Дисертації з теми "Energy conversion technologie"
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Yu, Xiaoting. "Transformation of Nanocrystals in Electrochemical Energy Technologies." Doctoral thesis, Universitat de Barcelona, 2020. http://hdl.handle.net/10803/670922.
Повний текст джерелаEsta tesis se centra en la síntesis de diferentes tipos de nanocristales, su aplicación a las tecnologías de conversión y almacenamiento de energía, particularmente LIBs, KIBs y DEFCs, y su transformación estructural durante los procesos electroquímicos dentro de estas aplicaciones de almacenamiento y conversión de energía. La morfología y composición de nanocristales de óxidos de metales de transición, bimetálicos e intermetálicos que incroporan fósforo se caracterizan en detalle para seguir las alteraciones durante la aplicación. La comprensión de la correlación entre las propiedades estructurales, químicas y electroquímicas permitirá un diseño más racional de nanomateriales funcionales. El primer capítulo ofrece una introducción general al rápido desarrollo y la importancia de las tecnologías de energía renovable en la sociedad moderna. Entre ellas, las tecnologías de conversión y almacenamiento de energía electroquímica son particularmente atractivas en términos de costo, seguridad y respeto al medio ambiente. Se discuten los principios básicos de las tecnologías de baterías de iones de litio, sodio y potasio, incluidas las estructuras de las baterías, los materiales de los electrodos y los mecanismos de trabajo. Además, describo el principio de funcionamiento de las DEFCs y el EOR electrocatalítico. También se explican las estrategias para sintetizar nanocristales de alto rendimiento para aplicaciones de almacenamiento y conversión de energía electroquímica. Finalmente, en este capítulo discuto el fenómeno de la evolución estructural y química de los nanocristales durante las operaciones electroquímicas y cómo se necesita su caracterización en cada sistema para una comprensión profunda de las propiedades y aplicaciones de los nanomateriales. El capítulo 1 también incluye los objetivos de la tesis. El Capítulo 2 describe un método de crecimiento simple mediado por semillas a baja temperatura para crecer Mn3O4 en nanoparticulas huecas de Fe3O4. Se lleva a cabo un proceso de sinterizado a temperatura moderada (500 °C) para promover la reacción en estado sólido de las NPs y obtener partículas huecas de MnxFe3-xO4. Al ser usados como materiales de electrodo anódico, la cubierta policristalina, el espacio vacío interno y la gran área de superficie de las NPs de MnxFe3-xO4 pueden amortiguar de manera efectiva el cambio de volumen de los nanocristales durante el proceso de litiación y delitizacion para mejorar la estabilidad y la vida útil del ciclo. Se evalúa la actividad electroquímica de las NPs de MnxFe3- xO4 hacia la reacción de litio y se explora la relación entre la estructura y las propiedades electroquímicas. El excelente rendimiento de las NPs huecas de MnxFe3-xO4 está asociado con su estructura y composición cristalinas, y con la presencia de ligandos carbonizados, que promueven aún más la conductividad eléctrica y acomodan y liberan rápidamente iones de litio mientras retienen una estructura estable incluso después de ciclos continuos de carga/descarga . Este trabajo fue publicado en Nano Energy en 2019. El Capítulo 3 vesra sobre el rendimiento de los NPs bimetálicos como ánodos en LIBs y KIBs. NPs monodispersas de CoSn y NiSn se sintetizan mediante co-reducción y se soportan en materiales comerciales de carbono. Los nanocompuestos obtenidos se prueban como materiales anódicos en LIBs de media celda y KIBs y LIBs de celda completa. Los electrodos CoSn@C muestran excelentes capacidades de carga y descarga en media celda y celdas completas LIB. Las capacidades para KIB se estabilizan alrededor de 200 mAh g-1 con alta eficiencia culombiana durante 400 ciclos para CoSn@C y 100 mAh g-1 para NiSn@C durante 300 ciclos. La oxidación de las NPs, la formación de la capa SEI, el vasto cambio de volumen durante la litiación y la delitiación causaron la disminución de las capacidades. Este trabajo fue publicado en ACS Applied Materials & Interfaces en 2020. En el capítulo 4, se detalla un enfoque simple para producir nanocubos intermetálicas de Pd3Pb con geometría cúbica bien definida y un tamaño promedio de 6 nm a 10 nm. Los catalizadores de Pd3Pb/C presentan actividades y estabilidades electrocatalíticas EOR mejoradas. La actividad EOR de las NPs de Pd3Pb se investiga en función de su tamaño a través de técnicas CV y CA. Todos los catalizadores exhiben una disminución de corriente pronunciada durante los primeros 500 s de operación EOR continua, que está asociada con la acumulación de intermedios de reacción fuertemente adsorbidos y el bloqueo relacionado de los sitios de reacción. Los catalizadores pueden reactivarse simplemente ciclando para eliminar eficazmente las especies adsorbidas en la superficie y recuperar la actividad electrocatalítica. Una reorganización de los elementos Pd y Pb ocurre en las NPs de Pd3Pb durante EOR, lo que implica una difusión hacia afuera/hacia adentro de Pd/Pb para equilibrar la estequiometría de la superficie de los NCs, que es impulsada por la diferente afinidad de Pb y Pd hacia el oxígeno y posiblemente el etanol, y la oxidación/reducción electroquímica de Pd. Este trabajo fue publicado en Chemistry of Materials en 2020. El Capítulo 5 demuestra la síntesis de NRs coloidales de Pd2Sn que incorporan P a través de la fosforización de las NPs de Pd2Sn con un reactivo altamente activo. El catalizador Pd2Sn:P/C exhibe una actividad significativamente mejorada hacia EOR en medios alcalinos en comparación con Pd2Sn/C, PdP2/C y catalizadores comerciales de Pd/C. La mejora del rendimiento se racionaliza con la ayuda de los cálculos de DFT teniendo en cuenta los diferentes entornos químicos de fósforo. Dependiendo de su estado de oxidación, el fósforo superficial introduce sitios con adsorción de OH de baja energía y/o influye fuertemente en la estructura electrónica del paladio y el estaño para facilitar la oxidación del acetilo al ácido acético, que se considera el paso limitante de la tasa de EOR. El Pd2Sn:P se caracteriza por una superficie rica en Sn y P, que se correlaciona bien con los porcentajes más altos de estaño oxidado y fósforo, y la mayor tendencia a la oxidación de Sn en comparación con Pd. Los cálculos de DFT demuestran que la presencia de P puede inducir una mayor adsorción química de OH- para facilitar la formación de CH3COOH, lo que resulta en un aumento de la actividad EOR. Este trabajo fue aceptado en Nano Energy en 2020.
