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809 Uppsatser om Passive heat - Sida 5 av 54
Latent värmelagring i vattenburet uppvärmningssystem med elpanna för byggnadsapplikationer
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.
Brännkammare för träpulver : Teoretisk analys och praktisk försök
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..
Utvärdering av befintliga passivhus : En byggnadsfysikalisk bedömning och mätningar om temperatur, och fukt analys på ytterväggarna
Energy price are on the way up to a high level that will not diminish in the future make us to focus more on the sustainable development for a better solution of residential houses. Passive house or low energy housing are one of the solution to make residential more environment friendly, in same time it´s a financial security using less energy, and saving money. The last 10 years in Germany and all around Europe the concept of passive house been developed, and people aim to know more about these concept that leading the market more attractive for passive houses. A passive house is a well designed building highly insulated and air tight with mechanical ventilated system for the whole building envelope that minimizes the use of energy for heating [1].The housing company Mimer has chosen to invest in low energy consumption in every new housing project. These future plan projects are decided to use less than 75 kwh per square meter annually in purchased energy [2].This thesis is about new constructed passive houses, and focuses on the evaluations of the temperature, and moisture condition for attic, external walls and joist.
Konceptstudie av Waste Heat Recovery System på Tunga Fordon
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.
Personlighetens inverkan på aktivt och passivt jobbsökande, karriärambition och arbetstillfredställelse
Previous research has focused limited attention on how personality affects job search for university educated people in work and no studies have focused on the difference between active and passive job seekers. This survey-based study that examined university educated economists and engineers with 5-25 years of experience, showed that career ambition mediated active job search for the personality dimensions of openness, agreeableness and extraversion and also gave clear evidence that active job seekers have lower levels of job satisfaction, and higher levels of career ambition, agreeableness and extraversion, compared with passive job seekers. These findings provide a more nuanced picture of the impact of different recruitment strategies and provide a starting point for in-depth studies on passive job seekers.
Solenergi och värmelagring i kvarteret Lagern
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.
Företagsstudie om värmeöverföring : Beskrivning av värmeflöden hos en lagerbyggnad
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.
Värmeförluster vid utvändigt placerade ventilationssystem
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.
Plusenergi och dess installationer : Kvarter Trettondagen
The latest thing in the area of environmental building today is energy-plus-house. The idea behind the energy-plus-house is to create a house that produces more energy than it consumes. To accomplish this, the house uses renewable energy, in this particular case solar energy. With the help from a proper construction and thoughtfully projected installations you can achieve a surplus of energy. The surplus energy can then be sold to the surrounding buildings and thereby conduce to a financial profit for the household.
Värmeöverföring i bergvärmesystem : En numerisk analys av den ringformade koaxiala borrhålsvärmeväxlaren
The borehole heat exchangers of today suffer from poor thermal and hydrodynamic performance. The purpose of this thesis is to improve the performance of ground source heat pump systems and thermal energy storages by increasing the energy efficiency of the borehole heat exchangers. For this reason, the annular coaxial borehole heat exchanger (CBHE) has been analyzed. This type of heat exchanger is interesting in terms of both thermal and hydrodynamic performance. A model has been set up in the program Comsol Multiphysics in order to investigate the heat transfer characteristics along the borehole.
Ny teknik för småskalig kraftvärme : - med fokus på Organisk RankineCykel (ORC)
As a part of the fight against the global warming the energy production needs to be more efficient and redirected towards sustainable options. One alternative is cogeneration, which means that electricity and heat is produced in one plant. The purpose with this survey is to examine if there are any commercial available combined heat and power techniques, based on combustion of solid moist biomass, which are suitable to small-scale applications. The technique must be able to produce between 2 and 10 MW thermal and the heat demand is a Swedish district-heating system. When already published reports had been studied, the Organic Rankine Cycle (ORC) was chosen as the most suitable technique.
Beräkningsalgoritm för fouling i pelletervärmeväxlare inom plasttillverkning
Sweden?s energy consumption is divided into three major sectors. One of them is the industry sector. One third of Sweden?s energy consumption is converted in the industries.
Ledarskapsideal : - ur ett demokratiskt-, auktoritärt- och låt-gå (laissez-faire) perspektiv
The purpose of this essay is to identify and analyze the term leadership based on democratically-, authoritarian-, and passive (laissez-faire) leadership and find out which of these types are to be preferred among employees. Our main aspects are:Do employees prefer democratically-, authoritarian-, or passive leadership?Are there any differences regarding ideal leadership considering sex, age, length of service and sector?We have chosen to make a quantitative study of two equivalent organizations, one in the private and one in the public sector. Our method is an explorative method were we seek to find new knowledge about our fenomena. Our study is based on the already established theories on leadership and our empirical data is gathered by questionnaires.The conclusions to be drawn from this study is that our respondents to a large extent prefer a democratic leadership towards an authoritarian and passive leadership. Most of them prefer a democratic leadership with elements of the other leadership types.
Motor till unikt luftvärmeväxlarsystem
Gtherm is an innovation company who has an unique air heat exchanger underdevelopment. The purpose of this thesis is to provide data of suitable motors for theheat exchanger and to find suitable motor suppliers.A motor specification was designed. It is an important basis for the search of suitablemotors. A compilation was made of nine motor suppliers and the suitable motorsfrom those. The compilation can be used by GTherm in their choice of suppliers andmotors.The compilation of the demands on the motor and analysis of suppliers indicated thatthere were no standard motors available to GTherms air heat exchanger.
Civilsamhället i Ryssland : En fallstudie om hur den ryska staten förhåller sig till civilsamhället.
When Vladimir Putin in the year 2000 came to power in Russia many believed that the Russian civil society were weak and had very little influence and with Putin people say that the situation have deteriorated. The purpose of this paper is to establish what kind of relationship exists between the Russian state and the civil society and to analyze this from a top-down perspective. We are looking at Russia during Putins first term in office from the year 2000 until 2004. In order to establish the relationship we have used John S. Dryzeks theory of inclusive and exclusive state and whether it?s active or passive in this process.