Hydropower plants have the ability to go from a full load to no load in just a few seconds. In order to go from full load to no load in a few seconds the flow is controlled by movement of guide vanes. At fault detection the guide vanes closes quickly for safety reasons. This causes hydraulic transients in the waterways, which leads to a pressure rise in the spiral case and a pressure drop in the draft tube.   There have been a few accidents related to these quick closures of the guide vanes where the runner blades break and entire power stations are damaged. These incidents are caused by a full column separation in the draft tube. An early sign of a full column separation is large cavities. The main objective of this degree project is to analyse the effects of a quick closure of the guide vanes and to make a guide book of how to find indications of large cavities when performing closure tests. Data taken from commissioning and status tests for several turbines were analysed.   In conclusion, the guide book of how to find indications of large cavities will help analyse the results of a quick closure of the guide vanes. Due to the unique appearance of pressure transients for each power station this guide book will not be enough for a complete analyse of a closing test. Although, it will help to notify when there is a need for further analyses by expert personnel.

Hydropower is the most important domestic energy source of Turkey. Thus, wise planning and development of the unused hydropower potential of the country is vital. There are many hydroelectric power plants under planning stage in our country. Altiparmak HEPP is one of them. General Directorate of Electrical Power Resources Survey and Development Administration (EIE) and ANC Enerji conducted two separate feasibility studies for Altiparmak HEPP in 2001 and 2009, respectively. Traditionally, the energy income calculations for HEPPs are based on DSI or EIE Methods in Turkey. Both of these methods evaluate the firm and the secondary energy generations separately. Besides they use fixed prices for these two types of energies. However, hourly electricity prices are used for electricity trading in Turkey. A detailed economic analysis of Altiparmak HEPP is conducted in this study. The economic analysis included various factors, such as tailwater level change, varying operating levels for different seasons and precipitation and evaporation amounts which are not conventionally included in feasibility studies. Moreover, the energy income calculations are conducted with four different methods, the DSI Method, the EIE Method, the ANC Method and the Variable Price Method (VPM). The VPM is developed in this study and it allows utilization of hourly electricity prices in calculating energy income of the HEPP. To shed some light on how hourly electricity prices develop, this thesis includes a chapter on the electricity market which explains the details of electricity trading in our country after the Electricity Market Balancing and Settlement Regulation became active in 2009.

Darbu siekiama išryškinti pagrindinių klimatinių-hidrologinių veiksnių sąveikos su hidroelektrinių gaminama elektros energija ryšį. Siekta: apžvelgti hidroelektrinių darbo režimo ypatumus pastarųjų keturių dešimtmečių periode; paanalizuoti bendras hidroelektrinių darbo proceso tendencijas Baltijos šalyse; padaryti įžanginę analizę į tolimesnius tyrimus, kurie padėtų efektyviau panaudoti turimus hidroenergijos išteklius ir sumažinant neigiamų klimato svyravimų įtaką. / The aim of work is to emphasize the connection of the main climate-hydrological factors interaction with generated electricity of hydropower plant. The task was to review the peculiarities of hydropower work regime in the period of recent four decades; to analyse general work process tendencies in the Baltic States; to make introductory analysis for further researches which could help use effectively hydropower resources, minimising the influence of negative climate variations.

No description available.

Electricity availability and stability have a great contributory share of industrialization growth rate, poverty statistics, unemployment, foreign investors' participation, medium and small scale encouragement, crime and mortality rates recorded in any country. Nigeria as a country has been challenged with unstable and unreliable power supply. There are many problems associated with electricity production in Nigeria. Such problems are recorded in the generation, transmission and distribution facets of electricity production. With a multi-faceted problem, this document has been developed to deal with the economic aspect of power generation in Nigeria. Out of numerous technologies that are used in power generation, Nigerian predominantly sources its electricity supply from gas power plants and hydropower systems located within the country. Unfortunately, the Nigeria hydropower has been challenged with hydrological shortfalls. The gas power plant which is now conventional is being challenged with the developing gas technology around the globe. This development has adversely affected the cost of gas and subsequently the cost of power production using gas power plants. As a result of hydrological limitations on Nigerian hydropower dams, effect of gas price on cost of energy produced and diversifying gas technology, harnessing electric energy from Inga falls of River Congo was considered as an economic choice of power production in Nigeria. The choice of power production adopted in this document was made from an economic viability studies carried out between Nigerian gas power plants and hydropower production from the River Congo. The choice of technology employed for harnessing electric energy is largely dependent on the economic factors that go with the development. While some of these technologies go with large initial capital investment some are challenged with geometric increase of running cost. As applied in this work, the Net Present Value, Internal Rate of Return, Levelized Cost of Energy and Cash Flow Trend Analysis are suitable tools to determine choice of power plant. These tools were integrated and developed as an NILC model. In the analysis presented in this dissertation, the economic viability of the two power plants selected was determined with the use of the Net Present Value, Internal Rate of Return, Levelized Cost of Energy and Cash Flow Trend Analysis (NILC) model. The model was used to measure the economic viability quantities of the two power plants selected for economic comparison. After the completion of economic comparative analysis, hydropower production from the River Congo was concluded to be a better choice of power production compared to the conventional gas power plant option in Nigeria. / Thesis (M.Ing. (Development and Management Engineering))--North-West University, Potchefstroom Campus, 2009.

