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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
161

Metodologia de especificação e projeto aplicado a usinas nucleares móveis / Specification and design methodology applied to mobile nuclear power plants

Freire, Luciano Ondir 08 October 2018 (has links)
A importância de métodos de projeto vem crescendo nos últimos anos à medida que sistemas sócio-técnicos complexos se tornam mais numerosos. Além da complexidade, o tamanho e o investimento financeiro destes sistemas amplificam a gravidade dos erros de projeto. O objetivo geral deste trabalho foi desenvolver uma metodologia de especificação e projeto que reduza o tempo e energia para desenvolver um sistema complexo cujas funções sejam conhecidas a priori, gerenciando em paralelo os riscos. O objetivo específico foi verificar a viabilidade econômica de usinas nucleares móveis de pequeno porte. Este trabalho adotou como princípio a lei construtal que prevê o sucesso de sistemas que facilitem os fluxos necessários à sua existência. Após a identificação dos fatores chave para facilitar o fluxo de informações, esta tese desenvolveu um conjunto de conceitos para facilitar o trabalho de engenharia. Aplicando tais conceitos, este trabalho desenvolveu sequências de atividades que descrevem o método proposto, sendo cada atividade detalhada por uma lista de requisitos. A demonstração das vantagens do método proposto foi feita por meio de análise de árvore de eventos e árvore de falhas. Usando o método, esta tese desenvolveu especificações e projetos em vários níveis (empresarial, usina, caldeira nuclear, circuito primário e gerador de vapor). Baseando-se em dados da marinha americana, esta tese desenvolveu um modelo de custo para reatores de pequeno porte. Concluiu que a energia nuclear pode ser competitiva se a potência elétrica média efetiva ao longo da vida útil ficar acima de 30MWe e se o tempo de vida útil for igual ou maior do que 60 anos. Tal fato decorre dos altos custos de aquisição que requerem uma vida longa para compensar o investimento e dos efeitos de economia de escala especialmente pronunciados para reatores a água pressurizada. / The importance of design methodologies has been growing in recent years as complex socio-technical systems become more common. In addition to complexity, the size and financial investment of these systems amplifies the severity of design errors. The general goal of this work was to develop a specification and design methodology that reduces the time and energy to develop a complex system whose functions are known a priori, managing the risks in parallel. The specific goal was to verify if small modular reactors could be economically possible. This work adopted as principle the Constructal law, that predicts the success of systems that ease the necessary flows to its existence. After finding the key factors to ease the flow of information, this work developed a set of concepts to ease the engineering work. Applying such concepts, this work developed sequences of activities that describe the proposed methodology. Lists of requirements gave guidance for each activity. Event tree and fault tree analyses showed the advantages of the proposed methodology. Using the methodology, this work developed specifications and designs at many product breakdown levels (enterprise, nuclear power plant, nuclear steam supply system, reactor coolant system and steam generator). Using data from US Navy, this work developed a cost model for small reactors. This work concluded that nuclear power may be competitive if average electrical power extracted during the life is larger than 30 MWe and if life time is superior to 60 years. The first condition is consequence of the high overnight costs of nuclear power. The second is consequence of the strong scale economy effects of pressurized water reactors.
162

Fully FPGA-based Sensorless Control for synchronous AC drive using an Extended Kalman Filter / Fully FPGA-based Sensorless Control for synchronous AC drive using an Extended Kalman Filter

