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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

Energy Balance and Quantification of Rest Energies at SSAB Oxelosund AB

Datta, Rajarshee January 2015 (has links)
The iron and steel industry is an energy intensive energy that consumes vast quantities of fossil fuels as the primary source of energy due to the dependence on coal for steel making. Although the SSAB integrated iron and steel plant at Oxelosund generates electricity and district heat from the process gases, the overall efficiency of the system is a mere 58%. In order to meet future climate targets and energy prices, the iron and steel industry has to improve its energy and resource efficiency. Furthermore, an extensive energy balance for SSAB Oxelosund has not been conducted till date. This served as the main motivation for this project. This report forms the basis of such a study and also provides a near accurate picture of the energy balances at SSAB Oxelosund, encouraging future work in this domain. This report shows that there is lot of waste heat at present that can be utilized by SSAB if such a demand exists. A few improvements have been suggested to improve the overall efficiency, however major changes may not be profitable due to the fact that the steel industry is in a decline today and major process changes will not be a viable solution.
52

Energikartläggning av förskolor - en fallstudie

Holmén, Malin, Härdelin, Sofia January 2015 (has links)
This study was performed in order to evaluate the difference in energy performance between two buildings, Temmelburken 1 and Temmelburken 2, by comparing the measured and the expected values calculated during the planning process. The two buildings were built after almost the same blueprints with the exception that the floor plan was mirrored from one another. In this study, energy measurements have been done and with these measurements as foundation, the energy demand was calculated. After this, a sensitivity analysis of the input parameters has been carried out. The result of the energy calculations were that the specific energy usage of the buildings were; 129,2 kWh/m2 and year for Temmelburken 1 and 111,0 kWh/m2 and year for Temmelburken 2. The expected energy performance of Temmelburken 1 and Temmelburken 2 were 94,36 kWh/m2 and year and 89,69 kWh/m2 and year, respectively. The major difference between the expected energy usage and the measured was for the domestic hot water, where the real value was over 300 percent more. The heating demand for the ventilation system showed the lowest difference compared to the values assumed during the planning, and were 17 percent higher for Temmelburken 1 and 21 percent higher for Temmelburken 2. Whereas the energy demand for the radiator systems were calculated to values 100 and 46 percent higher for Temmelburken 1 and Temmelburken 2, respectively. The study also showed that the radiator system’s energy demand was where the two building significantly differed. The sensitivity analysis of the simulation model concluded that the indoor dry bulb temperature and the climate file made the greatest difference in the result. When increasing or lowering the indoor dry bulb temperature with one degree, the total energy demand increased or lowered by 5.3 percent respectively. When another climate file was used, the total energy demand increased with 6.8 percent. / Denna studie har sökt svar på varför två byggnader, Temmelburken 1 och Temmelburken 2, byggda efter spegelvända riktning har påvisat olika energianvändning. Studien har även undersökt varför byggnaderna ifråga har påvisat sämre energiprestanda än vad som projekterades. För att göra detta har energimätningar i byggnaderna gjorts samt energiberäkningar med mätningarna som grund. En undersökning av valda indataparametrars känslighet har även gjorts. Resultatet av beräkningarna av byggnadernas specifika energianvändning visade att Temmelburken 1 använder 129,2 kWh/m2 och år och Temmelburken 2 använder 111,0 kWh/m2 och år. Detta ska jämföras med de projekterade värden som var 94,36 kWh/m2 och år respektive 89,69 kWh/m2 och år. Den största skillnaden mellan de projekterade och beräknade värdena var för varmvattenanvändningen som var mer än 300 procent högre. Elanvändningen i de två byggnaderna visade sig vara lägre än de projekterade värdena, 13 respektive 14 procent lägre. Ventilationens värmebehov var det fjärrvärmebehov som var närmast de projekterade värdena - 17 respektive 21 procent högre. Radiatorsystemets värmebehov beräknades till 100 och 46 procent högre gör Temmelburken 1 respektive Temmelburken 2. Anledningen till det den stora skillnaden för radiatorsystemet har inte kunnat kartläggas, då studien genomfördes under månader då byggnaderna saknade värmebehov. Känslighetsanalysen visade att de indataparametrar som påverkade den totala energianvändningen mest var inomhustemperaturen samt den klimatfil som användes. En höjning eller sänkning av inomhustemperaturen med en grad resulterade i en ökning respektive minskning av det totala energibehovet med 5,3 procent. Att använda en annan klimatfil gav utslag med 6,8 procent på den totala energianvändningen.
53