Reynaud, Jean-François. "Recherches d'optimums d'énergie pour charge/décharge d'une batterie à technologie avancée dédiée à des applications photovoltaïques." Phd thesis, Université Paul Sabatier - Toulouse III, 2011. http://tel.archives-ouvertes.fr/tel-00559630.
Повний текст джерелаConceição, Ricardo Filipe Carrão da. "Soiling in solar energy conversion technologies: assessment and mitigation." Doctoral thesis, Universidade de Évora, 2019. http://hdl.handle.net/10174/25527.
Повний текст джерелаLiu, Junfeng. "Colloidal Metal Phosphide Nanocrystals for Electrochemical Energy Technologies." Doctoral thesis, Universitat de Barcelona, 2019. http://hdl.handle.net/10803/666970.
Повний текст джерелаLos fosfuros metálicos son materiales funcionales de gran interés e impacto en la sociedad debido a su gran rendimiento en almacenamiento y conversión de energía. Sin embargo, la síntesis de nanopartículas de fosfuros metálicos y su escalabilidad es limitada. En la presente tesis, se ha desarrollado un proceso de producción para nanopartículas de fosfuros metálicos simple, escalable y rentable. El éxito de los resultados radica en el uso de fosfito de trifenilo, considerado como una fuente de fósforo barata, estable al contacto con el aire y no tóxica, que además permite la síntesis de una gran variedad de nanocristales (NCs) (fosfuros de Ni, Co, Cu, Fe, Mo, así como fosfuros ternarios de Ni2-xCoxP). Optimizando los parámetros experimentales, es posible producir NCs de diferente composición, morfología y tamaño. Además, el uso de solventes de alto punto de ebullición, facilita la síntesis de materiales menos estudiados como el CrP. Los NCs de Ni2-xCoxP y CrP NCs pueden ser combinados con carbono dando lugar a electrocatalizadores útiles para reacciones tales como evolución de hidrógeno y reducción de oxígeno, respectivamente. El uso de otras fuentes de fósforo, como por ejemplo la triamida de hexametilfósforo, permite a su vez producir NCs de SnP y PdP2. En el caso particular de SnP, los NCs demostraton poseer una geometría esférica y una fase cristalográfica trigonal con una superestructura atribuida a los pares difósforos ordenados. Mezclados con carbón negro y utilizados como ánodos en baterías de ion sodio, estos NCs demostraron una alta capacidad reversible de 600 mA h g-1 a una densidad de corriente de 100 mA g-1 y estables durante más de 200 ciclos. Por otro lado, los NCs de PdP2 soportados sobre óxido de grafeno se utilizaron como electrocatalizadores para la oxidación de etanol, mostrando una alta densidad de corriente de hasta 51.4 mA cm-2 y una actividad de masa de 1.60 A mg-1Pd. En resumen, se han desarrollado métodos de síntesis basados en estrategias coloidales para poder producir una gran variedad de fosfuros metálicos a escala nanométrica, mostrando estos un gran rendimiento para su uso en conversión y almacenamiento de energía electroquímica.
Mousselmal, Hadj Daoud. "Conception de dispositifs piézoélectriques de récupération d’énergie utilisant des structures multidirectionnelles et nanostructurés." Thesis, Lyon, INSA, 2014. http://www.theses.fr/2014ISAL0124.
Повний текст джерелаThis thesis work focuses on the development of new piezoelectric energy recovery systems from environmental mechanical vibration. The goal is to provide solutions to some strong constraints on the miniaturization of these systems, their integration in MEMS technology. The 2 major lines followed in this work are: (i) the nanostructuring by porosification silicon substrate. This method allows to create functionalized areas having local properties of density and lower rigidity than those of the silicon substrate. This allows on the one hand to improve the overall electromechanical coupling coefficient of the structure and, secondly, to maintain the resonant frequency of the operational mode in a low frequency range (< 1KHz) compatible with the spectrum of Many conventional vibratory sources. A series of finite element modeling of a type converter (beam with seismic mass) established the optimum dimensional parameters of nanostructured area. The effectiveness of this localized nanostructuring method was then evaluated experimentally on silicon membranes. It was observed a reduction of the resonance frequency of the fundamental mode, while minimizing losses by a judicious choice of the location and the width of the porous zone. (Ii) The development of recovery devices multidirectional sensitivity. These devices allow to recover energy regardless of the direction of the external load. They use 3 different eigenmodes bending each solicited by a particular component (ax, ay and az) vector solicitation characteristic acceleration. These devices based on a planar structure type double orthogonal beams with central seismic mass can be easily integrated and can be broken down to centimeter scale at the millimeter scale using in this case the MEMS technologies. A simple analytical model was first updated energy mechanisms that enable a constant amount of energy when the device is subjected to a bias vector in any direction. The optimization of the electromechanical coupling coefficient of each functional mode, and the adjustment of their resonance frequency were obtained using a finite element model. All these theoretical results has been experimentally validated using centimeter prototypes
Mary, Charlotte. "Physico-chemistry, high pressure rheology and film-forming capacity of polymer-base oil solutions in EHL." Thesis, Lyon, INSA, 2014. http://www.theses.fr/2014ISAL0013/document.
