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4596 Uppsatser om MIKE 21 Flow Model - Sida 8 av 307

Flödesoptimering på sjukhuslaboratorium: En praktisk implementering av lean

This study has investigated the possibilities of implementing lean in a division of a hospital in Stockholm. The goal was to reduce the lead time for the patient to get his diagnose by implementing lean in the two production flows of this division. In order to accomplish it, a complete map over the value stream has been done. With the help of the value stream map and lean theory a list over the processes in contradiction with lean has been made. Finally propositions to implement lean and by this way reduce the lead times in this stream have been made out.

Simulering av vindkraftverk och närliggande elnät vid Risholmen i Göteborg i SimPowerSystems

With background in the rapidly growing need to find solutions for sustainable energy production and the increasing interest for wind power, this report was written. With take-off point from the wind power plant Big Glenn, which has been built in the harbour of Gothenburg, a model of the adjacent power grid has been created in Simulink/SimPowerSystems. Parameters for the power grid and its components has been provided by Göteborg Energi Nät, that has also been the supplier of measurement data of produced power, the power need from loads in the vicinity, voltage levels, current values and also the variation of power factor at the wind power plant.The SimPowerSystems model has been used to perform simulations of power flow in the grid. These simulated values have then been compared to the measured values to verify the functionality of the model. Further, the model has been used to perform simulations of a grid fault, which causes a voltage drop.

Demonstrationsprojektets roll i framväxten av ny teknik: Fallstudier av två vindkraftprojekt

This report describes a synchronous machine model with magnetic saturation in d-axis, neutralconnection and electrical exciter interface for the transient simulator PSCAD/EMTDC. It hasbeen designed and verified in comparison to the regular machine model in EMTDC.The performance of the model is very good when incorporating a linear as well as a saturatedmagnetising inductance. The dynamic deviation is only thousandths to ten thousandths perunit. By using a cubic interpolation of the saturation curve, the model gives a good representationof the saturation effect. The open source code implementation of the synchronousmachine model gives the possibility to easily adapt the model to specific requirements.The derived model makes it possible to simulate a synchronous machine with its excitationsystems, e.g.

Skattning av den integrerade hydrauliska konduktivitetens variation kring Tunåsens infiltrationsanläggning : En utredning av påverkan från möjliga osäkerheter i befintlig information

Estimation of the variation in the integrated hydraulic conductivity around the Tunåsen infiltration facility - An investigation of the effects of uncertainties in existing informationAlmost half of Sweden?s drinking water volume is produced from groundwater. The main fraction of this is extracted from eskers, some of which allow for very large extraction rates. Despite this, the groundwater volume is not sufficient in some areas. This has led to an extensive use of artificial recharge.In Uppsala, the total volume added through artificial recharge is divided between four infiltration facilities.

Modellering av en panna med rörlig rost :  

The aim of this master thesis was to create a dynamic model for the processes in a solid fuel boiler of the moving grate type. Another aim with the model was to keep it as simple as possible but still able to catch the dynamics of the processes in the bedplate of the boiler. The creation of the model had its origin from drying and combustion equations used in earlier modeling work of boilers. The represented model has been used to simulate different kinds of disturbances in a boiler and different ways to control the boiler. These tests show that controlling a number of parameters in the bed of the boiler is an effective way to keep the grate stable during disturbances.

Adaptiv katalysatormodell för reglering

This master?s thesis describes the development of a model of the catalystsystem aiming at control by an MPC. A well functioning model, which is suitable in control purpose, is important while emission legislation become more and more hard to fulfill for the car manufacturers. Much research has been done in the field of physical modeling of the system, but in this work a linear adaptive time discrete ARX-model is developed and validated.The systems tendency to change its dynamic during usage implies that the model must be adaptive. The developed model proved to be well functioning and shows promising conditions for the MPC design.

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.

Redovisningens värderelevans av fritt kassaflöde : för den svenska aktiemarknaden

Problem: Is the free cash flow a value relevant accounting measure in relation to the Swedish stock market?Objective: The aim is that by using an investment strategy to examine whether the free cash flow is an accounting measure that could be perceived as value relevant in relation to the Swedish stock market.Method: The paper is based on a quantitative survey of empirical evidence that has been collected from companies listed on the Large and Mid-Cap lists of the Swedish stock market.Theoretical Frame of reference: value relevance, cash flow, portfolio theory, drive theoryResults: It was concluded that the study results conform to the Finnish survey results. The portfolio shows higher returns than the OMX index..

Reducering av ledtid genom en värdeflödesanalys En fallstudie på Lammhults Möbel AB

The purpose of this study is to increase the understanding of activities, flows and waste in a company's production process. By performing a value stream analysis, non-value adding activities are identified in a production process and then the suggested improvements that can reduce lead times will be stated. The value-stream mapping identifies the flow of information and the flow of material in a production process and this provides the basis for the identification of non-value adding activities.We conducted the study at Lammhults Möbel AB in Lammhult Sweden, where the production flow of Spira-21 has been investigated. This to identify any non-value adding activities that affect the flow negative and consumes time and money in a non-value adding way.A reasonable approach for the project was taken by studying the methodologies and theories. We conducted interviews and site surveys at Lammhults Möbel AB where the flow of information and material in the production process were investigated.

