere, hemisphere and spherical cone.

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“…The failure of thermoelectric devices is mainly due to the mismatched thermal expansion coefficients of different components. Various defects are caused by thermal stress, which reduce the lifespan of thermoelectric devices, causing their eventual failure [28]. Hence, it is necessary to research the thermal stress distribution of thermoelectric devices and find high stress locations within them.…”

Section: Introductionmentioning

confidence: 99%

Cooling and Mechanical Performance Analysis of a Trapezoidal Thermoelectric Cooler with Variable Cross-Section

Zhang

et al. 2020

Energies

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In this study, a full-scale three-dimensional trapezoidal thermoelectric cooler model is constructed to study its cooling performance and mechanical reliability using finite element simulation. Temperature dependent material properties are considered in this work. The boundary conditions similar to those in a real experimental environment are applied. The effects of the input electrical current and geometry of the thermoelectric leg on the cooling performance and reliability of a trapezoidal thermoelectric cooler are analyzed, and a comparison is made with a rectangular thermoelectric cooler. The results indicate that increasing the leg height and the variable cross-sectional design of the leg can improve the cooling performance of the trapezoidal thermoelectric cooler. Compared to the original rectangular thermoelectric cooler, the minimum chip temperature was reduced by 0.87% under the trapezoidal thermoelectric cooler with optimized geometry. Furthermore, increasing the leg height enhances the mechanical reliability of the trapezoidal thermoelectric cooler, while the trapezoidal design of the leg reduces its mechanical reliability. The maximum von Mises stress of the leg for the trapezoidal thermoelectric cooler with optimal cooling performance increased by 40.1%. The results of this work provide useful guidance for the structural design of trapezoidal thermoelectric coolers.

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Thermally induced vibration and strength failure analysis of thermoelectric generators

Cited by 19 publications

References 54 publications

Legs Geometry Influence on the Performance of the Thermoelectric Module

Legs Geometry Influence on the Performance of the Thermoelectric Module

Fractional Order Dual-Phase-Lag Model of Heat Conduction in a Composite Spherical Medium

Cooling and Mechanical Performance Analysis of a Trapezoidal Thermoelectric Cooler with Variable Cross-Section

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