Feasibility Study of Vertical Axis wind turbines in Urban areas of Sweden

Awan, Muhammad Rizwan January 2013 (has links)
No description available.
54

Framtida energiförsörjning till off-grid basstationer

Bramberg, Gustav January 2013 (has links)
Telekombranschen har de senaste decennierna upplevt en stark tillväxt, framförallt i urbana områden och västvärlden. Nu när denna tillväxt även sker i utvecklingsländer och dess landsbygd, söks det efter nya sätt att försörja basstationer som ej är kopplade till elnätet med energi. Syftet med detta examensarbete är att studera och analysera framtida hållbara energilösningar för basstationer inom telekombranschen. Detta görs genom att kartlägga alternativ, analysera vilka hinder och möjligheter som finns samt undersöka vilka kompetenser som krävs för en vidare utveckling. Arbetet har framförallt baserats på intervjuer av aktörer i telekombranschen samt litteraturstudier. Studien visar att de tekniker som i framtiden har störst potential att ersätta dieselgeneratorerna idag är solceller samt småskalig vindkraft. För att denna utveckling skall ske krävs det innovationer och nya sätt att implementera energisystem med basstationer. I framtiden kommer det även finnas ett stort behov av projektering och modeller för att dimensionera samt optimera basstationers energisystem. / In recent decades, the telecom industry has experienced a rapid growth in urban areas and the western world. This growth is now spreading towards developing countries and their rural areas, where proper energy grids may be lacking. In order to cope with insufficient energy infrastructure and improve their services in rural areas, the telecom industry is now looking to develop better off-grid telecom base stations. The purpose of this thesis is to study and analyse future sustainable energy solutions for off grid base stations in the telecom industry. This is purpose will be met by mapping possible alternatives and analysing what advantages and disadvantages these alternatives have, as well as investigating what competencies the industry needs. The work is foremost based on literature studies and interviews of stakeholders in the telecom industry. The study concludes that photovoltaic solar cells and small scale wind power are the two energy generating technologies that has the greatest potential of replacing the diesel generators that are now commonly used on off grid base stations. In order for this to happen, two important areas that the industry needs to focus on is innovation and new ways of implementing the energy systems with base stations. The demand of planning, dimensioning and designing the energy systems will increase in the near future as the renewable energies increases their market share.
55

Evaluation of Energy Saving Measures in Ice Rinks

Zhang, Zhongyuan January 2013 (has links)
No description available.
56

Promising thermo-chemical conversion pathways for perennial crops

Tovar-Garza, Alejandro January 2013 (has links)
No description available.
57

Systemintegration av solcellsel och värmeåtervinning från spillvatten i flerbostadshus : Modellering av Evertherm SEW i kombination med solceller i tre svenska städer / Integrated system of photovoltaic electricity and heat extraction from wastewater in multi-family buildnings : Model of Evertherm SEW in combination with photovoltaic cells in three Swedish cities

