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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.
231

Zubové čerpadlo v turbinovém provozu / The tooth pump in the turbine regime

Tyburec, Adam January 2020 (has links)
The objective of this diploma study is to develop and secure production of gear turbine with very low specific speed in comparison with conventional turbines. The first part of the work deals with already performed research of similar hydrostatic turbines. It is followed by construction design, including complete drawing documentation. The production of the prototype is secured by an external company. Finally, an experimental measurement of the characteristics of the designed turbine is performed in the laboratories of Fluid Engineering.
232

Studie proveditelnosti průtočné MVE / Feasibility study of the small hydropower station

Patočka, Filip January 2013 (has links)
The aim of the present master’s thesis is to explore the feasibility of small hydropower plant for cur-rent hydro energetic potential of the weir on Ohře river, located in the city of Terezín in Ústecký re-gion, Czech Republic. The target of the thesis itself was to design minimally two variants of constructional and technological part. Due to requirements related to maintaining of all functions of the weir construction was decided to design small hydropower plant completely under the water surface, with flap mounted to the roof of the hydropower plant. Part of the thesis was also an economical assessment of designed hydropower project.
233

Návrh vírové turbiny pro konkrétní lokalitu ČEZ,a.s / The design of swirl turbine for the concrete locality for ČEZ

Šebela, Radek January 2014 (has links)
This thesis deals with the design of water turbine enabling optimal utilization of hydro-energetic potential of given location (barrage on Úpa river) chosen by ČEZ a.s. company. Moreover, the option of multi-unit layout is discussed. Because of the low-head profile of given location, the technology of swirl turbine in siphon configuration was chosen. Technology of swirl turbine presents new modification of Kaplan turbine with no need of guide vane. Swirl turbine is characterized by its high discharge and high speed. The main part of this thesis is focused on hydraulic design of the turbine.
234

Použití předpovědního modelu při řízení hydroenergetické funkce vybrané soustavy nádrží / Application of the prediction model on the control of hydropower function of selected multi-reservoir system

Šejnoha, Michal January 2016 (has links)
The diploma sthesis is focused on verifying the influence of the length of the prediction period and the accuracy of the predicted mean monthly inflows of water sources in the management of hydropower function selected water management system. To determine the predicted inflows into the reservoir system is applied zonal prediction model. When the solution is used a simulation model that is hand-built in Microsoft Excel and optimization model, which is automatically built into the program SOMVS and is applying the principles of adaptive control.
235

Návrh vodní mikroelektrárny pro malé spády a malé průtoky / Design of a micro waterpower turbines for low head and low dicharge

Macek, Libor January 2016 (has links)
This diploma thesis discusses the issue of finding type of water turbine for very low heads and low discharges, which could be operated as mobile micro hydropower plant in island mode. Thesis deals with summary of appropriate choices of water turbine for needs of micro hydropower plant. Essential part of diploma thesis deals with design of optimized waterwheel. Waterwheel was chosen because commercial high-speed turbines have low efficiency for low heads. Waterwheel was manufactured and measured in laboratories of Fluid engineering. Measurement output was discharge and efficiency characteristic of turbine. The price calculation was made after manufacture.
236

Vodohospodářské řešení nádrže Vlachovice na vodním toku Vlára / A Water Management Analysis of the Vlachovice Reservoir on the Vlára Watercourse

Rajsiglová, Veronika January 2017 (has links)
The thesis focuses on a process of water management analysis of storage and protective function of the Vlachovice reservoir on the Vlára watercourse. The work contains an alternative proposal of the reservoir storage volume in Microsoft Excel, spreadsheet program with accessible functions whereby progression of arithmetic and logical algorithm simulating operation of reservoir storage function is created. An alternative proposal of protective volume of the reservoir is created in HYDROG program, where calculations of transformation of flood waves for PV 100, PV 1 000, and PV 10 000 are performed. Moreover, the work includes simplified analysis of the hydropower potential of the proposed reservoir.
237

Staustufen - Mühlgräben: Längst vergangene Zeitzeugen

Gürtler, Eberhard 04 August 2009 (has links)
... Es ist sicher gut und nützlich, sich in diesem Zusammenhang einmal mit der Wassernutzung vergangener Jahrzehnte und Jahrhunderte zu beschäftigen, wie ich sie an Hand der Weißeritz dargestellt habe. Die vielfältige Nutzung des Wassers in der Vergangenheit nötigt uns Respekt ab, bereichert unser Wissen, verpflichtet uns aber gleichzeitig die Wasserressourcen sinnvoll einzusetzen sowie für eine Pflege des Flusses und seiner Ufer Sorge zu tragen. Das Thema - Staustufen, Mühlgräben ... - ist sehr vielgestaltig. Eine umfassende Darstellung war im Freitaler Stadtgebiet unter Einbeziehung der Talsperren, von Interesse. ... (aus der Einleitung)
238

