DOCSLIB.ORG

Power Generation from Low Grade Waste Heat Using Thermoelectric Generator

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Power Generation from Low Grade Waste Heat Using Thermoelectric Generator IJRECE VOL. 7 ISSUE 2 (APRIL- JUNE 2019) ISSN: 2393-9028 (PRINT) | ISSN: 2348-2281 (ONLINE) POWER GENERATION FROM LOW GRADE WASTE HEAT USING THERMOELECTRIC GENERATOR Mr. Parul Raghav1, Mr. Rakesh Kumar2 1M. Tech (Power System and Control), Noida International University, Uttar Pradesh, India 2Assistant Professor, Noida International University, Uttar Pradesh, India Abstract - In the conventional method for generate electricity They have the capacity to operating at elevated is converting thermal energy into mechanical energy then to temperatures. electrical energy. In recent years, due to environmental issues The source for the power generation is Heat not Light, so like emissions, global warming, etc., are the limiting factor for day and night operation is possible. the energy resources which resulting in extensive research and They are mostly used for convert the waste heat so it is novel technologies are required to generate electric power. considered as a Green Technology. Thermoelectric power generators have emerged as a promising another green technology due to their diverse We can increase the overall efficiency of the system (4% advantages. Thermo Electric Power Generator directly to &7%). converts this Thermal energy into Electrical energy. So They can be alternative power sources. number of moving and rotating part has been eliminated. By When compare to exciting conventional power system it this it eliminated emission so we can believe this green require less space and cost technology. Thermoelectric power generation offer a potential Less operating cost. application in the direct exchange of waste-heat energy into electrical power where it is unnecessary to believe the cost of In any industry, the three top operating expenses are often the thermal energy input. The application of this option green found to be energy (both electrical and thermal), labour and technology in converting waste-heat energy directly into materials. If one were to relate to the manageability of the cost electrical power can too improve the overall efficiencies of or potential cost savings in each of the above components, energy conversion systems. Heat source which is need for this energy would invariably emerge as a top ranker, and thus conversion is less when contrast to conventional methods. In energy management function constitutes a strategic area for this paper, a background on the basic concepts of cost reduction. This contribution analyzes approaches that led thermoelectric power generation is presented and recent to discovery of thermo electricity. Thermoelectric restrictions patents of thermoelectric power generation with their imposed on the application areas of thermoelectric generators important and relevant applications to waste-heat energy are and, accordingly, theensuing rational lines of their practical reviewed and discussed. applications are considered. The possibilities of thermoelectric systems’ contribution to “green” technologies, in particular, to Keywords: - Thermoelectric power generator, waste-heat waste heat recovery from industry exhausting flue gases. recovery, alternative green technology, direct energy Attention is focused on the selection of the thermoelectric conversion, thermocouple system and the experimental model representing the system. Finally there is theoretical model calculation for generation of I. INTRODUCTION emfs (voltage) and validation comparing the experimental A Thermoelectric power generator is a solid state device that results of the emfs (voltage). The Drawback of thermoelectric provides direct energy conversion from thermal energy (heat) power generator is their relatively low conversion efficiency into electrical energy based on “Seebeck effect”. The (typically ~5%) and Less power output. Application over the thermoelectric power cycle, with charge carriers serving as the past decade included industrial instruments, military, medical working fluid, follows the fundamental laws of and aerospace and home reason and applications for portable thermodynamics and intimately resembles the power cycle of or remote power generation. Though, in recent years, an a conventional heat engine. Advantages of Thermoelectric increasing anxiety of environmental issues of emissions, in power generators over other