Klippmark, Joel, Eriksson Sjögren, Ella January 2022 (has links)
För att minska samhällens påverkan på klimatet finns ett antal mål och strategier såväl på global som nationell nivå. En av dessa är Agenda 2030 där Mål 7: hållbar energi för alla bland annat syftar till att öka takten för energieffektiviseringar. En viktig sektor för energieffektiviseringar är byggnads- och bostadssektorn, då denna i dag står för 35 % av det globala energibehovet. För att minska energianvändningen och/eller inköpt energi i byggnader finns ett flertal möjliga åtgärder så som tilläggsisolering, uppgradering av värmeväxlare och installation av värmepump. En effektiviseringsåtgärd som tidigare inte varit vidare uppmärksammad men som kommer spela en stor roll för att nå effektiviseringsmål är värmeåtervinning från byggnaders spillvatten. Det finns olika tekniker för att ta vara på denna, i detta arbete undersöks tekniken Evertherm SEW som består av värmeväxlare, tankar och en värmepump och som tar vara på restvärmen. Då implementering av en värmepump leder till att behovet av inköpt el ökar undersöks även solceller, som kan reducera detta behov. I examensarbetet skapas en modell som undersöker de möjliga energi- och kostnadsbesparingar som erhålls vid implementation av solceller, Evertherm SEW samt dessa kombinerade i en systemlösning i tre svenska städer. Hur energipriser påverkar lönsamheten och vilken inverkan en storskalig implementering av Systemlösningen skulle ha på Sveriges el- och fjärrvärmesektor undersöks också. Resultaten visar att det geografiska läget för de tre systemen spelar roll då energi- och kostnadsbesparingarna varierar till följd av de lokala förutsättningar. För Solcellssystemet återfinns störst potential i Malmö till följd av hög solinstrålning och höga elpriser, medan lägst potential återfinns i Umeå. När Evertherm SEW studeras framgår att de höga elpriserna i Malmö i kombination med låga fjärrvärmepriser leder till att detta är staden med lägst potential för en implementering. I stället återfinns störst potential i Stockholm med liknande potential även i Umeå. Eftersom Systemlösningen är en sammankoppling av Solcellssystemet och Evertherm SEW är potentialen större i Malmö för denna än för ett fristående Evertherm SEW system, men fortfarande lägst då de tre städerna jämförs. Jämförs de tre olika systemen med varandra framgår det att Systemlösningen genererar de största årliga besparingarna, följt av Evertherm SEW och därefter Solcellssystemet. För återbetalningstiderna har Solcellssystemet de kortaste, följt av Systemlösningen och sedan Evertherm SEW. Lönsamheten för Evertherm SEW och Systemlösningen ökar, enligt resultatet, då det genomsnittliga fjärrvärmepriset ligger närmre eller är högre än det genomsnittliga elpriset som använts i beräkningarna. De genomförda modelleringarna visar också på att en storskalig implementering av Systemlösningen i Sverige skulle medföra ett reducerat årligt nettobehov av såväl fjärrvärme som el. Detta leder till att koldioxidutsläppen från el- och värmeproduktion i el- och fjärrvärmenäten kommer att minska på årsbasis. Studeras i stället påverkan på månadsbasis kommer elbehovet under vinterhalvåret öka medan överskottsel från solcellerna i Systemlösningen under sommarhalvåret skickas ut på nätet. Utifån resultaten rekommenderas den tekniska möjligheten att implementera Systemlösningen undersökas vidare då denna visar på förbättrad lönsamhet och minskat årligt behov av inköpt el och värme. / There are several strategies and goals in place to reduce societies impact on the climate, on a national level as well as a global. One of these goals is Agenda 2030 where Goal 7: Sustainable energy for all among others aims to increase the rate of implemented energy efficiency measures. One important sector for these measures is the building and housing sector, since this sector accounts for 35% of the global energy demand. There are several available measures to reduce the energy usage in buildings, such as additional insulation, upgraded heat exchangers and installation of heat pumps. One energy efficiency measure that has not previously been widely used, but that will play a part in reaching the energy efficiency targets, is heat recycling from the buildings wastewater flows. There are multiple technologies that try to harness this heat source, and one of these is examined in this master thesis. This technology is called Evertherm SEW and uses a system solution consisting of heat exchangers, buffer tanks and a heat pump to recycle the heat from the wastewater. Since the implementation of a heat pump increases electricity usage, the ability for photovoltaic (PV) cells to compensate for this is also being examined.  Through constructed models, the thesis examines the possible energy and cost savings obtained when implementing PV cells, Evertherm SEW and these combined in a system solution in three Swedish cities. How energy prices affect profitability and what impact a large-scale implementation of the system implementation would have on Sweden's electricity and district heating sector is also examined.  The results show that the geographical location of the three systems have an impact on the energy and cost savings which vary as a result of the local conditions. For the PV system, the greatest potential for implementation is found in Malmö due to high solar radiation and high electricity prices, while the lowest potential is found in Umeå. When Evertherm SEW is studied, it appears that the high electricity prices in Malmö in combination with low district heating prices lead to this being the city with the lowest potential for implementation. Instead, the greatest potential is found in Stockholm with similar potential in Umeå as well. Since the system implementation is an interconnection of the PV system and Evertherm SEW, the potential is greater in Malmö for the system implementation than for an independent Evertherm SEW system. Despite this, Malmö still has the lowest potential when all three cities are compared. If the three different systems are compared with each other, it appears that the System implementation generates the largest annual savings, followed by Evertherm SEW and then the PV system. For payback times, the PV system has the shortest, followed by the System implementation and then Evertherm SEW. Profitability for Evertherm SEW and the System implementation increases, according to the result, when the average district heating price is closer to or higher than the average electricity price used in the calculations. The constructed models also shows that a large-scale implementation of the System implementation in Sweden would lead to a reduced annual net demand for both district heating and electricity. This means that carbon dioxide emissions from electricity and heat production will be reduced on an annual basis. If the impact is studied on a monthly basis instead, the need for electricity will increase during the winter, while surplus electricity generated from the PV-system during the summer will be sent out on the grid.  Based on the results, it is recommended that the technical feasibility of the System implementation is investigated further as it is shown to improve profitability and reduce annual need for purchased electricity and heat.
58

