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6260 Uppsatser om HVAC pipe design - Sida 2 av 418

TV-stativ med nytt ställdon

The purpose of this thesis work is to evaluate how the physical behaviour of a pipe bend is affected by the pipe bending procedure. Effects such as initial ovalization, thinning, thickening and plastic hardening from the bending procedure are examined and the mechanical properties of pipe bends containing these effects are investigated.This has been evaluated by creating a detailed Finite Element model of a pipe that is being bent. Then the differences compared to a bent tube in a virgin state, so called Elbow elements and an analytical in-house program have been evaluated. The virgin state refers to a model of a pipe that is bent from the beginning, thus having a homogeneous thickness and not containing any plastic hardening. The Elbow element is a calculationally cheap element, specially developed for accurate calculations of pipe bends in an initially virgin state.The goal with the thesis work is to get a better picture of what happens to a pipe as it is being bent, how this affects the mechanical properties and to evaluate the possibility to develop an easy method for taking these effects into account when using the Elbow element.This report describes the layout of the work and how the detailed FE-model has been constructed.

Simulering av ett värmesystem i COMSOL Multiphysics : Pipe Flow Module

Syftet med detta arbete är att simulera ett värmesystem i COMSOL Multiphysics, Pipe Flow Module, Non-Isothermal Pipe Flow som innehåller ekvationer och randvillkor för att modellera inkompressibel strömning och värmeöverföring i rör.Data om processen och dess komponenter har samlats in från industrin där arbetet är utfört och i vissa fall modifierats för att bättre beskrivas i programmet.Utifrån insamlad data har en modell byggts upp och två simuleringar har gjorts. En stationär för starten av systemet, den har sedan legat till grund för en dynamisk som simulerar förloppet från start till normaldrift.Tiden det tar för det aktuella fallet att nå drifttemperatur är 16 timmar. En felströmning upptäcktes samt att en av pumparna inte kommer att klara en start från 20 °C..

Analysmetoder för rörsystem

The purpose of this thesis work is to evaluate how the physical behaviour of a pipe bend is affected by the pipe bending procedure. Effects such as initial ovalization, thinning, thickening and plastic hardening from the bending procedure are examined and the mechanical properties of pipe bends containing these effects are investigated.This has been evaluated by creating a detailed Finite Element model of a pipe that is being bent. Then the differences compared to a bent tube in a virgin state, so called Elbow elements and an analytical in-house program have been evaluated. The virgin state refers to a model of a pipe that is bent from the beginning, thus having a homogeneous thickness and not containing any plastic hardening. The Elbow element is a calculationally cheap element, specially developed for accurate calculations of pipe bends in an initially virgin state.The goal with the thesis work is to get a better picture of what happens to a pipe as it is being bent, how this affects the mechanical properties and to evaluate the possibility to develop an easy method for taking these effects into account when using the Elbow element.This report describes the layout of the work and how the detailed FE-model has been constructed.

Verifiering av ventilationsbrandskydd: Med hjälp av FDS 6 HVAC- funktion

Det är svårt att förutse om det finns risk för brandgasspridning via ett ventilationssystem och det krävs ofta analytisk dimensionering för att verifiera ett fullgott brandskydd. Idag används olika simuleringsprogram för att verifiera ventilationsbrandskyddet. FDS är ett simuleringsprogram som genom utgåva sex kommit med en tilläggsfunktion, HVAC (Heating, Ventilation, and Air Conditioning) där naturlig- och mekanisk ventilation kan simuleras med hjälp av ett system byggt av noder (nodes) och kanaler (ducts). Funktionen tillåter även att läckage simuleras på ett beräkningstekniskt stabilare sätt än i tidigare versioner. HVAC- funktionen är indirekt kopplad till de övriga CFD- beräkningar i FDS för att inte behöva gridcellsindela systemet vilket hade krävt betydligt mer datorkapacitet.

