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957 Uppsatser om Thermal heat losses - Sida 19 av 64
Energieffektivitet i datahallar
The number of data centers and their capacity is increasing throughout the world. Theenergy used in these data centers and the emissions from the use are increasing at thesame rate. The total use of energy will double from 2008 to 2011 based on the trends indata centers use. Research in this area says that the emissions from data centers willhave surpassed the level of airline traffic in 2020. The index used today to compare howefficient a data center is, called PUE, is lacking some information.
Optimerad styrning av kondensatorbatterier - Ny möjlighet att minska förluster med elektronisk brytteknik
Transmission of reactive power is well known to cause active power losses. Thus, newcomponents who can help minimizing these expensive reactive power flows are ofgreat interest to the power distribution companies. ABB Corporate Research hasdeveloped the first electronic power breaker. One possible application for thisbreaker is transient-free switching of capacitor banks. This could prove a usefuldistribution voltage complement to the switch-sync technique, mainly applied to transmissionvoltage level.
Utvärdering av möjligheten att tillvarata energi ur processvatten : En undersökning gjort vid Olofsfors AB på uppdrag av UMIA AB.
The company Olofsfors AB manufactures drive belts for forest machinery, known as ECO-Tracks, and abrasion-resistant steel and cutting edges for graders, excavators and tractors, known as Bruxite and SharqEdges. Manufacturing these products requires the steel to be heated and molded, then submerged in water and hardened. The water used in the hardening of steel is pumped to the process from pits below the floor and then pumped back to the pit after it?s been used. Since the temperature of this water rises after being used to harden the steel the temperature of the pumping pit needs to be adjusted to maintain its setpoint of 21°C.
Värmestrålning för förebyggande av isbildning på strömskenan
Detta examensarbete har utförts med begäran från Trafikförvaltningen. Arbetets huvudmål är att undersöka om det är möjligt att använda värmestrålning direkt mot ytan av strömskenan för att hindra isbildning på en kortare tid då absorptiviteten är som bäst..
Strömkontroll till aktiva magnetlager med noggrann och störningsreducerad strömmätning
There is always a need for more effective ways to store energy in order to reduce the human impact on the environment. One step on the way can be the use of flywheels as kinetic energy storage devices. Low frictional losses are essential for a flywheel to be effective. To minimize these losses active magnetic bearings (AMB) can be used to keep the shaft centered instead of the more conventional ball-bearings. AMBs use actuators and a fast control system that needs correct and noise-free measurement data of the shaft position and the current in the actuators to work properly.This thesis explains the process of constructing power electronics and a current measurement system for active magnetic bearings (AMB).
Kraftvärmeverk i glesbygd - en möjlighet?
Our purpose in this paper is to examine if there is any profitability for a company with a factory in the timber industry to invest in a combined heat and power, CHP. Based on analysis and the results that the paper generates, we will give Derome AB a suggestion on how it is a profitable investment or not to installing in a CHP.By investing in a CHP plant, you can get a high efficiency, which means that companies can use their resources more effectively. The Swedish wood industry has by-products of production that can be used for combustion in their boiler which is an advantage.The essay is a qualitative study where we have a case company, Derome AB. In this company, we interviewed two employees who have knowledge in the study. They have helped us to provide information and data about their business.We chose to use the pay-off- and the net present value method, NPV, to see if there are profitable advantages for the investment.
Solvärme för en skola i Lerum. Studier av olika systemalternativ.
Two elementary schools are now being built in Gråbo (in the municipality of Lerum),Röselidsskolan and Ljungviksskolan, which are both designed with solar thermalcollectors for the schools domestic water heating. During the summer while thelargest amount of solar heat can be generated, the activity hence the domestic wateruse in the schools are heavily reduced. Both schools are connected to the local districtheating system which makes it possible to use the solar collectors to deliver heat tothe district heating.The purpose of this thesis is to evaluate the two systems mentioned above and todetermine which system is more suitable to apply on a school. The building whichconditions were used for this evaluation is Röselidsskolan.A solar heating plant of each system type was dimensioned from the expected andknown conditions of the building. The purpose with the dimensioning was to makethe solar plants replace the ordinary energy source as much as possible.
Dietary fibre composition and sensory analysis of heat treated wheat and rye bran
When grains of wheat and rye are conventionally milled, large quantities of bran classified as by-products are left and are mainly used for animal feed. Bran is a complex material composed of the aleurone layer, nucellar epidermis, a seed coat, a fruit coat and a small proportion of the germ and endosperm depending on extraction rate. The bran fraction consists of approximately 40-50 % dietary fibre which can contribute to increase the nutritional quality of human cereal food. It would also be valuable for the food industry to convert by-products as bran to products with higher commercial values.
