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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

Analýza proudových poměrů v okolí nové vodní elektrárny / Hydraulic analysis in the surrounding of hydro power plant

Lorenc, Václav January 2018 (has links)
The diploma thesis deals with analysis of flow ratios at the hydraulic plant Klecany – Roztoky, located in the region of Střední Čechy at Vltava river (km 37,08). At this site 3D streaming of superficial water was simulated aiming to evaluate the influence of potencial construction of the new hydroelectric power plant Klecany II on existing Klecany I. Using all of the base documentation available, 3D models of current and planned conditions were created to serve as base for calculation in FLOW 3D. The first part of the thesis describes, how the planned construction of the new hydroelectric power plant Klecany II could influence the current fairway at the inlet 400 m3/s. The second part analyses shape of planned flow hydroelectric power plant Klecany II for flow Q90d, equal to 180 m3/s. All of the results are presented in intelligible charts and images.
162

Založení firmy působící v oblasti ekologických zdrojů el. energie / Foundation of the Ecological Energy Firm

Dostál, Jaroslav January 2010 (has links)
The master’s thesis follows up the possibility of using renewable for making electric power. It detects conditions of further development in this discipline and external factors which are applied to business. It rates from economic view little hydroelectric, wind and photovoltaic power stations. In business plan it elaborates in detail prosecution of the little hydroelectric plants, which is at the end subjected to financial analysis and it’s decided if this business makes sense.
163

Studie MVE v rámci plavebního stupně Přelouč II / Feasibility study of a small hydropower station within the navigation lock Přelouč II

Bolek, Marek January 2019 (has links)
The aim of this dissertation is to prepare a study of a small hydroelectric power plant as part of the Přelouč navigation level II. The preparation deals with one of the possible variants for the layout design of given constructions. The layout design of a weir with an adjacent lock chamber which secures navigability for the stretch of the Elbe River located between the river kilometers 949,23 and 951,20 near the city of Přelouč in the Pardubice District is also included in the study. The introduction chapter contains the assessment of the environment, which is followed by the specification of the exact placement of the constructions. In the following chapter, a particular type of the hydroelectric power plant machinery is designed based on the available hydrological information and gradient conditions. The final chapter contains the design of the constructional technological layout of an machine room in the form of a technical report and drawing documentation.
164

Agricultural vs. hydropower tradeoffs in the operation of the High Aswan Dam

Thompson, Katherine Oven January 1981 (has links)
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Civil Engineering, 1981. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING. / Bibliography: leaves 135-137. / by Katherine Oven Thompson. / M.S.
165

Voltage Regulation for an Electrical Grid

Alzubaidi, Jaafar, Antonsson, Rasmus January 2019 (has links)
The aim of this study is to analyse the voltage regulation of a power grid when wind power parks are connected to an existing power grid. Secondary the project have studied the placement of these wind power parks and costs related to connecting them to the grid. The goal was to achieve this grid with a smaller than 5% voltage margin and preferably a low phase deviation. The power grid is located in the area around Lule älven. Several issues with constructing and connecting windpower parks to an electrical grid have been studied by numerical analysis of a fictive grid but with real world variables. A balanced and stable grid is achieved with wind and hydro power and is able to successfully operate without non-renewable energy sources.The data was simulated in Matlab to analyse the power grid and the modification of it when connecting the wind power parks. The method used is power flow analysis through Matlab. All required unknown voltages and phase angles are determined and whether they are within given specifications. This entails that a stable electrical grid can be constructed
166

Development of methods for the separation and characterization of natural organic matter in dam water.

