[pt] No presente trabalho realizou-se um estudo experimental preliminar sobre o desempenho térmico do sistema de resfriamento da contenção de um reator LWR do tipo AP-600. Foi projetado, construído e testado um aparato experimental similar ao vaso de contenção dotado de uma piscina com fonte quente e resfriado externamente por circulação forçada de ar. Neste arranjo, foram testados os efeitos do volume de água, potencia dissipada e da vazão externa do ar. Nos ensaios, foram observadas três regiões típicas nos perfis de temperatura, regime de pré-saturação da água da piscina, regime transitório com ebulição interna e finalmente, equilíbrio térmico global, onde todo o calor fornecido pela fonte quente era removido pelo ar externo. / [en] In the present work, na experimental primliminary study of the thermal perfomance of a AP-600 type reactor containment cooling system was performed. It was designed, constructed and tested an experimental apparatus similar to the containment vessel equipped with a hot source inside a water pool and cooled externally by means of forced air circulation. Several tests were performed to observe the effects of the water volume, the dissipated power and external air flow rate. During the tests, threee typical regions were observed, pre-saturation water regime, transitory regime with internal boilling and, eventually, steady state regime where all the heat generated by the heat source was removed by the external air.

[pt] As grandes companhias de energia eólica buscaram durante muito tempo por uma solução eficiente e economicamente viável para integração de sistemas e obtenção de maior alinhamento entre o negócio e tecnologia. SOA apareceu e vem sendo adotado por algumas destas empresas para tal finalidade. Estatísticas dizem que entre as dez maiores empresas de energia, cinco já adotam SOA como solução para seus problemas gerenciais. SOA foi elaborado pensando-se nestas corporações, mas recentemente passou-se a discutir sua aplicabilidade no mercado exclusivo de energias. Neste contexto, este trabalho se propõe analisar a aplicabilidade de SOA a Energia Eólica, propondo algumas idéias para que esta adequação possa ocorrer e realizando um estudo de caso na implantação para estas empresas, fazendo uso de tecnologias e ferramentas gratuitas. / [en] Currently, sustainable technology is an objective study everywhere in the world, since the energy industry needs intelligent alternatives to transform Green Energy into something profitable, having little environmental impact and greater efficiency in its production processes. Wind power is an alternative energy source with the largest number of studies by industry and science displaying all the proper factors to healthy living with Green Energy. With the research conducted over the past two years, the need was perceived, in real cases, for a technology associated with the Intelligent Computational Wind Energy in terms of better energy use for both the producer and for end consumers. In situ monitoring and research were carried out by wind energy companies based in Fortaleza, Brazil, having wind farms in their respective cities, such as at the Port of Pecém by Bons Ventos Engenharia and also in the state of Rio Grande do Norte. Monitoring was performed and, while headquartered in Denmark (Europe), on site research was carried out by a generator supplier for wind energy (Suzlon Brazil). These field studies took nearly three months to complete while adhering to all procedures, addressing all issues and holding several internal meetings. In all companies, components such as generators and transformers are bought from European suppliers, but the software used to manage such parts are Brazilian and often made within the company since they have no specific products with the necessary quality they need. The analyses of the visited companies are made in simple Excel spreadsheets (Microsoft Office) for workers with little skill in completing spreadsheets. The purpose of this work is to allow greater control and higher quality information to the company and the consumer. Making wind power into something extremely productive and financially viable would prove to be quite salutary for all mankind. Aiming to avoid malfunction of aero generators resulting from errors or from maintenance worker in order of achieving increased productivity, as well as enabling companies to have greater access to their factories in real time, reducing the risk of loss and a greater production control which facilitates decision making for administrators. The proposed Service Oriented Architecture (SOA) provides greater flexibility and integration between technology and business strategy. One of the principles governing this type of architecture is the integration of existing systems through an integration layer. Service-Oriented Architecture (SOA) proposes a kind of bus (ESB - Enterprise Service Bus), through which legacy applications can be aggregated and shared. The purpose is to make the most common features