The Efficiency of PV Modules: Expectations vs. Reality : A study of the Degradation of Solar Panels in Sweden

Forssblad, Julia, Lisper, Linnea, Stålnacke, Olivia, Tonell, Vera January 2022 (has links)
Solar energy is one of the fastest growing green energy sources worldwide today. Thepioneer modules in Sweden have been in use for quite some time. The aim of the reporthas been to examine how PV modules in Sweden have degraded a few years into theirlife cycle. This was accomplished using data from PV modules installed no later than2014. Data was collected from different arrays across the three regions set in the report,the southern, middle, and northern regions to examine how the efficiency changesdepending on location, size, and panel type. The efficiency over time was calculated usingthe solar energy received by the panels divided by the actual produced energy. The reportfound that the degradation of the panels was negative but a lot slower than what isexpected in warmer climates. This is thought to be due to the mild weather in the northernclimate and will result in the panels gaining a longer life cycle. The report did not find anydifference between rooftop modules and ground mounted modules, nor was there adifference between the monocrystalline and polycrystalline modules.
59

Energy efficient solutions within a manufacturing facility : Solutions​​ and suggestions to develop the energy efficiency at Wavin

Hermodsson, Fredrik, Ekstrand, Erik, Frostvik, Anna, Levin, Moa January 2022 (has links)
This bachelor's thesis examines four scenarios related to energy efficiency at the Wavin manufacturing facility in Eskilstuna, Sweden. The four scenarios are: (i) keeping the current production processes, (ii) replacing the electric boilers with biofuel boilers, (iii) installing solar cells and (iv) installing biofuel boilers and solar cells. Results show that the most favorable solution is to install biofuel boilers combined with 2500 m2 (462.5 kWp) solar cells, which yields total savings of 72 MSEK over a 25 year period compared to the current factory set up. Moreover, the results were more sensitive to fluctuations in electricity prices compared to biofuel prices, which indicate that the proposed solution makes the factory less dependent on fluctuating electricity prices.
60

Sustainable Energy Use in Agriculture : A Case Study of a Swedish Farm

Holmgren, Klara, Larsson, Ida, Mårlid, Tilde, Vangeli, Marius January 2022 (has links)
The aim of this study is to find possibilities for a more sustainable energy consumption inSwedish agriculture with Rådde Gård as a case farm. The study assesses the current situationand evaluates possible future measures that could help Rådde Gård become more sustainable.To find effective measures, a model of the energy system is constructed in MATLAB whichsimulates different scenarios.The study is delimited to the direct energy usage in the on-farm processes at Rådde Gård.Indirect energy usage as a result of off-farm processes and transportation is not included.The three main energy sources used at Rådde Gård was shown to be wooden pellets forheating, diesel for engines in vehicles and equipment, and electricity used for lighting, airconditioning, among other things.The total annual energy consumption at Rådde Gård was estimated at 443.1 MWh, of which115.2 MWh diesel, 184.7 MWh electricity, and 143.2 MWh wooden pellets. The fossil part of theenergy consumption at the farm is due to combustion engines in vehicles and equipment, andgenerates 31.5 tonnes of CO2 emissions annually. Two measures were suggested to remedythis. A fuel change to HVO or a change of engines from combustion to electric. At Rådde Gård,a fuel change to HVO would result in a reduction of CO2 emissions to 8.5 tonne per year. Since,electrification of agricultural vehicles is still in early stages, technologically, HVO could be seenas a transition step between fossil use and electrification.Other suggested measures were related to a change of heating system. Either by electrificationthrough an installation of an air-water heat pump, or through a biochar pyrolysis boiler which,although it generates less heat than conventional boilers, coproduces both heat and biochar.These two heating systems can also be combined.The study also found that roof-top solar panels could be an important future aspect of anelectrification of agriculture. For example, since harvesting and grain drying consumes muchenergy during the summer, the seasonal variation of solar production could be utilized.A sensitivity analysis was also performed which indicated that sensitive parameters were to alarger extent related to current electricity consumption and solar electricity production than tothe efficiencies of engines, boilers, and a heat pump.

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