technologies. particular global warming has resulted in extensive research They are extremely reliable and they have no mechanical into nonconventional technologies of generating electrical moving parts and require considerably less maintenance. power. Thermoelectric power generation offers a promising They have very small size and weightless. technology in the direct conversion of low-grade thermal energy, such as waste-heat energy, into electrical power. INTERNATIONAL JOURNAL OF RESEARCH IN ELECTRONICS AND COMPUTER ENGINEERING A UNIT OF I2OR 2059 | P a g e IJRECE VOL. 7 ISSUE 2 (APRIL- JUNE 2019) ISSN: 2393-9028 (PRINT) | ISSN: 2348-2281 (ONLINE) Perhaps the earliest application is the use of waste heat from a kerosene lamp to provide thermoelectric power to power a wireless set. Thermoelectric generators have also been used to provide small amounts electrical power to remote regions for example Northern Sweden, as an alternative to costly gasoline powered motor generators. Oldest technology behind this technology is seebeck effect on Thermocouple now this tech using in seebeck effect on semiconductors so it can eliminate wires, so wireless technology is possible. An important purpose in thermoelectric power generation using waste heat energy is to decrease the cost-per-watt of the devices. Moreover, cost-per-watt can be reduced by optimizing the device geometry, improving the manufacture quality and simply by operating the device at a larger temperature All these studies were experimental and some of them were difference. Analyze the thermoelectric property of the module able to generate significant amount of electrical power. So, material is very important. Good thermoelectric material has above literature only concentrated on testing commercially seebeck property in between 200-300μV/K. Material available TEG performances; none of current literature make thermoelectric material figure-of-merit property should be known to an optimization technique to maximize the net near or more than 3×10-3 for good material. This TEG is used electrical power by considering losses due to thermal to convert the waste heat emitted from Jet Engine, IC Engines, resistance and parasitic power losses. In this works, a system Furnace, Heat water conveyor tubes. has considered which consisted thermoelectric modules sandwiched between hot water and cold-water channel. TEG II. LITERATURE SURVEY can produced electricity from the temperature difference Method for generating power such as burning of wood, petrol, between hot and cold water. This power generation is diesel, coal, is continuously depleting with nature, so that increased with the higher temperature difference and higher exceeded usage of electricity according to the consumer mass flow rate, but there is a penalty for higher mass flow rate demand. Global warming is the increase in the average called parasitic loss. This parasitic loss also depends on the measured temperature of the Earth's near surface air and size of the heat exchanger. So, the amount of net power/ Oceans since the mid-20th century, and its projected useful power from this system depends on size of channel, continuation. Global surface temperature increased 0.74 ± mass flow rate, efficiency of TEG modules, number of 0.18 °C (1.33 ± 0.32 °F) during the Thomas Jon Seebeck modules and parasitic power. For chosen TEG modules, (1934) invented that a temperature formed between two efficiency is fixed and number of TEG has considered also dissimilar conductors produces a voltage and current. At the fixed for this study. So, maximum net power depends on heart of the thermoelectric generator effect is the fact that a proper selection of length, width and gap height of water temperature difference in a conducting material results in heat channel and depends on suitable selection of mass flow rate. flow between one side to another side The novelty of this study is proposed mathematical model to predict gross power, parasitic power and net power where Table 1: Summary from related literature mass flow rate, gap height, length and width have taken as variables. Number of TEG and its property(such as dimensions, efficiency and thermal resistance)have considered as fixed. As the number of TEG and its dimensions fixed, channel length and width are interrelated [6]. Proposed model will help to predict maximum net power, optimized channel dimensions ands uitable flow rate for defined conditions. Predicted results from proposed model will be validated by experiments. This