Electricity availability and stability have a great contributory share of industrialization growth rate, poverty statistics, unemployment, foreign investors' participation, medium and small scale encouragement, crime and mortality rates recorded in any country. Nigeria as a country has been challenged with unstable and unreliable power supply. There are many problems associated with electricity production in Nigeria. Such problems are recorded in the generation, transmission and distribution facets of electricity production. With a multi-faceted problem, this document has been developed to deal with the economic aspect of power generation in Nigeria. Out of numerous technologies that are used in power generation, Nigerian predominantly sources its electricity supply from gas power plants and hydropower systems located within the country. Unfortunately, the Nigeria hydropower has been challenged with hydrological shortfalls. The gas power plant which is now conventional is being challenged with the developing gas technology around the globe. This development has adversely affected the cost of gas and subsequently the cost of power production using gas power plants. As a result of hydrological limitations on Nigerian hydropower dams, effect of gas price on cost of energy produced and diversifying gas technology, harnessing electric energy from Inga falls of River Congo was considered as an economic choice of power production in Nigeria. The choice of power production adopted in this document was made from an economic viability studies carried out between Nigerian gas power plants and hydropower production from the River Congo. The choice of technology employed for harnessing electric energy is largely dependent on the economic factors that go with the development. While some of these technologies go with large initial capital investment some are challenged with geometric increase of running cost. As applied in this work, the Net Present Value, Internal Rate of Return, Levelized Cost of Energy and Cash Flow Trend Analysis are suitable tools to determine choice of power plant. These tools were integrated and developed as an NILC model. In the analysis presented in this dissertation, the economic viability of the two power plants selected was determined with the use of the Net Present Value, Internal Rate of Return, Levelized Cost of Energy and Cash Flow Trend Analysis (NILC) model. The model was used to measure the economic viability quantities of the two power plants selected for economic comparison. After the completion of economic comparative analysis, hydropower production from the River Congo was concluded to be a better choice of power production compared to the conventional gas power plant option in Nigeria. / Thesis (M.Ing. (Development and Management Engineering))--North-West University, Potchefstroom Campus, 2009.

This thesis is primarily focused on flow-field upstream of hydropower intakes, with emphasis on the use of temperature control curtains and predicting the flow acceleration zone. By reviewing the available literature, it is concluded that the flow-field upstream of hydropower intake systems can be modeled by potential flow theory. The understanding of near intake flow-field can be useful in fish entrainment studies and in designing fish repulsion systems. To control downstream river temperatures, a flexible curtain was installed upstream of several dams in California. Flow downstream of the curtain was analyzed using a Computational Fluid Dynamic (CFD) solver with rigorous validation by experimental data. The experiment was conducted with a 4 beam Acoustic Doppler Velocimeter (ADV) probe. The study shows that wall jet properties downstream of the curtain are affected by the water depth and the inlet Reynolds number. Empirical expressions were developed to predict jet properties and the wall shear stress. Flow upstream of the curtain was analyzed using potential flow theories with validation by the CFD solver. In this part, a theory based on Schwarz-Christoffel transformation was developed to predict the flow-field upstream of the curtain without accounting for any density stratification in the water body. It is observed that the acceleration zone upstream of the curtain can be affected by sink opening size, its location and water depth. The effect of boundaries on flow upstream of a line sink and the interaction of multiple sinks were analyzed. The effect of stratification on a line sink is also analyzed. A theory is developed to predict the incipient withdrawal condition when a sink is located on the horizontal bottom. The theory is also extended to a tilted bottom. The effect of boundaries on the incipient withdrawal condition is analyzed. When only one layer is being withdrawn, it is shown that a homogenous equation can be applied to a stratified condition by assuming an upper layer boundary at the interface. In addition to these works, a despike algorithm for ADV data is developed, and a numerical analysis on central difference scheme is presented. / Water Resources Engineering