of a system capable of reuse regardless of the technology they were built upon, but this should be translated into a language or protocol standard, XML. The goal implicitly in the SOA model is that business applications may one day be treated with reference to services that are used. The model used for the SOA in the Wind Energy is called Software Engineering by Prototyping. After some improvements of companies with SOA, some plants were already able to generate power for small towns or neighborhoods, since, before the SOA, were sold to smaller power plants and then passed on to consumers. With the arrival of new technology it is possible to transfer immediately to homes, apartments or industries. This example was identified in Wind Station located in the Beach Park in Fortaleza (CE). Case Study in Choice of SOA Wind Energy In field trials conducted in Ceará and RN, wind farms were seen as very small, less than 15 aero generators, where the company does not know, for example, the best time to turn off its aero generators due to lack of wind, leaving only one input port of the ESB (Enterprise Service Bus), SOA equipment, thus a Java program may be installed to measure the wind velocity and once it becomes less than 2 m / s the aero generators stop automatically, maintaining the parts’ condition and decreasing expenses for these small wind farms. With companies that have wind farms in several places, the need for SOA is extreme because we have to choose the best software in order to address the needs of all wind farms. After all, one reason for using SOA is the reuse of programming code which is implemented in various plants, immense profitability and all will be controlled remotely by one simple computer. By establishing a central SOA along with a powerful ESB (Enterprise Service Bus), many doors will be opened for the central computer and for each path set a wind farm; within each one specify each aero generator and obtain real-time wind speed, creating profit by each aero generator every second of use. With this solution, the company s management team would know who would be profiting, who would be at a loss, which would be required to stop all activities, and know the wind speed of each aero generator in wind farms in each business group, control of any wind farm is made possible, avoiding loss, machine problems, substantially lower maintenance cost and improved profitability. After months of research in the field (in situ) and advanced studies for two years, the vulnerability of computer systems was identified in the wind energy industry. There are companies with investments in some cases millions of dollars which have no real-time results of their aero generators, profits, preventing errors or scheduled maintenance, putting many in financial loss. With SOA, a program written in JAVA programming language within the ESB (Enterprise Service Bus) can be used, for example, to calculate the amount of times that a lamp was lit, allowing the user to be aware of how much energy would be spent in each bulb in your home or office. Throughout this work were presented concepts of SOA and Wind Energy. The question of using SOA by these wind farms was addressed, addressing some particular questions that should be taken into consideration in order for this adoption to be made in its best form. We propose some ideas and a change in the strategy of adopting SOA, which were put into practice through two softwares and a screen ESB Integration Sterling. Surely the part that will benefit most from adopting SOA in the wind energy industry will be the management area, since the advance of information technology and engineering enhances efficiency and provides minimal losses, things in which prior to SOA technology with wind energy were normal, but Bons Ventos in Fortaleza already use these techniques based in this dissertation and is satisfied with the results achieved in its company. In real time, they can immediately stop the aero generators so that the wind do not financially compensate the maintenance of those left on, permitting facility operators to work more at ease. After all, when no wind is present and the aero generator is off by SOA equipment is exactly the best time to provide maintenance. In this current scenario, the recommendation for a company desiring to use wind energy is to wait for the development of this technology in regard to the cost-benefit ratio. The standards established for this type of captured energy are almost completely formatted, however investments are still quite expensive, namely equipment, skilled labor and control software. The use of SOA is revolutionizing information technology and this work contributed to the achievement of growth and development in the wind energy industry. Open source tools specifically made for SOA have not reached the same degree of maturity as other proprietary solutions. Future efforts can be directed towards this as well as how they can be improved by the best combination and adding new features.