model will be useful for system optimisation. III. PROBLEM DEFINITION Some developing countries and most populated industrialized countries (India china Mongolia Korea)etc. have average of 3 to 10 hours of daily power-cuts because the increase in demand of consumer utilization electricity exceeds so that the INTERNATIONAL JOURNAL OF RESEARCH IN ELECTRONICS AND COMPUTER ENGINEERING A UNIT OF I2OR 2060 | P a g e IJRECE VOL. 7 ISSUE 2 (APRIL- JUNE 2019) ISSN: 2393-9028 (PRINT) | ISSN: 2348-2281 (ONLINE) production of electrical energy is lesser then the consumer 3) By installed in the vehicle above the radiator means the dem and. And also shortage of fossil fuel and coal i.e. about vehicle battery will charge self 60% of electricity
Load more

Recommended publications
  • A Review on Thermoelectric Generators: Progress and Applications
    energies Review A Review on Thermoelectric Generators: Progress and Applications Mohamed Amine Zoui 1,2 , Saïd Bentouba 2 , John G. Stocholm 3 and Mahmoud Bourouis 4,* 1 Laboratory of Energy, Environment and Information Systems (LEESI), University of Adrar, Adrar 01000, Algeria; [email protected] 2 Laboratory of Sustainable Development and Computing (LDDI), University of Adrar, Adrar 01000, Algeria; [email protected] 3 Marvel Thermoelectrics, 11 rue Joachim du Bellay, 78540 Vernouillet, Île de France, France; [email protected] 4 Department of Mechanical Engineering, Universitat Rovira i Virgili, Av. Països Catalans No. 26, 43007 Tarragona, Spain * Correspondence: [email protected] Received: 7 June 2020; Accepted: 7 July 2020; Published: 13 July 2020 Abstract: A thermoelectric effect is a physical phenomenon consisting of the direct conversion of heat into electrical energy (Seebeck effect) or inversely from electrical current into heat (Peltier effect) without moving mechanical parts. The low efficiency of thermoelectric devices has limited their applications to certain areas, such as refrigeration, heat recovery, power generation and renewable energy. However, for specific applications like space probes, laboratory equipment and medical applications, where cost and efficiency are not as important as availability, reliability and predictability, thermoelectricity offers noteworthy potential. The challenge of making thermoelectricity a future leader in waste heat recovery and renewable energy is intensified by the integration of nanotechnology. In this review, state-of-the-art thermoelectric generators, applications and recent progress are reported. Fundamental knowledge of the thermoelectric effect, basic laws, and parameters affecting the efficiency of conventional and new thermoelectric materials are discussed. The applications of thermoelectricity are grouped into three main domains.
    [Show full text]
  • Thermoelectric Phenomenon in Hollow Blocks M
    THERMOELECTRIC PHENOMENON IN HOLLOW BLOCKS 1 1 1 M. Wehbe , J. Dgheim *, E. Sassine 1Laboratory of Applied Physics (LPA), Group of Mechanical, Thermal & Renewable Energies (GMTER), Lebanese University, Faculty of Sciences II. *Corresponding Author Email: [email protected] ABSTRACT The work presented in this article describes thermoelectric effect in hollow blocks for heat waste harvesting purposes. The study consists of developing a numerical model formed by a heat transfer equation coupled to thermoelectric effects equations to study thermoelectric generators(TEG) incorporated inside Lebanese hollow blocks through two simulations using finite difference scheme and using finite element scheme. Results showed a voltage of 5.85mV produced from a single 8.6 x 0.4 x 0.4 cm3 thermoelectric leg made of Bismuth Antimony Telluride for ΔT=30K. A design with 3 TEGs incorporated inside a hollow block was tested and validated numerically using both methods, the main results obtained for ΔT=30K, showed a voltage ΔV=0.72V, a current I=0.06 A and a figure of merit ZT=0.55. The design was then optimized for economic purposes. Key words: thermoelectric effect, thermoelectric generator, bismuth antimony telluride, hollow blocks, optimization. Nomenclature T: Temperature [K] ∆V: Electric potential [V] u, v: Velocity [m/s] σ: Electric conductivity [S/m] ρ: Density[Kg/m3] ZT: Merit factor V: Voltage [V] P: Power [W] S: Surface[m2] 푬: Electric field density [V/m] I: Electric current [A] Q: Heat energy [J.s-1] 흉: Thomson coefficient [ V/K] 푱: Current density vector[A.m2] 휶: Seebeck coefficient [V/K] q: Thermal power [W] m: Mass[Kg] Cp: Specific heat for constant pressure [J⁄Kg.
