Sökning: "Hydropower Development"

Visar resultat 21 - 25 av 60 avhandlingar innehållade orden Hydropower Development.

  1. 21. Modelling and analysis of multiphysical interactions in hydropower rotor systems

    Författare :Martin Karlsson; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Datorstödd maskinkonstruktion; Computer Aided Design;

    Sammanfattning : In this thesis the objective is to develop rotordynamical models of hydropower units, where coupling between mechanical, electromagnetic and fluid dynamical system systems is of certain interest. Both fluid-rotor and electromechanical interactions are known to change the system coefficients of the rotor system, which affects eigenfrequencies, damping, stability and response. LÄS MER

  3. 22. Transient Electricomechanical Analysis of Hydropower Generators Using Field and Circuit Models

    Författare :Johan Lidenholm; Uppsala universitet; []
    Nyckelord :TECHNOLOGY; TEKNIKVETENSKAP;

    Sammanfattning : The large-scale conversion of the electrical energy system to incorporate other renewable sources of power, concurrently with vast refurbishment of the present machinery, brings the Swedish hydropower industry face to face with new challenges. Introduction of new technical solutions in systems originally designed for a slightly different purpose implies that fundamental conceptions need to be questioned. LÄS MER

  4. 23. Development of New Multiscale Polymer Composites for Water Lubricated Tribological Contacts

    Författare :Hari Shankar Vadivel; Nazanin Emami; Sujeet Kumar Sinha; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; UHMWPE; Tribology; Composite; Friction; Wear; Tensile; Creep; Ageing; Machine Elements; Maskinelement;

    Sammanfattning : Moving towards a Green Economy, there is a growing demand to use environmentally friendly tribological systems that has resulted in industries turning towards new mate-rials and water-based lubrication to satisfy their needs. Considering the low viscosity of water, tribological contacts lubricated with it are likely to operate in boundary/mixed lubrication regime for relatively long periods. LÄS MER

  5. 24. Development of the pressure-time method: final integration point and head losses

    Författare :Mehrdad Kalantar Neyestanaki; Michel Cervantes; Jonathan Nicolle; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Pressure-time method; head loss calculation; endpoint determination; Strömningslära; Fluid Mechanics;

    Sammanfattning : Hydropower is an efficient renewable energy source able to regulate electrical grid fluctuations. However, many hydropower plants were built decades ago, and now it is the time for a major refurbishment. The turbine's efficiency is essential and needs to be determined before and after refurbishment. LÄS MER

  7. 25. Rock mass behavior under hydropower embankment dams with focus on fracture erosion and rock mass stability

    Författare :Alexander Bondarchuk; Ignacio Escuder-Bueno; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Mining and Rock Engineering; Gruv- och Berganläggningsteknik;

    Sammanfattning : In Sweden there are about 190 large hydropower dams of varying age. According to the definition by the International Commission of Large Dams (ICOLD), if the height of the dam exceeds 15 m it is referred as large. Majority of these dams are of embankment type. LÄS MER