Spillvärmeåtervinning ur kylvattensystemet ismältverket på Sapa Profiler AB i Sjunnen

The smelting process at Sapa Profiler AB in Sjunnen generates large quantities of waste heat which is absorbed by the cooling water when the aluminum is cooled down. This paper is the result of a Master?s Degree Project aiming to present the conditions for recycling the waste heat. The cooling water absorbs the heat from the aluminum at an average rate of 600 kW and the paper shows that it can be used to replace electrical power consumption for heating the production plant?s facilities.

Vad behöver en speldesigner tänka på vid utvecklingen och analys av ett implementationsförslag till ett spelgränssnitt?

Denna reflexiva rapport undersöker processen att utveckla ett implementationsförslag för ett användargränssnitt till ett spel som ska lära ut riskhantering till körskoleelever. Den reflexiva rapporten genomför också en analys av användargränssnittet och innehåller därför en kort genomgång av riktlinjer och gränssnittsprinciper från människa-datorinteraktion (MDI) samt teorin om Flow. Den reflexiva rapporten avslutas med en utvärdering av arbetsprocessen och lärdomar kring arbetet. Slutsatsen som dras är att riktlinjer och principer från MDI samt Flow inte alltid kan appliceras på ett gränssnitt i ett sådant tidigt utvecklingsskede men en designer kan fortfarande få mycket användbara reslutat av att göra en analys..

Hur bestraffningstyp påverkar flow

Syftet med detta arbete är att undersöka hur olika implementeringar av Juuls uppdelning av bestraffningstyper kan påverka möjligheten för spelare att hamna i tillståndet som Csikszentmihalyi identifierade som flow. För att undersöka påverkan av olika bestraffningstyper på spelares upplevelse skapades tre olika versioner av ett plattformsspel med olika implementationer av bestraffningstyper baserade på Juuls uppdelning av bestraffningstyper. Ett antal respondenter fick spela alla tre versioner för att därefter, via semi-strukturerade intervjuer, försöka förmedla hur deras upplevelse varierade från en version till en annan. Undersökningsdeltagarna observerades under spelning för att försöka fånga spår av flow-tillståndet i deras kroppsspråk. Även deras prestation i varje spelsession lagrades för att möjliggöra en jämförelse av spelversionerna.

Modell av en synkronmaskin för PSCAD/EMTDC med magnetisk mättning i d-led och elektriskt gränssnitt för fältmatare

This report describes a synchronous machine model with magnetic saturation in d-axis, neutralconnection and electrical exciter interface for the transient simulator PSCAD/EMTDC. It hasbeen designed and verified in comparison to the regular machine model in EMTDC.The performance of the model is very good when incorporating a linear as well as a saturatedmagnetising inductance. The dynamic deviation is only thousandths to ten thousandths perunit. By using a cubic interpolation of the saturation curve, the model gives a good representationof the saturation effect. The open source code implementation of the synchronousmachine model gives the possibility to easily adapt the model to specific requirements.The derived model makes it possible to simulate a synchronous machine with its excitationsystems, e.g.

Analys, modellering och återskapande av fordonsdynamiska rörelser i tåg

The purpose of this thesis was to analyse, model and finally generate dynamic vehicular motions in a train. The objective with the analysis was to find important motions for a realistic train experience. The motions from the analysis were then weighted against possibilities for generation in a motion platform.A dynamic motion model was created to model the selected motions. The model was implemented in a simulation environment, more specifically MATLAB/Simulink. The simulation environment was used to simulate the model and to generate outputs to control a motion platform.

CFD-BERÄKNING AV INSTRÖMNING TILL ETT VATTENKRAFTVERK : ?EN FALLSTUDIE AV FINNFORS KRAFTVERK

I Sveriges kalla klimat innebär isrelaterade problem årliga produktionsförluster för vattenkraftföretagen. Kravisbildning på intagsgrinden till ett vattenkraftverk betyder att den grindarea genom vilken vatten kan strömma in reduceras och inströmningsförlusterna ökar. De förebyggande åtgärderna handlar ofta om att sänka vattnets ythastighet tillräckligt mycket för att ett stabilt istäcke ska kunna utbredas. Istäcket isolerar vattnet från fortsatt nedkylning så att temperaturen i vattnet inte understiger 0 °C och kravisproduktionen i vattnet upphör.I detta examensarbete tillämpas CFD-beräkningar för att åskådliggöra hastighetsfördelningen i magasinet vid Finnfors kraftverk med dess nuvarande batymetri och med modifierade batymetrier motsvarande potentiella åtgärder för att sänka vattnets hastighet. Anläggningsägaren Skellefteå Kraft hade identifierat två problem som ansågs kunna bidra till turbulens och höga inströmningshastigheter och utöver dessa kunde simuleringar med magasinets nuvarande batymetri identifiera i vilka områden åtgärder borde genomföras.

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