    [Show full text]
  • Modeling and Simulation of a Segmented Thermoelectric
    MODELING AND SIMULATION OF A SEGMENTED THERMOELECTRIC GENERATOR _______________________________________ A Thesis presented to the Faculty of the Graduate School at the University of Missouri-Columbia _______________________________________________________ In Partial Fulfillment of the Requirements for the Degree Master of Science _____________________________________________________ by Qiuyi Su Dr. Thomas G Engel, Thesis Supervisor DECEMBER 2017 The undersigned, appointed by the dean of the Graduate School, have examined the thesis entitled MODELING AND SIMULATION OF A SEGMENTED THERMOELECTRIC GENERATOR presented by Qiuyi Su, a candidate for the degree of master of science, and hereby certify that, in their opinion, it is worthy of acceptance. Professor Thomas G. Engel Professor Mark Prelas Professor Yuyi Lin ACKNOWLEDGEMENTS I feel much indebted to many people who have instructed and favored me in the course of writing this paper. First and foremost, I would want to show my deepest gratitude to my supervisor, Professor Thomas G. Engel, a respectable and responsible teacher. He taught me three courses during my study in Mizzou. His patient, kindness and enlightening instruction help me to complete my study. Additionally, I would like to thank Professor Mark Prelas and Professor Yuyi Lin for their advice and willingness to serve on my master advisory committee. I shall also express my gratitude to all my teachers helped me to develop the fundamental and essential academic competence. Last but not least, I wish to thank all my friends,
    [Show full text]
  • Radioisotope Power Systems Reference Book for Mission Designers and Planners
    https://ntrs.nasa.gov/search.jsp?R=20160001769 2019-08-31T04:26:04+00:00Z JPL Publication 15-6 Radioisotope Power Systems Reference Book for Mission Designers and Planners Radioisotope Power System Program Office Young Lee Brian Bairstow Jet Propulsion Laboratory National Aeronautics and Space Administration Jet Propulsion Laboratory California Institute of Technology Pasadena, California September 2015 JPL Publication 15-6 Radioisotope Power Systems Reference Book for Mission Designers and Planners Radioisotope Power System Program Office Young Lee Brian Bairstow Jet Propulsion Laboratory National Aeronautics and Space Administration Jet Propulsion Laboratory California Institute of Technology Pasadena, California September 2015 This document was generated by the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration. It summarizes research carried out at Jet propulsion Laboratory and by Glenn Research Center. For both facilities, funding was provided by the NASA Radioisotope Power Systems (RPS) Program Office at Glenn Research Center. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise, does not constitute or imply its endorsement by the United States Government or the Jet Propulsion Laboratory, California Institute of Technology. © 2015 California Institute of Technology. Government sponsorship acknowledged. Abstract The RPS Program’s Program Planning and Assessment (PPA) Office commissioned the Mission Analysis team to develop the Radioisotope Power Systems (RPS) Reference Book for Mission Planners and Designers to define a baseline of RPS technology capabilities with specific emphasis on performance parameters and technology readiness. The main objective of this book is to provide RPS technology information that could be utilized by future mission concept studies and concurrent engineering practices.
    [Show full text]
  • (TEG) System for Automotive Exhaust Waste Heat Recovery
    energies Article Analytical and Experimental Study of Thermoelectric Generator (TEG) System for Automotive Exhaust Waste Heat Recovery Faisal Albatati * and Alaa Attar Department of Mechanical Engineering, Faculty of Engineering at Rabigh, King Abdulaziz University, Jeddah 21589, Saudi Arabia; [email protected] * Correspondence: [email protected] Abstract: Nearly 70% of the energy produced from automotive engines is released to the atmosphere in the form of waste energy. The recovery of this energy represents a vital challenge to engine designers primarily when a thermoelectric generator (TEG) is used, where the availability of a continuous, steady-state temperature and heat flow is essential. The potential of semi-truck engines presents an attractive application as many coaches and trucks are roaming motorways at steady-state conditions most of the time. This study presents an analytical thermal design and an experimental validation of the TEG system for waste heat recovery from the exhaust of semi-truck engines. The TEG system parameters were optimized to achieve the maximum power output. Experimental work was conducted on a specially constructed setup to validate the analytically obtained results. Both analytical and experimental results were found to be in good agreement with a marginal deviation, indicating the excellent accuracy of the effective material properties applied to the system since they take into account the discrepancy associated with the neglection of the contact resistances and Thomson effect. Keywords: thermal design of thermoelectric system; energy balance of thermoelectric generator; waste heat recovery system Citation: Albatati, F.; Attar, A. Analytical and Experimental Study of Thermoelectric Generator (TEG) 1. Introduction System for Automotive Exhaust Generally, it is estimated that about one third of total energy is usefully used while the Waste Heat Recovery.