Idkhajine, Lahoucine 24 November 2010 (has links)
L'objectif du travail réalisé dans le cadre de cette thèse est de montrer l'intérêt d'utiliser les FPGAs (Field Programmable Gate Array) comme support pour l'implantation d'algorithmes complexes dédiés à la commande de machines électriques. Pour ce faire, une commande sans capteur mécanique utilisant un filtre de Kalman étendu et basée sur FPGA est réalisée. Cette commande est destinée à piloter une machine synchrone à pôles saillants. Le modèle d-q de la machine basé sur l'approximation d'inertie infinie est implanté. L'ordre du Filtre de Kalman est donc égal à 4 et la complexité totale de la boucle de régulation est évaluée à près de 700 opérations arithmétiques (dont plus de 53% de multiplications). Les apports des solutions FPGAs en termes de performances de contrôle et en termes de capacité d'intégration sont quantifiés.En terme de performances de contrôle, il a été démontré qu'en utilisant de telles solutions matérielles, le temps de calcul est très réduit (de l'ordre de 5µs, 5% de la période d'échantillonnage). Cette rapidité de calcul permet d'avoir un contrôle quasi-instantané ce qui améliore la bande passante de la boucle de régulation. A ce sujet, une comparaison avec les performances obtenues avec une solution logicielle telle que le DSP est effectuée. Dans les deux cas, le comportement dynamique de la boucle de régulation s de vitesse ans capteur est quantifié.En termes de capacité d'intégration, il est possible de développer une architecture commune qui peut être adaptée à plusieurs systèmes. A titre d'exemple, il est possible de développer un filtre de Kalman sur un même FPGA capable d'estimer les grandeurs de plusieurs systèmes sans pour autant affecter les performances de contrôle. En outre, une méthodologie de développement dédiée à de tels algorithmes complexes est proposée. Il s'agit là d'une adaptation des méthodologies proposées dans des travaux de thèse précédents, [62] et [63]. En effet, une étape de spécification préliminaire du système ainsi que des procédures d'optimisation supplémentaires y sont introduites. Ces dernières sont particulièrement nécessaires dans le cas de commandes complexes et permettent une adéquation entre l'algorithme développé et l'architecture FPGA correspondante. De plus, cette méthodologie a été organisée de façon à distinguer l'étape du développement de l'algorithme et l'étape du développement de l'architecture FPGA. Un état de l'art sur les technologies FPGA est également proposé. La structure interne des FPGAs récents est décrite. Leur contribution dans le domaine de la commande des machines électriques est quantifiée. Les différentes étapes de la méthodologie de développement sont présentées. Le développement d'une commande numérique (basée sur FPGA) d'une machine synchrone à aimant permanent associée à un capteur de position Resolver est par la suite traité. Cette application s'inscrit dans un contexte avionique où l'objectif était d'avoir une solution FPGA hautement intégrée. Pour ce faire, le FPGA Actel Fusion est utilisé. Ce composant intègre un convertisseur analogique numérique. La commande, le traitement des signaux Resolver ainsi que la conversion analogique numériques sont implantés sur le même composant.En ce qui concerne la commande sans capteur basée sur le filtre de Kalman étendu, il a été décidé de structurer les chapitres correspondants à travers la méthodologie de développement proposée. Ainsi, la phase de spécification préliminaire du système, la phase du développement de l'algorithme, la phase du développement de l'architecture FPGA et la phase d'expérimentation sont séparément traitées. Durant la phase d'expérimentation, la procédure «Hardware-In-the-Loop (HIL)» est incluse afin de valider le fonctionnement de l'architecture développée une fois la phase d'implantation physique achevée. / The aim of this thesis is to present the interest of using Field Programmable Gate Array (FPGA) devices for the implementation of complex AC drive controllers. The case of a sensorless speed controller using the Extended Kalman Filter (EKF) has been chosen and applied to a Salient Synchronous Machine (SSM). The d-q model based on the infinite inertia hypothesis has been implemented. The corresponding EKF order is then equal to 4 and the complexity of the whole sensorless controller is equal to 700 arithmetic operations (more than 53% of multiplications). The contribution of FPGAs in this field has been quantified in terms of control performances and in terms of system integration. In terms of control performances, the proposed FPGA-based solution ensures a short execution time which is around 5µs (5% of the sampling period). This treatment fastness ensures a quasi-instantaneous control which improves the control bandwidth. To this purpose, a comparison with a software DSP-based solution is made. The dynamic behavior and the influence of the execution time, in both cases, on the control bandwidth have been quantified. In terms of integration capacity, it is possible to implement a generic FPGA architecture that can be adapted to the control of several systems. Thus, it is possible to develop a common EKF architecture that is able to estimate variables from many systems without affecting the control performances.In addition, a design methodology adapted to such complex controllers has been proposed. The particularity of this updated methodology, compared to the previous ones ([62], [63]), is to provide an enlarged set of steps starting from the preliminary system specification to the ultimate experimentation. Optimization procedures have also been introduced. These optimizations are necessary in case of complex controllers and lead to the adequation between the developed algorithm and the corresponding hardware FPGA architecture. A state of the art FPGA technology is also presented. The internal structure of the recent devices and their corresponding technology are discussed. Their contribution in the field of AC drive applications is quantified. An in-depth presentation of the proposed design methodology is made.Besides, the development of a fully integrated FPGA-based controller for a Permanent Magnet Synchronous Machine (PMSM) associated with a Resolver sensor is presented. This controller has been developed in for an aircraft application where the main objective was to develop a fully integrated FPGA solution. The Actel Fusion FPGA device has been used. This device integrates an Analog to Digital Converter (ADC). The current controller, the Resolver Processing Unit (RPU) and the analog to digital conversion are implemented within the same device. When it comes to the sensorless controller, the corresponding chapters have been structured according to the presented design methodology: the preliminary system specification, the algorithm development, the FPGA architecture development and finally the experimentation. The latter includes Hardware-In-the-Loop (HIL) tests and the final experimental validation.
163