För att ta fram vårflodsprognoser används idag en hydrologisk modell, HBVmodellen, som används operationellt både i Sverige och i andra länder för att ta fram tillrinningsprognoser. Ett av problemen med dessa prognoser är dock att de ofta har felaktigheter i beräkning av tillrinningsvolymer. I den här studien undersöks Vängelsjöns delavrinningsområde. Ett prognosområde där HBV-modellens tillrinningsprognos tidigare gett stora volymfel. Rapporten undersöker därför om det går att korrigera den operationella modellens snömängd genom snödjupsobservationer, för att ta fram mer tillförlitliga vårflodsprognoser. I rapporten har snödjupsobservationer och densitetsmätningar från Vattenregleringsföretagen (VRF), tillsammans med snödjupsobservationer från Sveriges meteorologiska och hydrologiska institut (SMHI), analyserats för att se om de kan användas för att förbättra tillrinningsprognosen för Vängelsjöns delavrinningsområde. Studien visar att det finns potential till att använda snödjupsobservationer för att minska osäkerheter i tillrinningsprognosen för Vängelsjöns delavrinningsområde. Det bästa resultatet gavs genom att använda tre stationer från SMHI tillsammans med två stationer från VRF. Resultatet för dessa fem stationer gav ett volymfel i uppmätt vattenekvivalent på 6 %, 7 %, 22 % och 17 % för mars månad perioden 2014-2017, vilket gav en markant förbättring mot det modellerade prognosvärdet med volymfel på 40 %, 77 %, 24 %, och 49 % för samma period. / Today, spring flood forecasts are calculated through a hydrological model, the HBVmodel. It is a model that is used operationally both in Sweden and in other countries to obtain catchment forecasts. One problem with these forecasts is that they often give errors in calculations to the inflow volume. In this study the Vängelsjö sub catchment will be examined. A forecast area where the HBV-model flow forecasting has given large volume errors. In the report it is therefore examined if the operational model can be corrected with snow measurement data. In this report snow depth observations and density measurements from Vattenregleringsföretagen (VRF) have been analyzed, together with snow depth observations from the Swedish Institute for Meteorology and Hydrology (SMHI) to see if the data can be used to improve the forecasting for Vängelsjö sub catchment. The study shows that there is a potential in using snow measurement observations to reduce insecurities in the flow forecast for Vängelsjö sub catchment. The best result was received by using three snow stations from SMHI and two from VRF. The result from those five stations gave a volume error in measured snow water equivalent (SWE) at 6 %, 7 %, 22% and 17 % for Mars during the period 2014-2017, which gave a significant improvement against the modelled forecast value with volume errors of 40 %, 77 %, 24 % and 49 % for the same period.