Sobantu, Pinkie 15 January 2015 (has links)
Submitted in fulfillment of the requirements of the Degree of Master of Technology: Chemistry, Durban University of Technology, 2014. / This project arose out the need for a simple method to analyse NOM on a routine basis. Water samples were obtained from the Vaal dam, which is one of the dams used by a hydroelectric power station. Analysis was preceded by separation of NOM into the humic and non-humic portions. The humic portion was separated into two fractions by employing a non-ionic resin (DAX-8) to separate humic acid from fulvic acid. High performance size exclusion chromatography (HPSEC), equipped with an Ultraviolet( UV) detector and an Evaporative Light Scattering (ELS) detector connected in series, was used to obtain molecular weight distribution information and the concentration levels of the two acids. Mixed standards of polyethylene oxide/glycol were employed to calibrate the selected column. Suwanee River humic acid standard was used as a certified reference material. The molecular weight distributions (MWDs) of the isolated fractions of humic and fulvic acids were determined with ELSD detection as weight-average (Mw), number-average (Mn) and polydispersity (ρ) of individual NOM fractions. The Mw/Mn ratio was found to be less than 1.5 in all the fractions, indicating that they have a low and narrow size fraction. An increase in Mn and Mw values, with increasing wavelength for all three humic substances (HS) examined was observed. The HS, isolated from the dam water, was found to be about the same molecular weight as the International Humic Acid Standard (IIHSS). For the fulvic acid standard, the molecular weight was estimated to be around 7500 Da. Characterization of NOM was done to assist in the identification of the species present in the water. FTIR-ATR was used to as a characterization tool to identify the functional groups in the structure of the humic and fulvic acid respectively present in the Vaal Dam. Analysis of the infrared (IR) spectra indicated that the humic acids of the Vaal dam have phenolic hydroxyl groups, hydroxyl groups, conjugated double bond of aromatic family (C=C), and free carboxyl groups. The isolation method has proved to be applicable and reliable for dam water samples and showed to successfully separate the humic substances from water and further separate the humic substances into its hydrophobic acids, namely, humic and fulvic acids. It can be concluded that the Eskom Vaal dam composes of humic substance which shows that the technique alone gives a very good indication of the characteristics of water. The HPSEC method used, equipped with UV and ELSD was able to identify the molecular weight range of NOM present in source water as it confirmed that the Eskom Vaal dam contains humic substances as humic acid and fulvic acid and these pose a health concern as they can form disinfectant byproducts in the course of water treatment with chemicals. FTIR characterization was successful as important functional groups were clearly assigned. Lastly, the use of the TOC and DOC values to calculate SUVA was also a good tool to indicate the organic content in water. It is recommended to use larger amounts of water must be processed to obtain useful quantities of the humic and fulvic acid fractions.
167

Caracterização tecnológica das rochas basálticas da Usina Hidroelétrica Canoas I, rio Paranapanema, SP/PR / Technological characterization of basaltic rocks of Canoas I Hydroelectric Power Plant, Paranapanema river, SP/PR

Marrano, Antonio 23 April 1997 (has links)
Tipos litológicos basálticos provenientes do maciço de fundação da UHE Canoas I foram submetidas a ensaios de caracterização tecnológica com o propósito do seu emprego como material de construção. Foram determinados os valores dos índices físicos (massa específica, porosidade, absorção d\'água), da velocidade de propagação de ondas ultra-sônicas e efetuados ensaios de compressão uniaxial e diametral, entre outros, além de análises petrográficas. Executaram-se, também, ensaios de alterabilidade acelerada (água-estufa, imersão em etileno-glicol) e de alterabilidade natural, tanto em fragmentos de rocha como em testemunhos de sondagens rotativas. São descritos em maior detalhe, os procedimentos utilizados para a realização do ensaio de alterabilidade natural em testemunhos de sondagens rotativas. Analisa-se a influência de uma feição geológica (caixa de falha com cerca de 10 m de espessura e 20º de ângulo de mergulho), presente na fundação, nas propriedades tecnológicas dos tipos litológicos por ela interceptados. São indicados os tipos litológicos selecionados para a utilização como material de construção. / Basaltic litotypes from the rock mass foundation of Canoas I Hydroelectric Power Plant were submitted to technological characterization tests, in order to verify their suitability as construction material. Physical and mechanical properties (density, porosity, water absorption, ultrasonic velocity, compressive and splitting tensile strength, among others) were determined, besides petrographic analyses. Weatherability tests were also performed, not only through wetting-drying cycles and by immersion in ethylene glycol but by outdoor exposure as well, using crushed and core drilled specimens. Detailed procedures for the weatherability test using core specimens from rotary drilling are given. It is analysed the influence of a geological feature (fault zone, about 10 meters thick and 20 degrees dip), that occurs in the rock mass foundation, on the technological properties of these rocks. Basaltic litotypes selected as construction material are then pointed out.
168

Proposta de metodologia e de modelo para modernizações de sistemas de automação de unidades geradoras hidráulicas de grande porte. / Proposal of methodology and of model for modernizations of automation systems of large hydraulic generating units.