Design av en ejektorspädare samt ett system för partikelmassmätning av dieselavgaser

This master thesis was a subtask of a project called EMIR-1. The goal with the thesis was tobuild a system for particulate mass measurements in one of the engine test cells at KTH. Theparticulate mass measurements are planned to be measured with a TEOM.The exhaust gases must first be diluted with air before the sample is sent to the TEOM.Therefore an ejector diluter for this matter also was designed and evaluated in the thesis.Emissions measurements have been done both with and without dilution to determine thedilution ratio. Tests have been done for different speeds and loads.Problems with stability of the dilution ratio have been an issue throughout the process andpressure pulsations in the exhaust pipe are believed to be the cause. More tests have to be done tomake sure that this is the problem.One idea is to make the inner diameter of the diluter nozzle smaller and see if it changes thedilution ratio stability.

En miljo?ja?mfo?relse av traditionellt stambyte kontra relining av tappvattenro?r : Med hja?lp av livscykelanalys

This study was a final thesis, for the bachelor program in civil engineering at theUniversity of Uppsala, which was made on behalf of Riksbyggen in Uppsala. Acomparative study of two stain renovation methods; tradition pipe replacement andrelining was done with an environmental perspective. A simplified life cycleassessment (LCA) was done according to the International Organization ofStandardization (ISO) with the LCA tool Eco-indicator 99, in order to be estimate theimpact on the environment. LCA is a method that follows a product or a system?from the cradle to the grave?, which means that all the environmental impact over alifetime is considered.The work was executed by using a stairway with nine apartments in a house called?Uppsala Hus 9? as a reference object, which was provided by Riksbyggen.

Hälsoeffekter från trafikbuller vid Bäckegatan

The purpose of the study is to investigate the possible effects of an unstable ventilation system and its influence on energy use and thermal comfort. The report also explores how qualified personal working with HVAC view and handles system control.In order to meet the requirements in energy efficiency and a comfortable indoor climate control regulation is a prerequisite. With optimized increased complexity of the climate systems, it becomes more challenging to control the system and the risk of unstable control increases. No previous studies about what affect an unstable system can have on energy use and thermal comfort have been found.The report is based on several tests were the controlling variable has been increased until the system becomes unstable. Two different types of unstable systems have been investigated.

Påverkan på energianvändning och termisk komfort vid reglerinstabilitet

The purpose of the study is to investigate the possible effects of an unstable ventilation system and its influence on energy use and thermal comfort. The report also explores how qualified personal working with HVAC view and handles system control.In order to meet the requirements in energy efficiency and a comfortable indoor climate control regulation is a prerequisite. With optimized increased complexity of the climate systems, it becomes more challenging to control the system and the risk of unstable control increases. No previous studies about what affect an unstable system can have on energy use and thermal comfort have been found.The report is based on several tests were the controlling variable has been increased until the system becomes unstable. Two different types of unstable systems have been investigated.

Termisk analys av kompakta jordvärmesystem - Sensitivitetsanalys och korrektions faktorer baserat på fältmätningar i referensanläggningar i Östergötland

Chapter 1 defines the aim of the project and gives a general orientation about ground heat extractors. In chapter 2 physical processes that could be expected to be involved in the heat transport around a ground heat exchanger are discussed. It is shown from a literature study what amount of moisture transport due to thermal gradients there could be expected in a ground heat exchanger. The conclusion is drawn that the moisture gradient (Sr) is of same magnitude as the driving temperature gradient (°C). At the expected amount of increased moisture around the pipes the moisture transport could be considered to have a little effect on the brine temperature.

Investeringsförslag till slipstation för servicearbete av skruvmatare

The project ?Investment proposal for grinding station for service work of screw feeders? has been performed during the spring semester 2014 for the course Bachelor?s thesis for degree of  Bachelor of science in machine engineering at Karlstad?s University. The project has been performed in cooperation with Fiber Workshop which is a service department in the company Valmet AB. Valmet AB is a company that develops and manufacture soft paper tissue machines. The screw feeder is a part that is used to feed, and squeeze out the water out of woodchips.

