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357 Uppsatser om Wind turbine - Sida 12 av 24

Vindkraft: en undersökning av fem europeiska länders vindkraftutveckling och faktorer som kan påverka den

En del länder väljer att investera och utveckla vindkraftmarknaden mycket, medan en del länder väljer att inte göra det. I Europa startade vindkraftutvecklingen under 1970-talet. Efter en trög start är den europeiska vindkraftutvecklingen nu marknadsledande och fortsätter att expandera i hög takt. Tyskland har den högsta installerade kapaciteten av vindkraft i världen, och Danmark har den högsta installerade kapaciteten per capita. Dessa länder, samt Spanien, Sverige och Storbritannien har alla satt nationella mål för utvecklingen av vindkraften.

Modell och analysverktyg för beräkningav frekvensförlopp

The power system modelled in this thesis work has been developed for simulationwhen e.g. the production in some part of the power system is changed. The powersystem has been modelled according to the swing mass of the system, the frequencydependency of the load and the turbine governor. The model determines the systemfrequency, the period of regulation and the power exchange between the differentsubsystems in the Nordic synchronized system.In this model the system frequency is assumed to be the same in all different parts ofthe power system and the voltage conditions in the power system are neglected. Forthat reason power swings does not occur between different subsystems in the powersystem, which usually occur as a result of the swinging connection between thetransmissions line.

Vindkraftverk av UHPC 2.2 : En undersökning av högpresterande betong med syntetfiberarmeringen STRUX

Användandet av betong som ersättare för stål vid produktionen av vindkraftverkstorn har ökat den senaste tiden. Betongtorn är betydligt billigare än ståltorn men problem som sprickbildningar, frostsprängningar och följaktligen armeringskorrosion har uppstått bl a på grund av vibrationer från rotorn. I fundamentet i vindkraftverk kan ovan nämnda problem också uppstå och det uppfyller således inte alltid funktionskraven. Det här examensarbetet undersöker möjligheten att eliminera dessa problem genom att använda en sorts högpresterande betong kallad UHPC 2.2 med syntetfiberarmeringen, STRUX. Jämförelser mellan tidigare empiri om högpresterande betong och laborativa tester på UHPC 2.2 visar att den senare är beständigare och ger möjligheter till en större sprickfrihet.

Småskalig elproduktion i Arvika

Arvika Fjärrvärme AB, a district heating company from Arvika, today cover 74 % of their total energy production with biofuel wich runs a 16 MW bioler giving process water at saturated liquid state.In recent years Vaporel AB has introduced a new tecnique that gives an external generation of steam after boilers. The concept is built on an adiabatic pressure drop of the saturated liquid in a so called Flashbox which makes a small part of the liquid to evaporate. The generated steam is lead into a turbine where electricity is in a conventional manner.The purpose with this rapport was to do a basic study for the specific system at Arvika where it?s possible to see the potential production of electricity that follows an installation of a flasbox.The final goal was to introduce an economic analysis of a flashox installation at given conditions.To reach our goals we have created a model in Excel where we used the given conditions at Arvika Fjärrvärme to do our calculations. The model has been tested at three different states, of process water returning to potboiler, to be able to decide the optimal operation for the system at present.The studies have resulted in a pressure of the processwater at 14,5 bar (at) and a pressuredrop to 9,5 bar (at) in the flashbox.

Beståndsutveckling i stormskadade granbestånd

The storm Gudrun in 2005 led to massive windthow damage in forests in southern Sweden. Since then there has been a growing interest in factors influencing wind damage in above all Norway spruce (Picea Abies) stands. Although many other interesting areas still need to be examined. In 2005 there where a lot of stands that suffered different degrees of damage, a lot of these stands weren?t cut, but instead left to grow. The future development of these stands is uncertain and the guidelines are unclear.

Reglering av turbins ledskenor i vattenkraftverkmed hjälp av elektriska ställdon

Hydropower is the largest renewable energy source available in today's society. Operation and production is handled by high-tech electronics. This thesis is done on behalf of Statkraft Sweden AB who wants to explore the possibility of replacing the hydraulic cylinder with an electric actuator, generally as well as a case of a small power station on the river Nissan. Whether it is the chaplain or francis turbine vanes are actuated by hydraulic cylinders. Because of Gustavsberg hydropower is inconstant operation, this report is based on power calculations, which are read and computed according to the available hydraulic diagram.

Vindkraftsturism : En studie av teknisk turism med särskilt fokus på vindkraftsparker

This study investigates and describes the phenomenon of ?technical tourism?, in the case ofwind power plants in Sweden. The main purpose of the study is a greater understanding ofa field which to date has remained largely uncharted.Technical tourism is a type of visits to a production site, where the technical aspect ofthe production is the main focal point for the visitor. The definition of technical tourism isbased on concepts within ?Industrial tourism?.