Orientadora: Profa. Dra. Roseli Frederigi Benassi / Tese ( doutorado)- Universidade Federal do ABC. Programa de Pós-Graduação em Energia, 2016. / Os reservatórios de água, além de garantir a potencialidade das usinas hidrelétricas, contribuem para o abastecimento público de muitas cidades localizadas próximas a seus domínios hídricos. Na perspectiva de uma pesquisa qualitativa, este trabalho tem como objetivo analisar criticamente a gestão pública do reservatório Billings e a gestão privada do reservatório de Barra Bonita, ambos localizados no Estado de São Paulo, buscando compreender os conflitos que envolvem o uso dos reservatórios e analisar os fatores que resultam nos principais passivos ambientais envolvidos. A hipótese geral sustenta a ideia de que a análise dos conflitos pelo uso da água em reservatórios pode contribuir na compreensão da gestão das empresas que sobre eles atuam e subsidiar a análise dos passivos ambientais existentes nos reservatórios. Trata-se de uma pesquisa realizada por meio da análise de ações desempenhadas por empresas controladas pelo poder público e privado, além da participação da Marinha do Brasil, representada pela Capitania Fluvial do Tietê-Paraná. As análises dos resultados foram norteadas por referenciais teóricos e experimentais. Como metodologia, foram aplicadas entrevistas a representantes da Empresa Metropolitana de Águas e Energia S.A. (Emae), Companhia de Tecnologia de Saneamento Ambiental (Cetesb), Companhia de Saneamento do Estado de São Paulo (Sabesp) e American Electrical Systems (AES-Tietê) e a um representante da Capitania Fluvial do Tietê-Paraná (Marinha do Brasil) visando compreender os conflitos no uso dos reservatórios e permitir analisar sua gestão e os fatores que resultam nos principais passivos ambientais envolvidos. Os resultados identificaram dificuldades em conduzir uma gestão compartilhada entre os usuários e operadores dos reservatórios e que a existência de conflitos pode estimular uma gestão compartilhada em prol da melhoria dos recursos hídricos. A partir de tais análises, será possível elaborar medidas que reduzam os passivos ambientais que atingem os reservatórios. / Water reservoirs, besides ensuring the potential of hydropower plants, contribute to the public supply of many cities located in the surrounding environment. In the perspective of a qualitative research, this study intended to analyze the public management of Billings reservoir and the private management of the Barra Bonita reservoir, both located in the state of São Paulo, trying to understand the conflicts involving the use of reservoirs and analyze the factors that result in major environmental liabilities involved. The general hypothesis supports the idea that the analysis of conflicts over the use of water reservoirs can contribute to the understanding of the management of the companies that explore them and can subsidize the analysis of existing environmental liabilities in the reservoirs. This survey is conducted by the analysis of actions performed by companies controlled by private and public authority, as well with the participation of the Navy of Brazil, represented by the River Captaincy of Tietê-Paraná. The analyzes of the results were guided by theoretical and experimental reference. Interviews were applied to representatives of Metropolitan Water and Energy Company (Emae), Environmental Sanitation Technology Company (Cetesb), Sanitation Company of the State of São Paulo (Sabesp) and American Electrical Systems (AES Tiete) and a representative of the River Captaincy of Tietê-Paraná (Brazil Navy) aiming to understand the conflicts in the use of reservoirs and allow to analyze their management and the factors that result in major environmental liabilities involved. Results identified conflicting actions and difficulty in driving a shared management between reservoirs users and operators to improve water resources. This way, it is possible to suggest measures to reduce environmental liabilities that reach reservoirs.