[pt] O presente trabalho descreve o desenvolvimento de um gerador termoelétrico cujos termoelementos são obtidos a partir de um composto de dissiliceto de ferro (FeSi2). A originalidade do trabalho reside na simplificação do processo de obtenção do termoelemento e na utilização de matérias-primas com grau de pureza industrial, em contraposição aos processos usuais que utilizam materiais de custo elevado, com alto grau da pureza e sofisticados processos de fabricação. O composto é obtido pelo processo de fusão num forno de indução à vácuo. A forma geométrica do termoelemento é assegurada pelo processo de sinterização. Um processo de recozimento garante a formação da fase Beta, assegurando a existência das propriedades termoelétricas. O coeficiente de Seebeck mostrou-se dependente do tempo de recozimento. Para os materiais desenvolvidos, o termoelemento tipo P apresentou um coeficiente de Seebeck de 250 MV/K e o material tipo N, um coeficiente de 75 MV/K, valores estes que qualificam o material para construção de geradores termoelétricos. Estima-se que o custo de fabricação do material desenvolvido reduziu de oito para dois dólares o custo de fabricação de materiais termoelétricos por watt de eletricidade gerado. Experiências preliminares utilizando a técnica de serigrafia para fabricação de termoelementos parecem confirmar a possibilidade de uma redução ainda maior do custo de fabricação. / [en] This work describes the development of a thermoelectric generator whose thermoelements are made of a new thermoelectric material, FeSi2, an iron disilicide alloy. The originality of this work relies on the simplicity of the process by which the termoelements are obtained and also on the possibility to use a raw material with industrial purity grade, as opposed to conventional techniques which use costly materials, with a high degree of purity, and sofisticated process of fabrication. The alloy is obtained by a process of fusion in a vacuum induction type furnace. The geometric shape of the thermoelement is obtained by a process of sinterization. An annealing process garantees the formation of the Beta phase, thus assuring the existence of thermoelectric propertyes. The Seebeck coefficient proved to be dependent on the time duration of the annealing. As for the material developed, the P Type material presented an average Seebeck coefficient of 250 MV/K and the N type material, a coefficient of 75 MV/K, these figures qualify the materials for construction of thermoelectric generators. It is estimated that the manufacturing cost of the material developed reduced the cost of thermoelectric materials per watt of electricity generated from eight to two dollars. Preliminary experiments using the silk-scream technique in manufacturing of thermoelements seems to promise an even greater reducting in the manufacturing costs.

[pt] que torna complexo o processo de formação do preço da energia, já que o mesmo depende do comportamento das afluências futuras, que é altamente incerto. Em função dessa incerteza, o preço pode apresentar comportamento volátil, se tornando um fator de alto risco para os agentes do setor elétrico. No entanto, é comum que comercializadoras utilizem o mercado a vista para alavancar seus ganhos, visto que podem negociar energia elétrica entre diferentes submercados lucrando com as diferenças de preços existentes entre eles. A gestão do risco inerente a essas operações geralmente é realizada pelas próprias empresas que utilizam modelos financeiros para otimização de portfólio de contratos levando em conta métricas de risco. Uma prática comum é o Swap de energia elétrica no mercado a vista que consiste na compra e venda de energia para liquidação em determinada data. Na prática a comercializadora fica vendida na ponta ativa e comprada na ponta passiva, em submercados diferentes. Quando da liquidação financeira a comercializadora irá receber ou pagar um valor em dinheiro dependendo dos preços de cada submercado. Nesse contexto, o presente estudo oferece um modelo de decisão ótima em Swaps de energia elétrica utilizando como balizador de desempenho a medida Ômega com restrição de valor em risco (VaR – Value at Risk) de forma a auxiliar comercializadores a maximizarem seus lucros minimizando riscos por meio de operações casadas. Os resultados mostraram que a medida Omega é uma excelente métrica de decisão ótima de Swaps de energia elétrica visto que consegue incorporar toda a curva estatística da distribuição dos resultados simulados para as operações. A medida Omega também leva em conta um nível de retorno ou valor meta chamado de limite (L) definido pelo gestor, o qual é a fronteira entre o que se considera