The aim of this thesis was to analyse the content and composition of dietary fibre of heat treated wheat and rye bran according to the Uppsala method with some modifications in order to analyse soluble and insoluble dietary fibre separately. Half of the bran samples were precooked, dried and roasted and the other half dried and roasted (uncooked).
Akustisk mätning av U-värde
This pre-study investigates the possibility of U-value measurements through an acoustic method. A hypothesis about an acoustic model built on acoustic theories combined with U-value theories is presented to answer the questions:
? Can U-value theory be combined with acoustic theories?
? Can the coefficient of heat be affirmed trough an acoustic measurement?
The idea for this dissertation begun with a logical idea in mathematical similarity, between the coefficient of heat transmission units and sound intensity units.
The U-value theory is based on assumptions such as initial resistance for inner walls and initial resistance for outer walls. The resistance in the material is interpreted through sound intensity theory.
The argument is built upon mass law theory, which means if the frequency or thickness of the material layer doubles it implies an increase of sound reduction by 6 dB.
Möjligheter att öka effektiviteten och det ekonomiska utfallet av barkhanteringen vid Seskarö sågverk :
The sludgebark and to a certain extent the bark were until a decade ago waste products without any economic value that were thrown away. A number of environmental laws and increcing energy prices have improved the prerequisites for increasing the use of these materials. At Seskarö sawmill they burn the sludgebark and a great deal of the bark in the sawmill furnace. The sludgebark has a number of disadvantages compared to bark during burning. The sludgebark is often wet which means the energy net from burning often gets low.
Effektivare elanvändning på avfallskraftvärmeverk : Förslag till handlingsplan för minskad elanvändning på Renovas anläggning i Göteborg
This thesis has identified and studied measures to allow for reduced use of electricity in a waste incineration plant in western Sweden. The energy extracted from the waste at the powerplant is utilized and sold in form of electricity and heat. Technical and environmentally the combined heat and power plant is by today's standards among the leading waste incineration plants in the world. The owners are constantly striving to improve the efficiency of the waste incineration plant. They have seen the opportunities for savings in reducing internal usage of electricity.
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.
Utveckling av en ny tillverkningslina
This report contains results of our study at CTC in Ljungby. CTC produces heating products such as boilers, heat pumps and additional products to their heating systems.The purpose of the report is to make a proposal how CTC will supply their new production line for heat pumps with materials. The proposal includes a production layout and a scheme for how to place the material in the production storage.The new production line will produce two different products and both of them have several variants. The line will also have a mixed flow, so the products can be produced in a random order. These conditions demand that the production line has great flexibility and that the material to all the variants can be stored in the production storage.With these conditions as input we made a layout proposal to the company.
Identifiering av områden med risk för fosforförluster genom ytavrinning : metodutveckling med GIS
The eutrophication of lakes and seas with the algal bloom and deficiency inoxygen that follow, has been given priority by the Swedish government as oneof 16 environmental objectives. The purpose of this project was to develop a toolbased on a simple model, limited amount of data and geographic informationsystem (GIS) to identify areas with risk for phosphorus losses due to surfacerunoff. This tool can act as a decision support to decide where appropriatemeasures should be applied with the aim of reducing phosphorus losses and bythat the eutrophication.The method that has been used is a combination of two models, one calculatingthe potential erosion while the other one identifies areas of erosion (net erosion)or deposition. This ability is of great importance because potential erosionshould be calculated on areas with net erosion. Areas with high potential erosionhave an increased risk for phosphorus losses due to surface runoff.The potential erosion was calculated based on factors which describe how topography(LS), land use (C), soil type (K) and precipitation (R) effect the erosion.All of them have been modified to a greater or lesser extent.
Low Temperature Waste Heat Solutions : with proposals for energy technological actions based on Scania?s building 64
The report comprises two separate parts:part 1: Temperature needs for district heating in the paint shop for axles in building 210part 2: Energy and low temperature waste heat solutions in heating and cooling systems for building 64 with surroundingsThe paint shop for axles in part 1 has air quality requirements in places for coating of axles. Toachieve desired air properties there are different process ventilation systems, which consist ofventilation coils for heating and cooling, plus air humidifier. The ventilations coils for heating usedistrict heating. Today the ventilation coils use water of 100°C to achieve necessary air demands inthe coating boxes. This part of the report investigates whether the existing system would achievethe air requirements with a water temperature of 75°C instead of 100°C in the ventilation coilsduring the coldest parts of the year.