Developing thermoelectric materials with superior performance means tailoring interrelated thermoelectric physical parameters – electrical conductivities, Seebeck coefficients, and thermal conductivities – for a crystalline system. High electrical conductivity, low thermal conductivity, and a high Seebeck coefficient are desirable for thermoelectric materials. Therefore, knowledge of the relation between electrical conductivity and thermal conductivity is essential to improve thermoelectric properties. In general, research in recent years has focused on developing thermoelectric structures and materials of high efficiency. The importance of this parameter is universally recognized; it is an established, ubiquitous, routinely used tool for material, device, equipment and process characterization both in the thermoelectric industry and in research. In this paper, basic knowledge of thermoelectric materials and an overview of parameters that affect the figure of merit ZT are provided. The prospects for the optimization of thermoelectric materials and their applications are also discussed.

A review on thermoelectric renewable energy: Principle parameters that affect their performance

A review of thermoelectric cooling: Materials, modeling and applications

Thermoelectric cooler and thermoelectric generator devices: A review of present and potential applications, modeling and materials

Alternative renewable energy sources are immensely important in view of the increase in worldwide energy needs and environmental effects. The thermoelectric (TE) technology is being seen as the perfect solution for both issues due to its ability to convert heat directly into electricity without CO2 emission. However, the application of TE materials for commercial devices is still limited due to their low conversion efficiency of ~10–15%. Currently the improvement of TE efficiency is challenging due to the relationship among physical properties, i.e., electrical conductivity, thermal conductivity and Seebeck coefficient which often counter each other and are restricted by the carrier concentrations. Fortunately, nanostructures have been shown to be able to disconnect the link among these physical properties to enhance the conversion efficiency of materials. Thus, the purpose of this review paper is to present the different nanostructured approaches for enhancing the TE properties of materials. The various techniques have been widely used to synthesize the bulk nanostructure and low dimensional systems were also described. A discussion on potential heat resources for the TE conversion, as well as the recent progress in TE is provided in terms of material, process and technology. Nanostructured skutterudites, half - Heusler, oxides and Si-Ge binary system were focused in this review paper due to the fact that the TE materials are among the best candidates for high-temperature applications. We also included our estimation in output electrical power of thermoelectric generation (TEG) for these type TE materials. Besides that, some innovations for the development of TE materials were mentioned. In addition, we also discussed the estimation of the TE cost to shed some light on commercializing considerations. We concluded that the high cost of the heat exchanger and ceramic substrate system components proved to be barriers in reducing the cost of TEG.

A review on nanostructures of high-temperature thermoelectric materials for waste heat recovery

Entropy generation analysis of graphene–alumina hybrid nanofluid in multiport minichannel heat exchanger coupled with thermoelectric cooler

Thermoelectric air-cooling module for electronic devices

Thermoelectric water-cooling device applied to electronic equipment

This study experimentally investigated the thermal performance of a two-phase closed-loop thermosyphon with a thermal resistance model for electronic cooling. The evaporator, rising tube, condenser, and falling tube, which are the four main devices, formed a closed-loop system with water as the working fluid. The experimental parameters were the evaporator surface type, fill ratio of working fluid, and input heating power. The results indicated that the evaporator and condenser thermal resistance decrease with increasing input heating power. The condenser thermal resistance clearly increased with increasing fill ratio. A groove-type evaporator surface with 0.2 mm height and 1 mm width had the best performance, decreasing the evaporator thermal resistance about 15.5% compared to a smooth surface. Correlations for evaporator and condenser thermal resistance were also developed, and their precisions, when compared with the experimental data, were about 9.6 and 11.6%, respectively. Because of the intermittent...

Two-Phase Closed-Loop Thermosyphon for Electronic Cooling

This article experimentally and numerically investigates the thermal performance of a 2350-kW completely enclosed motor, which is cooled through an air-to-air heat exchanger. The air in the heat exchanger includes external and internal flow paths. The external air driven by the rotation of the centrifugal fan goes through the heat exchanger mounted on the top of the frame. The internal air absorbs heat released from the stator and the rotor and then transfers the heat to the heat exchanger through the motion of two axial fans and the rotor. Several test rigs have been set up to measure the performance of the fan and the motor. The Fluent software package is adopted to analyze the complicated thermal-fluid interactions among the centrifugal fan, two axial fans, heat exchanger, stator, and rotor. The measured data, including the fan performance curves and the temperature profiles of the heat exchanger and the stator, show good agreement with the simulated results. The numerical calculations also show that the nonuniform external flow distribution through the heat exchanger and the air leakage between the axial fan and the rotor reduces the cooling ability of the motor. A detailed discussion is also included to improve the motor cooling performance.

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Experimental and Numerical Investigations of Air Cooling for a Large-Scale Motor

From the perspective of combining macroscopic and microscopic properties, this paper simulates the freeze–thaw cycle process at different freezing low temperatures based on the climate simulation equipment and by setting the curing conditions with different temperatures and relative humidity to produce different moisture conditions in concrete. The frost resistance properties and microscopic air void performance of concrete with different internal water content under different freezing low temperatures in freeze–thaw cycles were systematically studied. The results show that the higher the internal water content of concrete, the more obvious the mass loss rate and dynamic elastic modulus loss of concrete in the freeze–thaw process, and the more serious the deterioration of the air void parameter performance of the air-entraining agent introduced into concrete, which is manifested as the average bubble diameter and bubble spacing factor become larger and the bubble specific surface area decreases. In addition, in the case of the same internal moisture content of concrete, the freezing temperature used in the freeze–thaw cycle also has an important impact on the frost resistance of concrete and air void parameters; the lower the freezing temperature used, the more significant the decline in the frost resistance of concrete, the more obvious the deterioration of air void parameters.

/pdf/effect-of-the-internal-humidity-of-concrete-on-frost-w4j8hkhg.pdf

Ming-Tsun Ke

Papers

Thermoelectric air-cooling module for electronic devices

Thermoelectric water-cooling device applied to electronic equipment

Two-Phase Closed-Loop Thermosyphon for Electronic Cooling

Experimental and Numerical Investigations of Air Cooling for a Large-Scale Motor

Effect of the Internal Humidity of Concrete on Frost Resistance and Air Void Structure under Different Low Temperature Conditions