Повний текст джерелаThe development of high value-added lubricants overcoming more and more drastic operating conditions, fuel-efficient and providing excellent performance during a long time remains a huge challenge for oil makers. This thesis is dedicated to the study of the role and the actions of Viscosity Index Improvers (VII) in engine lubricants. The first objective targeted in this work is the characterization of the rheological behaviors and the modeling of viscosity in function of realistic conditions of temperature, pressure and shear stress for polymer-thickened base oil solutions without functional additives. Several polymers (PAMA, OCP and PISH) with different molecular weights and conformations (comb, linear and star) are used with a concentration of 1.2% (w/w) in a hydrocracked mineral base oil. The originality of the thesis lies in the use of non-commercial rheometers under high pressure (up to 800 MPa). A second challenge is the understanding of the relationship between the rheological response of simplified engine lubricants and the mechanisms occurring at the molecular scale by exploring the notions of conformation, solubility and hydrodynamic radius by the extension of the Einstein’s law at high pressure. Finally, the study focuses on the link between rheology and tribology and by extrapolation, between the chemical composition of the lubricant and tribology. The film thickness is measured and compared with the Hamrock-Dowson analytical predictions and with the numerical simulations based on the generalized Reynolds’ equation including the rheological models. Both experimental and numerical data are in good agreement
Haboubi, Walid. "Développements de circuits Rectennae bi-polarisation, bi-bande pour la récupération et conversion d’énergie électromagnétique à faible niveau." Thesis, Paris Est, 2014. http://www.theses.fr/2014PEST1089/document.
Повний текст джерелаImproving energy autonomy of communication systems constitutes one of the major concerns for their massive deployment in our environment. We want to make these electronic devices (sensors and sensor networks) completely autonomous, avoiding the embedded energy sources that require replacement operations or periodic charging. Among the available energy sources that can be harvested, there are electromagnetic waves. The device that can capture this energy and convert it into useful DC power is called Rectenna (Rectifying antenna), combining antenna with diode-based rectifier. In recent few years, rectennas have reached a significant number of papers in the literature. The main challenge consists in improving performances in term of efficiency, in an attempt to overcome the electromagnetic wave attenuation and the low available field level. According to this context, this PhD work supported by the ANR project REC-EM has taken place. In this study, we have developed, designed and characterized planar structures that have interesting properties:- In term of orthogonal polarizations, so energy harvesting becomes feasable regardless the arbitrary orientation of the incident wave on the rectenna. A dual-circularly polarized rectenna at 2.45 GHz with dual-access will be set up to overcome the 3 dB power loss in the case of linearly-polarized incident wave with unknown orientation.- In term of multiple resonances, so the amount of total RF power collected by the antenna can be increased and consequently the converted DC power level can also be improved. A dual-frequency rectenna (1.8 and 2.45 GHz) with single access will be designed, as well as a rectenna based upon a dual-frequency antenna array.- In term of size compactness by avoiding the use of the HF filter between the antenna and the rectifier for all developed rectenna structures during this work. In all cases, it will be necessary to define the most suitable rectifier topology to each antenna and select, if it is appropriated, the optimum DC recombination technique to overcome the effects of RF power imbalance that may occur between the different antenna accesses. Besides, single-diode circuits will be designed and fulfilled for each structure. Finally, we will miniaturize the dual-circularly polarized dual-access antenna, and exploit it to power a LCD display temperature sensor. To enhance the DC voltage level required to activate the sensor, a DC-DC converter is inserted between the rectenna and the sensor. Such energy management device should be able to operate under low delivered DC power. Two converters will be used. The first one is developed by Ampere Lab at Ecole Centrale de Lyon and SATIE Lab at ENS Cachan. This converter was the subject of another dissertation also supported by the ANR under the REC-EM project
Grabbe, Mårten. "Marine Current Energy Conversion : Resource and Technology." Licentiate thesis, Uppsala University, Electricity, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-113365.
Повний текст джерелаGrabbe, Mårten. "Hydro-Kinetic Energy Conversion : Resource and Technology." Doctoral thesis, Uppsala universitet, Elektricitetslära, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-195942.
Повний текст джерелаMalik, Mohammad Rafi. "Reduced-orderCombustion Models for Innovative Energy Conversion Technologies." Doctoral thesis, Universite Libre de Bruxelles, 2021. https://dipot.ulb.ac.be/dspace/bitstream/2013/318799/4/TOC.pdf.
