Special Issue "Thermodynamics of Thermoelectric Devices and Applications"

A special issue of Entropy (ISSN 1099-4300). This special issue belongs to the section "Thermodynamics".

Deadline for manuscript submissions: 20 March 2020.

Special Issue Editors

Prof. Roop L. Mahajan
E-Mail Website
Guest Editor
Virginia Polytechnic Institute and State University, Department of Mechanical Engineering, Blacksburg, USA
Interests: thermal sciences; energy engineering; nanomaterials; artificial neural networks; interdisciplinary research and innovation
Dr. Ravi Anant Kishore
E-Mail Website
Guest Editor
Building Energy Science Group, National Renewable Energy Laboratory (NREL), Golden, CO 80401, USA
Interests: thermal-fluid sciences; thermoelectric; energy harvesting; waste heat; wind; magnetocaloric/thermomagnetic

Special Issue Information

Dear Colleagues,

Thermoelectric effects and devices have been analyzed and investigated using classical heat transfer methods and equations of thermoelectricity for several decades. Although extensively explored, commercial thermoelectric devices still have a poor thermal-to-electrical conversion efficiency. Evaluating thermoelectric phenomena using thermodynamic arguments can provide new insights and lead thermoelectric research towards enhancing the figure-of-merit, ZT, and potential for achieving the Carnot efficiency.

In this Special Issue of Entropy, we cordially invite you to submit review, perspective, and original papers on thermoelectric effects, devices, and applications, with a particular focus on the thermodynamics of thermoelectricity.

Prof. Roop Mahajan
Dr. Ravi Anant Kishore
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All papers will be peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Entropy is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 1600 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • Thermoelectric
  • TEG
  • TEC
  • Thermodynamics
  • Entropy
  • Carnot
  • Optimization
  • Heat recovery
  • Thermal energy harvesting

Published Papers (3 papers)

Order results
Result details
Select all
Export citation of selected articles as:

Research

Jump to: Review

Open AccessArticle
Role of Heat Expansion with a Series of Ionic Liquids: The Case for Isochoric Thermoelectric Generators and Minimal Steric Repulsion
Entropy 2019, 21(11), 1086; https://doi.org/10.3390/e21111086 - 06 Nov 2019
Abstract
The role of convection in liquid thermoelectric cells may be difficult to predict because the inter- and intramolecular interactions are not currently incorporated into thermodynamic models. Here, we study the thermoelectric response of a series of five anhydrous 1-methyl-3- alkylimidazolium halide ionic liquids [...] Read more.
The role of convection in liquid thermoelectric cells may be difficult to predict because the inter- and intramolecular interactions are not currently incorporated into thermodynamic models. Here, we study the thermoelectric response of a series of five anhydrous 1-methyl-3- alkylimidazolium halide ionic liquids with varied chain length and counterion in a high-aspect-ratio, horizontal-temperature-gradient geometry, where convection is minimal. While a canonical constant-volume thermodynamic model predicts that the longer aliphatic groups exhibit larger Seebeck coefficients, we instead measure the opposite: Longer aliphatic chains correlate with lower densities and greater heat expansion, stronger intermolecular associations, stronger steric repulsion, and lower Seebeck coefficients. As evidence of the critical role of thermal expansion, we measure that the Seebeck effect is nonlinear: Values of −2.8 mV/K with a 10 K temperature difference and −1.8 mV/K with a 50 K difference are measured with ether ion. Our results indicate that steric repulsion and heat expansion are important considerations in ionic liquid design; with large temperature differences, the Seebeck coefficient correlates negatively with heat expansion. Our results suggest that Seebeck values will improve if thermal expansion is limited in a pressurized, isochoric, convection-free design. Full article
(This article belongs to the Special Issue Thermodynamics of Thermoelectric Devices and Applications)
Show Figures

Graphical abstract

Open AccessArticle
Experimental Investigation of a 300 kW Organic Rankine Cycle Unit with Radial Turbine for Low-Grade Waste Heat Recovery
Entropy 2019, 21(6), 619; https://doi.org/10.3390/e21060619 - 23 Jun 2019
Cited by 1
Abstract
The performance of a 300 kW organic Rankine cycle (ORC) prototype was experimentally investigated for low-grade waste heat recovery in industry. The prototype employed a specially developed single-stage radial turbine that was integrated with a semi-hermetic three-phase asynchronous generator. R245fa was selected as [...] Read more.
The performance of a 300 kW organic Rankine cycle (ORC) prototype was experimentally investigated for low-grade waste heat recovery in industry. The prototype employed a specially developed single-stage radial turbine that was integrated with a semi-hermetic three-phase asynchronous generator. R245fa was selected as the working fluid and hot water was adopted to imitate the low-grade waste heat source. Under approximately constant cooling source operating conditions, variations of the ORC performance with diverse operating parameters of the heat source (including temperature and volume flow rate) were evaluated. Results revealed that the gross generating efficiency and electric power output could be improved by using a higher heat source temperature and volume flow rate. In the present experimental research, the maximum electric power output of 301 kW was achieved when the heat source temperature was 121 °C. The corresponding turbine isentropic efficiency and gross generating efficiency were up to 88.6% and 9.4%, respectively. Furthermore, the gross generating efficiency accounted for 40% of the ideal Carnot efficiency. The maximum electric power output yielded the optimum gross generating efficiency. Full article
(This article belongs to the Special Issue Thermodynamics of Thermoelectric Devices and Applications)
Show Figures

Figure 1

Review

Jump to: Research

Open AccessFeature PaperReview
High Power Factor vs. High zT—A Review of Thermoelectric Materials for High-Temperature Application
Entropy 2019, 21(11), 1058; https://doi.org/10.3390/e21111058 - 29 Oct 2019
Abstract
Energy harvesting with thermoelectric materials has been investigated with increasing attention over recent decades. However, the vast number of various material classes makes it difficult to maintain an overview of the best candidates. Thus, we revitalize Ioffe plots as a useful tool for [...] Read more.
Energy harvesting with thermoelectric materials has been investigated with increasing attention over recent decades. However, the vast number of various material classes makes it difficult to maintain an overview of the best candidates. Thus, we revitalize Ioffe plots as a useful tool for making the thermoelectric properties of a material obvious and easily comparable. These plots enable us to consider not only the efficiency of the material by the figure of merit zT but also the power factor and entropy conductivity as separate parameters. This is especially important for high-temperature applications, where a critical look at the impact of the power factor and thermal conductivity is mandatory. Thus, this review focuses on material classes for high-temperature applications and emphasizes the best candidates within the material classes of oxides, oxyselenides, Zintl phases, half-Heusler compounds, and SiGe alloys. An overall comparison between these material classes with respect to either a high efficiency or a high power output is discussed. Full article
(This article belongs to the Special Issue Thermodynamics of Thermoelectric Devices and Applications)
Show Figures

Figure 1

Back to TopTop