Metodologia para projeto, construção e ensaios em máquina síncrona de imã permanente - MSIP / Methodology for design, construction and testing on permanent magnet synchronous machine - PMSM

Fernando Henrique Pisani Teixeira 18 August 2006 (has links)
A grande aplicação residencial de motores de indução monofásicos é em sistemas de refrigeração doméstica/comercial. O desenvolvimento de motores mais eficientes, associado ao controle de velocidade, fez com que, dentro os mais diversos tipos de motores, o motor síncrono de imã permanente tornasse objeto para a criação de uma metodologia de projeto, construção e realização de ensaios. Assim, para adequar o projeto do motor MSIP para substituição do motor de indução monofásico, foram feitos estudos de como aproveitar as laminações já existentes, através de definições das características básicas do estator e do rotor. O imã permanente a ser utilizado foi definido principalmente em função do custo do material e de suas propriedades magnéticas estarem adequadas à necessidade do projeto. O projeto magnético foi feito para maximizar o fluxo nos dentes, considerando as características construtivas e a curva de trabalho dos imãs. O projeto elétrico, a partir de um circuito equivalente do motor, permitiu explicar as relações de torque, corrente e tensão do motor MSIP, bem como a definição das bobinas do motor, quanto ao espaçamento destas entre as ranhuras, o cálculo do número de espiras e o diâmetro dos fios em função da área permitida pela ranhura da lamina do estator. Com as informações obtidas após o cálculo do motor MSIP, passou-se a construção de um protótipo constituído pelo estator, rotor e um sistema de suporte que permitisse o levantamento dos parâmetros do motor. Os parâmetros necessários foram definidos levando-se em consideração a necessidade para o projetista do conversor elétrico, sendo estes dados utilizados em simulações computacionais para a determinação do projeto do acionador. Com isto, os ensaios do motor MSIP permitiram o levantamento dos seguintes parâmetros: resistência, indutância, curvas de tensão de fase e linha da eletromotriz por velocidade em diversas rotações, momento de inércia e atrito viscoso, concluindo assim a proposta deste trabalho, e finalizando a metodologia para o motor MSIP. / A major residential application of single-phase induction motors is in domestic refrigeration. The development of more efficient motors, associated with speed control, has made that, among the most diverse types of electrical motors, the permanent magnet synchronous machine becomes an object of study for a design, construction and testing methodology. Therefore, to suit the PMSM design to replace the single phase induction motor, studies were made on how to take advantage of existing laminations, through definitions of the basic characteristics of the stator and rotor. The permanent magnet used was defined mainly as a function of the cost of the material and its magnetic properties since they suit the design requirements. PMSM magnetic design was made to maximize the magnetic flow in the slots considering the constructive characteristics and the magnet curve. The electric design, starting from a motor equivalent circuit, allowed to explain torque, current and voltage of the PMSM motor, as well as the definition of the motor windings regarding their filling in the slots, the calculation of coil number and the wire diameter as a function of the area allowed by the stator lamination slot. With the information obtained after the PMSM motor calculation, a prototype construction was initiated consisting of the stator, rotor and a support system to allow determining the motor parameters. The required parameters were defined taking into account the need the designer had of an electronic drive had. This data was used in computational simulations to determine the electronic driver design. After this, the motor testing allowed to identify the parameters, namely: winding resistance and inductance, various speed curves versus phase to phase and line voltage for back emf´s, moment of inertia and viscous friction, thus completing this work proposal, finalizing the project methodology for PMSM motor.
164

Os espaços experimentais das escolas públicas de arquitetura do Brasil: realidade ou utopia? / The experimental workspaces in public schools of architecture in Brazil: reality or utopia?

