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2676 Uppsatser om Energy efficient ventilation - Sida 42 av 179
Håller vindkraften vad den lovar?
The purpose of this study is to investigate how much of the estimated annual electric energy production from Swedish wind power that actually was produced, as well as the history of this agreement over time. The aim is to also examine if there are properties that have caused some group of wind power plants to produce more or less, compared to their estimated production. Operational data on wind turbines collected by the Swedish Energy Agency was analyzed. A survey was made among owners of wind power plants with a nominal power of at least 2 MW. Two different methods for normal year correction of production data were used and compared.
Biobränsle från det jämtländska jordbruket : en studie om lantbrukarnas alternativkostnader vid odling av rörflen
The use of fossil fuels such as coal and gas are a contributor to the global warming. The climate change is a worldwide problem with far reaching consequences that is believed to be very expensive. The United Nations has been introducing a framework convention on climate change. One component of the convention is the Kyoto protocol. The protocol is obligating the developed countries to decrease their emissions of greenhouse gases by 5.2 percent during the time period 2008-2012.
Elektromagnetisk och mekanisk design av en 20MW turbogenerator
At the Division of Electricity at UppsalaUniversitythere are ongoing researches, including a research concerning turbo generators.Turbo generators produce a large share of electricity in the world; however they are costly mainly due to the fact that the cooling and ventilation that are needed to eliminate the excess heat from the generators are expensive. Turbo generators work with high efficiency and in this project, the main task is to simulate a generator while taking into account that the generator must be designed against self-oscillation, centrifugal force, exhaustion and heat. The turbo generator must be simulated without being too expensive and complicated.In this project, the dimensions of the turbo generator depend on the efficiency of it, and where the losses are in the generator. Furthermore, the optimum values need to be chosen with the help of the ACE simulation program. The report begins with an introduction describing the project followed by a task description that is dealing with the project.
TILLFÄLLIGA EFFEKTTOPPAR I FJÄRRVÄRMEN : Kan man med hjälp av lagrad värme undvika att de uppstår i betonghus?
Climate and environmental issues is now high on the agenda. We live in a generation that must try to solve some major environmental problems. Buildings and habitations account for approximately 40 % of Sweden's total energy today. To reduce this figure, as needed, more research in the field of energy efficiency is required.This thesis concerns the heating of buildings. The load on district heating is heavy during certain times of the day.
Temperaturzoner för lagring av värmeenergi i cirkulärt borrhålsfält
The thermal response of a borehole field is often described by non?dimensional response factors called gfunctions.The g?function was firstly generated as a numerical solution based on SBM (Superposition BoreholeModel). An analytical approach, the FLS (Finite Line Source), is also accepted for generating the g?function. In thiswork the potential to numerically produce g?functions is studied for circular borehole fields using the commercialsoftware COMSOL.
Optimerade material för optiska komponenter i koncentrerande solfångare
The energy consumption continues to increase as the use of electronics and energy consuming equipment increases. The use of fossil fuels has to be phased out for this to be sustainable in the long run while the use of renewable energy continues to increase. A renewable energy source is solar energy but the production of heat and electricity are today very expensive compared to other energy sources and an important task for the solar energy market to grow is therefore to minimize the production cost of the solar collectors while increasing its efficiency to produce heat and/or electricity. One way to convert solar energy into heat is by using solar collectors and electricity can be produced by utilizing the produced heat, or by applying solar cells.This thesis aims to recommend a reflective material for the next generation solar collectors from Absolicon and to recommend a commercially available coating for the receiver tube of the solar collector. A market study has been carried out to investigate the cost-related aspects along with the optical and durable aspects for the optical material of the solar collector.
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..
Värdet av att bygga grönt för kommunala bostadsbolag
AbstractThe real estate sector is today responsible for 40 per cent of the total amount of energy consumption within the members of the EU. All over the world there are collaborations within research and projects to find ways of reducing the amount of energy consumed by the real estate sector. In Sweden, a directive from the European Union has posed demands on authorities as well as on the private sector to reduce the amount of energy consumed by new building constructions. Together with the directive from the EU there are also new requirements and demands from Boverket for the real estate sector. These requirements mostly concern the energy consumption of kilowatt-hour per square metre and that the consumed energy also should be renewable. The aim of this study is to explain what kind of value municipalities experience in using certifications and environmental investments for new and existing buildings. Within the chapter theory, essential areas are described such as; environmental certification systems, economical viability, proceeds connected to building green, difficulties with building green, the performance of green buildings when affected by the behaviour of tenants and customer value. The following chapter describes the methodology with which we have conducted this study.
