Göteborg Energi has a surplus of district heating during spring, summer and fall. The heat surplus is due to a constant production of waste heat from oil refineries and heat from waste incineration over the year. It would be desirable to increase the demand for heat and the uptime for the newly built combined heat and power generation plant, Rya Kraftvärmeverk. One alternative could be to integrate Rya Kraftvärmeverk with a pellet production facility. By producing heat, electricity and pellet in a joint process the energy use can be decreased.

Det här är ett projekt i industriell design som gick ut på att lösa ett problem. Projektet var ett samarbete med kontors- och utbildningsmöbelföretaget Abstracta. Problemet var att det på arbetsplatser idag lätt blir högljutt och bullrigt, speciellt i öppna kontorslösningar. För att ta fram en produkt som löser problemet gjordes undersökningar och analyser av marknaden, kunden, användaren, akustik och material. Det utgjorde grunden för en idégenerering som resulterade i ett koncept, som sedan vidareutvecklades till en serie akustikabsorbenter.

My questions at issue for this report has it´s beginning in the growing problems of thenegative effects of burning fossile fuels and the rapidly growing energyprices.1. Is it possible to design a micro scale powerplant?2. Is it economically interesting for a potential customer to by such a product?The aim with this report is therefor, with the help of design work and calculations, to answerthese questions and to create a platform for building a fully functional micro scale powerplant.The material used in the report is mostly product catalogs from various industries but alsostudy course littrature about steam engines.The result of the report is that it is fully possible to design a fully functional micro scalepower plant.

In modern society in terms of economics and environmental impact, it is important to ensure that a company is as energy efficient as possible to reduce the amount of energy used. About 10 TWh of electricity used annually to pump drives in Swedish industry. Therefore, pumping system has great potential for energy savings.The objective of this report was to determine how much energy and money that can be saved with the insertion of variable speed drive to six pumps on Bleach plant 4 in Skutskär Mill. The work was performed with electrical measurements during one week, analysis of pump curves and the compilation of production data over a year.The results show that four of these six pumps were profitable and yielded an annual saving of 1172 MWh of electricity and 560 000 SEK. With an economic lifetime of 10 years and a discount rate of 6.8% the final result for the entire life-cycle savings became 3 355 000 SEK.

In a sustainable society the use of renewable energy and recycling of materials is of high importance. Wastewater treatment plants use large amounts of energy in the processing of wastewater. This study seeks to evaluate wastewater as an energy resource and to examine treatment plants potential to become sustainable energy producers. The study is based upon the internal processes of Himmerfja?rdsverket.

AbstractBackgroundThe Swedish district heat market of today is a subject being discussed regarding the reasonableness of the heat district supplier?s price settings. The issue is currently on a government level where a new investigation is being executed at the time of writing. Many real estate owners are growing tired of the situation where the heat district suppliers are taking advantage of their monopoly position, thus feeling that the price of district heating has been increasing far too much for many years. The market can be described as a natural monopoly because the real estate owner has no possibility to choose another supplier if they are unsatisfied with the present.

En hanteringsutrustning för att underlätta förberedelser av gips på sjukhus.

Latent heat storage is a way to store thermal energy when a phase change material undergoes a phase change. The advantage of latent heat storage is the capability to store more energy per mass unit than other heat storage methods. The most commonly used phase change in latent heat storage is the transition between solid and liquid. Phase change materials can be divided into organics, inorganics and eutectics.In the Nordic electricity market the price of electricity is set every hour by Nordpool spot, which leads to price fluctuations because of changes in demand. The main goal of this report is to create a latent heat storage system in a single-family home and investigate the possibility to save money by charging the latent heat storage system when the price of electricity is low, and discharge when the price is high.The thermodynamic model consisted of a ?tube-in-tube? heat exchanger with phase change material in the outer tube and water as the heat transfer fluid in the inner tube.

Drain water heat recovery is an uncommon measure in multi-unit residential buildings. There istechnology available for the purpose but the knowing and experience of the heat recovery systems islittle. The purpose of this thesis is to evaluate the future potential of drain water heat recovery inmulti-unit residential buildings.A major part of the multi-unit residential buildings in Sweden were built during modernismen andrekordåren (1940?1975). Many of the buildings have worn out drain and water supply systems andmany are in need of a general refurbishment.

The thesis describes a completely new biofuel system to generate particle-free heat from combustion of ash-containing biofuel particles at high temperatures.The suggested system gives opportunities to introduce biofuels in new areas.Main components in the suggested system is a heat radiating combustion chamber intended for pulverized wood, combined with regenerators to extract heat from flue gases and simultaneously preheating the combustion air.The thesis contains a description of the suggested system, theoretical considerations, calculations regarding the combustion, and includes results from tests performed.The results from calculations and tests performed concludes that the system is workable and possible to apply..

In today?s fast growing and closely connected society, a reliable and energy efficient transportation system is more than ever desirable. Nowadays the significant part of the transportation sector?s energy demand is supplied by fossil fuels.Improving energy efficiency in combustion engines will result in reduction of fuel consumption and CO2 emissions. A modern internal combustion engine has an efficiency of 30-45 %, where the most energy loss occurs as result of heat losses in the exhaust and cooling systems.

Humanity stands before a huge challenge to lower its emissions of carbon dioxide and its use of energy at the same time as the global population is rising and the developing countries are being industrialized. A lot of newly built buildings are due to this challenge, designed to be more energy efficient but also use renewable energy resources instead of pollutant fossil fuels .Solar energy is one of the purest forms of energy that exists in abundant amounts, which is why it is most likely that it could come to play a major part in the future energy market. The main purpose of this report is to investigate the possibility to implement a sustainable energy system with solar thermal heat and  heat storage as main sources of energy in the neighborhood ?kvarteret Lagern?, which is the area where the old football stadium ?Rasunda Stadion? was located. New developments within different heat storage techniques have opened up new approaches to enable buildings an all year round heat supply from solar energy. This report will focus on heat storage in boreholes. At the present here is only a preliminary plan of how the neighborhood is supposed to be designed.

The study took place at a food corporation in Växjö, Sweden. It describes a building that contains four tanks in which glucose syrup is stored. The purpose of the study was to calculate the amount of heat that leaves the building and the amount of heat that is supplied by the installed heating equipment. Before the calculations could be implemented, all the systems that supply the building with heat had to be examined. With a small amount of information from earlier studies, the work to gather all the data necessary for the calculations began.

Magnesium is an essential mineral that is important for several physiologic and biochemical processes in the body. Deficiency of magnesium is mainly associated with grass tetany, but can also appear in cows during the indoor period. Since long it is known that potassium has a negative effect on the absorption of magnesium. Due to the fact that potassium fertilisation leads to a higher potassium content in forage, it is of interest to study interactions of potassium on the magnesium balance in dairy cows. There are few studies about magnesium feeding to dairy cows in Sweden and the purpose of this study was to investigate how much magnesium and from which feed-sources dairy cows in Sweden get their magnesium. Data was collected from seven farms in the northern part of Uppland and from seven farms in Skaraborg in Sweden.

To be able to handle tomorrows need for limited energy consumption we need to reduce our use of energy. The building sector stands for around 40 % of all energy consumption in the society. The government has put up a goal to reduce the energy consumption in our buildings with 20 % by year 2020 and 50 % by year 2050 compared with year 1995. To be able to do reach that goal we need a more energy efficient building stock.The main part of the energy used in our buildings is used for space heating. By installing ventilation systems with heat recovery on the exhaust air it is possible to use the heat-energy in the exhaust air to warm up the incoming air.