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117 Uppsatser om Steam Valve - Sida 7 av 8

Beskrivning av systemfunktioner i kärnkraftverk med hjälp av objektorienterat modelleringsverktyg

In order to facilitate design and maintenance of such a large and complex site as a nuclear power plant, all system functions must be described in a stringent way. In the past, these descriptions consisted of text documents and logical diagrams, but today there are an increasing number of object-oriented programs available on the market which might be used for this purpose. This Master Thesis has made a closer study of one of these programs named Rational Rose. The principal of the program is to facilitate software design and development, not to create models of plants. However, using the program the same way as developing software, specifying actors then gradually extend the model with use cases, use cases diagrams etc, the same methods can be used when modelling plants.

Miljövärdeflödesanalys av Risifruttiproduktionen : En utvärdering av värdeflödesanalys och miljövärdeflödesanalys

This report is the result of a thesis work carried out on the Risifrutti production at the company Procordia Food AB. The thesis is at a master level and is the final work for the author to receive a Master of Science in Innovative production at Mälardalen University. The thesis comprises 30 credits and has lasted for 18 weeks. The thesis is mainly a research on whether it is possible to perform an Environmental Value Stream Map (E-VSM) in a food processing industry and an evaluation if the tools E-VSM and Green Performance Map (GPM) are useful in this type of industry. An extra part to this research is to use the results from the E-VSM and give Procordia Food AB information on improvement potentials in the Risifrutti production. The author has found it difficult to collect some of the quantitative data to the E-VSM, mainly regarding energy, but by using the Value Stream Mapping (VSM) tool and other Lean tools the author was able to identify and quantify several wastes in the Risifrutti production. Recommendations for improvements based on these wastes have been given to the company. In the research part of this report the utility of the Value Stream Map, Environmental Value Stream Map and Green Performance Map in a food processing industry have been analyzed. The author has found that the Value Stream Map has been a useful tool since waste and unevenness in the tact of the production has been identified. The Environmental Value Stream Map and the Green Performance Map are also great tools when a company wants to analyze their environmental impact and then invest in environmental improvements. However, no profound energy analyzes has been done in the Risifrutti production because of the lack of energy meters for steam, electricity and compressed air in the production lines..

Storleksoptimering av en etanolfabrik för integrering med ENA Energis kraftvärmeverk. : Baserat på en regional energibalans mellan tillgång på etanolbränsle i Enköping kommun och producerad etanol med hjälp av tillgänglig ånga från ENA kraftvärmeverk.

AbstractThe future of ethanol is depending on good solutions for the production. ENA energy power plant produces electrical power and district heating by heating biofuel. By building an integrated bioenergy plant surplus steam could be used to produce ethanol as fuel to vehicle.This would mean that ethanol is produced renewable energy and the energy for the process derives from the surplus of power.  ENA energy, MDH (the University of Mälardalen) and the energy authority has initiated a research project were different bioenergy combinations integrate with existing power plant.  As a part of the project which size an integrated factory should be to gain the best efficiency for the plant was investigated. Consideration will be taken to the cost of the production in order to be competitive to the price of imported ethanol.  Etanolens framtid vilar på bra lösningar för framställning.  I ENA energi kraftverk i Enköping produceras el och fjärrvärme genom eldning av biobränsle.  Genom att bygga ett integrerat bioenergikraftverk där skulle man kunna använda överskottsånga till att framställa etanol som fordonsbränsle.

Irak : Mellan islamisk identitet och demokratisk process

This is an essay about the political development of Iraq after the overthrow of the Baath regime by the coalition forces in 2003. Almost seven years later, the political scene is still characterised by chaos, even though the country entered a new phase with the adoption of democratic thinking and a new openness to the world. The unstable political situation is a product of inter-ethnic conflict and the interference by neighbouring countries. Iraq is up against two formidable tasks ? building democracy and building a nation.

Reglerna om ränteavdragsbegränsningar : är tioprocentsregeln och ventilen i behov av en skärpning?

Den 1 januari 2009 infördes regler som begränsar rätten för företag att göra ränteavdrag, vilket har till syfte att förhindra aggressiv skatteplanering som sker genom ränteupplägg. Två undantag till denna begränsade rätt till ränteavdrag benämns tioprocentsregeln och ventilen. Genom dessa får ränteavdrag göras om mottagaren av ränteinkomsten beskattas med tio procent eller om förfarandet är affärsmässigt motiverat. Dessa undantagsregler har dock blivit utsatts för kritik. Kritiken som har framförts är att den aggressiva skatteplaneringen som sker genom ränteupplägg inte minskat trots tillkomsten av reglerna om ränteavdragsbegränsningar och det finns även frågetecken om tioprocentsregeln är förenlig med etableringsfriheten inom EU.

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.

Energieffektivisering genom förvärmning av flis till kokare med sekundärvärme

The Swedish pulp and paper industry meets higher demand for energy efficiencyi mprovements with increasing energy prices and changes in the Swedish renewable energy certificate system. One action of energy efficiency improvement is by using secondary heat, that otherwise would have been treated as waste heat, for use in a system with lower temperature demands. The aim of this Master´s thesis is to identify possible secondary heat sources in a typical Swedish pulp and paper mill and to investigate what economic benefits the secondary heat will provide when being used for pre heating of wood chips to a kraft digester.The Master´s thesis focuses on three secondary heat sources; dry warm air, warm water and moisture saturated warm air located inside the pulp or paper mill. Two types of kraft digesters are simulated within this study, a typical Scandinavian digester and a modern twin vessel steam phase digester.Due to quality aspects and low temperature level drying is the drying technology with dry warm air rejected. Using warm water in direct contact with wood chips increases the quantity of water to the evaporation plant and thus reduced pulp or paper production and is therefore also rejected.