    [Show full text]
  • A Thermoelectric Energy Harvester Based on Microstructured Quasicrystalline Solar Absorber
    micromachines Article A Thermoelectric Energy Harvester Based on Microstructured Quasicrystalline Solar Absorber Vinícius Silva Oliveira 1,* , Marcelo Miranda Camboim 1 , Cleonilson Protasio de Souza 1 , Bruno Alessandro Silva Guedes de Lima 2 , Orlando Baiocchi 3 and Hee-Seok Kim 3 1 Department of Electrical Engineering, Federal University of Paraíba, João Pessoa, PB 5115, Brazil; [email protected] (M.M.C.); [email protected] (C.P.d.S.) 2 Department of Mechanical Engineering, Federal University of Paraíba, João Pessoa, PB 5045, Brazil; [email protected] 3 School of Engineering and Technology, University of Washington Tacoma, Tacoma, WA 98195-2180, USA; [email protected] (O.B.); [email protected] (H.-S.K.) * Correspondence: [email protected] Abstract: As solar radiation is the most plentiful energy source on earth, thermoelectric energy harvesting emerges as an interesting solution for the Internet of Things (IoTs) in outdoor applications, particularly using semiconductor thermoelectric generators (TEGs) to power IoT devices. However, when a TEG is under solar radiation, the temperature gradient through TEG is minor, meaning that the TEG is useless. A method to keep a significant temperature gradient on a TEG is by using a solar absorber on one side for heating and a heat sink on the other side. In this paper, a compact TEG-based energy harvester that features a solar absorber based on a new class of solid matter, the so-called quasicrystal (QC), is presented. In addition, a water-cooled heat sink to improve the temperature Citation: Silva Oliveira, V.; gradient on the TEG is also proposed.
    [Show full text]
  • Multi-Mission Radioisotope Thermoelectric Generator (MMRTG)
    National Aeronautics and Space Administration Multi-Mission Radioisotope Thermoelectric Generator (MMRTG) Space exploration missions require safe, reliable, five decades and counting. The Apollo missions long-lived power systems to provide electricity to the moon, the Viking missions to Mars, and the and heat to spacecraft and their science instru- Pioneer, Voyager, Ulysses, Galileo, Cassini and ments. One flight-proven source of dependable New Horizons mission to Pluto and the Kuiper power is Radioisotope Power Systems (RPS). Belt all used RPS. The spectacular Voyager 1 and A type of RPS is a Radioisotope Thermoelectric 2 missions, operating on RPS power since their Generator (RTG) — a space nuclear power launches in 1977, continue to function and return system that converts heat into electricity using scientific data, with both having now reached the no moving parts. void of interstellar space. The Department of Energy (DOE), in support How RTGs Work of NASA, has developed several generations of such space nuclear power systems that RTGs work by converting heat from the natural can be used to supply electricity — and useful decay of radioisotope materials into electricity. excess heat — for a variety of space exploration RTGs consist of two major elements: a heat missions. The current RPS, called a Multi- source that contains the radioisotope fuel (mostly Mission Radioisotope Thermoelectric Generator plutonium-238), and solid-state thermocouples (MMRTG), was designed with the flexibility to that convert the plutonium’s decay heat energy to operate on planetary bodies with atmospheres, electricity. such as at Mars, as well as in the vacuum of space. An MMRTG generates about 110 watts of Conversion of heat directly into electricity is electrical power at launch, an increment of power a scientific principle discovered two centuries that can be matched with a variety of potential ago.
