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10844 Uppsatser om Electric power system - Sida 4 av 723
Expansionsmaskiner istället för strypventiler - en effektivisering
In Uppsala CHP Plant, there are six pressure reducing valves to reduce the pressure from 15 to 3 bars, before six absorption heat pumps. During the process the energy is conserved but losses occur in form of exergy. The aim of this thesis is to reduce the losses of exergy. This can be done by letting turbines replace the pressure reducing valves.In this thesis an investigation has been done of the conditions today, the conditions after the change from pressure reducing valves to turbines and a comparison of three different types of turbine solutions. The three examined solutions are one turbine, several helical screw expanders and several small turbines in parallel with asynchronous generators.The six absorption heat pumps have been divided into two groups; one group of four and one group of two absorption heat pumps.
Möjliga alternativ för att ersätta direktverkande el i flerbostadshus
I have in my thesis, examined the possibilities in terms of energy for a condominium association.To have an effective and good energy is becoming increasingly important with today's rising electric and oil prices. In my thesis I have used the condominium association Kärralyckan, which is situated in Falkenberg. The buildings at Kärralyckan are built in the mid-1970s, and are heated by electric radiators. The tap water is heated by an electric boiler.Based on that calculation I can show the various energyststem. The different solutions have been developed by contact manufacturers and installers through phone calls and e-mail.According to the results shows that geothermal heating has been a great solution for Kärralyckan.
Faktorer som påverkar vindkraftsutbyggnaden
Wind power is expanding rapidly in Sweden. Increasing amounts of wind power sets higher requirements on balancing power and grid expansions and would affect the whole Swedish electricity system. The aim of this report is to examine the factors affecting the wind power expansion in Sweden. How many wind power plants projects will obtain building permissions and what costs and revenues can be expected? How much balancing power will be required and does a changing geographical distribution of the wind power plants reduce the need of balancing power?A survey of the county board?s official applications has been made and out of all the applications, corresponding to 80 TWh produced per year, about half of the applications are expected to obtain a permit with a major portion of them located in the north of Sweden.Especially older wind power plants, deriving revenue from Nord pool, find themselves today in a complicated financial situation.
Chalmers oanvända datorkraft - Distribuering av arbete och energihantering med HTCondor
Chalmers University of Technology today have numerous computers which are never powereddown, at the same time there is a need for more computation power for researchers.Hence, we have investigated the possibility to use the computers for computing power andsecondly, if there is no work to be done, to put them into power saving mode.We have made a thorough study where we compared different distributing systems andin the end HTCondor was chosen as the best to implement. HTCondor is an excellent systemfor opportunistic use of computing power, i.e. make use of computers that no one elseis currently using. The system is used at several universities around the world with goodresults and would be excellent at Chalmers, where there is a need for such a system.Our implementation shows that HTCondor is well capable of handling unused computingpower. HTCondor can handle most file types that may be run on the system.
Konceptstudie av drivmodul till bandskotare med hybriddrift
BAE Systems Hägglunds has a long history of producing high performance terrain tracked vehicles (mostly for military applications), and they are now aiming at developing a tracked forwarder with similar techniques.The forwarder will be of series hybrid type where a diesel engine via a generator will power the motors (one for each drive wheel). Thanks to individually controlled motors and the gentle rubber tracks, this forwarder is calculated to have a considerably higher average speed in the terrain and to be more gentle to the soil. The forwarder with a weight of 11 metric tons and a load capacity of 15 metric tons is specified to have an average working speed of 7-10 km/h, a top speed in terrain of 15 km/h and a top speed on roads of 40 km/h.This master?s thesis aims at developing a conceptual design of the forwarder?s drive module which includes electric motor, gear unit, brake and drive wheel.To investigate if the requirements can be fulfilled a study of the dimensioning loading scenarios has been carried out. The resulting needs regarding the torque has been considered in order to determine the required gear ratios for different motor options.
Metoder för kartläggning och analys av nätförluster i lågspänningsnät
An important process for grid companies in order to reduce power losses in electricity distribution grids is to figure out where and how they appear. This report describes the factors that cause power losses in low voltage distribution grids and methods for how they could be measured and analyzed. Measurement data for consumed and injected energy were collected for twelve low voltage distribution grids owned by Gävle Energi AB in order to analyze the size of the power losses and how the measurement uncertainty affects the collected data. Then models of three of the grids were created in MATLAB in order to analyze the data and the power losses were calculated to be compared to the collected data. Curve fitting were also used as a method in order to analyze the power losses from collected data.The results show that the losses in the studied grids are low.
