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809 Uppsatser om Passive heat - Sida 26 av 54
Underlag för bedömning av energibrunnar inom vattenskyddsområde
Denna rapport beskriver arbetet med utvecklingen av en ny modell för kaplanturbiner. Utvecklingen bygger på två kopplade differentialekvationer som under arbetets gång anpassats och implementerats i turbinmodellen.Modellen beskriver hur vattenflöde och turbinmoment påverkas av avvikelsen från den optimala kombineringskurvan för vinklarna på turbinens ledskena och löphjul, och är anpassad för ett referensaggregat med tillgängliga provdata. Även övriga enheter i vattenkraftaggregatet modelleras och sätts samman med frekvensregulator och elnät för att simulera aggregatets reglerstabilitet i önätsdrift.Verifieringen av turbinmodellen sker genom försök att återskapa de befintliga verkningsgradskurvorna med hjälp av modellen. Resultatet visar en god följning av de verkliga kurvformerna, dock med något lägre maximal verkningsgrad.Verifieringen av önätmodellen sker genom att prova stabiliteten i nätfrekvens och turbineffekt vid stegpålastningar. Resultatet ger en stabilare reglerstabilitet än i verkligheten, men uppfyller ändå förväntningarna på en fungerande modell.This report describes the development of a new kaplan turbine model.
Smarta lokala energisystem, Vision-Teknik-Tillämpning
The energy sector is facing an impending paradigm shift. Today?s technology enables the end-user to generate their own energy locally at home. Furthermore, recently developed storage technologies make it possible to balance energy demand with stored energy and integrate district heating with the local power grid. This means that in the future heat and electric power will interact and energy flows is converted over energy boundaries.
Effektmätning i pump
The interest for power and energy measurement has greatly raised with todays increasing electricity prices and enviromental awareness. In the search for energy efficient solutions, the measurements are more complex due to increasing of non linear components. Harmonics and non sinusoidal voltages put high demands on sampling and filtering. Meanwhile, the price must be controlled so the customer still will find it interesting to invest in smaller plants. ITT W&WW asks for a robust, heat resistant power meter with compact dimensions to allow mounting inside the casing of a pump.
Bearbetning av befintligt bostadsprojekt med syfte att uppnå passivhusstandard
I detta examensarbete har energiberäkningar och analyser enligt FEBY12 gjorts på ett radhusområde för att undersöka vad som krävs för att lågenergihusen ska uppnå passivhusstandard. Att uppföra energisnåla byggnader är i dagens samhälle viktigt för alla företag eftersom människor blir allt mer energimedveten och krav från beställare blir allt högre. I arbetet har en modell av radhusområdet modellerats i Revit Architecture för att på ett smidigt sätt få korrekta värden i de olika energiberäkningsprogrammen Vasari, Energihuskalkyl och PHPP. Programmen har helt olika kvalitéer därför har en jämförelse och analys av programmen utförts. Analyser har tydligt visat att det krav som finns för att uppnå passivhusstandard på värmeförlusttalet är betydligt svårare att uppnå än det krav som ställs på den levererade energin. För att uppnå passivhusstandard vidtogs diverse åtgärder såsom U-värde för väggar förbättrades, ventilationsaggregatets verkningsgrad höjdes samt fönsterpartierna reducerades avsevärt. .
Lustfyllda horor och älskande kvinnor : En diskursanalys av nätprostituerade kvinnors identitet
Abstract. The trade in prostitution/sexual services is regarded as a major social problem in Sweden. The prostitutes are seen as a group of passive, neglected and exploited victims, subject to repeated and forced outrage. However, there exists a network of sexworkers who claim their free will in selling sex as a trademark. They describe themselves as active subjects with a business of selling sex out of free will.
Olika fönster mot samma omvärld ? En undersökning av omvärldsbevakningen på Stockholms stadsbibliotek och Akademibokhandeln i Stockholm
The aim of this thesis is to explore how a bookstore chain and a public library meet the needs of their customers through environmental scanning. The empirical material is derived from six semi-structured interviews with six informants, three from each organization, together with an analysis of internal documents. The method used is a case study and the theoretical framework is based on models used in the process of environmental scanning, as described by Choo, Hamrefors and Hedin & Sandström among others, and which facilitate a comparison of the environmental scanning of the two organizations. The results of the study indicate that the library, as a public organization with a mission in society, perceives the environment as society as a whole and all its members as their users, whereas the bookstore concentrates on the sectors of the environment that affect their sales. The consequences of these different views are that the library is more active in the environment and uses surveys as a basic source of information, while the bookstore is more passive, and relies on statistics for information.
Utvärdering av energieffektiviseringsåtgärder på Bokelundskolan i Växjö
The purpose with this report is to examine how the implemented energy efficiency measures on Bokelundskolan in Växjö have had impact on the energy use. The measures which have been implemented are, new ventilation system, new heating system, optimized adjustment of the heating system, new windows with U-value 1.2 and lower window height, insulation under windows and in the crawl space. The school's energy use before and after rebuilding has been calculated with the calculation program, Vip-Energy 1.5.5.Calculations of energy use for the school with windows on U-value, 0.9 and 0.7 have also been done. The replacement of windows has been studied from a cost perspective. The conclusion is that the exchange of heat and ventilation system was the biggest contributor to reduced energy use on Bokelundskolan.