    [Show full text]
  • Thermoelectric Generator Using Polyaniline-Coated Sb2se3/Β-Cu2se Flexible Thermoelectric Films
    polymers Article Thermoelectric Generator Using Polyaniline-Coated Sb2Se3/β-Cu2Se Flexible Thermoelectric Films Minsu Kim 1, Dabin Park 1 and Jooheon Kim 1,2,* 1 School of Chemical Engineering & Materials Science, Chung-Ang University, Seoul 06974, Korea; [email protected] (M.K.); [email protected] (D.P.) 2 Department of Advanced Materials Engineering, Chung-Ang University, Anseong-si, Seoul 17546, Korea * Correspondence: [email protected] Abstract: Herein, Sb2Se3 and β-Cu2Se nanowires are synthesized via hydrothermal reaction and water evaporation-induced self-assembly methods, respectively. The successful syntheses and mor- phologies of the Sb2Se3 and β-Cu2Se nanowires are confirmed via X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, field emission scanning electron mi- croscopy (FE-SEM), and field emission transmission electron microscopy (FE-TEM). Sb2Se3 materials have low electrical conductivity which limits application to the thermoelectric generator. To improve the electrical conductivity of the Sb2Se3 and β-Cu2Se nanowires, polyaniline (PANI) is coated onto the surface and confirmed via Fourier-transform infrared spectroscopy (FT-IR), FE-TEM, and XPS analysis. After coating PANI, the electrical conductivities of Sb2Se3/β-Cu2Se/PANI composites were increased. The thermoelectric performance of the flexible Sb2Se3/β-Cu2Se/PANI films is then measured, and the 70%-Sb2Se3/30%-β-Cu2Se/PANI film is shown to provide the highest power factor of 181.61 µW/m·K2 at 473 K. In addition, a thermoelectric generator consisting of five legs of the 70%-Sb2Se3/30%-β-Cu2Se/PANI film is constructed and shown to provide an open-circuit Citation: Kim, M.; Park, D.; Kim, J.
    [Show full text]
  • Small Thermoelectric Generators by G
    Small Thermoelectric Generators by G. Jeffrey Snyder hermoelectric generators are all solid-state devices that convert T heat into electricity. Unlike traditional dynamic heat engines, thermoelectric generators contain no moving parts and are completely silent. Such generators have been used reliably for over 30 years of maintenance-free operation in deep space probes such as the Voyager missions of NASA.1 Compared to large, traditional heat engines, thermoelectric generators have lower efficiency. But for small applications, thermoelectrics can become competitive because they are compact, simple (inexpensive) and scaleable. Thermoelectric systems can be easily designed to operate with small heat sources and small temperature differences. Such small generators could be mass produced for use in automotive waste heat recovery or home co-generation of heat and electricity. Thermoelectrics have even been miniaturized to harvest body heat for powering a wristwatch. Thermoelectric Power A thermoelectric produces electrical power from heat flow across a temperature gradient.2 As the heat flows from hot to cold, free charge carriers (electrons or holes) in the material are also driven to the cold end (Fig. 1). The resulting voltage (V) is proportional to the temperature difference (∆T) via the Seebeck coefficient, α, (V = α∆T). By connecting an electron conducting (n-type) and hole conducting (p-type) material in series, a net voltage is produced that can be driven through a load. A good thermoelectric material has a Seebeck coefficient between 100 µV/K and 300 µV/K; thus, in order to achieve a few volts at the load, many thermoelectric couples need to FIG. 1.
    [Show full text]
  • Photovoltaic Hybrid Systems Based on Wide-Gap Solar Cells
    Applied Energy 300 (2021) 117343 Contents lists available at ScienceDirect Applied Energy journal homepage: www.elsevier.com/locate/apenergy Practical development of efficient thermoelectric – Photovoltaic hybrid systems based on wide-gap solar cells Bruno Lorenzi a,*, Paolo Mariani b, Andrea Reale b, Aldo Di Carlo b,c, Gang Chen d, Dario Narducci a a Dept. Materials Science, Univ. of Milano Bicocca, Milano 20125, Italy b CHOSE, Center for Hybrid and Organic Solar Energy, University of Rome Tor Vergata, Rome 00133, Italy c ISM-CNR, Institute of Structure of Matter, National Research Council, Rome 00133, Italy d Dept. Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA HIGHLIGHTS • The efficiency gain due to hybridization of wide-gap PV was theoretically evaluated. • The optimized working temperatures and thermoelectric generator layout were found. • A hybrid device based on a perovskite solar cell and a Bi2Te3 TEG was developed. ARTICLE INFO ABSTRACT Keywords: The decrease of solar cell efficiency with temperature is a known problem for photovoltaics (PV). Temperature Hybrid sensitivity can lead to a considerable amount of energy losses over the lifetime of solar panels. In this perspective Photovoltaic Hybrid Thermoelectric-Photovoltaic (HTEPV) systems, which recover solar cell heat losses to produce an addi­ Thermoelectric tional power output, can be a suitable option. However only hybridization of wide-gap solar cells is convenient in terms of efficiency gains and deserves investigation to evaluate HTEPV devices effectiveness. In this work we report the modeling and the development of customized bismuth telluride thermoelectric generators, optimized to be hybridized with amorphous silicon (aSi), Gallium Indium Phosphide (GaInP) or Perovskites solar cells.
