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5338 Uppsatser om Electrical Power Systems - Sida 11 av 356

Energieffektivisering av ventilationssystemet i konsthallen Sandgrund Lars Lerin

Uppsala County has ambitious environmental aims for the planned residential area inÖstra Sala backe. In this thesis different energy sources have been evaluated todetermine which system that would be most favorable given currently availableinformation about the project. Planned energy usage has been divided into tap waterheating, space heating and power. Three base case scenarios were made with districtheating, small scale bio fuel and heat pump. Solar power and solar heating were thensimulated and the production from the two could individually be deducted from theenergy need in the base cases, constituting 9 different scenarios.

OSE och Linux : En studie om prestanda

There are some key elements which distinguish a general operating system, such as Linux, from a Real Time operating system, such as OSE. The later belongs to the category of soft Real Time systems while Linux is a general operating system, with significantly improved real time properties after version 2.6. These improvements make it interesting to compare the two systems.When comparing two operating systems, there are a number of issues which have to be considered. One way to measure the performance of the systems is by studying the time consumption for the same functionality and hardware.During the study, the items that appeared as the most important for the performance of the systems, were: process primitives, system primitives, interprocess communication, context switches and interrupt latency.This work demonstrates that it is possible and reasonable to do performance testing on two different operating systems. The implemented tests cover a number of basic functionalities, which appeared to be the most crucial ones for the performance of the systems..

Development of Liquid Cooling for PCs

In recent years, existing solutions for cooling personal computer CPUs have been supplemented by a new product category, factory sealed water cooling loops. These systems, consisting of a water block with an integrated pump, a fan and a radiator, perform well compared to the air cooling solutions but are less effective than larger, custom-built water cooling systems.This project aims to explore the most important aspects of a factory sealed system and to identify possible cost-effective enhancements of the performance.The most significant differences between the different groups of water cooling loops are the block design and the pumping power. The performance of both categories is also largely dependent on the fan power, but increasing fan power has a large negative impact on the noise level.Both radiator size and fan model choice appear, in tests, to be relatively unimportant, presuming that the noise level is kept constant. The position and direction of the fan, however, has significant impact on both the temperature and the sound level.Water blocks can be designed in several different ways, both regarding the heatsink design and the flow direction. In simulation, flow with the inlet centered above the heatsink result in considerably lower pressure drop and slightly higher temperatures than flow through the block, for heatsinks with fin arrays.Creating a competitive product in this product segment certainly seems possible, as there are performance-increasing changes to be made that seemingly has little impact on the production cost.

Hur miljövänlig är dagens optikerbutik, och hur miljövänlig kan den bli?

SUMMARYEnvironmental issues are currently a hot topic of debate. Studies within the optics branch have not specifically been conducted previously, so the aim of this study was to determine the extent of environmental-awareness specifically within this branch.A survey, consisting of questions relating to environmental issues, was distributed to 100 randomly-selected opticians in Sweden. Of these 100 surveys, 64 were returned and showed a varied branch-engagement for environmental issues.Results of this survey showed that opticians were best in sorting newspapers, magazines, other paper and hazardous waste. Metal and rigid plastic were not sorted to any larger extent.Choosing environmentally-safe products was not so popular and only six stores always do this. 25 shops turn off electrical machines and equipment over night; while the majority of the remaining stores leave the machines on during the night.27 stores did not know if their electrical company provided ?green electricity?.Results showed that there is a lot of work to be done in making the stores more environmentally friendly.

Utvärdering av ett Bränslecellsdrivet Flygplan.

 With the increases in fuel costs due to the depletion of the world oil reserves and the increase of greenhouse gasses as a consequence to using oil as a fuel many companies are looking to new and innovative ways to power their aircraft. One of these new ways to power an aircraft is using fuel cells powered using hydrogen and oxygen, thus producing nothing but water vapour and small amounts of nitrogen dioxide as well as trace amounts of other emissions. Both Boeing (1) and Politecnico di Torino (2) have shown that it is possible to build an all-electric aircraft powered by fuel cells. Both flights used small, two-seater aircraft and a constant between them was the loss of the co-pilot seat due to weight and lack of space. As this paper will deal with a commercial aircraft a primary concern is the cargo and passenger capacity and whatever impact switching propulsion system has on these.

Analys av designalternativ för snabbare dynamik i kolkraftverk med koldioxidavskiljning

Combustion of fossil fuels is today the dominating source of energy. During combustion,carbon dioxide is formed. The carbon dioxide accumulates in the atmosphere,which raises the global average temperature on earth through the so called greenhouseeffect. The only way to reduce the emissions of carbon dioxide from combustionin a coal fired power plant is through carbon capture and storage (CCS).Post-combustion capture is a technology to separate carbon dioxide from the uegas after the combustion for efficient transport and storage. The steady state operationof coal fired power plants with post combustion capture has already beenthoroughly investigated on a pilot scale, however much work remains to investigatethe plants dynamic operation.

Undervattensvågbrytare - En modellstudie

Today?s wind power plants are only compensated for their reactive power consumption at no-load. As the wind power plants grow bigger the amount of reactive power they need also increases. This is no longer a problem that can be ignored, especially as the net owners are beginning to charge the reactive power they transport.In this thesis a couple of different methods of compensation and their prices will be discussed and evaluated. Problems, such as self-excitation, that can occur if one fully compensates the wind power plant will also be brought to surface.

