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665 Uppsatser om District cooling - Sida 2 av 45
Restvärmeåteranvändning från absorptionsvärmepumpar : en kartläggning av möjligheter och begränsningar vid Vattenfall Värme Uppsala Block 5
Vattenfall district Heating power plant in Uppsala produces District cooling with absorption heat pumps which leads to a large amount of waste heat that has to be cooled with evaporative cooling towers. The Environmental Court has ordered Vattenfall to survey the possibilities to recover the heat, which is the focus of this thesis.The study begins with an overview of the system, and conditions and limitations for waste heat recovery is examined. In the next step alternatives to recycle the heat is evaluated, either by direct recovering or by upgrading.First, the technical possibility of each alternative is discussed, and then the operation time and the amount of recovered heat is calculated. Those alternatives which are possible are brought further to an economic analysis.The cost of investment for each alternative constitutes the basis for a present value analysis. The results are put together in a table where the total amount of recovered heat is compared with the present value for the different alternatives.
Utformning av kylkanaler och spånrum på superturbofräsar
This thesis describes how the chip space and coolant channels are designed in today?s mills, the ideas behind the design and what is considered to be the best method of cooling. It contains ideas on how the chip space can be simplified. It contains several concepts on how the cooling could be designed for better efficiency and manufacturability. There are also suggestions on how the cooling could be stopped when the cutter isn?t cutting.
NEDKYLNING HOS VANLIG B?NA, PHASEOLUS VULGARIS
Beans are a global source of plant-based protein, and in some countries, they constitute a primary source of protein intake. With ongoing climate change, including rising temperatures, it is necessary to adapt beans to ensure a reliable food supply. An important mechanism that many plants have, to cope with high temperatures, is cooling through transpiration. During transpiration, stomata open and release water vapor. Water molecules use heat energy from the leaf to convert into gas, thereby cooling the leaf.
Bergkyla och bergvärmeutredning för industrilokalen Rödbergsmyran 5 i Umeå, Västerbotten.
Grubbe Ventilation AB is a sheet metal and ventilation company who provides design, installation, service, and repair of ventilation. The company is expanding their business by building a new facility in Umeå, Västerbotten. The property is designed to be used for both office and industrial work.Grubbe Ventelation AB has not yet decided upon wish system which is to be established to provide the building with heating and cooling. The consulting firm Umeå Projekt Team has therefore been asked to investigate the possibilities to invest in geothermal- heating and cooling.If the investigation of a geothermal heating- and cooling system would provide favorable results it would be a very appropriate alternative that provides energy at low costs and are an environmentally friendly option as the energy comes from stored solar energy in the ground is provided by stored solar energy in the ground.The facility ´s heating and cooling consumptions are calculated in the program BV2 and the result indicate a heating demand of 185 000 kWh per year due to thermal transmittance, transmission losses, heating of warm water and a cooling requirement of 5500 kWh.Three different systems of geothermal heating and cooling were tested in the computer program Energy Earth Design. The results show no difference in the dimensioning of the drill hole if merely heating were to be used or both heating and cooling were to be established.
Development of Liquid Cooling for PCs
In recent years, existing solutions for cooling personal computer CPUs have been supplemented by a new product category, factory sealed water cooling loops. These systems, consisting of a water block with an integrated pump, a fan and a radiator, perform well compared to the air cooling solutions but are less effective than larger, custom-built water cooling systems.This project aims to explore the most important aspects of a factory sealed system and to identify possible cost-effective enhancements of the performance.The most significant differences between the different groups of water cooling loops are the block design and the pumping power. The performance of both categories is also largely dependent on the fan power, but increasing fan power has a large negative impact on the noise level.Both radiator size and fan model choice appear, in tests, to be relatively unimportant, presuming that the noise level is kept constant. The position and direction of the fan, however, has significant impact on both the temperature and the sound level.Water blocks can be designed in several different ways, both regarding the heatsink design and the flow direction. In simulation, flow with the inlet centered above the heatsink result in considerably lower pressure drop and slightly higher temperatures than flow through the block, for heatsinks with fin arrays.Creating a competitive product in this product segment certainly seems possible, as there are performance-increasing changes to be made that seemingly has little impact on the production cost.
Utredning av solenergi för drivning av sorptiv kylprocess för inomhusluften på Stockholmsarenan
Cooling down the indoor air can be done in several ways. One way is desiccantcooling which will be used at the Stockholm Arena. This method is used in airhandling units that use temperature changes and moisture fluctuations in the air. Oneof the steps is to add heat during the cooling process in order to reduce the relativehumidity of the exhaust air. The air passes thru an adsorptions rotor which thenabsorbs moisture from the supply air.
Morgondagens effektiva fjärrvärme : En beskrivande litteraturstudie
This report is made as a literature review, focusing on the work done to increase understanding of efficiency in the categories of substations and secondary heating systems, with respect to the deviation from the theoretically possible cooling off in the distribution network as well as the economic benefit that appear. The main purpose of a considerable part of the literature used in this report addresses the issue of identifying individual causes of reduced cooling in district heating systems. These literature resources have been compiled and summarized as part of the report.The technology of district heating is associated with benefits such as better use of the energy in a fuel. This is the case of cogeneration plants where serial generation of electricity and thermal energy increases efficiency compared with the parallel generation where heat is generated locally and electricity is generated centrally. Serial generation thus allows for lower primary energy demand.
