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858 Uppsatser om Coefficient of heat transmission - Sida 21 av 58

KORTSIKTIG PRODUKTIONSPLANERING I MINDRE FJÄRRVÄRMESYSTEM : En studie vid Strängnäs Energi AB

District heating covers around 80 % of the heating demand in apartment buildings and 10 % in single-family homes in Sweden. In the year 2010 the total input of energy to the Swedish district heating grids was about 70 TWh, which corresponds to 11 % of the total energy input to the whole energy system in the country. Through the combined production of heat and power the CHP-plants often reaches an efficiency of 90 % from energy in the fuel to produced heat and power. In order to keep the efficiency high it is important for the owners of the plant to have good knowledge about the plants performance at different operation points. Strängnäs Energi AB initiated this diploma work together with FVB Sverige ab in order to come up with a program for short term planning of the production of heat and power at the company´s CHP-plant.The work consists of three main parts.

Analys av sorptiv kylning i industri- och kontorsbyggnader

Energy efficiency is important both to reduce costs and to reduce greenhouse gas emissions in the atmosphere. Reducing costs will also help maintain business competitiveness.Scania in Södertälje is a company where the optimization of energy use is an ongoing and continual process. One area with potential to make energy and cost savings is the effectiveness of the ventilation systems in offices and industrial premises at Scania. During the summer months an increased demand for cooling occurs, leading to increased ventilation and a peak in district cooling system usage. Sorptive cooling is a technology where the supplied air is cooled by applying external heat.

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.

Solenergi på Nya Karolinska Solna

In today?s society climate change has grown to one of the largest global issues. To reduce emissions of greenhouse gases, large changes of the energy system are required. An increasingly popular solution is investments in local production of renewable energy resources like wind, solar or geothermal power. The following report examines the possibility for implementing a solar power plant on the new hospital Nya Karolinska Solna. Two different technologies for extraction of solar energy has been studied, solar thermal collectors  to meet the need of heating and solar cells to satisfy the need for electricity linked to operating the hospital building.

Energieffektivisering av Åhlénshuset i Umeå : Utredning av åtgärder för ventilation, värme och kyla

Sweden is a country that has made some progress in developing energy efficient solutions. The problem in Sweden is that many houses and apartment buildings are old and have inefficient ventilation- and heating systems. This energy is lost when systems are inefficient, which then results in huge economic costs. Luckily, more and more people are becoming aware of this, which means that Sweden is on track to become even better within energy efficiency.Energy use for the housing- and service sector amounts to 166 TWh of total use at 616 TWh. Without distribution and conversion losses, these figures show that the housing- and service sector accounts for almost 40 % of the country's total energy consumption.

Implementation av fältbuss ASIC i FPGA

HMS Industrial Networks AB is in need of changing a communications solution that iscurrently based on an ASIC. This will be achieved by moving the communications solution toa FPGA with the help of the programming language VHDL. By doing this, it is possible toreduce the need for specific circuits, get a more flexible platform and thus get a cheapersolution.This report describes a solution for how to move a network protocol from an ASIC to anFPGA. The report shows that the network slave device is working under the guidelines forthis project. This means that it is quite realistic to implement a fieldbus protocol on an FPGA,using VHDL and to maintain the same functionality as the earlier communications solution..

Tidsupplösning vid miljövärdering av fjärrvärme : Kontorsbyggnad med solvärmeproduktion - en fallstudie

The demand for environmental assessments on buildings and energy consumption is increasing as well as the energy performance requirements for buildings. At the same time it is increasingly common with self-producers of heat and electricity generation.The main purpose with this master thesis is to investigate how time resolution affects the environmental assessment of energy consumption in office buildings connected to district heating (DH). Environmental assessments were done with both attributional LCA and consequential LCA with system expansion.Fortum´s DH system in Stockholm was analyzed and district heating production was simulated in a Matlab-model. Greenhouse gas (GHG) emissions for the production were calculated. The heat demand of the office Gångaren 16 in Stockholm was simulated in IDA ICE.

Rabies, dogs and education : A cross-sectional study on the knowledge, attitude and practice in school children in Tamil Nadu

Although known and feared for thousands of years, rabies remains a real and present threat to thousands of people, especially in low- and middle income countries. In India, rabies is an endemic disease, causing human deaths every year. The primary mode of transmission is through the bite of an infected dog. Fighting the disease in the dog population through vaccinations remains the most efficient way to eradicate the disease. The knowledge of rabies in India is unsatisfactory, as a lot of people lack awareness about the severity of the disease and the importance of washing the bitten area and seeking medical attention for post exposure prophylaxis when bitten by a dog.