Tillförlitlighet hos trafikolycksklassificering

Today?s wind power plants are only compensated for their reactive power consumption at no-load. As the wind power plants grow bigger the amount of reactive power they need also increases. This is no longer a problem that can be ignored, especially as the net owners are beginning to charge the reactive power they transport.In this thesis a couple of different methods of compensation and their prices will be discussed and evaluated. Problems, such as self-excitation, that can occur if one fully compensates the wind power plant will also be brought to surface.

Utökning av mätområdet för turbinverkningsgraden på avgasturbo

The Goal with this Master of Science thesis is to expand the possible turbine efficiencymeasurements on an exhaust turbocharger. It was done as a part of the CICERO competencecentre. To feed the turbine with air a special flow rig has been used. Instead of loading theturbine by just restricting the compressor flow a docking system for an electrical dynamometer isdesigned to use the dynamometer as an additional loading source. By using an electricaldynamometer as loading device for the turbine, measurements are not depending on compressorperformance.A large part of the work consists in designing accessories for the dynamometer.

Effektiviseringspotential inom industrisektorn : Energibesparing vid frekvensstyrning av centrifugalpumpar ? en fallstudie

The project was performed at SiemensIndustry Drive Technologies with theobjective to provide actual values forthe energy savings potential withinSiemens scope of practice.In Sweden the electrical drives standfor about 30 % of the total electricityconsumption and about 60 % of theelectricity consumption within theindustry. During the pre-study phaseelectrical drives with pump applicationswere identified as large energy users.Because of this a case study at one ofSiemens customers, Stora Enso Fors wasperformed. The system that was evaluatedduring the case study was a throttledsystem with a centrifugal pump forpumping pulp.The results yielded that a saving ofover 50 % could be achieved by replacingthe throttle valve with a variable speeddrive, a frequency converter. Thepayback period was two years and twomonths and the present value for thetotal life cycle cost of the variablespeed system was 662.566 SEK lower thanfor the throttled system. As aconsequence, Stora Enso Fors is advisedto invest in a frequency converter forregulation of the system.The general conclusion is that a focuson system efficiency is the mostimportant factor in energy efficiencyprojects and that the system regulationmethod has a large impact on the overallsystem losses and hence its efficiency.Energy efficiency potential forthrottled systems with centrifugal pumpsis large and significant economicalsavings can be made through investmentswith short payback time..

Kärnkraftens värde i framtiden : en jämförelse med kraftvärmeteknologi från biobränsle

The debate on the future of Nuclear power in Sweden has increased with the discussion on global warming. The uncertainty of fossil fuel- and carbonprices the latest years has aroused considerable interest in Nuclear from power companies, industry and politicians. Nuclear power plants have negligible CO2 emissions and are not directly affected by increased price of emission rights and fossil fuels. The future power production needs to reduce its emissions of greenhouse gases to become sustainable. The purpose of this study is to examine the value for power producers to have the option to invest in Nuclear power and how a Nuclear power venture would affect future electricity prices. The study uses two methods, a traditional cash flow model and real option analysis, to estimate the value of Nuclear power.

Experiment: Tillväxtvilja : En studie om varför småföretagare önskar tillväxt

This thesis treats the normative power of the European Union and its affect on Macedonia. The main purpose has been to look closer with the use of the application of Ian Manners theory of normative power on the Macedonian case. The focus will be to answer the following questions: Does the European Union act as a normative power in relation to Macedonia, if so, how are these values diffused? Has there been any effect of the spreading of these values? Based on six interviews and the available material of European Union strategies for the Macedonian membership I have attempted to understand to what extent the European Union?s normative power has had an influence in Macedonia. The result of my analysis is confirmation of the European Union as a normative power in Macedonia and the understanding of the methods of application..

Electrolux och patenten. En studie av Electrolux patentstrategiska agerande 1950-1970.

Application Lifecycle Management (ALM) is a genre of computerized systems which allows system development corporations to efficiently and more easily manage, maintain and handle the applications lifecycle. These ALM systems have a wide variety of tools which can be integrated to enable and support collaborative work, while they act at the core of the organisation. Todays ALM systems support flexible system development methods throughout the entire development process. This paper focuses on a case-study of a Swedish business- and technology corporation and their use of two ALM systems with an aim to unravel the differences between these systems and their functionality to serve as a basis for decision making regarding their utilization of best practice with their ALM-Systems. Meanwhile we studied their approach to ALM systems to see if they were using them according to the initial idea of ALM systems.

Neutral bolagsskatt? : Analys om SOU 2014:40 skapar neutralitet mellan lånat och eget kapital

This paper examines the power producing dams along the Ume-river as an integral part of and a result from the urbanization process in Sweden during industrial capitalism. The aim of the paper is to contribute to the knowledge of the urbanization process in Sweden in general and of its traces along the Ume river in the county of Västerbotten in particular. The paper applies the theory of concentrated urbanization and extended urbanization put forward by Neil Brenner and Christian Schmid (2015) and argues that the building of power producing dams along the Ume-river is part of an extended urbanization process. This becomes particularly evident when examining the vast physical structures that is the dams, situated in an otherwise remote and sparsely populated area. These vast physical structures are also very well connected to a nation wide electric grid that has connections to bordering countries as well.

Optimerad styrning av kondensatorbatterier - Ny möjlighet att minska förluster med elektronisk brytteknik

Transmission of reactive power is well known to cause active power losses. Thus, newcomponents who can help minimizing these expensive reactive power flows are ofgreat interest to the power distribution companies. ABB Corporate Research hasdeveloped the first electronic power breaker. One possible application for thisbreaker is transient-free switching of capacitor banks. This could prove a usefuldistribution voltage complement to the switch-sync technique, mainly applied to transmissionvoltage level.

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