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957 Uppsatser om Thermal heat losses - Sida 9 av 64
Jordbrukets påverkan på Östersjön : en jämförelse av indikatorer för att beskriva näringsbelastningen
The Baltic Sea, due to its special conditions, is a unique and vulnerable marine environment. There are many pressures that have an impact on the sea and one of the major problems is the extensive flow of nutrients from land. The most visible effect of the supply of nutrients is the annual algal blooms.
One of the main sources of nitrogen and phosphorus supply is agriculture. Nutrient losses
from arable land have been increasing as agricultural production has intensified. At the end of the twentieth century an increased awareness of these problems led to the formation of organizations such as HELCOM and Baltic 21.
Elimineringen av korridormetoden - Hur svenska företags nyckeltal påverkas
In 2011 the International Accounting Standards Board issued amendments to IAS 19 Employee Benefits. The new standard is effective from January 1st 2013 and one of the largest changes in the standard is the elimination of the corridor method. Through the corridor method companies had the possibility to defer actuarial gains and losses resulting from their defined benefit obligations (pension obligations) and leave them unrecognized off the balance sheet. According to the new standard companies reporting under International Financial Reporting Standards will have to recognize all actuarial gains and losses immediately in other comprehensive income. The aim of this thesis is to examine how the financial key ratios of Swedish listed companies will be affected by the elimination of the corridor method.
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.
Analys av hur byggnadens höjd påverkar energiförbrukningen i flerbostads- och kontorshus
This diploma work has been carried out in collaboration with the building contractor Sh Bygg Fastighetsutveckling AB in Uppsala with the intention to investigate how the height of a building affects various energy aspects such as transmission losses, infiltration, and the specific energy usage. Three different reference objects have been studied. The reference objects have been simulated for four different heights in the calculation program VIP-Energy.The results show that an increase in floor number can lead to both advantages and disadvantages. As the number of floors increases, transmission losses per square meter floor area decreases. However, as the height of the building increases, the reduction rate decreases.
GNSS-Styrning : Information för platschefer
An investigation of the heat impact of laser cutting on the material properties when producing tensile and impact test specimens of different steel types of varying thickness has been performed. The purpose of the thesis project was to provide recommendations regarding how much material that needs to be milled from the laser cut edge before tensile and impact tests. The study has been performed partly by investigating the test specimens by heat camera when the specimens were cut in the laser cutting line and partly by performing hardness tests, investigation by microscopy, and tolerance and roughness measurements and tensile tests of the laser cut material and material produced in the traditional multi operation machine. The results show that the heat affected zone in the thicker materials is greater than previously thought of, and that the currently used recommendation has to be adjusted. The study clearly shows that the thicker the material, the greater the heat affected zone, independently of the steel type, since the thicker material takes longer time to cut.
Småskalig biobränsleeldad kraftvärmeproduktion : teknik och investeringsutrymme
To achieve the requirements to decrease emissions of greenhouse gases by 20 % by 2020, Swedenneeds to increase its use of bioenergy. In doing so it seems natural that those who already haveaccess to large amounts of biofuels in the form of by-products such as straw, wood chips anddigestible materials take advantage of these assets locally. By combining production of heat withpower production at the farm it may be possible to not only reduce the direct use of fossil fuel forheating but also reduce energy costs.The purpose was to simulate different cases of using a small scale biofueled combined heat andpower plant for farm-based systems. A MatLab-model was developed and used to draw conclusionsabout the costs for production of heat and electricity with different conversion technologies.The model uses climate data to simulate the variations in heat energy demand on a day-to-day basis.The given heat demand is the base of the simulation and from this the possible electric output iscalculated. This study has focused on the impact of the following properties: electric-, heat- andtotal efficiency, fuel, fuel price and specific fuel requirements.
Vibrationsdämpning av värmepump
Thermia Värme AB is one of the market leading manufactures of heat pumps. In order tomaintain this position, the company wants to improve the vibration characteristics of theirproducts. The aim of this thesis is to develop product design changes that lead to a reductionof vibrations in the heat pump Thermia Diplomat 8.The main cause for vibrations in the system is flow pulsation and mechanical forces inducedby the scroll compressor. Vibration is transmitted through the compressor piping and receivedby the heat exchangers, from where it is further transmitted to the connection points for theradiator and heat source circuits.A number of design changes in order to improve the vibration characteristics have beenevaluated through calculations and practical experiments. The changes have included thecompressor and heat exchanger mountings, the compressor suction and discharge line pipingand also pulsation dampening.The results of the experiments show that the vibration levels in the connections for the heatingand brine circuits can be decreased strikingly through changes in suction and discharge linepiping.
