Sökresultat:
809 Uppsatser om Passive heat - Sida 10 av 54
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.
Finns det ett samband mellan avgifter och avkastning hos fonder? : En kvantitativ studie av svenska aktiefonder 2007-2011
Purpose: The intention of this study is to distinguish if there is a correlation between mutual funds administration fee and their return. The study will also observe if there is a difference regarding the return between active and passive management fees.Method: The study is founded on a deductive approach because the study is based on existing theories. Quantitative research based on statistical data has been used. A correlation analysis has been applied to determine if there is a correlation between the chosen variables.Conclusion: The conclusion of the study is that active management of funds mainly do not give a higher return than passive management funds. Neither is the administration fee dependent on the risk a fund has..
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.
Enegiutredning Hotell Princess
This report will show the energy usage of Hotel Princess in Sandviken, Sweden. When the hotel changed owner an examination of the hotels heating, ventilation and sanitary systems were done. The report showed flaws in the ventilation system, and is why the new owner wanted a closer look at the energy use of the hotel. The original building was built in the 1930s and two major extensions have been built, one in the 1950s and the most recent in the 1980s. An assumption made is that the building parts were built to the restrictions during the time. Activities on the hotel include sleep over, conference, night club, massage and swimming in the hotels pool section.
Aktiv bullerdämpning i ventilationssystem
Active headsets have been on the market for years and now it is time for something else to enter the stage. The technology of active noise reduction can for exmple also be used in ventilation systems for reducing ventilation noise. An active control system principally consists of four important components, namely the downstream error microphone, the upstream detection or reference microphone, the digital signal processor (DSP) and a loudspeaker. The upstream reference microphone listen to the primary ventilation noise and sends it to the DSP which makes a phase shift to the signal and sends it to the loudspeaker. The loudspeaker sends out the opposite waveform of the incoming one and reduce the primary ventilation noise.
Värdet av vinglaset : En studie om hur vinglasets sensoriska och estetiska egenskaper påverkar gästens vinupplevelse
The aim of this study is to examine how preschools contribute to the forming of identity in children, with a specific focus on the quiet and socially withdrawn child. How do the teachers describe the quiet child and the socially withdrawn child? Are there any opportunities for children to be quiet/withdrawn in preschools? These questions have also been analysed from a gender perspective. The method chosen is qualitative method. Nine preschool teachers from two Swedish preschools have been interviewed.
Aktiv bullerdämpning i ventilationssystem
Active headsets have been on the market for years and now it is time for
something else to enter the stage. The technology of active noise reduction can
for exmple also be used in ventilation systems for reducing ventilation noise.
An active control system principally consists of four important components,
namely the downstream error microphone, the upstream detection or reference
microphone, the digital signal processor (DSP) and a loudspeaker.
The upstream reference microphone listen to the primary ventilation noise and
sends it to the DSP which makes a phase shift to the signal and sends it to the
loudspeaker. The loudspeaker sends out the opposite waveform of the incoming
one and reduce the primary ventilation noise.
Ska man tro på aktie-Nostradamus? : en studie om aktierekommendationers värde för privata investerare
Intro: 80 percent of the Swedish population own shares. This makes Sweden the leading country in private investment in securities. It can be difficult for the private investor to know where, when and which security to invest in. The strategies are as ambivalent as the stock markets fluctuations. If the investor prefers to refrain from investing money himself, there are brokers who carry out these types of services.
Welcome to Holland ? a study in parent experience, copingstrategies and interaction with school and municipality, of parents to children with Asperger syndrome.
The purpose of the study is to examine, describe and analyse how a selection of parents to children with Asperger syndrome understand, experience and cope with their parenthood. To attain this purpose we focused on these following questions;How does the respondents view their parenthood?; What kind of strategies does the respondents use to cope with their parenthood on the basis on their child with Asperger syndrome?; How does the respondents experience the mesosystem interact with them regarding situations contenting strenuous and stress?We chose to do a qualitative study by conducting separate interviews with eight parents to children with Asperger syndrome. Then we analyzed the answers using an abductive research, we tested the empirical data against our choice of theoretical perspectives. The results shows; that several of the parents in the study have experiences of high strenuous and stress in combination the several roles their parenthood contained.
Expansionsmaskiner istället för strypventiler - en effektivisering
In Uppsala CHP Plant, there are six pressure reducing valves to reduce the pressure from 15 to 3 bars, before six absorption heat pumps. During the process the energy is conserved but losses occur in form of exergy. The aim of this thesis is to reduce the losses of exergy. This can be done by letting turbines replace the pressure reducing valves.In this thesis an investigation has been done of the conditions today, the conditions after the change from pressure reducing valves to turbines and a comparison of three different types of turbine solutions. The three examined solutions are one turbine, several helical screw expanders and several small turbines in parallel with asynchronous generators.The six absorption heat pumps have been divided into two groups; one group of four and one group of two absorption heat pumps.
Uppvärmd konstgräsplan : Beräkning av utnyttjningstid för en uppvärmd konstgräplan med alternativa rörplaceringar
For Skattkärr IF a turf field with warming has been projected to increase field?s utilization hours and to have a longer period for athletes to perform their activities outdoors. The technique chosen to heat the plan is a type of a geothermal heating system without a heat pump. The brine, which is water with 30% ethanol, collects heat from the borehole and discharges it to a coil in the field. There is at position 11 boreholes but it is planned to increase the number to 31, which is the design for the facility.
Tysta barn i förskolan : tillgång eller problem?
The aim of this study is to examine how preschools contribute to the forming of identity in children, with a specific focus on the quiet and socially withdrawn child. How do the teachers describe the quiet child and the socially withdrawn child? Are there any opportunities for children to be quiet/withdrawn in preschools? These questions have also been analysed from a gender perspective. The method chosen is qualitative method. Nine preschool teachers from two Swedish preschools have been interviewed.