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Showing result 1 - 5 of 125 swedish dissertations matching the above criteria.

  2. 1. Comparative Assessment of Fuel-Based Systems for Space Heating

    Author : Åsa Karlsson; Miljö- och energisystem; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Energiforskning; Energy research; cogeneration; district heating; electric heating; external cost; carbon dioxide mitigation; detached houses; fossil fuels; Energy systems; bioenergy;

    Abstract : Replacing fossil fuels by biofuels and increasing energy efficiency are often considered to be options for reducing the net emission of greenhouse gases. This thesis presents the results of analyses of energy efficiency, emission and cost of whole energy system chains, from the natural resource to the end user when heating detached houses in a Swedish context. READ MORE

  4. 2. Process Control and Simulation of Ferromagnetic Strip in the Power Transformers and Electrical Machines Applications : Electric power systems

    Author : Kourosh Mousavi Takami; Jafar Mahmoudi; Örjan Danielsson; Mihai Nicolescu; Mälardalens högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Strip; electrical machines; transformer; cold rolling mills; process; automation; control; Band; elektriska maskiner; transformatorer; kallvalsningsverk; processautomation; reglerteknik; Electric power engineering; Elkraftteknik; Energy- and Environmental Engineering; energi- och miljöteknik;

    Abstract : This thesis investigates optimization of the control of electrical and thermal equipment by using FEM and CFD modeling in combination with dynamic simulation models. The thesis focuses on the production of electrical strips and the control system with the aim of reducing losses and improving magnetic properties. READ MORE

  5. 3. Low-temperature District Heating : Various Aspects of Fourth-generation Systems

    Author : Helge Averfalk; Sven Werner; Brian Elmegaard; Högskolan i Halmstad; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; District heating; low temperature; three-pipe systems; 4GDH-3P; District heating; low temperature; three-pipe systems; 4GDH-3P;

    Abstract : With decreasing heat demand and less availability of high-temperature heat supply in future energy systems, the current district heating systems may experience increased competition on the heat market. A viable option to mitigate increasing competition is to operate systems with lower temperature levels, and the most conceivable way to achieve lower temperature levels is to decrease return temperatures. READ MORE

  6. 4. Auroral Electric Fields From Satellite Observations and Numerical Modelling

    Author : Tomas Karlsson; KTH; []
    Keywords : Satellite measurements; electric fields; ionosphere; magnetosphere; diverging electric fields; downward current region; black aurora; westward travelling surge; auroral bulge; subauroral ion drifts SAID ; subauroral electric fields SAEF ; mid-latit; TECHNOLOGY; TEKNIKVETENSKAP;

    Abstract : This thesis is about electrodynamics of thehigh-latitude/auroral region of near-Earth space. The work ismainly based on electric field measurements made by the doubleprobe instrument on the Freja satellite at altitudes ofapproximately 800-1700 km, together with measurements fromother instruments on the same satellite, and ground-basedinstrumentation. READ MORE

  7. 5. Modelling District Heating Network Costs

    Author : Luis Sánchez-García; Urban Persson; Helge Averfalk; Erik Möllerström; Marcus Thern; Magnus Åberg; Sweden Lund Lund University; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; District Heating; Pipe network; Cost analysis; Distribution Capital Cost; Effective Width; Plot Ratio; Heat Density; GIS; Smart Cities and Communities; Smarta städer och samhällen;

    Abstract : The solution of the undergoing climate and energy crises requires a radical transformation of the energy system, in which sustainability, no carbon emissions and energy efficiency ought to play a paramount role. This revolution should extend to all areas of the energy system, including the space heating and cooling sector, which accounts for a third of the European final energy demand and, in the European continent, it is still mostly supplied by fossil fuels. READ MORE