Повний текст джерелаLe double défi de l'énergie et du changement climatique mettent en avant lanécessité de développer des nouvelles technologies de combustion, étantdonné que les projections les plus réalistes montrent que la plus grandeaugmentation de l'offre d'énergie pour les décennies à venir se fera à partirde combustibles fossiles. Ceci représente donc une forte motivation pour larecherche sur l'efficacité énergétique et les technologies propres. Parmicelles-ci, la combustion sans flamme est un concept nouvellementdéveloppé qui permet d'obtenir des rendements thermiques élevés avecdes économies de carburant tout en maintenant les émissions polluantes àun niveau très bas. L'intérêt croissant pour cette technologie est égalementmotivé par sa grande flexibilité de carburant, ce qui représente uneprécieuse opportunité pour les carburants à faible valeur calorifique, lesdéchets industriels à haute valeur calorifique et les combustibles à based'hydrogène. Etant donné que cette technologie est plutôt récente, elle estde ce fait encore mal comprise. Les solutions d'une application industriellesont très difficiles à transposer à d'autres. Pour améliorer les connaissancesdans le domaine de la combustion sans flamme, il est nécessaire de menerdes études fondamentales sur ce nouveau procédé de combustion afin defavoriser son développement. En particulier, il y a deux différencesmajeures par rapport aux flammes classiques :d’une part, les niveaux deturbulence rencontrés dans la combustion sans flamme sont rehaussés, enraison des gaz de recirculation, réduisant ainsi les échelles de mélange.D'autre part, les échelles chimiques sont augmentées, en raison de ladilution des réactifs. Par conséquent, les échelles turbulentes et chimiquessont du même ordre de grandeur, ce qui conduit à un couplage très fort.Après un examen approfondi de l'état de l'art sur la modélisation de lacombustion sans flamme, le coeur du projet représentera le développementd'une nouvelle approche pour le traitement de l'interaction turbulence /chimie pour les systèmes sans flamme dans le contexte des simulationsaux grandes échelles (Large Eddy Simulations, LES). Cette approche serafondée sur la méthode PCA (Principal Component Analysis) afin d'identifierles échelles chimiques de premier plan du processus d'oxydation. Cetteprocédure permettra de ne suivre sur la grille LES qu'un nombre réduit descalaires non conservés, ceux contrôlant l'évolution du système. Destechniques de régression non-linéaires seront couplées avec PCA afind’augmenter la précision et la réductibilité du modèle. Après avoir été validégrâce à des données expérimentales de problèmes simplifiés, le modèlesera mis à l'échelle afin de gérer des applications plus grandes, pertinentespour la combustion sans flamme. Les données expérimentales etnumériques seront validées en utilisant des indicateurs de validationappropriés pour évaluer les incertitudes expérimentales et numériques.
Doctorat en Sciences de l'ingénieur et technologie
info:eu-repo/semantics/nonPublished
Li, Junshan. "Ni- and Sn-based Colloidal Nanoparticles for Electrochemical Energy Technologies." Doctoral thesis, Universitat de Barcelona, 2019. http://hdl.handle.net/10803/667475.
Повний текст джерелаDijoux, Alexandre. "Influence du fluide du travail, de la technologie des échangeurs et du pilotage dynamique d’un cycle ORC sur l’intérêt et les performances d’un système de conversion d’Énergie Thermique des Mers." Thesis, La Réunion, 2020. http://www.theses.fr/2020LARE0036.
Повний текст джерелаThe temperature difference between the hot surface seawater (of tropical solar origin) and the cold one at depth (which comes from the poles) constitutes a stable, environmentally-friendly and renewable source of energy available in the ocean. This ocean thermal energy conversion (OTEC) can be used to produce electricity by the way of an organic Rankine cycle (ORC). However, the small temperature difference between hot and cold sources represents a technical challenge both for heat transfers and for cycle performances. The objective of this thesis is then to explore the operation improvement possibilities of an ORC applied to OTEC, to complete the knowledge of the system components and to highlight the advantages of this new technology on a non-connected grid such as that of Reunion Island. This work is based both on simulations and on experimental results obtained on a 450 kW thermal energy onshore prototype named PAT ETM. In the first chapter, a new method for the choice of the working fluid is proposed. The study brings out some fluids so far little considered for OTEC. In the second chapter, the experimental tool (the PAT ETM) is presented extensively. The third chapter reports the heat exchanger technologies that have been tested and characterized. The fourth chapter deals with the dynamic modeling of an OTEC system. This study leads to the assessment of the control-lability of a complete power plant and shows a still little explored opportunity: that of using OTEC as a management tool to control an electrical network
Abedini, Amin. "Piezoelectric Energy Harvesting via Frequency Up-conversion Technology." OpenSIUC, 2019. https://opensiuc.lib.siu.edu/dissertations/1716.
Повний текст джерелаYuen, Katarina. "System Aspects of Marine Current Energy Conversion." Licentiate thesis, Uppsala University, Electricity, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-113339.
Повний текст джерелаFree-flowing water currents such as tides and unregulated water courses could contribute to world electricity production given the emergence of robust technical solutions for extracting the energy. At Uppsala University, a concept for converting water currents to electricity using a vertical axis turbine with fixed blade pitch and a direct drive permanentmagnet generator is studied. A system approach is desired, and in this thesis, a first analysis of two system components, the generator and the turbine, is presented. This thesis also deals with some issues concerning the design and construction of a low speed generator for this application. An experimental generator for verification of simulations has been designed and constructed. For the electromagnetic design, a FEM simulation tool has been used. The construction work has given valuable practical experience concerning for example handling permanent magnets and winding the generator with cable. Simulations and measurements of the experimental generator have been carried out for different speeds and loads. The generator can operate at the speeds and loads corresponding to maximum power capture for different turbines for water current velocities between approximately 0.5 and 2.5 m/s. At higher water current velocities the turbines may need to be run at a tip speed ratio that gives a lower power capture in order to limit the electrical currents in the generator, cavitation of the blades, or mechanical loads. Comparisons of measurements and simulations show an agreement. The FEM simulation tool can be used to simulate and design electrical machines with a low electrical frequency, i.e. 2–16 Hz.
