Sökresultat:
2397 Uppsatser om IDA Indoor Climate and Energy - Sida 45 av 160
Energieffektivisering genom förvärmning av flis till kokare med sekundärvärme
The Swedish pulp and paper industry meets higher demand for energy efficiencyi mprovements with increasing energy prices and changes in the Swedish renewable energy certificate system. One action of energy efficiency improvement is by using secondary heat, that otherwise would have been treated as waste heat, for use in a system with lower temperature demands. The aim of this Master´s thesis is to identify possible secondary heat sources in a typical Swedish pulp and paper mill and to investigate what economic benefits the secondary heat will provide when being used for pre heating of wood chips to a kraft digester.The Master´s thesis focuses on three secondary heat sources; dry warm air, warm water and moisture saturated warm air located inside the pulp or paper mill. Two types of kraft digesters are simulated within this study, a typical Scandinavian digester and a modern twin vessel steam phase digester.Due to quality aspects and low temperature level drying is the drying technology with dry warm air rejected. Using warm water in direct contact with wood chips increases the quantity of water to the evaporation plant and thus reduced pulp or paper production and is therefore also rejected.
Energieffektivisering av aerbo reningsprocess : Tillsats av biprodukter i skogsindustriellt avloppsvatten
In the production of pulp, paper and cardboard, a large amount of water is used daily. The water has to be purified in the internal purifying plant before it reaches the receiving body of water. In the biological purifying stage at the Stora Enso Skoghall mill, an aerated basin is used where the microorganisms, using oxygen, oxidize the organic material to carbon dioxide. The air is pumped from the bottom of the basin and the oxygen can then be transported from the air bubbles to the water through diffusion. The problem with aeration of waste water from the forest industry is that wood residues, such as fatty acids, are making the transport of oxygen in water more difficult.
Konstruktion av en fotobioreaktor för odling av alger : ett småskaligt försök
The prevailing food and energy crisis of the world, due to the declining reserves of fossil energy and a never ending rise of consumption, forces us to look into new fields to supply our energy demand. The boom of bio energy is criticized, as food crops are used to provide biodiesel and ethanol and the volumes are ridiculously small to supply world demand. Algae are one of the world?s oldest life forms and exist in many different phyla, providing a great variety to choose from, for different purposes. Cultivating microalgae offer a way to produce energy at great volumes without competing with food production and at the same time the algae offer a way to use our expensive nutrients in a more efficient way, besides this the algae are carbon dioxide neutral since their carbon source can be supplied by the atmosphere and the additional energy required can be supplied by algal oil or other renewable sources.
Kraft och Deformationsmätningar på Snap Load gummi
The power consumption has grown rapidlyin the last decade. Fossil fuels and theneed for alternative energy sources aregreat. Ocean waves are a renewable andsustainable source of energy that hasbeen relatively untapped. At UppsalaUniversity research and development havebeen done for several years. Severaltypes of wave energy converters (WEC)have been created.
Undersökning av ljudnivåer på skolgårdar : - samt hur fasad och fönster dimensioneras med uppmätta värden
This report is written on commission by WSP Acoustics. The report studies the outdoor sound levels on school yards in Stockholm. The questions given by the company to be answered was what are the actual sound levels at diffrent school yards with low traffic noise and how can you construct a facade element that reduces the sound level from the outside and meet the indoor requirements. Mesurements for four hours was done at eight schools set north and south of the city centre. The measurement period included one school break and one lunch break.
Livscykelanalys av flerbostadshus ? energieffektiviseringsåtgärder för minskade koldioxidutsläpp
The importance of energy- and environmental issues has increased, and the work towards reducing carbon dioxide emissions plays a major part. The European Union has set up goals for the membership countries to work towards this to happen. The carbon dioxide emissions in Sweden have been reduced the last few years, but there is still a lot to do. About 30 per cent of Sweden?s carbon dioxide emissions generate from energy usage related to housing, this is why the housing sector is of interest to examine.
Modeling of a step motor for position feedback in a climate system
Med detta examensarbete vill vi belysa problematiken runt tredimensionell fastighetsbildning. Som objekt har vi använt oss av ett bergrum på Liljeholmskajen i Stockholm..
Traditionell ekologisk kunskap i en framtid med lokala, självförsörjande och urbana samhällen
Several scenarios point toward a future where we are far more people on Earth than today, where most of those people will live in cities and where oil no longer dominates in the transport systems and in agriculture as an energy source and where less energy will be available to us. The report investigates what areas in traditional ecological knowledge that can contribute to the transition that follows a future with less energy and establishes three areas with the potential of becoming important: areaspecific biological knowledge in societies that are more dependent upon its surrounding environment and its natural prerequisitesthe local management of these biological resources, which often means a fair sharing and sustainable handling of the resources and which has been observed in Nobel price awarded Elinor Ostrom?s researchthe world views that lie behind how the environment is considered and managed, world views that can inspire and point toward how we in the future should formulate world views that do not give the destructive modern management of the environment It is also noted that the magnitude of the city living in the future is a historical news and that very little research has been done in how traditional knowledge can be transferred into this kind of living..