Albenise Laverde 23 June 2017 (has links)
Esta tese está inserida no debate sobre a utilização da experimentação construtiva ao longo da concepção da materialidade e seu papel como recurso pedagógico. Trata mais especificamente, dos espaços e práticas experimentais no contexto acadêmico nacional, objetivando compreender o processo de configuração dos espaços da área técnico-construtiva implantados nas escolas públicas de arquitetura de acordo com as particularidades advindas de diferentes contextos do país, das políticas educacionais e das ações dos atores envolvidos, com a identificação das condições essenciais para que estas práticas sejam implantadas e potencializadas no contexto acadêmico. O trabalho foi desenvolvido a partir de pesquisas documentais e por meio de visitas técnicas realizadas em 21 escolas públicas de arquitetura localizadas em diferentes regiões do país, com entrevistas direcionadas aos principais atores que atualmente estão à frente da área da Tecnologia da Construção. O trabalho trouxe contribuições de ordem teórica a partir da sistematização de uma bibliografia abrangente sobre um tema pouco estudado no contexto nacional. Quanto às contribuições de ordem prática, os dados obtidos nas visitas técnicas possibilitaram contextualizar os desafios enfrentados no ensino da Tecnologia da Construção, que não se resumem ao arranjo físico laboratorial, mas a uma dimensão mais ampla, abrangendo aspectos político-educacionais, estruturais e sócio-econômicos e também, questões de fundo, como as relações interpessoais e burocráticas. Estes resultados permitiram identificar as condições consideradas como essenciais na (re)formulação de estratégias voltadas à área da Tecnologia da Construção e sua infraestrutura, de maneira que as experiências existentes possam ser potencializadas e novas implantações tenham maior respaldo técnico de acordo com as particularidades contextuais. / This thesis is inserted in the debate about the use of experimentation in building along with the conception of materiality and its role as pedagogical resource. It approaches, more specifically, the experimental workspaces and practices in the Brazilian academic context. It aims to understand the process of shaping the workspaces of the technology and construction fields established in public schools of architecture according to the singularities from different contexts of the country, educational policies and activities of the actors involved, identifying the essential conditions for those practices to be implemented and strengthened in the academic context. The work was developed based on documentary research and through technical visits in 21 public schools of architecture located in different regions of the country, with interviews directed to the main actors who are currently in charge of the field of Technology of Construction. In relation to the practical contributions, the data obtained in the technical visits made it possible to contextualize the challenges faced in the education of Technology of Construction. These challenges are not limited to the physical arrangement of the laboratory; they embrace a broader dimension, covering education politics, structural and socioeconomic aspects and, still, background issues such as interpersonal relations and bureaucracy. These results enabled the identification of conditions considered essential in the (re) formulation of strategies directed to the field of Technology of Construction and its infrastructure, so that the existing experiences can be strengthened and new applications can have a greater technical support according to the contextual singularities.
165

Estudo do conversor D : an?lises qualitativa e quantitativa, crit?rios de dimensionamento e modelagem em espa?o de estados