Boström, Cecilia. "Electrical Systems for Wave Energy Conversion." Doctoral thesis, Uppsala universitet, Elektricitetslära, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-140116.
Повний текст джерелаFelaktigt tryckt som Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology 727
Alwaer, Ayad Almakhzum Mohamed. "A prototype desalination system using solar energy and heat pipe technology." Thesis, Cape Peninsula University of Technology, 2016. http://hdl.handle.net/20.500.11838/2455.
Повний текст джерелаThe water desalination process needs large quantities of energy, either directly from fossil fuel or electricity from the national grid. However, these sources of energy significantly contribute to problems such as global warming in addition to creating a drain on the economy, due to their high cost. This dissertation is a description of the research undertaken with the aim of producing a water desalination prototype; a novel approach that was designed using state-of-the-art solar water heating equipment, incorporating the technologies of evacuated tubes and heat pipes. During the execution of the project, various modifications to the original commercially-available solar water heating system were attempted, each aimed at increasing the production of pure water. Finally, the system proved capable of producing a reasonable amount of pure water after twelve lengthy indoor experiments conducted in a laboratory in the department of Mechanical Engineering at the Cape Peninsula University of Technology, Bellville Campus, Cape Town, South Africa. Each experiment lasted five days on the basis of seven hours of exposure to an average amount of simulated solar radiation, followed by seventeen hours daily of inactivity and partial cooling down of the system.
Fan, Liangdong. "Development and characterization of functional composite materials for advanced energy conversion technologies." Doctoral thesis, KTH, Kraft- och värmeteknologi, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-134111.
Повний текст джерелаQC 20131122
Augustine, Chad R. "Hydrothermal spallation drilling and advanced energy conversion technologies for Engineered Geothermal Systems." Thesis, Massachusetts Institute of Technology, 2009. http://hdl.handle.net/1721.1/51671.
Повний текст джерелаThis electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Includes bibliographical references.
The purpose of this research was to study the various factors affecting the economic and technical feasibility of Engineered Geothermal Systems, with a special emphasis on advanced drilling technologies. The first part of the thesis was devoted to modeling and analysis of the technologies used to develop EGS projects. Since the cost of completing wells is a major factor in determining the economic feasibility of EGS projects, it is vital to be able to accurately predict in determining the economic feasibility of EGS projects, it is vital to be able to accurately predict their costs. Historic well cost data was analyzed to identify trends, and a drilling cost index for updating historic geothermal well costs to present day costs was developed. The effects of different advanced drilling technologies on drilling costs were estimated and incorporated into a techno-economic model to estimate their impact, as well as the impact of advanced reservoir stimulation technologies, on EGS levelized electricity costs. A technical analysis of geothermal binary Rankine cycle surface power plants was also performed to determine the effect of novel working fluids on plant efficiency for both sub- and supercritical binary cycles. The objective of the second part of the thesis was the application of thermal spallation drilling to deep boreholes. Thermal spallation is the fragmentation of a brittle solid into small, disc-like flakes by rapidly heating a confined fraction of the rock. It was proposed that the necessary temperatures and heat fluxes needed to induce thermal spallation in the high pressure, high density deep borehole environment could be achieved using hydrothermal flame technologies. An autoclave reaction system was designed and constructed to create flame jets in water at a pressure of 250 bar. The temperatures of these flames were measured, and attempts were made to use the flames to spall small rock samples. The experimental system was modified to study the centerline temperature decay of supercritical water jets injected at temperatures up to 525 °C into ambient temperature water. A device for measuring the heat flux from these jets was designed, constructed, and used to determine the heat transfer coefficients of the jets impinging against a flat surface. Together, these studies indicate that the necessary temperatures and heat fluxes required to induce thermal spallation in rocks can be achieved in a deep borehole.
by Chad R. Augustine.
Ph.D.
Kalinauskaitė, Solveiga. "Environmental and energy efficiency evaluation of straw treatment and conversion technology." Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2014. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2014~D_20141223_145125-20389.
Повний текст джерелаTyrimų tikslas. Pagrįsti šiaudų biokuro optimalios sudėties paruošimo ir panaudojimo energinėms reikmėms efektyvumą, atlikti šiaudų biokuro paruošimo technologijos energinį vertinimą ir nustatyti deginimo metu išskiriamas emisijas. Tyrimų uždaviniai. Tyrimų tikslui pasiekti numatyta: 1) Atlikti šiaudų biokuro (briketų ir granulių) paruošimo deginimui technologinę analizę; 2) Pagristi kalkių priedo (CaO) įmaišymo į šiaudų biokuro sudetį tikslingumą; 3) Ištirti pagaminto šiaudų biokuro savybes; 4) Nustatyti ir įvertinti šiaudų biokuro deginimo metu išskiriamas emisijas; 5) Įvertinti šiaudų granulių gamybos technologinės įrangos energijos sanaudas.
Guerrero, Felipe Martinez. "Development of a wave energy basin to maximize wave energy conversion." Thesis, Stellenbosch : Stellenbosch University, 2012. http://hdl.handle.net/10019.1/20241.
Повний текст джерелаThomas, Karin. "Low Speed Energy Conversion from Marine Currents." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-8400.
Повний текст джерелаAfzal, Muhammad. "Nanocomposite Materials for New Energy Conversion Device." Thesis, KTH, Materialvetenskap, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-122675.