Made available in DSpace on 2015-03-26T13:33:56Z (GMT). No. of bitstreams: 1 texto completo.pdf: 7608406 bytes, checksum: 8ace6c23dc0baa460565d6d8e40d67bd (MD5) Previous issue date: 2013-07-05 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / The central aim of this thesis was to analyze the process of readjustment of the population of São Sebastião do Soberbo, located in the municipality of Santa Cruz do Escalvado on the basin of Upper river Doce/Minas Gerais, affected by the Candonga Hidroelectric Dam (UHE Candonga) and shifted to the resettlement of Nova Soberbo in mid-2003 and early 2004. It was done with emphasis on the limits, the possibilities and the capabilities of the residents in rebuilding their livelihoods about on the event of displacement and resettlement for the new spatiality. Therefore, the analysis presented was based on a case study in 2012 through archival research, participant observation, a structured questionnaire, a method of oral history and photographic resources. In this context, the study addressed the resettled population in three distinct time frames, namely the arrival of the UHE Candonga to São Sebastião do Soberbo, the process of construction and inauguration of the dam with its social, economic and cultural impacts on the order of everyday life and the social deployments of this event over 9 years in the resettlement. The theoretical axis guided itself with a view towards the interpretation of the phenomenon of hydroelectricity as a social event, which changes the daily lives of those who for the first time are faced with large infrastructure projects arising from the promotion of economic and social developments within society. Furthermore, the theory of the forced displacement and resettlement was tested, advocating various changes and breaks in the trajectory of population groups that undergo changes in their traditional ways of life. In general, resettlements are pointed as promoter of social change that implies the need to restructure the individual, family and community life. This restructuring was analyzed from the perspective of the approach towards the livelihoods and on the theory of human agency that highlight the ability of social actors to process experiences and incurring actions and strategies in an attempt to access the tangible and intangible resources in reinventing the ways of survival. The social deployments that occurred under the conditions offered and structured by the entrepreneur, mainly on the basis of the relationships established between the Consórcio Candonga and the residents of resettlement, implied in the constitution of the category dam-affected people. This finding also suggested a more detailed analysis of this social condition whose existence was triggered by the construction of the dam. Reflections on the case study showed definite changes in the forms of social production and reproduction of the residents; and the resettlement, as a possibility for the reconstruction of everyday life, presented itself as a space that marks impossibilities and difficulties in the reestablishment of the previous social relations and living activities in the fabric of new social references erected in the action and intervention of the Cansórcio Candonga. The reflections also showed the many subjective and emotional damages as a result of the feeling of uprootment caused by the impact of the dam, of the limitations of survival in resettlement and of the failure of the entrepreneur to mitigate and compensate for the various losses occurring in the shift from one place to another. And the resettles, when experience this process, forge new elements in their individual and social condition that constitute themselves as dam- affected people who incurring in the struggle for the recognition of their denied rights. Thus, the implementation of the dam reverberated in a profound process of social transformation for those who still live under the impact of the displacement/resettlement and comes into difficulties in appropriation of the new material and immaterial conditions to ensure social readjustment. / O objetivo central desta dissertação foi analisar o processo de readequação da população de São Sebastião do Soberbo, que vive no município de Santa Cruz do Escalvado, na bacia do Alto do rio Doce/Minas Gerais, atingida pela Usina Hidrelétrica Candonga (UHE Candonga) e que foi deslocada para o reassentamento de Nova Soberbo em meados de 2003 e início de 2004. Para tanto, buscou-se enfatizar os limites, as possibilidades e as capacidades dos moradores em recriar seus meios de vida frente ao acontecimento do deslocamento e do reassentamento para o novo espaço. A análise apresentada baseou-se em um estudo de caso realizado em 2012 com a utilização de pesquisa documental, da observação participante, da aplicação de questionários incluindo questões abertas, da história oral, bem como recursos fotográficos. Neste contexto, a pesquisa abordou os reassentados com base em três temporalidades distintas, a saber, a chegada da UHE Candonga a São Sebastião do Soberbo, o processo de construção e de inauguração da Usina com seus impactos sociais, econômicos e culturais na ordem da vida cotidiana e os desdobramentos sociais deste acontecimento ao longo de 9 anos no reassentamento. O eixo teórico considerou a interpretação do fenômeno da construção da barragem enquanto acontecimento social que altera o cotidiano daqueles que, pela primeira vez, se deparam com grandes empreendimentos de infraestrutura que se apresentam como promotores do desenvolvimento econômico e social da sociedade. Utilizou- se também de diferentes abordagens sobre deslocamentos e reassentamentos involuntários que preconizam diversas mudanças e rupturas na trajetória de contingentes populacionais que sofrem alterações nos seus modos de vida tradicionais. Os reassentamentos, em geral, implicam na necessidade de reestruturação da vida individual, familiar e coletiva. Reestruturação esta aqui analisada sob a ótica da abordagem dos meios de vida e sob a teoria da agência humana que destacam a capacidade dos atores sociais de processarem experiências e incorrerem em ações e estratégias na tentativa de acesso a recursos tangíveis e intangíveis na reinvenção das formas de sobrevivência. Os desdobramentos sociais decorrentes das condições oferecidas e estruturadas pelo empreendedor, principalmente, em função das relações estabelecidas com o Consórcio Candonga e a vivência no reassentamento, implicaram na constituição da categoria social atingido por barragem . Esta constatação sugeriu também uma análise mais detalhada desta condição social cuja existência foi desencadeada pela construção da barragem. As reflexões obtidas, a partir deste estudo de caso, apontaram algumas alterações definitivas nas formas de produção e reprodução social dos moradores, e o reassentamento, enquanto possibilidade de reconstrução do cotidiano, apresentou-se como um espaço que marca impossibilidades e dificuldades de reestabelecimentos das anteriores relações sociais e atividades de sustento na tessitura de novas referências sociais erigidas sob a atuação e a intervenção do Consórcio Candonga. Demonstraram, ainda, diversos danos subjetivos e emocionais ocasionados pela sensação de desenraizamento provocados pelo impacto da barragem, pelas limitações de sobrevivência no reassentamento e pelas falhas do empreendedor em mitigar e compensar as diversas perdas ocorridas com a mudança de um lugar a outro. E os reassentados, ao vivenciarem este processo, forjam novos elementos no âmbito da sua condição individual e social constituindo- se em atingidos por barragem que incorrem na luta por reconhecimento de seus direitos denegados. Assim, a implantação da barragem repercutiu em um processo profundo de transformação social para aqueles que ainda vivem sob o impacto do deslocamento/reassentamento e vêm se deparando com dificuldades na apropriação das novas condições materiais e imateriais na garantia da reprodução social.