Analyse des monetären und qualitativen Nutzens schwimmender Energiekonverter

Hadler, Jana, Brökel, Klaus January 2012 (has links)
Technische Neu- und Weiterentwicklungen sowie eine Änderung der Marktverhältnisse sind maßgebliche Motive für Investitionen. Im Bereich der Kleinwasserkraft sind Investitionen – quantitativ betrachtet – bedingt durch die aktuelle Konjunkturflaute nach der Finanzkrise gesunken. Auf der anderen Seite setzt die Politik verstärkt auf die Nutzung erneuerbarer Energien, um das Konzept der Nachhaltigkeit auf diesem Gebiet zu forcieren.
239

COMPUTATIONAL FLUID DYNAMICS MODELING FOR BENT SPILLWAY CHANNEL : Numerical validation of a small scale physical model

Björnfot, Mikael January 2020 (has links)
Hydropower plants with spillways exposed to high pressures because of large discharges can result in a dam failure which ultimately results in devastating consequences. Therefore properly designed and constructed spillways are important. In this project there is an interest in examining the pressure distribution on a guided wall, measuring the water level inside the spillway and examine the water flow characteristics. The main purpose was to numerically model the flow behaviors at two upper pool levels +29.82 m and +30.92 m in order to achieve a comparison between a numerical model and a physical model. A previous experiment was carried out at Vattenfall R&D in Älvkarleby where a physical model was built. The main purpose of that study was to find an optimal form of a guide wall for free weir flow. This study served as guidelines for what should be investigated in this project. The methodology of the project began with a development of an initial CAD model created by Vattenfall R&D. The CFD model could be constructed into a volume model containing also an upstream reservoir. Next, a mesh that could numerically calculate the flow behavior was created in order to enable execution of the calculations. Furthermore, a big part of the method was to adjust the settings in Fluent so that the numerical model could recreate the flow behaviors of the physical model tests. The results indicate that the numerical model is an accurate replica of the physical model. The deviation comprising the mass flow rate came as close as 0.6 % from the physical model for the lower upper pool level. Highest calculated pressure was positioned at the bottom of the guided wall for both upper pool levels, which the results conducted from the physical model also indicated. Furthermore, results regarding the water level at the guided wall confirmed same statement Vattenfall's examinations pointed out, that the roof placed at the guided wall is needed in order to avoid major splashing. The present project has shown great results regarding the flow characteristics, pressure distribution, and the water level at the guided wall. Therefore, it is considered trustworthy enough to be used as a tool for Vattenfall R&D in future studies comprising the targeted spillway.
240

Dynamic analysis of the impact of grid connection of "La Higuera" hydropower plant to the transmission grid

Felix, Isbi January 2006 (has links)
Studies regarding the development of a new hydropower plant exploiting the water resources offered by the upper Tinguiririca river, located about 150 km south-east of the capital Santiago in Chile, has been done by Pacific Hydro Ltd from Australia and Lahmeyer International from Germany. These studies have resulted in proposals to construct two Hydropower Stations, �La Higuera� and �Confluencia�. Both hydropower stations will have a total installed capacity of 300 MW. When setting up a new hydropower plant, it is important to foresee how the hydropower plant would affect the existing transmission grid in different situations during operation as well as how events in the grid may affect the La Higuera and/or Confluencia hydropower stations. In this report three kind of analysis are highlighted, which are static analysis, large signal stability and rotor angle stability. To perform these analyses a simulation tool named DigSilent is used. DigSilent is used to perform these analyses in a simulated network of the studied transmission system. These two hydropower stations as shown in the results will improve the existing transmission system by enhancing the stability margins in the presence of a fault. When performing the simulation of the existing transmission system with the newly installed hydropower plant we could see that it had a poor damping after a disturbance; this might be due to the large distance between production plants and the existing loads. This phenomenon can be alleviated if a power system stabilizer (PSS) is integrated in the hydropower plant. The final conclusion is that the integration of the two hydropower plants will improve the existing transmission system in Chile.

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