Повний текст джерелаDai, Siyang. "OPTIMIZED WTE CONVERSION OF MUNICIPAL SOLID WASTE IN SHANGHAI APPLYING THERMOCHEMICAL TECHNOLOGIES." Thesis, KTH, Industriell ekologi, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-187372.
Повний текст джерелаMahmood, Paracha Ayyaz. "Design and fabrication of Mems-based, vibration powered energy harvesting device using electrostatic transduction." Phd thesis, Université Paris-Est, 2009. http://tel.archives-ouvertes.fr/tel-00584339.
Повний текст джерелаZoric, I. "Multiple three-phase induction generators for wind energy conversion systems." Thesis, Liverpool John Moores University, 2018. http://researchonline.ljmu.ac.uk/8387/.
Повний текст джерелаClick, Kevin A. "Design and Synthesis of Organic Dyes for Solar Energy Conversion and Storage." The Ohio State University, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=osu1492448144094887.
Повний текст джерелаLakkala, A. (Aleksi). "Biomass-based energy carriers in iron and steel industry:techno-economic assessment of thermochemical conversion technologies." Bachelor's thesis, University of Oulu, 2017. http://urn.fi/URN:NBN:fi:oulu-201702221173.
Повний текст джерелаRauta- ja terästuotannon aiheuttamat kasvihuonepäästöt ovat merkittävä osa maailman kokonaiskasvihuonepäästöistä. Kandidaatintyön tavoitteena on vertailla eri biopolttoaineita, joilla olisi mahdollista korvata prosessissa käytettäviä fossiilisia polttoaineita. Vertailu tapahtuu pääosin tuotantokustannuksien ja -teknologioiden näkökulmista. Työssä käytetyt tiedot on koottu vuonna 2005 ja sen jälkeen julkaistuista bioenergiaa ja -polttoaineita koskevista artikkeleista. Biopolttoaineita vertaillessa on otettu huomioon niiden valmistuksessa käytettävät raaka-aineet, tuotantokapasiteetti, tuotantoteknologia, sijainti, perusvuosi ja tuotantokustannukset. Jokainen työssä käsitelty biopolttoaine on myös analysoitu tarkemmin omassa luvussaan. Tiedot ovat lopuksi taulukoitu helpompaa vertailua varten. Vaihtoehtojen valmistuskustannuksia on myös pyritty yhtenäistämään taulukossa. Tuloksista voidaan todeta tarkasteltavien biopolttoaineiden olevan pääsääntöisesti taloudellisesti kannattamattomia verrattuna rauta- ja terästeollisuudessa käytössä oleviin fossiilisiin polttoaineisiin. Biopelkistimien saaman kasvavan huomion voidaan kuitenkin olettaa tuovan uusia valmistusmenetelmiä sekä mahdollisuuksia niiden hyödyntämiselle tulevaisuuden teollisuudessa korvaten fossiilisten polttoaineiden käyttöä, samalla kasvihuonepäästöjä pienentäen
Reason, Joseph P. "A comparative study of nuclear technology and direct energy conversion methods for space power systems." Monterey, California. Naval Postgraduate School, 1997. http://hdl.handle.net/10945/8110.
Повний текст джерелаZeng, Liang. "Multiscale Study of Chemical Looping Technology and Its Applications for Low Carbon Energy Conversions." The Ohio State University, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=osu1354722135.
Повний текст джерелаReid, Patrick Earl Fitzgerald. "The integration of solid oxide fuel cell technology with industrial power generation systems." Thesis, Georgia Institute of Technology, 2000. http://hdl.handle.net/1853/18947.
Повний текст джерелаOpazo, Jose. "The politics of system innovation for emerging technologies : understanding the uptake of off-grid renewable electricity in rural Chile." Thesis, University of Sussex, 2014. http://sro.sussex.ac.uk/id/eprint/54509/.
Повний текст джерелаJones, Gavin Wesley. "Distribution system operation and planning in the presence of distributed generation technology." Diss., Rolla, Mo. : University of Missouri-Rolla, 2007. http://scholarsmine.umr.edu/thesis/pdf/Jones_09007dcc803b193d.pdf.
Повний текст джерелаVita. The entire thesis text is included in file. Title from title screen of thesis/dissertation PDF file (viewed November 16, 2007) Includes bibliographical references (p. 71-74).
Todeschini, Grazia. "Wind Energy Conversion Systems based on DFIG Technology used as Active Filters: Steady-State and Transient Analysis." Digital WPI, 2010. https://digitalcommons.wpi.edu/etd-dissertations/97.
Повний текст джерелаMilad, Muftah A. "UPS system : how current and future technologies can improve energy efficiency in data centres." Thesis, Brunel University, 2017. http://bura.brunel.ac.uk/handle/2438/14664.
Повний текст джерелаEriksson, Mikael. "Modelling and Experimental Verification of Direct Drive Wave Energy Conversion : Buoy-Generator Dynamics." Doctoral thesis, Uppsala universitet, Elektricitetslära, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-7785.
Повний текст джерелаLindroth, [formerly Tyrberg] Simon. "Buoy and Generator Interaction with Ocean Waves : Studies of a Wave Energy Conversion System." Doctoral thesis, Uppsala universitet, Elektricitetslära, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-160085.
Повний текст джерелаMaaroufi, Seifeddine. "Conception et réalisation d’un banc pour l’étude de fiabilité des micros dispositifs piézoélectriques de récupération d’énergie dédiés aux implants cardiaques." Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLS187/document.