Mendes, Marcos Fonseca 25 April 2011 (has links)
A geração de energia elétrica é importante para todos os ramos de atividades econômicas e tem demanda crescente. Isso implica constantes melhorias dos sistemas secundários, entre eles os sistemas de automação, que evoluíram muito nos últimos anos. Em várias usinas hidrelétricas esses sistemas estão obsoletos e apresentam outros problemas, portanto, carecem de atualizações tecnológicas. O objetivo desta tese é responder às principais questões relacionadas às modernizações dos sistemas de automação de unidades geradoras hidráulicas de grande porte: por que, quando e como modernizá-los? Para isso, foram estudados a evolução desses sistemas, o estado da arte, as modernizações já realizadas e planejadas. Os dados foram obtidos da bibliografia e diretamente de especialistas, através de pesquisa de campo envolvendo as principais concessionárias brasileiras. Baseando-se nos estudos, foram elaborados critérios para tomar a decisão por modernizar, foram escolhidas a forma de modernização e de realização mais adequadas para grandes usinas e foi criado um modelo de sistema de automação usando o estado da arte. Esse modelo é totalmente digital, utiliza uma única rede de comunicação em todos os níveis (incluindo o controle central), é à prova de futuro e fundamenta-se na norma IEC 61850. Todos os componentes e características do sistema foram examinados. Por fim, foi proposto um método para especificação e projeto do novo sistema incluindo todas as etapas. Concluiu-se que, um conjunto de indicadores quantitativos pode decidir a necessidade de modernização dos sistemas de automação de grandes unidades geradoras e, tomada a decisão por modernizar, a melhor solução é a substituição total de uma só vez (uma parada) usando o modelo criado. Os métodos e o sistema propostos podem ser usados como referências no setor elétrico para facilitar as atualizações tecnológicas e garantir resultados efetivos uniformes, com longo tempo de vida e independência dos fornecedores. / The generation of electricity is important to all branches of economic activities and faces a growing demand. This implies constant improvements of the secondary systems, including the automation systems, which have evolved a great deal in recent years. At several hydroelectric power plants these systems are obsolete and present other problems, therefore, technological upgrades are required. The objective of this thesis is to answer the key questions related to the modernizations of automation systems of large hydraulic generating units: why, when and how to modernize them? To this effect, studies were undertaken about the evolution of these systems, the state of the art, the modernizations already introduced and those planned. The data were obtained from the bibliography and directly from experts, through a field survey involving the major Brazilian utilities. Based on these studies, criteria to support the modernization decision were developed, the most suitable manner of modernization and of its implementation in large power plants were chosen and an automation system model using state of the art was created. This model is fully digital, uses only one communication network at all levels (including the central control), is future proof and is based on the IEC 61850 standard. All components and features of the system were examined. Finally, a method including all stages for specification and design of the new system was proposed. It was concluded that, a set of quantitative indicators can decide the need for modernization of the automation systems of large generating units and, once the decision to modernize is taken, the best solution is the total replacement during a single unit shut-down using the model created. The methods and system proposed can be used as references in the electricity sector to facilitate the technological upgrades and to ensure effective uniform results, with the prospect of a long service life and independence from the suppliers.
169

Análise hidrológica utilizando redes neurais para previsão de séries de vazões / Hydrologic analysis using Artificial Neural Networks for time series forecasting streamflow

Yoneda, Sergio Luis 20 March 2014 (has links)
O estudo de inventário tem por objetivo estimar o potencial hidroelétrico de rios ou bacias, analisando várias alternativas propostas de partição de quedas, sendo que cada alternativa contém um conjunto de aproveitamentos hidroelétricos. Essas alternativas são então estudadas individualmente para definição da alternativa ótima, ou seja, a que tem melhor custo beneficio e ao mesmo tempo cause menos danos ambientais. Para essa análise necessitamos calcular a potência de cada aproveitamento específico, assim como a energia gerada, para isso então precisamos conhecer a vazão do rio em estudo, no local desses aproveitamentos. Como a vazão dos rios varia com o tempo, pois depende de variáveis como clima, geologia dos solos, desmatamento, entre outras, se recomenda usar nos cálculos séries longas de vazões médias com no mínimo 30 anos de dados, o problema é que em muitos casos não temos essas séries ou temos séries menores e incompletas, nesse caso então necessitamos estimar os valores ausentes e ruidosos utilizando os dados de estações fluviométricas próximas, para depois transportá-las para o aproveitamento em estudo, para isso utilizamos de técnicas estatísticas de correlação. A ideia nesse trabalho é de utilizarmos redes neurais artificiais ao invés das técnicas convencionais e comparar os resultados obtidos. / The inventory study aims to estimate the hydropower potential of rivers or basins, analyzing several alternative proposals for partition of falls, each of which contains a set of alternative hydroelectric developments. These alternatives are then individually analyzed to define the optimal alternative, namely that which has the best cost benefit while causing less environmental damage. For this analysis we need to calculate the power of each specific use, as well as the energy generated for that then we need to know the flow of the river under study, the location of these usages. As the river flow varies with time because it depends on variables such as climate, geology, soils, deforestation, among others, we recommend using the long series of calculations mean flow at least 30 years of data, the problem is that in many cases we do not have these series or have smaller and incomplete series, in this case then we need to estimate the missing values and noisy data using next gauged stations, and then transport them to use in the study, for this we use statistical correlation techniques. The idea is that we use work instead of the conventional Artificial Neural Network techniques and compare the results.
170

OCORRÊNCIA E TRANSFORMAÇÕES SOCIOAMBIENTAIS DE ZOONOSES NA ÁREA DE INFLUÊNCIA DA USINA HIDRELÉTRICA CANA BRAVA - GO.