Bergförankrat vindkraftverk : Dimensioneringsprocessen för staglängder

Detta examensarbete har gjorts i syfte att få fram förankringslängder till ett bergförankrat vindkraftverk.Målet med examensarbetet har varit att få fram längder på förankringstag och en prövning av flera olika stagvarianter har gjorts.Det dimensionerande momentet och egentyngden på vindkraftverket har tagits från ett tidigare projekt beläget i Solberg. Dessa krafter har fördelats ut till stagen och förankringslängder har tagits fram. De delar som har hanterats i rapporten utöver dimensioneringen är stagvarianter, borrning av stag, injekteringsbruk och provdragning. En bottenplatta i form av en oktogon har använts i dimensioneringsprocessen. Stagen har placerats i en cirkulär form i ett lager.

Det självförsörjande passivhuset

The housing sector uses 40 % of the energy in Sweden and half of the electricity usage. Theuse of energy is the main reason to the increasing rate of carbon dioxide in the atmosphere.This is the main motive but also a wish of higher safety, that is a higher rate of selfsufficientenergy production in Sweden, we want to decrease the need of using fossil fuel. Now whenthe energy price rise, the interest in energy issues increase and more people discuss thepossibility of reducing the usage of fossil fuel. A change to renewable energy such as sun,wind and water is the only solution where we can get a sustainable development.One way to contribute to a better use of energy is to build in the principle of passive house.The house is being built with a thick and tight insulation. If you use a heat-exchanger withhigh degree of efficiency and a final heating battery on the ventilation system, the heat fromlamps, devices and the ones living in the house should be enough to fulfil the criteria ofliving.

Reinvestering i småskalig vattenkraft

I detta examensarbete behandlas investeringsalternativ för småskalig vattenkraft. Arbetet som riktar sig mot Skellefteå Kraft AB:s anläggningar, har således gåtts igenom, vartefter kandidater lämpliga för en reinvestering tagits fram med passande tekniker. Vidare nämns om dessa tekniker är lämpliga för minskning av förlusterna vid storskaliga utskov. De småskaliga anläggningarna är fördelade på två åar, Rickleån och Åman. I vardera finns två kraftverk som behandlas i detta arbete, Fredriksfors och Sågforsen i Rickleån, samt Åman övre och nedre i Åman.

Modeller för studier av ursprungsmärkt el

The EU has decided that it should be possible for consumers to get information about the origin of the electricity they buy. Therefore, there is a need to examine different systems for electricity disclosure. In this thesis two ways of disclosure have been studied:? Certificate system. A certificate system involves two parallel markets, one for trading electrical energy and one for trading certificates of origin.? Separated Markets.

Tillväxtreaktion hos skärmträd i högskärm av gran i Medelpad :

Different methods for shelterwood cutting have been used in differ-ent parts of Europe since the middle ages. The use of shelter wood cutting in Norway spruce (Picea abies (L.) Karst.) forests in Sweden met a revival in the early 1990s as an alternative for the dominating clear-cutting system when silvicultural costs increased dramatically for the latter. Shelterwood cutting systems involve some possible problems but also a lot of positive effects. Among the problems are increased risk of wind throw and damage of the remaining shelter trees caused by the cutting operation. Positive effects are for example a valuable growth in the remaining trees and increased biological di-versity. This study is based on a total of 79 trees from 4 different treatments in a spruce shelterwood, cut in 1994, in the middle of Sweden (62,4º N).

Examenskonserten - Är den utvecklande?

Den 31 mars 2006 genomförde jag min examenskonsert ackompanjerad av Spårvägen Malmö. Efteråt började jag fundera på om orkestern fick ut lika mycket av själva konserten och förarbetet som jag. För att ta reda på detta genomförde jag en enkätundersökning med orkestern samt intervjuer med utvalda musikanter. Arbetet tar upp relationen mellan amatörer och professionella och hur man väljer repertoar i en amatörorkester. I resultatkapitlet redovisar jag enkäten och intervjuerna.

Lantbrukaren som energiproducent : en fallstudie i energisatsningar inom lantbruket

The intrest and development of bioenergy and energy from renewable sources in Sweden has increased rapidly over the last few years. There are a whole lot of alternatives for those who would like to venture and invest in renewable energy production. Production of renewable energy opens up many opportunities for forestry and farming to venture a new branch of production, on basis of the primary production. Several of the new energy sources grows on farmland or in the forest. The opportunities exist in the primary products, as well as in refining and reselling, in the value chain of energy. The starting-point is the Farmer as an energyproducer. This master thesis studies the nature of farmer-own firms, who has invested in production of renewable energy.

Analys av off-design prestanda för ett absorptionskylsystem

This master thesis project at KTH is performed in the Mechanical and Aerospace Engineeringdepartment at University of Florida (UF). The thesis is a small part of a gas turbine researchproject where a vapour absorption refrigeration system (VARS) and a high pressure regenerativeturbine engine (HPRTE) are integrated together. The main objective is to build a computermodel of the VARS. The computer model is supposed to be used to analyse the off-designperformance of the VARS and should also be easy to integrate as a subroutine in a more complexsystem model. To model the VARS some knowledge of the absorbent/refrigerant mixture had tobe well known, in this case a mixture of ammonia and water.

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