Effekter av två olika hösilagefoderstater på tarmfloran och träcksammansättningen hos häst och gris :

The aim of this study was to investigate if the botanical composition of haylage affects pH, dry matter content and microbial composition of the faeces in horse and pig and ileal environment in pigs. Two separate studies were conducted where pigs and horses were fed two diets containing haylages with different botanical composition. The first haylage was from a tilled land dominated by timothy and meadow fescue and the other haylage came from a meadowland with a large inclusion of dandelion, 25 % and common couch. The dry matter content (70.8 % and 73.0 % respectively) and the pH-value (5.7) were similar in both feeds. The first study was made as a three-periods switch-back study with 7 Standardbred horses. In the first and the third period, 7 and 9 days long respectively, the diet consisted of the haylage from the tilled land, oats, sugar beet pulp, soy bean oil meal, lucerne pellets and brewers yeast.

Konstruktion av patientsimulator för anestesimaskiner

A patient simulator for testing anaesthesia machines has been developed at Maquet Critical Care AB, to reduce costly and time-consuming experiments on animals. The device simulates human lungs regarding lung dynamics and volume, uptake of anaesthetic agents and the production of carbon dioxide, heat and moisture. Further demands on the simulator are durability and size; the device shall be compact enough to be moveable.The resulting simulator fulfils the requirements and enables better repeatability and ability to test extreme cases than experiments on animals do.Uptake of the anaesthetic agent is achieved in a active carbon filter and controlled by regulating the flow. The flow is created by a regenerative blower and controlled using a proportional valve. The uptake can be set by the user or by a simple uptake model modified to recursively handle changes in the concentration of anaesthetic agent.Carbon dioxide is fed into the system from a tank by a mass flow regulator.

Fuktåterföring i roterande värmeväxlare

För att ha en chans att ändra trenden med ökande utsläpp av växthusgaser är internationella samarbeten nödvändiga. Därför har EU genom miljökvalitetsmålet Begränsad Miljöpåverkan satt krav på högsta tillåtna utsläpp av växthusgaser. Att sänka energianvändningen för upp- värmning är ett steg i att även sänka utsläpp av koldioxid, som är en av växthusgaserna. Sänkning av energianvändning kan göras på flera sätt, bl.a. genom att öka tjockleken på isoleringen eller återvinna värmen i frånluften. Men dessa åtgärder ska inte helt okritiskt göras.

Modell och analysverktyg för beräkningav frekvensförlopp

The power system modelled in this thesis work has been developed for simulationwhen e.g. the production in some part of the power system is changed. The powersystem has been modelled according to the swing mass of the system, the frequencydependency of the load and the turbine governor. The model determines the systemfrequency, the period of regulation and the power exchange between the differentsubsystems in the Nordic synchronized system.In this model the system frequency is assumed to be the same in all different parts ofthe power system and the voltage conditions in the power system are neglected. Forthat reason power swings does not occur between different subsystems in the powersystem, which usually occur as a result of the swinging connection between thetransmissions line.

Optimering av sotningsfrekvens i biobränsleeldad CFB-panna : panna 5, Mälarenergi AB, Västerås

During the past 30 years the fuels for energy production in heating and power plants have changed. Fossil fuels have decreased in usage whereas bio fuels in Sweden have increased with 60% since the 1970's. Different fuels affects combustion and the release of various substances and particles into the flue gas. This is caused by the diverse components and chemical structures of fossil fuels and bio fuels. When the flue gas leave the combustion chamber and enters the path to the chimney particles in the gas are being transported out of the combustion chamber.

Design av flödesorienterad montagecell : Utvärdering av layout och materialförsörjning vid Emhart Glass AB

Emhart Glass is the world?s leading manufacturer of equipment, controls and components to the glass container industry. The goal of this project has been to identify improvements and propose cost saving solutions when moving one of Emhart Glass work cells in Sundsvall. The changes shall result in improved work environment and increased product quality. The method contains value stream mapping, concept selection and P-FMEA and complies with Emhart Glass goal to become a more Lean focused business.

Analys av massapumps- och mixerarbete vid Metsä Board Sverige AB, Husums Fabriker : Energibesparingsåtgärder vid blekeri 4 & 5 med jämförelse mot ny utrustning

Husums plant has a selection of different pulp pumps at bleaching plant 4 and 5. The displacement- (HC-pump, Sund Defibrator PTD-60) and centrifugalpumps (MC-pump, MCA 42-200, MCP 30/20) are of interest in this report. The centrifugal pumps are controlled by throttle valves, which result in an energy loss. Chemical mixers are used to mix ClO2 into the pulp before proceeding into a holding tower where the bleaching process occurs.The energy demand of the different positions has been measured or calculated to be used in comparisons against new equipment. Quotations were requested and delivered from Valmet and Sulzer.

Vätedriven förbränningsmotor : Klarläggande av framtida hållbarhet

Today when new and harder demands on CO2 emissions are developed, vehicle manufacturers must work to develop new engine solutions to new kinds of fuels to replace fossil fuels. A fuel that could be applied is hydrogen. When hydrogen is combusted only water vapor occurs. Hydrogen is known to be explosive and flammable. These properties are both good and bad for combustion.

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