Повний текст джерелаWithin the framework of this PhD we present the design and realization of a bench dedicated to the study of the reliability of piezoelectric structures and more precisely micro-devices of energy harvesting for the new generation of active and autonomous medical implants. The structures studied are in the form of a free-clamped piezoelectric bimorph having a seismic mass at their tip. A good understanding of the aging of the materials and of the mechanical and electrical failure modes is essential for this type of system where the life of the patient implanted by this device is directly involved. To study the reliability and durability of the active part of the harvester, we propose to establish a new accelerated aging methodology via a dedicated test bench where the environment and stimuli can be controlled accurately over a large period of time. An electromechanical characterization of the structures is periodically carried out by the extraction of a series of indicators (blocking force, stiffness, tension in harmonic regime) within the bench throughout the aging process. Therefore it is possible to identify the different potential failure modes and to study their impact on the proper functioning of the system
Lundqvist, Alexander. "Future development of bioenergy in South Africa : A study of increased use of available biomass for the future development of renewable energy in South Africa." Thesis, Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-48919.
Повний текст джерелаRitter, Philipp. "Design and optimization of high speed flash analog-to-digital converters in SiGe BiCMOS technologies." Thesis, Lyon, INSA, 2013. http://www.theses.fr/2013ISAL0052.
Повний текст джерелаHigh speed Analog-to-Digital Converters (ADC) are essential building blocks for the reception and processing in high data rate reception circuits. The flash ADC archi- tecture performs the digitization by comparing the analog input signal to all refer- ence levels of the quantization range simultaneously and is thus the fastest architecture available. In the past the flash architecture has been employed successfully to digitize signals at Nyquist rates beyond 20 GS/s. However the inherent high speed operation has led to power consumptions of several watts and hence to poor energy efficien- cies. This thesis explores approaches to optimize the energy efficiency of flash ADCs. In particular, no dedicated track-and-hold stage is used at the high speed data input. This imposes very stringent requirements on the timing accuracy and level accuracy in the high speed signal distribution to the comparators. The comparators need to ex- hibit a very high speed capability to correctly perform the quantization of the signal against the reference levels. The main focus of this thesis is hence the investigation of design relevant high frequency effects in the analog ADC frontend, such as the bandwidth requirement of overdriven comparators, the data signal distribution over a passive transmission line tree and the dynamic linearity of emitter followers. The correctness and efficacy of the presented methods is demonstrated by measurement results of a 6 bit 20 GS/s Nyquist rate flash ADC fabricated within the context of this work. The demonstrator ADC operates without time interleaving, no calibration or correction whatsoever is needed. By employing design techniques borrowed from high speed analog circuits engineering and by exhausting the high speed potential of a state-of-the-art SiGe BiCMOS production technology, a flash ADC with a record energy efficiency could be realized
Ekren, Orhan Özerdem Barış. "Optimization of a hybrid combination of a photovoltaic syste and a wind energy conversion system: İzmir Institute of technology campus area case/." [s.l.]: [s.n.], 2003. http://library.iyte.edu.tr/tezler/master/enerjimuh/T000279.rar.
Повний текст джерелаSalamon, Natalia. "Développement de systèmes de récupération d’énergie thermique." Thesis, Université Grenoble Alpes (ComUE), 2018. http://www.theses.fr/2018GREAI011/document.
Повний текст джерелаThe goal of the present work was to design and fabricate a fully silicon oscillating device that converts thermal energy into electricity, applying phenomena of liquid to gas phase-change and piezoelectricity. It should be characterized by simplicity of construction, small size, and ease of manufacture. The diameter should not exceed 2 cm, while the thickness should be within 2 mm.The device was composed of three Si wafers comprising evaporation and condensing chambers, and the channel connecting these two elements. A PZT-based transducer mounted on top of the structure was applied to ensure energy conversion.The design process included the establishment of the device geometry, the type of the working fluid enclosed inside the system, a type, size and assembly technique of a piezoelectric element, as well as a bonding method of several silicon elements of the device.The practical realization of the designed prototypes was aimed at selecting the most suitable technological processes for structure fabrication. All the experiments had been performed in a clean room environment and employed wet oxidation, photolithography, a well-known, easily available wet chemical etching in KOH solution, and a silicon bonding technique with the use of SU-8 photoresist as an intermediate layer. Additionally, during the practical work a few tools have been designed and developed to enhance the device fabrication, amongst which a vacuum pump dedicated to bond the three silicon wafers as structural elements of the prototypesThe fabricated prototypes were tested in terms of oscillation mechanism and electrical properties. The influence of the filling ratio and the hot temperature value on the generated signal was established. Additionally, the power range of the prototypes has been evaluated. In the last part of the study, optimization steps for the devices developed in the present work have been proposed
Hoffmann, Viola [Verfasser]. "Conductive advanced carbon materials from biomass for the application in energy storage and conversion technologies (Electrochemical Double-Layer Capacitors and Direct Carbon Fuel Cells) / Viola Hoffmann." Düren : Shaker, 2020. http://d-nb.info/1222396181/34.
Повний текст джерелаMorse, Anthony T. "The transfer of oil and gas technology skills to the conceptual design and development of a novel low cost modular Tidal Energy Conversion deployment system." Thesis, Robert Gordon University, 2011. http://hdl.handle.net/10059/798.
Повний текст джерелаБухкало, Світлана Іванівна. "Моделювання процесів інноваційних енерготехнологій утилізації полімерів". Thesis, Одеська національна академія харчових технологій, 2017. http://repository.kpi.kharkov.ua/handle/KhPI-Press/31203.
