Thermoelectric (TE) materials have the capability of converting heat into electricity, which can improve fuel efficiency, as well as providing robust alternative energy supply in multiple applications by collecting wasted heat, and therefore, assisting in finding new energy solutions. In order to construct high performance TE devices, superior TE materials have to be targeted via various strategies. The development of high performance TE devices can broaden the market of TE application and eventually boost the enthusiasm of TE material research. This review focuses on major novel strategies to achieve high-performance TE materials and their applications. Manipulating the carrier concentration and band structures of materials are effective in optimizing the electrical transport properties, while nanostructure engineering and defect engineering can greatly reduce the thermal conductivity approaching the amorphous limit. Currently, TE devices are utilized to generate power in remote missions, solar-thermal systems, implantable or/wearable devices, the automotive industry, and many other fields; they are also serving as temperature sensors and controllers or even gas sensors. The future tendency is to synergistically optimize and integrate all the effective factors to further improve the TE performance, so that highly efficient TE materials and devices can be more beneficial to daily lives.

https://espace.library.uq.edu.au/view/UQ:722903/UQ722903_OA.pdf

High Performance Thermoelectric Materials: Progress and Their Applications

Thermoelectric (TE) devices for power generation have been attracting increasing attention on account of their advantages such as solid-state operation, good stability, and high reliability. This paper presents an overview of the design principle, fabrication methods and testing technology of TE power generation devices. Particular attention is paid to skutterudite-based devices regarding electrode fabrication, barrier layer design, interface optimization, protective coating, and evaluation of elements and modules. The development of Bi2Te3-based devices for power generation focusing specifically on the optimization of Bi2Te3/electrode joints and fabrication and evaluation of Bi2Te3-based modules is summarized. The future challenges concerning TE devices for power generation are discussed.

Thermoelectric Devices for Power Generation: Recent Progress and Future Challenges

https://cyberleninka.org/article/n/364500.pdf

Internal combustion engine cold-start efficiency: A review of the problem, causes and potential solutions

Performance analysis of a waste heat recovery thermoelectric generation system for automotive application

Automotive exhaust thermoelectric generators: Current status, challenges and future prospects

A numerical model has been developed to simulate coupled thermal and electrical energy transfer processes in a thermoelectric generator (TEG) designed for automotive waste heat recovery systems. This model is capable of computing the overall heat transferred, the electrical power output, and the associated pressure drop for given inlet conditions of the exhaust gas and the available TEG volume. Multiple-filled skutterudites and conventional bismuth telluride are considered for thermoelectric modules (TEMs) for conversion of waste heat from exhaust into usable electrical power. Heat transfer between the hot exhaust gas and the hot side of the TEMs is enhanced with the use of a plate-fin heat exchanger integrated within the TEG and using liquid coolant on the cold side. The TEG is discretized along the exhaust flow direction using a finite-volume method. Each control volume is modeled as a thermal resistance network which consists of integrated submodels including a heat exchanger and a thermoelectric device. The pressure drop along the TEG is calculated using standard pressure loss correlations and viscous drag models. The model is validated to preserve global energy balances and is applied to analyze a prototype TEG with data provided by General Motors. Detailed results are provided for local and global heat transfer and electric power generation. In the companion paper, the model is then applied to consider various TEG topologies using skutterudite and bismuth telluride TEMs.

/pdf/thermoelectric-generators-for-automotive-waste-heat-recovery-3ryosm4sb9.pdf

Thermoelectric Generators for Automotive Waste Heat Recovery Systems Part I: Numerical Modeling and Baseline Model Analysis

A comprehensive numerical model has been proposed to model thermoelectric generators (TEGs) for automotive waste heat recovery Details of the model and results from the analysis of General Motors’ prototype TEG were described in part I of the study In part II of this study, parametric evaluations are considered to assess the influence of heat exchanger, geometry, and thermoelectric module configurations to achieve optimization of the baseline model The computational tool is also adapted to model other topologies such as transverse and circular configurations (hexagonal and cylindrical) maintaining the same volume as the baseline TEG Performance analysis of these different topologies and parameters is presented and compared with the baseline design

https://engineering.purdue.edu/NanoLab/PDF/2013%20Thermoelectric%20Generators%20for%20Automotive%20Waste%20Heat%20Recovery%20Systems%20Part%20II_Parametric%20Evaluation%20and%20Topological%20Studies.pdf

Thermoelectric Generators for Automotive Waste Heat Recovery Systems Part II: Parametric Evaluation and Topological Studies

For a typical spark ignition engine approximately 40% of available thermal energy is lost as hot exhaust gas. To improve fuel economy, researchers are currently evaluating technology which exploits exhaust stream thermal power by use of thermoelectric generators (TEGs) that operate on the basis of the Seebeck effect. A 5% improvement in fuel economy, achieved by use of TEG output power, is a stated objective for light-duty trucks and personal automobiles. System modeling of thermoelectric (TE) components requires solution of coupled thermal and electric fluxes through the n and p-type semiconductor legs, given appropriate thermal boundary conditions at the junctions. Such applications have large thermal gradients along the semiconductor legs, and material properties are highly dependent on spatially varying temperature profiles. In this work, one-dimensional heat flux and temperature variations across thermoelectric legs were solved by using an iterative numerical approach to optimize both TE module and TEG designs. Design traits were investigated by assuming use of skutterudite as a thermoelectric material with potential for automotive applications in which exhaust gas and heat exchanger temperatures typically vary from 100°C to over 600°C. Dependence of leg efficiency, thermal fluxes and electric power generation on leg geometry, fill fractions, electric current, thermal boundary conditions, etc., were studied in detail. Optimum leg geometries were computed for a variety of automotive exhaust conditions.

/pdf/optimization-of-thermoelectric-components-for-automobile-1sizgt6lma.pdf

Optimization of Thermoelectric Components for Automobile Waste Heat Recovery Systems

In this present work, we attempt to maximize the electrical power generation by optimizing Thermoelectric Generator (TEG) geometry for a prescribed TEG volume. A plate-fin heat exchanger topology is assumed and consideration is given to additional pressure drops associated with the fins placed in the exhaust flow path; and the cross-sectional changes across TEG inlet-exit ports. The thermal profile in the TEG is computed such that different thermoelectric modules may be placed where they provide the maximum Seebeck coefficient and hence provide the maximum power output. Multiple filled skutterudites are employed in the higher temperature regions and Bismuth Telluride modules are used at lower temperature regions of the TEG. Separate calculations are performed for cases where the available maximum number of TEMs is limited for cost optimization.Copyright © 2012 by ASME and General Motors

Sumeet Kumar

Papers

Thermoelectric Generators for Automotive Waste Heat Recovery Systems Part I: Numerical Modeling and Baseline Model Analysis

Thermoelectric Generators for Automotive Waste Heat Recovery Systems Part II: Parametric Evaluation and Topological Studies

Optimization of Thermoelectric Components for Automobile Waste Heat Recovery Systems

Thermal Design of Thermoelectric Generators for Automobile Waste Heat Recovery