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234 Uppsatser om Thermal bridges - Sida 2 av 16
Metodik för identifiering av T-stycke med risk för termisk utmattning
Thermal fatigue is a serious problem in todays power plants. A large amount of damages around the world circles around that subject. The damage can come from the mechanism of two flows mixing with different temperatures in a T-junction. It is a fundamental prerequisite that these T-junctions are frequently tested for damages. An amount of criterias steers the rate of testings.
Vinterträdgårdar ur ett byggperspektiv : En undersökning om byggandet av vinterträdgårdar
The purpose of this of this essay is to explore the construction of a conservatory that is livable allyear around. When you build a conservatory there are several factors that need to be regardedthat usually are of no importance when you build a regular conservatory. The glassed facadeneeds to have a very good U-value and all the parts of the facade need to be isolated and theconstruction needs to prevent Thermal bridges.In this essay we will start by looking at the shape of the conservatory. Due to the façade consistsof glass the conservatory will need to have a good ratio between the area and the façade so thatthe heat losses will be at a minimum. However, due to the fact that one of the sides of the façadeis connected to the warm house, you quickly realize that the shape of the conservatory is of noimportance.There are two common ways to build a foundation for a conservatory, a molded concretefoundation and isolated wooden beams.
Inverkan av Kiselhalten på Värmeutvidgningskoefficienten hos Aluminiumlegeringar
The purpose of this report is to document the experiments carried out, methods used and results gained during research into how the silicon content of an aluminium alloy affects the coefficient of thermal expansion (CTE).The goal of this paper is to better understand and to find a relation between silicon content and the coefficient of thermal expansion.Experiments were carried out using carefully prepared samples of Al Si alloys (0, 7, 10 and 20% Si content). Using these alloys, the CTE could be measured using a dilatometer.Comparative analysis carried out could map the effects of silicon content on the coefficient of thermal expansion and an equation was created. Using simple graphs and the rule of mixture method, the authors were able to build a simple tool for calculating the CTE of specific aluminum silicon alloys..
Solenergisystem i Kista Galleria
Solar energy is the one most talked about among energy sources due to its huge potential amongst renewable energy technologies. A greater use of the solar energy may be the solution to today's climate threats. Normally there are two different types of solar technologies, solar cells and solar thermal collectors. Solar cells convert solar energy in to electricity whilst solar thermal collectors convert solar energy into heat, which can be used to heat hot water for households. This goal of this study has been to investigate the possibility of implementing solar energy into the energy system of Kista Galleria, one of Sweden's foremost venues.
Skapandet av ett byggnadsfysikaliskt detaljbibliotek åt byggnadskonstruktörer : fokus på fukt- och värmetillstånd i köldbryggor
Det konstrueras i stor utsträckning bristfälliga detaljlösningar på byggnader i dagsläget. Den bärande stommen i konstruktionen prioriteras ofta medan det inte ägnas lika mycket fokus åt att tillgodose de byggnadsfysiska aspekterna. Anledningen till de bristfälliga detaljerna är även att den som utför arbetet saknar rätt kunskap och tid. För att skapa en förbättring behövs ett hjälpmedel!Kunskap och erfarenhet om hur bra detaljer skapas finns redan i företag, svårigheten är dock att sprida kunskapen till de som är i behov av den.Målet med denna rapport är att skapa en metodik som blir startskottet för ett omfattande arbete kring framtagandet av ett detaljbibliotek, vars syfte är att sprida byggnadsfysiska kunskaper inom företaget och inspirera konstruktörer till att konstruera bra detaljlösningar. Biblioteket ska innehålla byggnadsfysiskt utredda detaljlösningar som analyserats enligt den utarbetade metodiken.
Avvikelser i energiprestanda
Calculated and measured energy in residential buildings is going to differ. The reason to this may be due to many factors. In this study there is a study on how these factors affect the energy use in a building. To get an insight in what defines energy, there is first a description of energy supply both worldwide and used in Sweden, followed by a description of the energy balance. In this study energy will be studied in residential buildings only.
Betydelsen av hästens hud och päls för reglering av kroppstemperatur i kyla ? vad händer vid klippning och täckning?
The horse is a homeothermic animal and to keep a constant body temperature in winter season is important. Acclimatisation is to provide means for a good thermal insulation consisting of skin, hair, and an outer air layer. The skin covers the horses body and it is composed of three main layers where the top layer of the epidermis consists of dead keratinized cells that are constantly being sheed. The dermis is composed of collagen connective tissue that give the skin its strength. The bottom layer with subcutaneous fat provides a thermal insulation and can be used as an energy reserve in cold weather.