Dutra, S?lvio Cesar Antunes 31 August 2018 (has links)
Submitted by PPG Engenharia El?trica (engenharia.pg.eletrica@pucrs.br) on 2018-10-31T13:57:50Z No. of bitstreams: 1 SILVIO CESAR ANTUNES DUTRA_DIS.pdf: 2550584 bytes, checksum: 3dae5cef4ef20b66d5c7a4db79ae5cad (MD5) / Approved for entry into archive by Sheila Dias (sheila.dias@pucrs.br) on 2018-11-01T11:50:43Z (GMT) No. of bitstreams: 1 SILVIO CESAR ANTUNES DUTRA_DIS.pdf: 2550584 bytes, checksum: 3dae5cef4ef20b66d5c7a4db79ae5cad (MD5) / Made available in DSpace on 2018-11-01T12:00:28Z (GMT). No. of bitstreams: 1 SILVIO CESAR ANTUNES DUTRA_DIS.pdf: 2550584 bytes, checksum: 3dae5cef4ef20b66d5c7a4db79ae5cad (MD5) Previous issue date: 2018-08-31 / Power converters are widely used in the context of power electronics. In the same way that transformers have a fundamental role in applications involving AC circuits, power converters modify voltage magnitudes in DC circuits. These devices can either present an output voltage higher than the input voltage, acting as a Boost converter, or lower, acting, in this case, as a Buck converter. The input and output signals can also present either a voltage source or a current source behavior, depending on the topology. This work presents a systematic study of the D converter operating in the continuous conduction mode, in permanent regime, including the qualitative and quantitative analyzes, resulting in a methodology of dimensioning of the converter, as well as its modeling in space of states, which makes feasible studies of control strategies for it. Although this is not a new topology, this converter has recently been reintroduced due to its ability to increase efficiency in the energy conversion process, especially in photovoltaic systems. However, this research is fully justified given the lack of similar work for the D converter topology. This study was validated from tests performed in the PSIM simulation software, in addition to MATLAB / SIMULINK. A laboratory prototype was specially constructed for validation purposes in a rapid prototyping platform, as well as the consequent implementation in a PCI, for use in future works. / Os conversores est?ticos s?o amplamente utilizados no contexto da eletr?nica de pot?ncia. Da mesma forma que os transformadores t?m papel fundamental nas aplica??es que envolvem circuitos alimentados em corrente alternada, os conversores est?ticos realizam a transforma??o de magnitudes de tens?o em circuitos de corrente cont?nua. Tais dispositivos podem tanto apresentar em sua sa?da um valor de tens?o superior em rela??o ao sinal de entrada, atuando como elevadores, quanto inferior, atuando, neste caso, como redutores. Estes tamb?m podem apresentar suas sa?das ou entradas com um comportamento de fonte de tens?o ou corrente, dependendo da topologia utilizada. Este trabalho apresenta um estudo sistematizado do conversor D operando no modo de condu??o cont?nua, em regime permanente, incluindo as an?lises qualitativa e quantitativa, resultando em uma metodologia de dimensionamento do conversor, bem como a sua modelagem em espa?o de estados, o que viabiliza estudos de estrat?gias de controle para o mesmo. Apesar de n?o se tratar de uma nova topologia, recentemente este conversor foi reintroduzido, devido a sua capacidade de aumentar a efici?ncia no processo de convers?o de energia, especialmente em sistemas fotovoltaicos. Esta pesquisa encontra justificativa dada a inexist?ncia de trabalhos semelhantes especificamente para a topologia do conversor D. Este estudo foi validado a partir de ensaios realizados no software de simula??o PSIM, al?m do MATLAB/SIMULINK. Um prot?tipo de laborat?rio foi especialmente constru?do para fins de valida??o em uma plataforma de prototipagem r?pida, bem como a consequente implementa??o do mesmo em uma PCI, para utiliza??o em trabalhos futuros.
166

Metodologia para projeto, construção e ensaios em máquina síncrona de imã permanente - MSIP / Methodology for design, construction and testing on permanent magnet synchronous machine - PMSM