Повний текст джерелаSome features of the possibilities of solving evidence-based problems of improving the use of wastes of different industries on a complex enterprise that can provide all its energy needs alone. The problem of wastes utilization and recycling is present as complex research and analysis of energy- and resource saving processes for treatment of polymer wastes of various origin. The research focused on the study of issues such as the development of models of waste-modifying polymer. The investigation are focused in researching such problems as selection of scientific based methods of wastes to be utilized or recycled; the development of appropriated process flow sheets and choice of modifications additives and equipment for polymers waste recycling. The choice of appropriate plants with selected energy resources is very important for projects realization.
Raji, Atanda Kamoru. "Performance evaluation and improvement of grid-connected technology." Thesis, Cape Peninsula University of Technology, 2012. http://hdl.handle.net/20.500.11838/1198.
Повний текст джерелаThe confluence of the limited resources of fossil fuels (e.g. coal, oil and natural gas), environmental degradations leading to climate change, security of supplies and fossil fuels high costs have demanded a tremendous efforts on humanity to seek for a sustainable and unlimited natural energy sources. Amongst these renewable energy sources stands out solar energy because of its ubiquitousness. Solar energy is converted to DC electricity by the photovoltaic effect. Photovoltaic (PV) power systems installed in commercial and industrial buildings are a good example of distributed power generation. Here the energy consumption and production match and thus electricity taken from the grid during daytime peak hours can be reduced. This is beneficial as the transmission losses in the grid are avoided and also transmission need is reduced. The cost effectiveness of a solar energy system has hindered its wide adoption and deployment in terms of the initial capital cost even though it has a zero energy cost and very minimal operating and maintenance costs. Different governments have instituted many financial incentives for fast adoption of PV systems for both residential and commercial applications. However, all these incentives are not sustainable in the longer term forecast. For PV system to attain grid parity requires more than unsustainable approach of many governments providing time limited subsidies. The technical solution to the problem is to reduce the overall system cost through technical innovations. One such method is the adoption of transformerless inverter technology as the grid interface system. Transformerless inverter topology provides galvanic isolation through innovative inverter topology and switching strategies that eliminates problems created by not employing the service of transformer.
Strübing, Dietmar [Verfasser], Jörg E. [Akademischer Betreuer] Drewes, Jörg E. [Gutachter] Drewes, Largus T. [Gutachter] Angenent, and Lars D. M. [Gutachter] Ottosen. "H2/CO2 biomethanation in anaerobic thermophilic trickle bed reactors - Development of a flexible and efficient energy conversion technology / Dietmar Strübing ; Gutachter: Jörg E. Drewes, Largus T. Angenent, Lars D. M. Ottosen ; Betreuer: Jörg E. Drewes." München : Universitätsbibliothek der TU München, 2020. http://d-nb.info/1212178165/34.
Повний текст джерелаSancho, Navarro Silvia. "Biomethanation of syngas: identification of metabolic pathways from CO in a natural anaerobic consortium." Thèse, 2012. http://hdl.handle.net/1866/8636.
Повний текст джерелаSyngas produced through the thermal gasification of biomass for energy recovery has received increased attention in the past decades due to its higher efficiency compared to other bioenergy processes. The gas components of syngas, CO and H2, can serve as substrates for the conversion of desirable chemicals and fuels, namely methane, by a wide range of microorganisms. Meanwhile, anaerobic wastewater-treating sludges have been reported as good sources of carboxidotrophic microorganisms which can be exploited for methane production. Thus it is important to investigate existing methanogenic consortiums which, in syntrophy, are able to convert syngas into useful fuels. This study is mainly focused on the assessment of the carboxidotrophic methanogenic potential present in a natural consortium of microorganisms from a UASB reactor and the identification of CO conversion routes to methane under mesophilic temperatures. To achieve this, a series of kinetic-activity tests with the anaerobic sludge were performed under CO partial pressures varying from 0.1 to 1.65 atm (0.09-1.31 mmol/L) in both the presence and absence of specific metabolic inhibitors. The non-adapted sludge presented an interesting carboxidotrophic activity potential for growing conditions on CO alone. Inhibition experiments with 2- bromoethanesulfonic acid (BES) and vancomycin showed that CO was converted mainly to acetate by acetogenic bacteria, which was further transformed to methane by acetoclastic methanogens. Moreover, it was possible to achieve higher methanogenic potential under 100% CO by acclimation of the sludge. This adaptation led to a shift in the microbial population predominated by hydrogenophilic methanogens. This suggests a possible enrichment potential with anaerobic biofilms for large scale methane production from CO-rich syngas, and further advances the knowledge base for anaerobic reactor development.
(9780230), Sharmina Begum. "Assessment of alternative waste technologies for energy recovery from solid waste in Australia." Thesis, 2016. https://figshare.com/articles/thesis/Assessment_of_alternative_waste_technologies_for_energy_recovery_from_solid_waste_in_Australia/13436876.
Повний текст джерелаVerissimo, Nuno Rafael Miranda. "Desenvolvimento e Validação Experimental de uma Solução de Pavement Energy Harvesting para Conversão da Energia Cinética de Pessoas em Energia Elétrica." Master's thesis, 2020. https://hdl.handle.net/10216/128312.
Повний текст джерелаVerissimo, Nuno Rafael Miranda. "Desenvolvimento e Validação Experimental de uma Solução de Pavement Energy Harvesting para Conversão da Energia Cinética de Pessoas em Energia Elétrica." Dissertação, 2020. https://hdl.handle.net/10216/128312.
Повний текст джерела