Utvärdering av Transportstyrelsens flygtrafiksmodeller

The Swedish Transport Agency has for a long time collected data on a monthly basis for different variables that are used to make predictions, short projections as well as longer projections. They have used SAS for producing statistical models in air transport. The model with the largest value of coefficient of determination is the method that has been used for a long time. The Swedish Transport Agency felt it was time for an evaluation of their models and methods of how projections is estimated, they would also explore the possibilities to use different, completely new models for forecasting air travel. This Bachelor thesis examines how the Holt-Winters method does compare with SARIMA, error terms such as RMSE, MAPE, R2, AIC and BIC  will be compared between the methods. The results which have been produced showing that there may be a risk that the Holt-Winters models adepts a bit too well in a few variables in which Holt-Winters method has been adapted.

En systemlösning för en framtida fjärrvärmeutbyggnad i Täby : ur Fortum Värmes perspektiv

At the moment in central Täby there are small district heating network operated by Fortum Heat. The distribution network has an annual heat demand of about 70 GWh, which is supported by the network's two plants, Galten and Farmen. Täby as a region is rapidly growing and there are grand plans to develop the area. Estimated market potential for a future district heating expansion in Täby is very high and as early as in 2007 Täby decided to invest in a large-scale expansion. In autumn 2009 Täby did a procurement process, known as the ?Täby initiative?, to find a partner that could implement those expansion plans. To secure a cheap basic production the partner also need to build a power plant at Hagby recycling center. Despite high interest during initial state of the process, only one procurement offer were received and Täby suspended the contract in March the following year.

En jämförelse ur energisynpunkt mellan roterande värmeväxlare och frånluftsvärmepump i universitetsbyggnad

För att tillgodose den studerande KTH byggnadens framtida krav kommer det befintliga ventilationssystemet att bytas ut. Två olika möjliga värmeåtervinningssystem har jämförts ur fjärrvärmebehovssynpunkt. Det befintliga systemet med vattenburen batterivärmeväxlare har en låg värmeåtervinningsgrad och Akademiska Hus önskar system med högre värmeåtervinning. I byggnaden har roterande värmeväxlare och frånluftsvärmepump för uppvärmning av tilluften jämförts. Då värmeåtervinning från dessa system inte är tillräckligt kommer fjärrvärme att används.I beräkningarna jämförs fem roterande värmeväxlare mot varierande antal frånluftsvärmepumpen.

Sekundärnät för lågtempererad fjärrvärme

Lower energy use in buildings is a result of increasingly stringent energy requirements across Europe. When conventional district heating technology is used in areas with low energy consumption heatlosses do not fall even though the amount of energy delivered is reduced. This reduces income for thedistrict heating company. To maintain their economic viability the district heating companies? majorchallenge is to implement new solutions that minimize heat loss.

Kommunicera, informera och modellera : Kommunikationsprocessen inom Clas Ohlson

Kommunikation har stor pa?verkan pa? hur en organisation fungerar och hur va?l den arbetar enhetligt mot sina uppsatta ma?l. Kommunikation a?r ett komplext a?mne som kan vara sva?rt att fo?rsta? och beskriva. O?vergripande finns tva? skolor vars synsa?tt a?mnar angripa fo?rklarandet av kommunikation.

Emerging infectious diseases : using PCV2 as a model of disease transmission dynamics at the livestock-wildlife interface in Uganda

Uganda anses vara ett högriskland för utveckling av nya plötsligt uppdykande sjukdomar (emerging infectious diseases, EID). Grisproduktionen i Uganda har ökat drastiskt de senaste åren och en stor del av Ugandas grisar är frigående. De kan därför lätt komma i kontakt med vilda djur i deras närområde. Porcint circovirus 2 (PCV2) är ett ubikvitärt virus och etiologiskt agens för bland annat porcine multisystemic wasting syndrome (PMWS). Förutom att infektera tamgrisar över hela världen så har PCV2 också visats kunna infektera vildsvin.

Lönsamhetsanalys av tekniker för utökad elproduktion i kraftvärme : Med hänsyn till elprisets variationer

This thesis aims to examine the viability of various techniques for increased electricity generation in CHP plants and the effect of electricity price fluctuations on the profitability.The techniques examined are fuel dryer, pellet production, methane production, combined methane- and pellet production, seasonal heating storages in caverns and pit heat storages and condensing tail. Using Excel and Matlab, the prerequisites for investment costs, revenues and expenses were calculated.What affects the price of electricity is a combination of economic and technological development, energy prices, economic structure, population changes and weather. Different scenarios for the electricity price were therefore examined. In the base case, the electricity price was given by the Nord Pool electricity price statistics of area three in 2011. Thereafter, WiMo was used to design the electricity scenarios for 2030, which was then applied to the data to obtain the viability of various scenarios. The techniques examined were found to give greater profits to the CHP plant by increasing and optimizing the production of electricity.

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