Konstruktion av upprätningssystem för CICLoPE

Today there is no way of measuring or simulating turbulent flow in high Reynolds numberenvironments. The computational power required to simulate these conditions is not expectedto be available for several decades so instead the CICLoPE project aims at solving thisshortage by the construction of a long carbon fiber wind tunnel in which real measurementscan be made. To do accurate measurements it is of importance that the wind tunnel, 0.9 metersin diameter and 110 meters long, is as straight as possible.This master thesis treat the design and construction of a device which may be used to align thetunnel along a reference laser beam. A design is presented which allows the pipe to be alignedwithin about a quarter of a millimeter along its entire length. Contents span over severalscience fields such as physics, mechanics, control theory and electronics.The result is a theoretically correct design.

Varför sprang dina partikamrater med järnrör på stan? : En undersökning av medias gestaltning av Sverigedemokraternas politiska skandal: ?Järnrörsskandalen?

The purpose of this paper is to make a qualitative content analysis. The used articles are taken from the time period 2012-11-13 until 2012-11-30 and the questions that this paper is based upon are:How do the tabloid Expressen and the morning newspaper Dagens Nyheter define and diagnose the causes and problems of the iron pipe scandal during the period 2012-11-13 until 2012-11-20?What kind of valuations and solutions does the tabloid Expressen and the morning newspaper Dagens Nyheter provide of the iron pipe scandal during the period 2012-11-13 until 2012-11-30?Does the framing of the iron pipe scandal during the period 2012-11-13 until 2012-11-30 differ between the tabloid Expressen and the morning newspaper Dagens Nyheter?The result of this paper shows that through the tabloid Expressen and the morning newspaper Dagens Nyheter way of framing the Swedish democrats during the period 2012-11-13 until 2012-11-30, the society cannot get another picture of the Swedish Democrats than that they are a right wing populist party..

Styrd borrning eller konventionell schaktning : en jämförelse av två rörläggningsmetoder

This is a diploma thesis executed as a part of the examination of the educationalprogram Building engineer ? Construction management at Halmstad University. The aim of the thesis is to compare and evaluate conventional open-cut pipe-laying withhorizontal directional drilling. The thesis includes a comparison of the economic,environmental and time-based aspects of both methods and discusses which factorsthat determine the optimal choice of method.The study is mainly based on previous studies regarding the subject and oninterviews with professionals from the industry.A fictional project with five realistic cases of pipe-laying scenarios was compiled,sent to different companies for calculation, evaluated and compared. Our conclusionregarding when it?s suitable to use which method is entirely dependent on thespecific project.

Anläggning av traditionellt VA-schakt : En fallstudie i logistik och byggstyrning

A growing issue in the construction industry is how production can become moreefficient by using logistical solutions. Companies can minimize the cost of a project byreducing the time to perform the work.The purpose of this report was to examine the logistics related to pipe trenches forSIAAB. The report's focus has been on solving problems and planning that wouldfacilitate the work of the project Vaksala-Lunda Etapp 3.The case study consists of interviews with SIAAB's employees and an observationwhere the progress of a traditional pipe trench has been documented using checklists.Questions to the report?s case study come from the theoretical part, which is basedon literature on construction management and logistics in general. The observationlasted five weeks and the biggest time-consuming events that affected the pipe trenchduring this time, has received most attention.

Partiell Urladdning- Mätmetoder och detektering med fokus på HVDC- kablar

Detta arbete behandlar mätmetoder för detektering av partiella urladdningar (kallad PD från engelska benämningen Partial Disharge) i HVAC- och HVDC- högspänningskablar. HVAC står för ?High Voltage Alternative Current? och HVDC står för ?High Voltage Direct Current?. När en viss hög spänningsnivå överskrids i kabeln uppstår olika typer av partiella urladdningar och dessa skadar kabelns isoleringsmaterial. PD- intensiteten ökar med tiden och om de tillåts fortlöpa under en längre tid kan de med tiden helt bryta ned isoleringsmaterialet vilket leder till ett fel.

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