como ganho e como perda. A decisão ótima de Swap com base na maximização da medida Omega para contratos de energia elétrica em um horizonte de 12 meses resultou no conjunto das seguintes operações: CSE-VNE+CSE-VN (Compra Sudeste e Vende Nordeste + Compra Sudeste e Vende Norte). / [en] The Brazilian electric sector underwent a major restructuring that began at the end of the 1990s, which aimed to increase the efficiency of the agents and the market as a whole. This process created the Regulated Contracting Environment (ACR) where the generators sell their energy through government-organized auctions, and the Free Contracting Environment (ACL) which enables deals between producers and consumers whose demand exceeds 3MW, directly or via brokers. Purchases in the ACL may be at fixed or previously-set prices, or even at floating prices based on the Spot Price (PLD). The PLD may be volatile, becoming a high risk factor for the electric sector agents. Energy supply is divided into four sub-markets: North, South, Northeast and Southeast/Midwest, and each presents a distinct PLD due to restrictions on the transmission lines and other factors. However, it is common for agents to trade in electric power swaps, which means trading energy among different sub-markets and profiting from price differences. The management of risk inherent in such operations is usually performed by the companies themselves, which use financial models to optimize contract portfolios, taking into account risk metrics. Thus, the trader will book a profit or loss depending on the prices in each sub-market. Against this backdrop, this study offers a model of optimal decision in Electric Power Swaps (buying and selling the same amount of energy) using the Omega Measurement as a performance indicator, restricted by value at risk (VaR) to help brokers maximize their profit while minimizing risks.

[pt] A indústria do petróleo sempre investiu em pesquisa de modo a otimizar as operações de perfuração. O objetivo é desenvolver tecnologia para aumentar a taxa de penetração e reduzir o tempo não produtivo durante a perfuração. As recentes descobertas de campos de petróleo localizados em camadas profundas, cobertas por espessas camadas de evaporitos aumentaram a importância dos estudos associados com a otimização nas bacias marítimas brasileiras do pré-sal. Existem muitos modelos para a previsão da taxa de penetração baseados em parâmetros operacionais tais como peso sobre a Broca (WOB), taxa de penetração (ROP), torque a rotação da broca (RPM), e resistência à compressão da rocha. A energia mecânica específica é o parâmetro freqüentemente usado como referência para estabelecer a eficiência das operações de perfuração assim como identificar o que deve ser modificado de modo a melhorar a perfuração. Esta dissertação analisa diferente métodos de otimização de perfuração baseados na energia mecânica específica. Estes métodos são aplicados a um conjunto de dados que consiste nos parâmetros de perfuração (WOB, T, RPM, ROP) obtidos ao longo dos trechos de evaporitos em 6 poços perfurados com broca PDC. Dados de ensaios de perfuração de grande escala realizados em laboratório também foram analisados nesta dissertação. Este estudo conclui que a energia mecânica específica ideal em muitas das operações está relacionada com uma parcela da resistência à compressão confinada da rocha. / [en] The oil industry has always invested in research in order to optimize drilling operation. The aim is to develop technology to increase the rate of penetration and reduce the non-productive time during drilling. The recent discovery of large oil reserves located in very deep layers that are covered with thick salt layers has increased the importance of studies associated with drilling optimization in Brazilian offshore sub-salt oil fields. There are many models to predict rate of penetration based on operational parameters, drill bit type and rock properties. The specific mechanical energy is the parameter often used as reference to guide the efficiency of the drilling operation as well as to identify what has to be changed in order to improve the drilling. This dissertation analyses different methods for drilling optimization based on the specific mechanical energy. These methods are applied to a data set that consists of drilling parameters (weight-onbit, torque, rate of penetration, rotation per minute) for 6 wells along the sections of evaporites. Large-scale drilling experiments carried out at the laboratory were also used. The study concludes that the ideal specific mechanical energy on most operations is related to a fraction of the confined compressive strength of the rock.

