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  • 301.
    Lee, Nicky
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Spränggenerator för rengöring av överhettare i avfallspanna: Utredning av drifterfarenheter och ekonomi i Umeå Energis kraftvärmeanläggning Dåva 12019Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The aim of this report was to evaluate a shock pulse generator installed at Dåva 1, the waste-fired combined heat and power (CHP) plant at Umeå Energi AB, located about 9 km northeast of Umeå. The study deals with the subject based on both technical aspects, in terms of operating experience and performance. Financial aspects, regarding repayment time and operating costs. With these results, an investment for a shock pulse generator has been discussed. Furthermore, proposals for improvements or combinations with ammonium sulphate should be discussed in order to prevent corrosion, in particular chlorine-induced corrosion.

    With the data logging program (ABB 800xa Smart Client), it was possible to study temperature trends and profiles at the superheaters. With these data, calculations have been performed to obtain a heat transfer coefficient (UA-value). The UA-value describes how the heat transfer changes over time and is therefore a measure of the degree of coating formation, and how the shock pulse generator influences this. Comparisons have been made for periods before and after the installation of the shock pulse generator. The study has included several interviews with the operation and maintenance staff concerning costs and experiences, to perform an economic calculation.

     

    The results show that the shock pulse generator have had a positive effect with an increase in the UA mean value by 7%. With reduced growth of deposits with the shock pulse generator, there are possibilities to reduce operating and maintenance costs. An improvement in the efficiency of the shock pulse generator could also have been achieved by increasing the frequency of explosion during periods where coating formation occurs. A future method could be to combine the UA-value with the shock pulse generator to create an intelligent soot-blowing system.

     

    The payback period for the installed shock pulse generator is estimated to be 5.7 years with a saving of SEK 385,000/year. For the assessment of an extra shock pulse generator, the evaluation indicate that it would probably not be as profitable as the present shock pulse generator.

    A minor literature study was also performed concerning deposit formation on superheater tubes and the effects of addition of ammonium sulphate. According to previous studies, deposits with a higher content of sulfur than chlorine are formed when using such additive, which causes deposits to become less corrosive and more porous, which makes them easier to be removed. This can be interesting for Dåva 1 and can be a suggestion for further investigation.

  • 302.
    Leonarde, Alexander
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Generationsskifte av vindkraftverk2011Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
  • 303.
    Limegård, Fredrik
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Pendelarm Hägglunds Forest Truck.: Analys av lastfall och hjullager samt konstruktion och beräkning av pendelarm till Hägglunds Forest Truck.2016Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
  • 304.
    Lind, Joakim
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Analys av SA-3 automatkoppel: Slitage-analys och utvärdering av förslag om minskat odämpat koppelspel.2013Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Detta examensarbete i maskinteknik behandlar mätning av slitage på de Bombardier byggda IORE-lokets koppelsystem som används av LKAB-malmtrafik. I rapporten ingår mätning av komponenter och jämförande av dess revisionsintervall för att hålla ned det odämpade koppelspelet som är en biprodukt av att komponenter slits och får ett glapp sinsemellan. Det behandlar även ett förslag på en lösning med shimsning av komponenter som är länken mellan lokkorgen och kopplet för att minska detta oönskade odämpade koppelspel.

    I rapporten sker mätningar på olika komponenter på tre olika lok där komponenternas ursprungliga mått och dess nuvarande mått efter konstaterat kilometerantal. Dessa siffror sammanställdes i diagram med kända gränser för slitage och revisionsintervall för att kunna singla ut komponenter som har det största slitaget och med kanske dåligt satta intervall.

    Det största uppmätta slitaget uppkommer i sfäriska ytan på fjäderpaketet i kontakt med koppelbakkappan och koppeltappshålet på både ok och koppelhuvud. Med detta i åtanke och de tidigare mätningarna utförda av Damill AB och LAF skulle föreslaget system med shims och fjäderpaket med sänkt arbetstryck skulle effektivt minska det odämpade koppelspelet i systemet.

    En FEM-analys har även utförts för att se hur stora påkänningar det finns i systemet samt om de är över utmattningsgränsen för materialen. Den visar att de utsatta ytorna i FEM-analysen även dom är de som konstaterats vid mätningar har haft det största slitaget. FEM-analysen konstaterar även den att shimsen inte deformeras under stora krafter.

    Det framlagda förslaget rekommenderas och de nya revisionerna av loken bör få det mjukare fjäderpaketet monterade i både A och B-ände. Revisionsintervallet för shimsning bör lämpligen bli runt 270 00 km.