Klimatsmarta Hyresgäster : Potential hos hyresgästen för minskning av energianvändning i en kontorsbyggnad på ett klimatsmart sätt
The starting point for this master thesis was the product of the company "Humlegården", which allows its tenants in office buildings to follow their electricity consumption in real time, through their Smartphone's. The idea that resulted from that application is to investigate if it is possible to direct the tenants in office buildings to reduce their energy consumptions, but also to be satisfied with the indoor environment. This work addresses the factors which are the main energy consumers in office buildings. It addresses legal requirements and standards which are important to follow in order to achieve good thermal comfort in buildings. Some of them are physical climate factors like thermal environment, air quality and lightning.
Solel och solvärme ur LCC-perspektiv för ett passiv-flerbostadshus
This master?s degree project concerns the combination of a multi dwelling passive house with solar energy for the generation of electricity and domestic hot water (DHW). Different alternatives with either solar thermal systems or photovoltaic (PV) systems are compared with two reference alternatives producing DHW from electricity or district heating. The economical comparison uses a life cycle cost (LCC) perspective based on the present value of expenditures for investment, energy and annual operating and maintenance.The energy yields from the solar energy systems were calculated by hand and with simulation software. Calculation and dimensioning of PV systems were carried out with a software called PVSYST.
Temperatursprickor i ung betong : Utvärdering av projektering och utförande av åtgärder, samt utveckling av dimensioneringsmetod för kylsystem
The report contains three parts. The first part is a summary and overall presentation of thermalcracks and preventing measures against such cracks. This is a theoretical part where theinterested designer can get acquainted with various alternatives, be guided to more detailedliterature, and receive some practical information regarding the design of the respectivemeasures.The second part deals with calculation of the risk for thermal cracks and design of water coolingas a limiting measure. Two complementary methods are reviewed for efficient calculation:?the handbook method CraX1(by Lulea University of Technology) is used for quickverification?finite differential analysis in the calculationtool ConTeSt Pro for more precise projectingHere is also presented a development of existing standards through design of the cooling systemby means of the Bernoulli equation.
Automatisk Cykelväxel : Förstudie och datainsamling
A fauna passage is a way for animals to cross roads separated from the traffic. In Sweden, there are an unknown number of passages with different functions and appearances. These passages would, with the question ?Which fauna passages can be found in Sweden, and how well do they work?? as a base, be compiled in a comparable way. This would be done with a number of questions asked to the different regions of Vägverket.
Energieffektivisering av arbetsbodar på byggarbetsplatser
Everyone has to take a greater responsibility in energy issues, both individuals and companies. There have been some major developments in the construction industry but there is still a lot to be done. This diploma work thesis presents different methods of making existing construction shed establishments to use less energy. What is possible to do and how much energy is there to be saved? A shed establishment consisting of 8 shed units were studied in this project and the building simulation tool VIP-Energy was used to simulate different types of material in the sheds. An infrared camera was used to locate Thermal bridges. There are several factors that can be improved to make a construction shed establishment to use less energy.
Datormodellering av en värmelagrande betongväggs inverkan på det termiska klimatet i ett växthus
This report describes the building of a computer model that makes it possible to simulate the thermal climate in a greenhouse. The computer model is built on the physical theory of heat exchange that occur in a greenhouse, such as radiation and convective heat exchange. The model also includes the heat storage that is active in a greenhouse.The computer model is used to simulate the thermal climate in a greenhouse under three periods, winter, spring and summer. It also investigates which effect a concrete wall has on the thermal climate in a greenhouse. The purpose of putting a concrete wall in the greenhouse model is to investigate the possibility to store heat during the day and then use this heat when the temperature drops during the night.The result from the simulations shows that a concrete wall levels the big difference in temperature that normally occurs under a day in a greenhouse.
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.
Inverkan av stora mängder halm som underlag i grisningsboxen på den nyfödda smågrisens temperaturreglering :
The aim of the present study was to evaluate the effects of large amounts of straw
in the farrowing pen on thermal regulation of the newborn piglet in different
weight classes. 20 sows were given 15 kg of straw in the farrowing pen
2 days prior to until 7 days after parturition. A control group of 18 sows
had no straw in the pen. 6 litters from each treatment were observed.
Measurements of piglet body temperature were made at 0h, 2h, 4h, 8h and 24h
after parturition. At ?8h? the body temperature of the piglets in the Straw group
were significantly higher (P=0,0149) than the piglets in the Control group.