Teixeira, Fernando Henrique Pisani 18 August 2006 (has links)
A grande aplicação residencial de motores de indução monofásicos é em sistemas de refrigeração doméstica/comercial. O desenvolvimento de motores mais eficientes, associado ao controle de velocidade, fez com que, dentro os mais diversos tipos de motores, o motor síncrono de imã permanente tornasse objeto para a criação de uma metodologia de projeto, construção e realização de ensaios. Assim, para adequar o projeto do motor MSIP para substituição do motor de indução monofásico, foram feitos estudos de como aproveitar as laminações já existentes, através de definições das características básicas do estator e do rotor. O imã permanente a ser utilizado foi definido principalmente em função do custo do material e de suas propriedades magnéticas estarem adequadas à necessidade do projeto. O projeto magnético foi feito para maximizar o fluxo nos dentes, considerando as características construtivas e a curva de trabalho dos imãs. O projeto elétrico, a partir de um circuito equivalente do motor, permitiu explicar as relações de torque, corrente e tensão do motor MSIP, bem como a definição das bobinas do motor, quanto ao espaçamento destas entre as ranhuras, o cálculo do número de espiras e o diâmetro dos fios em função da área permitida pela ranhura da lamina do estator. Com as informações obtidas após o cálculo do motor MSIP, passou-se a construção de um protótipo constituído pelo estator, rotor e um sistema de suporte que permitisse o levantamento dos parâmetros do motor. Os parâmetros necessários foram definidos levando-se em consideração a necessidade para o projetista do conversor elétrico, sendo estes dados utilizados em simulações computacionais para a determinação do projeto do acionador. Com isto, os ensaios do motor MSIP permitiram o levantamento dos seguintes parâmetros: resistência, indutância, curvas de tensão de fase e linha da eletromotriz por velocidade em diversas rotações, momento de inércia e atrito viscoso, concluindo assim a proposta deste trabalho, e finalizando a metodologia para o motor MSIP. / A major residential application of single-phase induction motors is in domestic refrigeration. The development of more efficient motors, associated with speed control, has made that, among the most diverse types of electrical motors, the permanent magnet synchronous machine becomes an object of study for a design, construction and testing methodology. Therefore, to suit the PMSM design to replace the single phase induction motor, studies were made on how to take advantage of existing laminations, through definitions of the basic characteristics of the stator and rotor. The permanent magnet used was defined mainly as a function of the cost of the material and its magnetic properties since they suit the design requirements. PMSM magnetic design was made to maximize the magnetic flow in the slots considering the constructive characteristics and the magnet curve. The electric design, starting from a motor equivalent circuit, allowed to explain torque, current and voltage of the PMSM motor, as well as the definition of the motor windings regarding their filling in the slots, the calculation of coil number and the wire diameter as a function of the area allowed by the stator lamination slot. With the information obtained after the PMSM motor calculation, a prototype construction was initiated consisting of the stator, rotor and a support system to allow determining the motor parameters. The required parameters were defined taking into account the need the designer had of an electronic drive had. This data was used in computational simulations to determine the electronic driver design. After this, the motor testing allowed to identify the parameters, namely: winding resistance and inductance, various speed curves versus phase to phase and line voltage for back emf´s, moment of inertia and viscous friction, thus completing this work proposal, finalizing the project methodology for PMSM motor.
167