Cruz, Lays Karolina Soares da 01 October 2012 (has links)
Made available in DSpace on 2016-08-10T10:54:49Z (GMT). No. of bitstreams: 1 LAYS KAROLINA SOARES DA CRUZ.pdf: 1634341 bytes, checksum: a948efcc44d98427594741f6c63b8d9d (MD5) Previous issue date: 2012-10-01 / This study aimed the evaluation of a possible interference of the construction of the Cana Brava hydroelectric power plant on the cases of zoonoses in the municipalities of Cavalcante, Colinas do Sul and Minaçu, which are under its direct influence. The occurrence of zoonoses, demographic conditions, morbidity, fauna of medical importance and the use of soil were taken into consideration in the three counties mentioned above. The information was obtained from existing official sources as DATASUS, IBGE, SINAN, IBAMA, INPE, PROBIO, and Naturae. The results were analyzed through statistic tests (ANCOVA). It was identified that morbidity rates have increased from 1995 to 2007 in the three municipalities, which is equivalent to the previous and posterior period of the installation of the power plant construction. According to DATASUS, 982 cases of Dengue Fever, 1 case of Chagas Disease, none of Yellow Fever, 234 cases of LTA, 4 cases of LV, and 17 cases Malaria were diagnosed in the three counties from 2001 to 2011. Two vectors of Dengue Fever, 7 vectors of Yellow Fever, 3 vectors of LTA, and 3 vectors of Malaria were found in the area. Two hosts of Chagas Disease, three of Yellow Fever, 1 of LTA, 2 of LV and 1 of Malaria were also found. The profile of the use of the soil shows the intensification of farming and cattle raising activities in the three counties along the years. The research presented some restrictions, mainly on the divergence of data and trends that were made public by numerous agencies. Although the acquired results of this research show some changes on the impact of diseases that appear in the region, these estimates and figures may show patterns of normality. The information obtained may not be sufficient to prove a linkage between the construction of the Cana Brava hydroelectric power plant and the status and trends of zoonoses in the three municipalities. / Este trabalho teve como objetivo fazer uma avaliação da possível interferência do processo de implantação da UHE Cana Brava nos casos de zoonoses nos municípios de Cavalcante, Colinas do Sul e Minaçu, que compõe sua área de influência direta. Foram considerados dados relativos à ocorrência de zoonoses, condições demográficas, morbidade, fauna de importância médica e o perfil de uso do solo dos três municípios. As informações analisadas foram extraídas das fontes oficiais existentes, DATASUS, IBGE, SINAN, IBAMA, INPE, PROBIO e Naturae. As análises dos resultados foram feitas por meio de teste estatístico (ANCOVA). Foi identificado que as taxas de morbidade dos três municípios se comportaram de maneira crescente, entre 1995 e 2007, que compreende período anterior e posterior à instalação do empreendimento. Foram diagnosticados 982 casos de Dengue, 1 caso de Doença de Chagas, 0 de Febre Amarela, 234 de LTA, 4 de LV e 17 de Malária nos três municípios entre 2001 e 2011 segundo DATASUS. Na área foram encontrados 2 vetores de Dengue, 7 vetores de Febre Amarela, 3 vetores de LTA e 3 vetores de Malária. Também foram encontrados 2 reservatórios de Doença de Chagas, 3 reservatórios de Febre Amarela, 1 reservatório de LTA, 2 reservatórios de LV e 1 reservatório de Malária. O perfil de uso do solo mostra a intensificação das atividades agropecuárias ao longo dos anos nos três municípios. O trabalho apresentou algumas limitações, principalmente acerca da divergência dos dados divulgados pelos diversos órgãos. Embora os resultados obtidos no presente trabalho mostrem algumas alterações no perfil de doenças que ocorrem na região, estes números podem estar dentro dos padrões de normalidade. As informações obtidas não são suficientes para provar uma ligação entre a instalação da UHE Cana Brava e o perfil de zoonoses dos três municípios.

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