Konceptstudie av Waste Heat Recovery System på Tunga Fordon
In today?s fast growing and closely connected society, a reliable and energy efficient transportation system is more than ever desirable. Nowadays the significant part of the transportation sector?s energy demand is supplied by fossil fuels.Improving energy efficiency in combustion engines will result in reduction of fuel consumption and CO2 emissions. A modern internal combustion engine has an efficiency of 30-45 %, where the most energy loss occurs as result of heat losses in the exhaust and cooling systems.
Utbyggnadsplan för laddinfrastruktur inom Uppsalahem AB:s bostadsområden
The electric car has existed for over a century and producers has tried to commercialize it earlier but has not succeeded. In recent years, however, a change occurred that may be significant for the electric car and it is now to commercialize in the market of passenger cars. The technology has in recent years elaborated as more car manufacturers have started to invest in development in the subject field. This thesis aims to compile an action plan for the development of charging infrastructure for electric vehicles in Uppsalahem ABs residential areas. It is based on a survey of different residential areas and a survey of charging infrastructure.
Validering av vattenkraftmodeller i ARISTO
This master thesis was made to validate hydropower models of a turbine governor,Kaplan turbine and a Francis turbine in the power system simulator ARISTO atSvenska Kraftnät. The validation was made in three steps. The first step was to makesure the models was implement correctly in the simulator. The second was tocompare the simulation results from the Kaplan turbine model to data from a realhydropower plant. The comparison was made to see how the models could generatesimulation result that was similar to the reference power station.
Molnet och dess möjligheter och utmaningar : En kvalitativ studie i hur molnet förändrar systemutvecklingsarbetet
As companies grow, their need for computing power will increase, which traditionally resulted in companies having to invest in more IT resources. Now, with cloud computing, companies can easily hire computer power over the Internet, on-demand. Cloud computing offers a highly scalable environment where companies can store data and host their services. This paper employs a qualitative study with interviews and literature studies to explore opportunities and challenges associated with cloud computing from a system developer perspective. The aim of the paper is to find out how cloud computing changes the conditions for system development. The paper contributes with four different opportunities and challenges that the system developer must handle to succeed in the world of cloud computing.
Bilden som kommunikationsverktyg
Transportation of pigs might be a welfare problem. Stress during and after transportation can negatively affect the meat quality or cause carcass damages, which leads to major economic losses every year. The transportation chain can be divided into several stages; loading, transport and unloading. This literature review focuses on unloading of pigs from a transport. When arriving at an abattoir pigs can be fatigued and need to be as smoothly unloaded as possible.
Factors influencing pig behaviour during unloading from a transport
Transportation of pigs might be a welfare problem. Stress during and after transportation can negatively affect the meat quality or cause carcass damages, which leads to major economic losses every year. The transportation chain can be divided into several stages; loading, transport and unloading. This literature review focuses on unloading of pigs from a transport. When arriving at an abattoir pigs can be fatigued and need to be as smoothly unloaded as possible.
Ryskt luftmaktsanvändande i Georgien 2008 ? ett fall av Warden?
The Russian-Georgian war of 2008 drastically changed Europe´s and Sweden´s political climate.Russiashowed that it is capable of successfully completing complex campaigns including ground, naval and air assets. However, not much has been said about the theoretical framework and doctrine of the Russian military of today. Even less has been researched about Russian use of air power and applied air theory. Are air power assets still considered primarily as support of ground offensives or has the theoretical framework changed?John A.
Utveckling av ett användbart IT-stöd : för att stödja operativa arbetsrutiner
Nuclear power production carries potential risks both for the environment and for the work force. Different safety measures are employed and they stem from local rules as well as from regulatory authorities. This work describes the development of a safety promoting tool at Forsmark Power Plant, one of Sweden?s three Nuclear power plants. We describe the development of a computer based system for Pre-Job Briefing and Post-Job Debriefing.
Anstaltens ambivalenta funktion : En studie av den samtida kriminalvårdsdiskursen
Due to the attention of several escapes, rescue attempts and hostage situations from Swedish prisons during the year of 2004 a debate about correctional system and safety arose. It resulted in official reports and proposals to improve the safety of the institutions. The incidents of 2004 will most likely have an effect on the discourse of the correctional system. The purpose with this study is to analyse which discourses that today can be distinguished in the correctional system and thereby will be the foundation of the correctional systemof tomorrow. The method used to answer the purpose of the study is a Foucauldian based discourse analysis.