Institutionella ägares inverkan på redovisningskonservatism - En empirisk studie av företag noterade på Stockholmsbörsen
The increasing holdings by institutional investors have raised concerns about the institutions passive investment strategies and the implications for corporate governance. A way for investors to address moral hazard and opportunistic behaviour of management is to demand conservatism in accounting practices. This paper analyses the relation between institutional ownership and accounting conservatism in the Swedish market by studying firms on the Nasdaq OMX Stockholm over a three-year period. Furthermore, the study investigates whether ownership by institutions with high probability of monitoring managers leads to higher conservatism in financial reporting. To measure accounting conservatism this study uses the asymmetric timeliness measure developed by Basu (1997).
Solenergi på Kvarnholmen
In recent years it has become more and more evident that man has contributed to much of the climate changes that have taken place during the last century. A major challenge today is to reduce emissions and energy usage at the same time as the global population is growing. To contribute to a better environment, Stockholms Stad has set at target of becoming fossil fuel free by the year of 2050. The construction of new districts is done with this goal in mind; energy efficiency and renewable energy sources are examples of methods to achieve this.Solar energy is considered to be a sustainable energy source and the most common techniques to harvest solar energy in Sweden are solar cells and solar collectors which produce electricity and heat respectively. This report aims to investigate whether an investment in any of these systems would prove to be economically beneficial at Kvarnholmen, a district under construction in eastern Nacka, Stockholm.Since the finished blueprints only cover a small portion of Kvarnholmen, the report examines the possibilities for a house where construction has already begun, Nya Kvarnen.
Utveckling av dataanalysprogram för Opcon Powerbox
Opcon Powerbox is a product developed by Opcon together with the underlying company SRM (Svenska Rotor Maskiner) where surplus heat from the industry is used through an Organic Rankine Cycle (ORC)?process to produce electricity. An ORC-process is a thermodynamic circle process in which a refrigerant is used as the working fluid. The refrigerant makes it possible for the circle process to operate at lower temperatures than the conventional Rankine process.In this master?s thesis a data analysis software for the Opcon Powerbox has been developed in which measurement data is retrieved and handled from the Opcon Powerbox.
Kunskapssyn och behov av IKT - verktyg
The sun is an endless energy source and the heat it produces can be used to heatup our homes. This technology is relatively old and was introduced in the late70-s. There are two kinds of solar collectors that are most frequently used todayand these are plain solar collectors and vacuum solar collectors. The plain solarcollectors are the once that are used the most but the vacuum solar collectorshave increased more as a percentage the last couple of years.The biggest question asked regarding an investment in solar heating is if theplant is economically profitable. This question has no direct answer because itis dependent on a couple of prerequisites.
En studie av ett grupporganiserat lärande
The sun is an endless energy source and the heat it produces can be used to heatup our homes. This technology is relatively old and was introduced in the late70-s. There are two kinds of solar collectors that are most frequently used todayand these are plain solar collectors and vacuum solar collectors. The plain solarcollectors are the once that are used the most but the vacuum solar collectorshave increased more as a percentage the last couple of years.The biggest question asked regarding an investment in solar heating is if theplant is economically profitable. This question has no direct answer because itis dependent on a couple of prerequisites.
GALS,Design och simulering för FPGA med VHDL
Heat, clock scew and frequency optimization are some of the problems a semiconductor designer must face. By splitting a synchrounous block into multiple pieces which comunicates asynchronously with eachother and provide them with independent clocks, these problems may be reduced. GALS (Global Asynchronous Local Synchronous) is a wrapper that wraps a synchronous block and provides it with a clock. Multiple GALS-elements will make the whole system. The clockfrequency may be independently adjusted between each block.
Design och tillverkning av en stereoanläggning med aktivt delningsfilter
This thesis is the result of the author?s interest in music and electronics, namely the design and manufacturing of a stereo sound system with an active crossover. In short it can be stated that an active crossover has many advantages over its traditional passive counterpart. The active design naturally results in a more complex system comprised of a multiple number of components. This report deals with the theoretical aspects of preamplifiers, crossovers and power amplifiers as well as power supply and control.
Gränsland : var går gränsen mellan mig och en fysisk plats?
I have investigated the interaction between man and environment, between my inner reality and a physical place, using a camera as my primary tool. What conceptions do I have and how do they affect how I relate to the outer world? I am not a passive receiver of the surrounding world. Instead I actively (but usually unconsciously) choose what to take in and how I experience it.
If we as landscape architects do not reflect upon our conceptions, they will unconsciously affect our decisions. Only when we accept our experiences as subjective, can honest communication take place.
By means of literature studies I have connected my own conceptions with different definitions of place: place as enclosure (location, space), place as inner meaning (genius loci) and place as action (the place-creating process).