Studie av skyddsavstånd mellan bergvärmeanläggning och skyddsobjekt i ett vattenskyddsområde
During installation and operation of a geothermal heat pump system leakage of an antifreezing agent can appear in a borehole and leak out in surrounding groundwater. To guarantee high quality drinking water for generations to come Sweden has dedicated some areas as water protection areas. The local authority gives permits for the installation of heat pump systems within water protection areas. Before giving a permit the local authority makes an evaluation of the risks involved in installation and operation of the system within the area. By keeping a certain distance between the protected object in the area and the heat pump system the risk of polluting the protected object with an anti-freezing agent can be reduced.This thesis makes a comparison between three different methods of calculating an appropriate distance between the protected object and the heat pump system.
Energianalys av Svensk Växtkrafts biogasanläggning i Västerås
Svensk Växtkraft is the owner of the biogas plant in Västerås. The company is planning to increase
their treatment capacity at their biogas plant. In connection to this work it is also possible to make
some energy saving changes to the biogas plant. The objective of this study was therefore to make
an electricity and heat survey of the biogas plant, a detailed study of the heat consumption in the
sanitation step and also a comparison of energy consumption with the present sanitation method
and an alternative strategy where the waste is treated in 55 °C during 10 hours (the current method
is heating to 70 °C during 1 hour).
The energy survey was conducted in close collaboration with staff at the biogas plant. The current
during normal operation was measured, power was calculated and multiplied by the time of usage to
obtain the energy consumed.
Termomekanisk utmattning av Sanicro 25 : Materialmodellering med finita elementmetoden
The report aims to describe the austenitic stainless steel Sanicro 25 from a thermomechanical point of view. The thermal and mechanical properties of the material make it suitable for use in coal ? and thermal power plants. By the use of Sanicro 25 it would be possible to bring the efficiency of these plants up while bringing the carbon emissions down.A material model is created from material testing and validated through simulation in the finite element software Abaqus. The model that has been derived describes the material behavior during loading and stress relaxation for the first cycle in a thermomechanical fatigue test well.
Sapa Heat Transfers koldioxidspår : En kartläggning av verksamhetens koldioxidutsläpp
Sapa Heat Transfer is a company that produces aluminum heat-exchanger strips for the automotive industry. Sapa Heat Transfer wish to chart their emissions of carbon dioxide in order to meet future demands on carbon dioxide reporting. They also would like to examine the meaning of the term ?green electricity? which is marketed as carbon dioxide free, and the sort of electricity that they purchase. This report includes both direct (liquefied petroleum gas and diesel) and indirect (water, process-water, long distance heating, waste) emissions from their company.
Påverkan på energianvändning och termisk komfort vid reglerinstabilitet
The purpose of the study is to investigate the possible effects of an unstable ventilation system and its influence on energy use and thermal comfort. The report also explores how qualified personal working with HVAC view and handles system control.In order to meet the requirements in energy efficiency and a comfortable indoor climate control regulation is a prerequisite. With optimized increased complexity of the climate systems, it becomes more challenging to control the system and the risk of unstable control increases. No previous studies about what affect an unstable system can have on energy use and thermal comfort have been found.The report is based on several tests were the controlling variable has been increased until the system becomes unstable. Two different types of unstable systems have been investigated.
Energiberäkningar för passivhus
AbstractClimate and environmental issues are of paramount importance. Researchers agreethat we must all contribute to a reduction of gases that contribute to climatechange. Energy consumption must decrease within all sectors and the promotionof renewable sources of energy must be introduced.Each sector should aspire to decrease its energy consumption. Energyconsumption is strongly linked to waste gases that contribute to climate change.Passive houses are a part of the construction industry's methods to attain energyconservation.Passive houses are derived from low energy houses and super insulated houses. Apassive house is intended to obtain heat from the inhabitants and through theiractivities.
Vad påverkar fjärrvärmepriser i Sverige?: En ekonometrisk analys
The purpose with this thesis is to analyse different factors that can explain district heating prices for energy companies in Sweden. We are further interested in examining if the prices is affected by the use of industrial waste heat in their production and the company?s ownership structure. The method applied is a multiple regression analysis using a panel data set of 50 companies over 5 years (2008-2012). The data used is yearly data obtained from the Swedish district heating association.
Energikartläggning och driftoptimering genom behovsstyrning i befintlig fastighet
Energy supply in Sweden year 2011 amounted to 577 TWh. The final energy consumption for industrial, residential and service was 379 TWh. Sweden has energy policy goals to reduce energy use in buildings. One of these goals is to reduce the energy use by 20 % in 2020 compared to the year 1995. An important step to achieve this goal is to target energy efficiency measures in existing buildings.