RAMVERK FÖR EFFEKTIV KUNDSUPPORT : Utifrån ITIL, CRM och supporthantering på mjukvaruföretaget Medius AB
The goal of customer support is to help clients achieve maximum value in their services and products. Customer support is the public face of a company, which means that it is important to give the customer a positive experience and live up to customer expectations. Efficient customer support has become more important and studies show that customers who leave a company do so because of poor service. Customers' growing demands for higher quality and easier access to services means that companies must recognize the need to satisfy each customer. It is important that each customer receives the attention required and that customer needs are met quickly and flawlessly.
Beräkningar med GPU vs CPU : En jämförelsestudie av beräkningseffektivitet med avseende på energi- och tidsförbrukning
Examensarbetet handlar om en jämförelsestudie av beräkningseffektivitet med avseende på energi- och tidsförbrukning mellan grafikkort och processorer i persondatorer och PlayStation 3.Problemet studeras för att göra allmänheten uppmärksam på att det går att lösa en del av energiproblematiken med beräkningar genom att öka energieffektiviteten av beräkningsenheterna.Undersökningen har genomförts på ett explorativt sätt och studerar förhållandet mellan processorer, grafikkort och vilken som presterar bäst i vilket sammanhang. Prestandatest genomförs med molekylberäkningsprogrammet F@H och med filkomprimeringsprogrammet WinRAR. Testerna utförs på MultiCore- och SingleCorePCs och PS3s av olika karaktär. I vissa test mäts effektförbrukning för att kunna räkna ut hur energieffektiva vissa system är.Resultatet visar tydligt hur den genomsnittliga effektförbrukningen och energieffektiviteten för olika testsystem skiljer sig vid belastning, viloläge och olika typer beräkningar..
Norra Djurga?rdsstaden som nollstad : En studie av miljo?projektets sista etapp och dess potential
All around the world more and more people move from rural areas to live in the cities. Because of this, the urban areas have become an important part in the debate about the effects on the environment and sustainability. In many countries word wide initiatives have been taken to build sustainable cities and eco cities, the Stockholm Royal Seaport is one example. The vision for the district is to become a world class sustainable city based on the three dimensions of sustainable development: social, economic and ecologic. The municipality of Stockholm has set requirements for the buildings? energy usage, emissions and amount of waste generated during the building process.
Kartläggning och utvärdering av produkter och tjänster kopplat till begreppet Smart Grids
The Smart Grids development is driven by forces concerning safe electrictransmission done in an energy efficient way. Vattenfall Eldistribution AB has a visionto transform their electricity network into Smart Grids. To invest in Smart Grids theyhave a need to show their customers what advantages they will get from thedevelopment. This led to the formulation of this dissertation project where the aim isto identify products and services related to Smart Grids that will increase thecustomer satisfaction for Vattenfall Eldistributions private customers.The project started with a mapping of existing products and services on the Swedishelectricity market. From the mapping several development possibilities for VattenfallEldistribution were identified.
Morgondagens effektiva fjärrvärme : En beskrivande litteraturstudie
This report is made as a literature review, focusing on the work done to increase understanding of efficiency in the categories of substations and secondary heating systems, with respect to the deviation from the theoretically possible cooling off in the distribution network as well as the economic benefit that appear. The main purpose of a considerable part of the literature used in this report addresses the issue of identifying individual causes of reduced cooling in district heating systems. These literature resources have been compiled and summarized as part of the report.The technology of district heating is associated with benefits such as better use of the energy in a fuel. This is the case of cogeneration plants where serial generation of electricity and thermal energy increases efficiency compared with the parallel generation where heat is generated locally and electricity is generated centrally. Serial generation thus allows for lower primary energy demand.
Incentive programmes ? a corporate governance perspective on Swedish commercial state owned firms
We would like to learn more about how the restrictive policy against incentive programmes affects the board?s of Swedish state owned commercial firms ability to govern management in an efficient way. We also want to find out if there are different consequences in reference to this that are not directly linked to corporate governance issues. Our empiric observations have been made in order to profoundly explore the subject and examine it through the eyes of professional individuals, all expressing different views and standpoints. We conclude that the most efficient structure is when an active board is complemented by a well structured and individualised incentive programme.
Logistiska lösningar för en lönsam byggprocess
This is a study, the purpose of which is to investigate how the construction company Sefab Bygg AB is able to increase its profitability and render a more efficient production process through logistic solutions. The study is made during one of Sefab´s present projects. The project includes sanitary renovation of 650 apartments in the co-operative Opalen in Norrköping.To find out whether changes of logistic routines are profitable or not, it?s necessary to evaluate the total cost of the changes. A total cost analysis is a mapping of all the costs for a particular material, on one hand for the present situation and on the other after the change.