Etude conceptuelle d’un cœur de quatrième génération, refroidi au sodium, à combustible de type carbure / Multi-criteria methodology to design a sodium-cooled carbide-fueled GEN-IV reactor

Stauff, Nicolas 08 December 2011 (has links)
Contrairement à ses prédécesseurs (Phénix, Super-Phénix, EFR…), le réacteur à neutrons rapides refroidi au sodium (RNR-Na) de IVième génération doit justifier un niveau de sûreté élevé tout en étant à la fois viable économiquement et non-proliférant. Profitant d’un large retour d’expérience, les combustibles de type Oxyde (U,Pu)O2 représentent actuellement la solution de référence en France. Cependant, les combustibles de type carbure (U,Pu)C sont considérés comme une option innovante pour apporter à la conception d’un RNR-Na des degrés d’optimisation supplémentaires. L’objectif de cette thèse était donc de mettre en avant les potentialités du combustible carbure en concevant un cœur de RNR-Na à la fois attractif d’un point de vue économique et au comportement naturel en transitoire incidentel. Pour un parc de réacteurs français, on s’intéressera plus particulièrement à des cœurs iso-générateurs de forte puissance électrique (1500 MWe).Cet objectif a requis la mise en place d’une approche pluridisciplinaire prenant en compte les contraintes de thermomécanique combustible et de thermo-hydraulique en transitoire incidentel dès les premières étapes de la conception. Des modèles simplifiés basés sur les contre-réactions globales K, G et H ont été développés pour estimer le comportement d’un projet de cœur en transitoire de type insertion de réactivité, perte de débit primaire et/ou secondaire. L’avantage de cette nouvelle approche est surtout d’apporter au concepteur des outils complémentaires l’aidant à avoir une vision globale des problématiques de conception, mettant ainsi en avant les innovations ou les paramètres à optimiser pour améliorer les performances d’un cœur de RNR-Na.Cette approche a été appliquée à la conception de cœurs à combustibles carbure avec des performances très intéressantes. Un cœur de forte puissance électrique est proposé : il est isogénérateur de faible volume, avec un inventaire fissile initial réduit et un comportement naturel en transitoire incidentel très satisfaisant. Cependant, le taux de combustion d’une aiguille carbure dans un tel cœur semble limité à 100 MWj/kg à cause du gonflement important du carbure et de sa faible capacité à fluer, ce qui conduit rapidement à l’Interaction Mécanique Pastille-Gaine. Une aiguille fonctionnant à forte puissance linéique nécessite à la fois un jeu pastille-gaine épais et un joint sodium pour retarder l’IMPG, mais aussi un acier de gainage capable d’accommoder l’interaction par son fluage.Les performances en irradiation d’un combustible carbure pour un cœur industriel semblent donc très inférieures à celles obtenues expérimentalement dans le FBTR, où des aiguilles ont atteint un taux de combustion maximal de 155 MWj/kg. Cette différence a été étudiée et en partie expliquée, notamment par la fluence beaucoup plus faible obtenue dans un réacteur expérimental, retardant le critère de gonflement volumique. Deux voies d’exploration ont été mises en évidence pour augmenter les performances du carbure tel qu’utilisé dans un réacteur industriel. La première utilise un jeu pastille-gaine avec une technologie de type « buffer » pour retarder l’IMPG. La seconde est un cœur de faible fluence utilisant un enrichissement accru en plutonium. Les résultats préliminaires obtenus montrent que des taux de combustion supérieurs à 100 MWj/kg devraient être atteignables.Pour conclure, l’approche de conception pluridisciplinaire mise en place au cours de cette thèse s’est révélée efficace pour mettre en avant les avantages du combustible de type carbure. Celle-ci a permis de concevoir une image de cœur de RNR-Na attractive d’un point de vue économique, avec un comportement pardonnant en transitoire accidentel et capable d’atteindre un taux de combustion élevé. / Compared with earlier plant designs (Phénix, Super-Phénix, EFR), GEN IV Sodium-cooled Fast Reactor requires improved economics while meeting safety and non-proliferation criteria. Mixed Oxide (U-Pu)O2 fuels are considered as the reference fuels due to their important and satisfactory feedback experience. However, innovative carbide (U-Pu)C fuels can be considered as serious competitors for a prospective SFR fleet since carbide-fueled SFRs can offer another type of optimization which might overtake on some aspects the oxide fuel technology. The goal of this thesis is to reveal the potentials of carbide by designing an optimum carbide-fueled SFR with competitive features and a naturally safe behavior during transients. For a French nuclear fleet, a 1500 MW(e) break-even core is considered.To do so, a multi-physic approach was developed taking into account neutronics, fuel thermo-mechanics and thermal-hydraulic at a pre-design stage. Simplified modeling with the calculation of global neutronic feedback coefficients and a quasi-static evaluation was developed to estimate the behavior of a core during overpower transients, loss of flow and/or loss of heat removal transients. The breakthrough of this approach is to provide the designer with an overall view of the iterative process, emphasizing the well-suited innovations and the most efficient directions that can improve the SFR design project.This methodology was used to design a core that benefits from the favorable features of carbide fuels. The core developed is a large carbide-fueled SFR with high power density, low fissile inventory, break-even capability and forgiving behaviors during the unscrammed transients studied that should prevent using expensive mitigate systems. However, the core-peak burnup is unlikely to significantly exceed 100 MWd/kg because of the large swelling of the carbide fuel leading to quick pellet-clad mechanical interaction and the low creep capacity of carbide. Moderate linear power fuel pins require both a large initial sodium-bonded gap, delaying the fuel clad mechanical interaction, and a clad able to accommodate it by its high irradiation creep capacity.Irradiated carbide fuel performances predicted for an industrial SFR design are lower than the one obtained in the FBTR reactor irradiations, where 155 MWd/kg was obtained. This difference was studied and partly explained by the lower flux of experimental reactor delaying the embrittlement criterion. Innovative designs are now being considered to enhance the carbide-fueled pins burnup performance of industrial cores. The first innovative design uses a buffer technology to induce a delay in getting to the fuel clad mechanical interaction. The second innovative design is a core using high plutonium content so as to optimize the fluence over burnup ratio. Preliminary results show that a burnup higher than 100 MWd/kg can be reached.As a conclusion, this global approach has proven to be efficient in revealing the benefits gained using carbide fuel in a SFR. An optimum SFR core was designed exhibiting economic competitiveness while having inherent behavior during transient and reaching high burnup performance.
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Systemic design methodology for changeable manufacturing systems / Méthodologie de conception systématique pour les systèmes de production changeables

