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983 Uppsatser om Heat transfer - Sida 11 av 66

Passivhus vid polcirkeln : Fungerar det?

This report is the product of the course AF101X, a bachelors degree in Samhällsbyggnad atKTH. The task of the course is to design a small house at a given location and also implement adeepening study. The house in this report is located in Kiruna in the north of Sweden, where theclimate is much colder than in the rest of the country.The deepening study of this report is to evaluates how realistic passive housing north of thePolar Circle is based on those facts. The house will to some extent be designed to fit the passivehousing standard.

Energikartläggning vid biogasanläggningen, Kungsängens gård

The purpose of this thesis was to make an energy survey and quantify energy flows of individual unit operations associated with the biogas production in Uppsala Vatten och Avfall AB:s biogas plant, located at Kungsängens gård. Moreover, large consumers of energy would be identified and analyzed. The objective of this energy survey was to obtain a detailed understanding of the energy use in the biogas production. The energy survey was divided into two parts: electricity and heat. Each part was treated separately and with somewhat different approach. To estimate the electricity usage during the projcet the rated power of each selected unit operation was noted and multplied with the measured time of usage.

Energikartläggning av biogasanläggningen, Kungsängens gård

The purpose of this thesis was to make an energy survey and quantify energy flows of individual unit operations associated with the biogas production in Uppsala Vatten och Avfall AB:s biogas plant, located at Kungsängens gård. Moreover, large consumers of energy would be identified and analyzed. The objective of this energy survey was to obtain a detailed understanding of the energy use in the biogas production.The energy survey was divided into two parts: electricity and heat. Each part was treated separately and with somewhat different approach. To estimate the electricity usage during the projcet the rated power of each selected unit operation was noted and multplied with thenmeasured time of usage.

Prestandaförändringen hos en bergvärmeanläggning efter fem års drifttid

The aim of this report was to do a case study at a geothermal heating system which has been in operation for about 5 years, and study if its performance has changed during this period of time. A literature study about the processes involved was also done in purpose of background knowledge.The tenant-owner?s association Duvan at Petterslundsgatan in Uppsala installed year 1999-2000 a geothermal heating system. The purpose of this installation was that they hoped it would lead to a smaller usage of district heating which would lead to a reduction of the heating expenses for their buildings. The geothermal heating system consists of 19 energy wells and 4 geothermal heat pumps, and it is one of the first systems of that size in the region of Uppsala.

Effektivare energianvändning på Totebo AB

The main goal with this thesis report was to come up with ideas of how to make the use of energy more effective and thus save money for the company.First a survey was made to find out where and how the energy consumers were divided within the company. The results were then used in calculations to find out how much money that could be saved and how long it would take to get back the investments.There is a big potential in saving money by recovering heat from the UV-lamps with a heat exchanger. It would also even out the pressure in the factory which is a source to heat loss and a cause for discomfort amongst the employees. It?s possible to save 105 000 kr in a year and the money needed for the investments is 600 000 kr.By using the recovery air more effectively the company could save up to 250 000 kr a year in lowered heat purchases, but this would require the use of automatic dampers.If you reschedule the running times for the wood chipper and invest in some kind of load management, for example Sydkraft?s ?Energidirigent? you can save at least 42 000 kr.

Beräkning av värmeförluster och energieffektivisering av elbussar

The ?civilized? world is in need of fossil fuel in order to function. Hybricon AB is a company in Umeå that is developing a technology that hopefully can reduce parts of this need. They are currently testing their two electrical busses (with Hybrid backup) in city traffic on the roads of Umeå in cooperation with the county of Umeå.                               The busses are originally diesel-busses, but the diesel motor has been replaced with two electrical hub-motors with a power of 145 kW each that are powered by batteries.The batteries are charged at the end station after each route. In case the batteries should run low on capacity during driving, they can be recharged by the so called genset.

Svårigheter vid andraspråksinlärning av det svenska språket : En studie av andraspråksinlärningen hos fyra spansktalande personer

Syftet med den här studien är att undersöka de språkliga svårigheter som fyra spansktalandepersoner från samma familj möter när de lär sig svenska som ett andraspråk och att se om devuxnas språkbruk skiljer sig från barnens. Undersökningen omfattas av fem språkligaaspekter. För att uppnå detta har enskilda samtal genomförts i en trygg och lugn miljö med varoch en i familjen där alla har fått berätta om sig själva och svara på personliga frågor.Mitt resultat visar att aspekterna tillämpning av inversionsregeln, placering av negation,uttal av vokaler, uttal av finala konsonanter samt uttal av konsonantkluster är svåra församtliga i familjen. Jag har kunnat se att det finns starka influenser från det spanska språketoch att negativ transfer är vanligt. Transfer visade sig vara vanligare vid fonetiska aspekterjämfört med de syntaktiska.

Jämförelse av solhybrider

Research in solar energy is taking big steps in both solar heating and solar electricity. It´s not only the technologies alone, but also the combination of both solar electricity and solar heating which is what is called a solar hybrid. The idea of a solar hybrid is that a solar cells efficiency decrease with increased temperature and can with help from a solar collector be cooled and the heat can be utilized. This thesis report compares heat production and electricity production with respect of, in first hand, a solar hybrids geometry in the cooler. The theory chapter describes solar heating and how different solar cell technologies work and their environmental impact at the production and how compatible these technologies are for the solar hybrid.