    [Show full text]
  • Thermoelectric Exploration of Silver Antimony Telluride and Removal of the Second Phase Silver Telluride a Thesis Presented in P
    Thermoelectric Exploration of Silver Antimony Telluride and Removal of the Second Phase Silver Telluride A Thesis Presented in Partial Fulfillment of the Requirements for the Degree Masters of Science in the Graduate School of The Ohio State University By Michele D. Nielsen, B.S. Graduate Program in Mechanical Engineering The Ohio State University 2010 Thesis Committee: Joseph Heremans, Advisor Walter Lempert © Copyright by Michele D. Nielsen 2010 Abstract As demands for energy increase throughout the world, the desire to create energy efficient technologies has emerged. While the field thermoelectricity has been around for well over a century, it is becoming increasingly popular, especially for automotive applications, as new and more efficient materials are discovered. Thermoelectricity is a technology in which a temperature difference can be applied to create a potential difference for the application of waste heat recovery or a potential difference can be used to create a temperature difference for heating and cooling applications. Materials used in thermoelectric devices are semiconductors with high Figure of Merit, zT. The dimensionless thermoelectric Figure of Merit is a function of Seebeck coefficient, S, electrical resistivity, ρ, and thermal conductivity, κ. Experimental testing is used to determine the properties of these materials for optimized zT. This thesis covers a new class of thermoelectric semiconductors based on rocksalt I-V- VI 2 compounds, which intrinsically possess a lattice thermal conductivity at the amorphous limit. It has been shown experimentally that AgSbTe 2, when optimally doped, reaches a zT =1.2 at 410 K. 3 Unfortunately, there is a metallurgical phase transition at 417 K (144 °C).
    [Show full text]
  • Chip-Scale Thermoelectric Energy Harvester for Room Temperature Applications
    Chip-Scale Thermoelectric Energy Harvester for Room Temperature Applications A Dissertation Presented By Samer A. Haidar to The Department of Electrical and Computer Engineering in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the field of Electrical Engineering Northeastern University Boston, Massachusetts May 2020 2 To my family. 3 Abstract Thermoelectric energy harvesters have emerged as a solution for power generation by converting wasted heat directly into electrical energy through the Seebeck effect. As a result, they play a critical role in the development of the Internet-of-Things (IoT) wireless devices and sensors. High efficiency thermoelectric (TE) materials are important for power generation and help reduce our dependence on fossil fuels and reduce greenhouse gas emissions. Recent advances in fabrication technology have enabled these devices to be constructed at the chip-scale level promoting the use with low power devices such as wireless sensors and wearable applications. Thermoelectric n-type bismuth telluride (Bi2Te3) films and p-type antimony telluride (Sb2Te3) films are grown on SiO2/Si substrates using RF magnetron sputtering via physical vapor deposition (PVD) process. The objective of this dissertation is to study the crystal structure, grain size and elemental composition for 1µm and 10µm thermoelectric films deposited using different deposition conditions and using various heat treatment recipes. The thermoelectric properties of the films are found to be strongly dependent on the sputtering method and deposition temperature that lead to the design and fabrication of micro-scale thermoelectric energy generator (µTEG) based on the vertical architecture, which is geared towards IoT and wearable applications close to room temperature.
    [Show full text]