[pt] Em muitos países, redes elétricas de grande porte são formadas pela interconexão de companhias de energia elétrica cada qual possuindo seu próprio centro de controle. Para supervisionar eficientemente tais sistemas de potência, técnicas de estimação hierarquizada de estado devem ser consideradas. Esta tese apresenta um novo algoritmo que utiliza conceitos hierárquicos para resolver o problema da estimação dinâmica de estado para sistemas de potência de grande porte em regime quase-permanente de operação. O processo de estimação é feito em dois níveis de cálculo de modo a se obter uma solução satisfatória do ponto de vista computacional para as etapas usuais da estimação dinâmica de estado: estimação dos parâmetros do modelo, previsão do estado e filtragem do estado. A nível local, algoritmos convencionais de estimação dinâmica de estado são executados simultanea e independentemente para todos os subsistemas. A coordenação dessas estimativas locais é obtida em um centro nacional de supervisão e controle, operacionalmente de hierarquia superior no sistema elétrico interligado. Resultados numéricos mostram o desempenho do algoritmo proposto em diferentes condições de operação: normal, mudança brusca do estado e presença de erros grosseiros. / [en] In many countries, huge power networks are formed from the interconnection of electric power companies each one having its own supervisory control center. In order to supervise efficiently such power systems, hierarchical state estimation techniques have to be considered. This dissertation presents a new algorithm using hierarchical concepts to solve the dynamic state estimation problem for large-scale electric power systems operating under quasi-static conditions. A two-level calculation is performed to give a satisfactory solution from the computational point of view for the usual steps of the dynamic state estimation procedure: model parameter estimation, state prediction and state filtering. At the local level, conventional dynamic state estimation algorithms are carried out simultaneously and independently for all subsystems. The coordination of these local estimations is obtained at a national center for supervision and control, which is at the top of operational hierarchy in the interconnected electrical system. Numerical results show the performance of the proposed algorithm under different operational conditions: normal, sudden variation of states and occurrence of bad data.

[pt] Uma análise experimental de um sistema termossifão para aquecimento d água com energia solar é feita. A vazão massica foi medida com um rotâmetro especialmente projetado. Coletores com e sem cobertura foram testados e seu desempenho comparado, como função da altura do tanque ao coletore outros parâmetros. Finalmente sugere-se uma faixa ótima de parâmetros para utilização do coletor sem cobertura para aquecimento d água. / [en] An experimental analysis of a thermosyphon loop used as a solar water heater is made. The mass flow rate was measured with a specially designed rotameter. Single glazed and unglazed collectors were tested and their performance compared as a function of collector-to-tank height and other parameters. Finally, it is suggested an Optimum range of parameters to be used in solar water heating systems with unglazed collectors.

[pt] Superpondo uma estrutura adequada em forma de colméia a um coletor plano é possível absorver mais eficientemente energia solar. Na formulação de modelo, a troca de calor por radiação entre as superfícies envolvidas foi considerada em duas bandas: solar e infravermelho. As equações resultantes formam um sistema íntegro-diferencial não-linear. Utilizou-se iteração de resolução de equações lineares algébricas para a solução do sistema discretizado. As eficiências obtidas foram comparadas com as de sistema planos, e determinadas para uma faixa dos dez parâmetros adimensionais envolvidos no modelo. Por fim, um programa é colocado à disposição para atender necessidades específicas de usuários interessados. / [en] By placing na appropriate structure in the form of a honeycomb on a plane collector it is possible to absorb solar energy in a more efficient manner. In formulating the model, the radiation heat transfer between the involved surfaces was considered in two bands: solar and infra-red. The resulting equations form a non-linear integro-differential system, an iteration of the resolution of algebraic linear equations was used. The efficiencies obtained were compared with those of plane systems and determined for a range of the ten non-dimensional parameters involved in the model. At the end, a program is offered for attending to specific needs of interested users of same.