Livscykelanalys för koldioxidutsläpp från flerbostadshus
Today, about 15 to 20 percent of Sweden?s total emission of carbon dioxide can be traced to the household sector. By examining apartment blocks in a life cycle perspective, the origin of the carbon dioxide emission has been charted and analyzed. This information has been used to create a computational model that calculates the total emission of carbon dioxide from a specific apartment block. The results from the analyzed apartment blocks indicate that both the use of energy and the emission of carbon dioxide have been reduced since the 1960s. Through the examination of building materials, it is possible to lower the emission of carbon dioxide that origins from the construction phase of an apartment block.
Går det att lära gamla hundar att sitta? : En studie om att ändra på en verksamhets utskriftsvanor.
The consumer society exploits the earth?s resources more than the earth itself has capability to produce. This over-consumption causes a mass production of products, which mean that more greenhouse gases are being emitted to the atmosphere. This is one of the reasons why the earth?s temperature is rising, where the result of it is worldwide disasters.
Det energiproducerande huset
We are heading towards a huge switch of how energy is produced with fossil fuels being replaced by renewable energy sources. It is not difficult to replace the energy you use in the house and there is no need for futuristic technology. There are already many established products on the market such as high efficiency vacuum solar collectors, heat pumps & small wind power stations that can supply the energy being used in a house. The company Sol & Energiteknik SE AB in Huskvarna has many different products which can reduce the need for an outside energy distributor. An average house in Sweden uses 15 000 kWh for heating, 5000 kWh for tap water and 5000 kWh for electricity.
Trådlös energiöverföring via elektromagnetisk induktion
This paper describes a method for wireless energy transfer via near-field electromagnetic inductionthat is inexpensive, simple and can be applied to almost any type of system, regardless of size andenergy demands.The method uses a primary unit consisting of an oscillator, amplifier and inductive coil thattransfers energy to a secondary unit consisting of a coil, rectifier and voltage regulator. Two typesof oscillators and several amplifier designs were realized and evaluated together with a multitudeof flat coils of both monofilar and bifilar type.The results show that it is important to use an oscillator whose frequency is dependent on theinductance of the connected transmission coil, such as the Colpitts oscillator. This is preferable toan oscillator with a preset frequency, such as a Schmitt-trigger oscillator..
Gestaltningsförslag för Norbyvreten : från kvarterspark till stadsdelspark
The prevailing food and energy crisis of the world, due to the declining reserves of fossil energy and a never ending rise of consumption, forces us to look into new fields to supply our energy demand. The boom of bio energy is criticized, as food crops are used to provide biodiesel and ethanol and the volumes are ridiculously small to supply world demand. Algae are one of the world?s oldest life forms and exist in many different phyla, providing a great variety to choose from, for different purposes. Cultivating microalgae offer a way to produce energy at great volumes without competing with food production and at the same time the algae offer a way to use our expensive nutrients in a more efficient way, besides this the algae are carbon dioxide neutral since their carbon source can be supplied by the atmosphere and the additional energy required can be supplied by algal oil or other renewable sources.
Minskad trädtillväxt under Lilla sitiden? : En dendroklimatologisk jämförelse mellan nutid och 1600-talet invid trädgränsen i norra Skandinavien
During the period called Little Ice Age (1400 ~ 1900) the climate of northern Europe was in an annual year-basis overall colder than it was before and after that period. The numbers of short, cold and rainy summers and long, bitter-cold winters where often repetitive under the approximately 500-years the period lasted. In Scandinavia, the coldest time during this period is estimated to have started around the end of the 16th century and lasted to the beginning of the 18th century. Trees growing at the tree-line are limited by temperature for their annual growth and hence showing differences of growth during changes in the climate, a method called dendroclimatology. The variations of growth can be read in the tree-rings either by analyze the width of the ring or by look into the density of the wood and is used to reconstruct past climates.
Underlag för solcellsproducerad el i Stockholm : Potential och klimatpåverkan
The City of Stockholm has decided to invest in renewable energy and especially in photovoltaics. The objective of this thesis is to investigate the photovoltaic potential on roof areas that the city possesses and to further investigate some buildings of the Property Management Department. The thesis also compares some existing photovoltaic plants with the solar irradiance map which shows available roof area on each building in Stockholm. The report ends with a literature study about the climate impact and greenhouse gas emissions of photovoltaic.The total available roof area suitable for photovoltaic plants is estimated to 700 000 m2, with a potential electricity production of 110 GWh per year. This corresponds to 17 % of the City of Stockholm?s yearly electricity consumption.