Benkamoun, Nadège 02 September 2016 (has links)
Les systèmes de production sont devenus des systèmes de grande échelle dont la complexité est accentuée par des contextes marqués de plus en plus par le changement. La capacité des systèmes a répondre au changement – appelée également changea-bilité – est reconnue comme étant une propriété essentielle pour leur cycle de vie, aussi bien dans le domaine des systèmes de production que dans le domaine de la conception en ingénierie. Au regard de la complexité des systèmes de production changeables, la méthodologie proposée par cette thèse a pour objectif de supporter la change-abilité dans la conception en souscrivant au domaine de l’ingénierie des systèmes. La première contribution est un formalisme pour la modélisation des systèmes changeables étayé d’après les principes de la conception systémique. Les concepts de flexibilité et de reconfigurabilité ne sont ici pas limités à des composants organiques du système, mais englobent l’ensemble des artefacts d’ingénierie dans le domaine du problème (exigences) et le domaine de la solution (blocs structurels). La deuxième contribution est une méthodologie pour la conception et la gestion des systèmes changeables. Elle repose sur un modèle du cycle de vie des systèmes changeables où des phases de conception des capacités de change-abilité du système s’alternent avec des phases de reconception tirant bénéfice de ces capacités existantes. Ces processus complémentaires garantissent la cohérence entre les décisions de conception pour intégrer et réutiliser des capacités de change-abilité, augmentant alors leurs potentiels tout au long du cycle de vie des systèmes complexes. Les concepts et les méthodologies développés ont été validés par des projets de conception de systèmes de production chez un équipementier automobile. Enfin, des développements possibles d’outils d’aide à la conception supportant la méthodologie proposée sont discutés. / Manufacturing systems have become large scale systems with increasing complexity particularly magnified by highly changing contexts. The system’s ability to cope with change (i.e. changeability) is recognized as a critical lifecycle property in the manufacturing system and engineering design domains. Given the complexity of changeable manufacturing systems, the proposed methodology of this dissertation aims to support design of changeability in subscribing to the domain of system engineering. The first contribution is a formalism for modeling changeability in a systemic way. Flexibility and reconfigurability paradigms are not limited to physical components of the system, but to the overall system architecture that encompasses all engineering artifacts relating to the designed system in both the requirements and physical solution domains. The second contribution is the methodology for the design and the management of changeability. The methodology utilizes a lifecycle model for changeable systems, in which design for changeability phases alternate with re-design phases that embrace and benefit from the existing changeability capabilities. These complementary processes allow a better consistency between design decisions to embed and reuse changeability, increasing changeability potential during the lifecycle of complex systems. The developed concepts and methodologies are validated in manufacturing system design projects from an automotive supplier. Finally, perspectives on design tools assisting the proposed methodology are discussed.
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Intryck, uttryck, avtryck : en studie av två formgivares designmetodiker, formspråk och inspirationskällor och sambandet mellan deras trädgårdar och konstnärliga uttryck.

Stagman, Siv, Adolfsson Hörberg, Karina January 2008 (has links)
<p>Detta examensarbete är en studie av glas- och silverformgivaren Gunnar Cyréns och modedesignern Gunilla Ponténs designmetodiker, formspråk och inspirationskällor.  Det undersöker också om de uttrycker sig konstnärligt i sina privata trädgårdar.  Kan deras formspråk spåras i trädgården och har trädgården inspirerat dem i deras formgivningsarbete?  Utifrån vad vi har funnit har vi skissat på trädgårdsidéer och tematrädgårdar med utgångspunkt i hur vi uppfattat deras formspråk.  I det arbetet har vi tillämpat de av dem beskrivna designmetodikerna.</p> / <p>This degree thesis studies the design methodology, artistic expression and source of inspiration of two renowned Swedish designers: Gunnar Cyrén, glass artist and silversmith, and Gunilla Pontén, fashion designer.  It also investigates if they express themselves artistically in their private gardens.  Can their artistic expressions be seen in their gardens?  Has the garden inspired them in their design work?</p>
170

Intryck, uttryck, avtryck : en studie av två formgivares designmetodiker, formspråk och inspirationskällor och sambandet mellan deras trädgårdar och konstnärliga uttryck.

Stagman, Siv, Adolfsson Hörberg, Karina January 2008 (has links)
Detta examensarbete är en studie av glas- och silverformgivaren Gunnar Cyréns och modedesignern Gunilla Ponténs designmetodiker, formspråk och inspirationskällor.  Det undersöker också om de uttrycker sig konstnärligt i sina privata trädgårdar.  Kan deras formspråk spåras i trädgården och har trädgården inspirerat dem i deras formgivningsarbete?  Utifrån vad vi har funnit har vi skissat på trädgårdsidéer och tematrädgårdar med utgångspunkt i hur vi uppfattat deras formspråk.  I det arbetet har vi tillämpat de av dem beskrivna designmetodikerna. / This degree thesis studies the design methodology, artistic expression and source of inspiration of two renowned Swedish designers: Gunnar Cyrén, glass artist and silversmith, and Gunilla Pontén, fashion designer.  It also investigates if they express themselves artistically in their private gardens.  Can their artistic expressions be seen in their gardens?  Has the garden inspired them in their design work?

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