[pt] A Sazonalização é o processo de dividir as quantidades anuais de um contrato de fornecimento de energia elétrica em montantes mensais. Trata-se de flexibilidade contratual facultativa geralmente determinada ou imposta pelo agente comprador. A participação das usinas eólicas na matriz energética brasileira tem aumentado nos últimos anos, sendo a energia dos ventos uma fonte renovável que apresenta uma característica interessante de complementaridade em relação à vazão das usinas hidrelétricas. As carteiras de empresas comercializadoras passam então a abrigar contratos com usinas eólicas e hidrelétricas. Tendo como meta auferir maiores ganhos algumas comercializadoras realizam operações descasadas e podem utilizar a flexibilidade da sazonalização de contratos. Neste trabalho foi tomada como referência uma comercializadora que possui uma carteira composta de um contrato de venda de um montante mensal fixo de energia, um contrato de compra da energia elétrica de uma usina eólica e um contrato de compra de energia de uma hidrelétrica que pode ser sazonalizado. Foi desenvolvida uma metodologia para determinar o perfil de sazonalização ideal a ser utilizado para aumentar os lucros da carteira de contratos. A maximização da medida Ômega delta foi a métrica utilizada para analisar os cenários e foram consideradas restrições de Value at Risk - VaR nas análises realizadas. Os resultados encontrados mostram que a maximização da medida Delta é obtida concentrando-se toda compra de energia da hidrelétrica no segundo semestre do ano. Entretanto, à medida que a restrição de VaR torna-se mais severa diminuindo o grau de liberdade para realizar a sazonalização a distribuição dos montantes de energia elétrica aproxima-se da uniformidade entre os meses do ano. / [en] The seasonal adjustment is the process of dividing the annual quantities of an electricity supply contract in monthly amounts. This is a contractual flexibility generally determined or imposed by the contract buyer. The share of wind farms in the Brazilian energy system has increased in the last few years and wind energy is a renewable source that presents an interesting feature of complementarity with hydroelectric power plants in Brazil. Therefore, contracts with wind farms and hydroelectric plants are becoming part of the trading companies portfolios. Aiming to reach higher gains, some energy traders enter into uncovered trading positions and use the flexibility of seasonal adjustments of contracts to combine these two sources in a portfolio. This study used as reference a trading company that has a portfolio composed of a sales contract for a fixed monthly amount of energy, a contract to buy electricity from a wind farm and a contract to purchase electricity from a hydroelectric plant that can be seasonally adjusted. A methodology is proposed to find the ideal profile of seasonal adjustments that should be used to increase the portfolio’s profits. The maximization of the Omega measure delta - along with Value at Risk (VaR) restrictions- , was the metric used to analyze the scenarios and choose the optimal portfolio. The results found show that the maximization of the Delta measure is obtained by concentrating all the energy bought from the hydroelectric in the second semester of the year. However, as the constraint VaR becomes more severe restricting the freedom to make seasonal adjustments, the distribution of energy amounts between the months of the year approaches the uniformity.

[pt] Tem-se descrito um modelo calculado pelo computador para prognosticar o rendimento térmico de aquecedores de água domésticos por energia solar, em base à circulação termosifónica entre o coletor e o tanque de armazenagem isolado. A intensidade da radiação solar e a temperatura do ar são determinados de modelos reais. Presupõe-se uma situação ideal de não consumo de água durante o dia todo. Os resultados são comparados com resultados experimentais obtidos nos modelos reias. Analisa-se como caso especial o que acontece com o aquecimento inicial da água no coletor, de dez em dez centímetros. / [en] A computer model for predicting the thermal performance of domestic solar water heaters, employing thermosyphon circulation between the collector and the insulated storage tank, is described. The solar radiation intensity and ambient air temperatures have been found from real models. Ideal condition of no drain-off during the day is assumed. Results are compared with experimental results obtained from real models. As special case, what happen with initial water heating each ten centimeters in the absordber plate is analized.