Hållbara uppvärmningsalternativ för hotellstugorna på Grinda : En kvantitativ studie gällande hållbara uppvärmningsalternativ på en skärgårdsö

Skärgårdsstiftelsen, which is responsible for several of the archipelago islands in Stockholm, has chosen to explore the possibilities for more sustainable heating systems in buildings on the islands in collaboration with KTH. A reduction of energy use and improving the efficiency of existing heating systems are included as part of the environmental work. This report studies the island of Grinda, which is located outside the area of Vaxholm in Stockholm. The study area consists of a guesthouse consisting of a restaurant as well as conference facilities and four neighboring cottages used for overnighting. The cottages now run solely on direct electricity, both for heating and hot water.

Utvärdering av ett större bergvärmesystem i en flerbostadsfastighet som har konverterats från fjärrvärme

This master thesis is an in-depth study of an existing heating system at a household cooperative in Uppsala that has been converted from district heating to a bedrock heat pump system. The study focuses on an economical system optimisation of the building?s complete heating system. The aim was to determine how well a heat pump system in large buildings actually work, find out possible ways to optimize the existing system and point out important system parameters for new heat pump installations in larger buildings.The project points out a possible energy cost reduction of 45 % without investment and further cost reductions with equipment investments. A reduction by 30 % is possible by improvements in the regulation system and 15 % is possible by maintaining the brine system.

Artificiell insemination av får

AbstractThe purpose of this bachelor thesis is to describe the use of artificial insemination (AI) in sheep and discuss the possibilities for AI in Sweden. Male and female fertility, heat detection, semen handling and insemination techniques in sheep are described. Advantages and disadvantages of AI are discussed. In order to achieve genetic progress it is important with well planned and implemented breeding programs. The Swedish Sheep Recording Scheme and computer software from Elitlamm are the basis for sheep breeding in Sweden.

Kyla i Nyköping och Motala : Kartläggning av kylapotential för Vattenfall Värm

The Swedish energy company Vattenfall is currently the owner of the district heatingsystems in Nyköping and Motala. To be able to also offer cooling solutions tocustomers are becoming more and more important. This report describes the resultsof an investigation of the cooling market in the two cities and the potential needs forcooling today and in the coming 20 years. The total potential for the coming 20 yearsis estimated to be roughly 17 MW for Nyköping and 9 MW for Motala.Two possible district cooling systems for each of the two city centers was modeledand a comparison was made between different cooling techniques namely absorptionand compressor chillers.Absorption chillers driven with district heating during the summer is one way ofincreasing the load in a combined heat and power plant and thereby the possibleelectricity generation. The cost of heat production must be low for absorption chillerto be able to compete as an alternative.

Trafikverkets effektstyrningssystem - EFS 132 kV : Bidraget till minskade förluster

The technological legacy from the early electrification of the Swedish railroads has resulted in a power grid with a lower grid frequency than the national power grid from which it is fed. Energy transfer between these power grids with different frequencies requires substations, adapting the grid frequency for the rail road power grid. For this purpose, a feeding power grid has been built, stretching across the country from Boden in the north to Tälle/Häggvik in the south.Power transfer in the Swedish power grid results in voltage angle differences which increase with increasing loads and transfer distance. These voltage angle differences are transferred from the power feeding substations to the rail road power grid, will in some extent cause loss of energy due to unwanted power flows from north to south.To minimize the losses due to this phenomenon, a power management system called EFS 132 kV has been developed and implemented. The system minimizes the unwanted power flows and controls the desired power flow for a good distribution of loads between the power feeding substations.This thesis investigates the extent of the transmission losses avoided due to the EFS 132 kV that coordinates the idling angles to a common reference point.The results indicate that EFS 132 kV affects the power flow, especially between the northern substations through an improved load distribution.

En studie om kunskapso?verfo?ring vid o?ppen innovation genom crowdsourcing

Organizations that want to maintain a good innovation capability can seek knowledge both within and outside its boundaries. Opening up innovation processes, through so-called open innovation, allows organizations to combine internal and external knowledge sources in order to include previously excluded perspectives to the innovation process. This study examines how knowledge is created and transferred when conducting open innovation through crowdsourcing. It is done based on Nonaka?s (1991; 1994) theory of how knowledge is created through conversion processes, where implicit knowledge can be converted into explicit knowledge and vice versa.

Dokumentationskrav vid internprissättning : En analys av lagförslagen till svenska dokumentationsregler i propositionen 2005/06:169

According to the arm?s length principle, transactions between associated multinational en-terprises (MNE) shall be based on the same conditions as transactions between unrelated parties. This means that intra-group prices on cross-boarding transactions must be at arm?s length range and consistent with conditions in the open market. The arm?s length principle is expressed in article 9.1 of the OECD Model Tax Convention and Chapter 14 section 19 of the Swedish Income Tax Act.When transfer pricing between associated MNEs is not reflecting the arm?s length princi-ple, states face the possibility of losing tax revenue.

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