Spillvärmeåtervinning
SAPA´s resource of waste heat is the basis for this thesis to investigate the possibility of energy assets in their cooling water and possible uses for it. The energy in the waste water is greater than the current need which has three uses which are (1) heating the factory, (2) converting liquid propane to propane gas and (3) local domestic heating. The average energy load that is available is 1, 7 MW and the average temperature in the cooling water is 41°C. The total energy load at dimensioning out side temperature is approximately 1,6 MW for the three current uses. The temperature is currently too low to be used directly in the existing systems so an upgrade is needed.
Inventering av processvattenbalans : fastställande av fjärrvärmedistributionens läckage inom Vattenfall Värme Uppsala AB
Heat is distributed to the district heating customers through pipes with water as a heat carrier. The district heating system is complex. To decide what is leakages from the district heating net versus what is the water consumption of the plant, is difficult.
Therefore, the purpose of this master thesis is to establish a model where the district heating net?s leakages but also the water consumption of the plant can be followed
daily. The project is performed at Vattenfall´s district heating power plant in Uppsala.
Information is gathered through discussions, drawings of the plant and guided tours of the plant.
Att förmedla trygghet : En studie om distriktssköterskor och derasrelation till patienter
Background One of the main demands on Swedish and global health care in general is to meet the patient?s need for safety. By general health care law this also comprises district nurses? field of responsibility. Although there are numerous studies describing the concept of safety and its different shapes, no research could be found exploring how safety is, or supposed to be, mediated by district nurses? in a Swedish context.
Succé mot alla odds
Uppsatsens syfte var att undersöka vilken betydelse yttre påverkan och inre drivkrafter har haft i fyra individers karriärutvecklingsprocess inom en hårt konkurrensutsatt bransch, samt hur dessa har hanterat denna. Datainsamlingen genomfördes med hjälp av semistrukturerade mailenkäter, och det insamlade materialet bearbetades med hjälp av deduktiv tematisk analys. De teman som ligger till grund för analysen är: studie- och yrkesvägledning, cooling down, empowerment, informationsteorier, forskningslitteratur samt karriärvalsteorin SCCT. Studien visar att samtliga respondenter har utsatts för dämpande påverkan, cooling down, under sin uppväxt, både från skolpersonal, och den egna familjen, men också att de erhållit empowerment från andra håll. Respondenterna har hanterat denna yttre negativa påverkan på olika sätt, men gemensamt för dem alla är att de visat på en inre drivkraft, som trots den nämnda negativa påverkan gjort att de nått framgång inom sitt gebit.
Vårdcentralschefers perspektiv på distriktssköterskors förskrivningsrätt
Background: In 1994 came the general prescription law in force for the district nurses with specific training in pharmacology and pathology in Sweden. According to The National Board of Health and Welfare from 2004 follow-up of the use of the prescription law revealed that nearly half of the district nurses used their prescription once a week. According to previous research the district nurses and patients were positive to the district nurses administration of prescriptions. Doctors, contrariwise, were not as favorable to the district nurses administration of prescriptions. The responsibility of the heads of the health centers is to promote the district nurses to prescribe and make sure that it works in a satisfactory manner.
Utveckling av kyl- och smörjsystem för ekobilen Agilis HCCI motor
Every year, KTH participates in the Shell Eco Marathon, a competition whose goal is to design a vehicle that can go as far as possible using only the equivalent energy of one liter of petrol fuel. This year, one of KTH?s contributions to this race is the Agilis prototype; a car powered by a uniquely configured HCCI-engine developed at the university. The engine is dependent of several subsystems in order to work properly, among other, systems for cooling and lubrication.Combustion engines are in need of a cooling system that reduces the heat developed during the combustion. In general, two main types of cooling systems are employed; either air cooling, where the outside of the cylinder is exposed to a flow of the surrounding air, ore water cooling, where water flows in tubes around the engine, and the heat are transferred by the water to the surrounding air through a heat exchanger.The purpose of the lubrication system is to prevent the friction that builds up in the interference between moving parts in the engine.
Konvertering från luft till vätskekylning av elektronik
A Swedish electronics company wants to make the cooling of one of their electronic components more efficient. They propose that a retrofit liquid cooler is the way to achieve this goal. The current air cooling has high energy cost due to the high amount of power needed to power fans and heat exchangers. Using high volumes of air for cooling also leads to noise pollution. The conversion from air to liquid cooling would possibly make the operation of the electronics more cost efficient and less noisy.The purpose of this project is to theoretically evaluate different concepts of drawing the heat generated by the electronic component in to a fluid, using numerical calculations in Matlab and FEM simulations in ANSYS.
Och då kommer jag osökt in på det här med alkohol En pilotstudie om hur distriktssköterskor använder AUDIT
Background: The district nurses profession has traditionally been health promotion. In order to find patients with excessive alcohol intake, district nurses use AUDIT. Research shows that health professionals find it difficult to face alcohol abusers in primary care. AIM: The aim is to describe how district nurses work with AUDIT. Method: Semi-structured interviews with six informants were carried out.