Author: Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Spectral Control for Thermophotovoltaic Energy Conversion
Author: Fundamentals of Thermophotovoltaic Energy Conversion
Author: Donald ChubbPublisher: Elsevier
ISBN: 0080560687
Category : Science
Languages : en
Pages : 532
Book Description
This is a text book presenting the fundamentals of thermophotovoltaic(TPV) energy conversion suitable for an upper undergraduate or first year graduate course. In addition it can serve as a reference or design aid for engineers developing TPV systems. Each chapter includes a summary and concludes with a set of problems. The first chapter presents the electromagnetic theory and radiation transfer theory necessary to calculate the optical properties of the components in a TPV optical cavity. Using a simplified model, Chapter 2 develops expressions for the maximum efficiency and power density for an ideal TPV system. The next three chapters consider the three major components in a TPV system; the emitter, filter and photovoltaic(PV) array. Chapter 3 applies the electromagnetic theory and radiation transfer theory presented in Chapter 1 in the calculation of spectral emittance. From the spectral emittance the emitter efficiency is calculated. Chapter 4 discusses interference, plasma and resonant array filters plus an interference filter with an imbedded metallic layer, a combined interference-plasma filter and spectral control using a back surface reflector(BSR) on the PV array. The theory necessary to calculate the optical properties of these filters is presented. Chapter 5 presents the fundamentals of semiconductor PV cells. Using transport equations calculation of the current-voltage relation for a PV cell is carried out. Quantum efficiency, spectral response and the electrical equivalent circuit for a PV cell are introduced so that the PV cell efficiency and power output can be calculated. The final three chapters of the book consider the combination of the emitter, filter and PV array that make up the optical cavity of a TPV system. Chapter 6 applies radiation transfer theory to calculate the cavity efficiency of planar and cylindrical optical cavities. Also introduced in Chapter 6 are the overall TPV efficiency, thermal efficiency and PV efficiency. Leakage of radiation out of the optical cavity results in a significant loss in TPV efficiency. Chapter 7 considers that topic. The final chapter presents a model for a planar TPV system. Six appendices present background information necessary to carry out theoretical developments in the text. Two of the appendices include Mathematica programs for the spectral optical properties of multi-layer interference filters and a planar TPV system. Software is included for downloading all the programs within the book. First text written on thermophotovoltaic(TPV) energy conversion Includes all the necessary theory to calculate TPV system performance Author has been doing TPV energy conversion research since 1980's Emphasizes the fundamentals of TPV energy conversion Includes a summary and problem set at the end of each chapter Includes Mathematica programs for calculating optical properties of interference filters and planar TPV system performance solution software
Thermophotovoltaic Spectral Control
Author: PM FourspringPublisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Spectral control is a key technology for thermophotovoltaic (TPV) direct energy conversion systems because only a fraction (typically less than 25%) of the incident thermal radiation has energy exceeding the diode bandgap energy, E{sub g}, and can thus be converted to electricity. The goal for TPV spectral control in most applications is twofold: (1) Maximize TPV efficiency by minimizing transfer of low energy, below bandgap photons from the radiator to the TPV diode. (2) Maximize TPV surface power density by maximizing transfer of high energy, above bandgap photons from the radiator to the TPV diode. TPV spectral control options include: front surface filters (e.g. interference filters, plasma filters, interference/plasma tandem filters, and frequency selective surfaces), back surface reflectors, and wavelength selective radiators. System analysis shows that spectral performance dominates diode performance in any practical TPV system, and that low bandgap diodes enable both higher efficiency and power density when spectral control limitations are considered. Lockheed Martin has focused its efforts on front surface tandem filters which have achieved spectral efficiencies of {approx}83% for E{sub g} = 0.52 eV and {approx}76% for E{sub g} = 0.60 eV for a 950 C radiator temperature.
Fabrication and Testing of an Infrared Spectral Control Component for Thermophotovoltaic Power Conversion Applications
Author: Francis Martin O'SullivanPublisher:
ISBN:
Category :
Languages : en
Pages : 157
Book Description
Thermophotovoltaic (TPV) power conversion is the direct conversion of thermal radiation to electricity. Conceptually, TPV power conversion is a very elegant means of energy conversion. A thermal source emits a radiative spectrum, which is incident upon a photovoltaic (PV) diode. The PV diode then converts some of the incident photons to electricity. The photons which are converted to electricity have energies greater than the electronic bandgap of the material from which the PV diode is fabricated. Unfortunately the thermal sources used in TPV systems are typically broadband, meaning that a significant amount of the emitted radiation cannot be converted to electricity because the photons are not energetic enough to produce electron-hole pairs in the PV diode. This unconvertible radiation is dissipated as heat in the PV diode and represents a very large loss in a TPV system's conversion efficiency. This thesis describes the development of a spectral control component which can be used to filter the radiation emitted from a TPV system's thermal source, such that only convertible radiation is incident upon the PV diode. The theoretical analysis of filter designs based on a Si/SiO2 dielectric stack is described in this text. The methods and processes used to fabricate physical samples of the spectral control component are discussed. The results of the spectral analysis of the physical samples are documented and a comparison between the predicted performance of the filter designs and the measured performance of the fabricated filter samples is made.
טרייבט מען יידן איבערן דניעסטער
Author: Optical Coatings for Thermophotovoltaic Spectral Control
Author: Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
The efficiency of thermophotovoltaic (TPV) energy conversion is dependent on efficient spectral control. An edge pass filter (short pass) in series with a highly doped, epitaxially grown layer has achieved the highest performance of TPV spectral control. Front surface, tandem filters have achieved the highest spectral efficiency and represent the best prospect for even higher spectral efficiency for TPV energy conversion systems. Specifically, improvements in the physical vapor deposition process, identification of other materials with a high index of refraction and a low absorption coefficient, and more efficient edge filter designs could provide higher TPV spectral performance.
דער וועג צום ציעל
Author: Engineering Spectral Control Using Front Surface Filters for Maximum TPV Energy Conversion System Performance
Author: Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Energy conversion efficiencies of better than 23% have been demonstrated for small scale tests of a few thermophotovoltaic (TPV) cells using front surface, tandem filters [1,2]. The engineering challenge is to build this level of efficiency into arrays of cells that provide useful levels of energy. Variations in cell and filter performance will degrade TPV array performance. Repeated fabrication runs of several filters each provide an initial quantification of the fabrication variation for front surface, tandem filters for TPV spectral control. For three performance statistics, within-run variation was measured to be 0.7-1.4 percent, and run-to-run variation was measured to be 0.5-3.2 percent. Fabrication runs using a mask have been shown to reduce variation across interference filters from as high 8-10 percent to less than 1.5 percent. Finally, several system design and assembly approaches are described to further reduce variation.
Author: 
Author: אנבל שלב-אלוני