    En fortsatt studie för att sänka toleransen på koppelhuvudets odämpade spel bör utföras med snävare tolerans på tolkar till kopplen mellan sektioner.

  • 305.
    Lindberg, Daniel
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Testrigg svängdämpare: Framtagning av ett konceptförslag till en testrigg för testning av bromsade länkar till kranar2015Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Nästan alla kranar på marknaden som används till bl.a. skogsbruket, materialhantering och transport har någon form av länkar som standardutrustning. Länkarna är monterade mellan kranen och redskapet, vilket gör det möjligt för redskapet att pendla i två riktningar och på så vis kunna hålla sig horisontellt i alla lägen. Många av länkarna är även försedda med bromsar som dämpar oönskade pendlande rörelser och dessa bromsade länkar kallas då för svängdämpare. Indexator Rotator Systems är en stor tillverkare av bl.a. sådana länkar och deras produkter ligger i framkant på marknaden. För att kunna bibehålla och stärka sin position måste produkterna ständigt utvecklas och förbättras. För att på ett så bra sätt som möjligt kunna göra detta är det bra att ha möjlighet att testa produkterna under realistiska och kontrollerade former. Till detta behövs en testrigg, vilket i dagsläget saknas för testning av svängdämpare.

    Detta arbete syftar till att ta fram ett konceptförslag på en sådan testrigg. Arbetet har begränsats till att ta fram ett förslag på hur problemet kan lösas och därför har en mer ingående analys av vilka komponenter som är bäst att använda för konstruktionen utelämnats.

    Arbetet inleddes med att en kravspecifikation skapades tillsammans med företaget där vissa funktionella krav på testriggen sattes utifrån önskemål. Med kravspecifikationen som grund togs sedan ett flertal skisser på olika lösningar fram och presenterades varefter en lösning valdes att gå vidare med. Diverse beräkningar utfördes för att undersöka rimligheten i olika utföranden samt visa på de funktionella förutsättningarna och slutligen konstruerades och presenterades en 3D-modell för att illustrera konceptförslaget.

    Resultatet av arbetet har lett fram till ett förslag på ett koncept för en testrigg som uppfyller de ställda kraven i kravspecifikationen och som möjliggör testning av svängdämpare på ett realistiskt sätt.

  • 306.
    Lindberg, Peter
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Produktionsoptimering av en lasercell: Konstruktion och framtagning av en justerbar dubbdocka i en robotbaserad lasercell2013Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Företaget Duroc Engineering AB tillverkar lasersvetsade produkter till flertalet olika industrier. Lasersvetsningen innefattar främst lasercladding, vilket är en metod där maskinen svetsar på ett ytskikt av metall på en befintlig metallbas. I denna process smälter en laserstråle ett finkornigt metallpulver, som sedan sprutas in i processområdet med argongas.

    De flesta produkter som företaget lasersvetsar är av axeltyp, därför använder laseroperatören en rotationsenhet i vilket axelmaterialet spänns upp i. På andra sidan av rotationsenheten har lasermaskinen en dubbdocka, detta för att stötta upp axeln likt en konventionell svarv.

    Duroc använder idag en fast rotationsenhet som bultas fast i golvet, vilket har ett nät av precisionsborrade hål. Processen med att ställa in dubbdockan för olika längder av axlar är tidsödande och kräver många justeringar innan axeln slutat kasta.

    Examensarbetet baseras på att utveckla en dubbdocka med längdjustering i z-led likt det som används i en vanlig svarv. Denna åtgärd skall uträttas för att minska ställtider i lasercellen och därigenom få en ökad produktionstakt. Produkten som detta projekt skall ge är en 3d-cad modell på en komplett dubbdocka med tillhörande ritningar, samt att beställning av alla delar som behövs till projektet.

    Konstruktionen av dubbdockan har skett i Ironcad 2012 och i Solidworks 2011, produkten har konstruerats i samråd med företagets teknikansvarige. Som hjälp tillhandahöll företaget en 3d-cad modell på den befintliga lasercellen, samt fri tillgång för mätning i den tidigare nämnda produktionsenheten.

    Resultatet av konstruktionsarbetet är ett underrede, som använder sig utav Durocs befintliga dubbdocka för att både minska kostnaderna och för att minska tillverkningstiden. Produkten består av två linjärstyrningar fastbultade på fyrkantsprofiler, den har sedan en vagga som går mellan de båda linjärstyrningarna. Dubbdockan bultas sedan fast i vaggan som därmed tillåter rörelse i z-led.

  • 307.
    Lindberg, Robin
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Utveckling av rökgaskondenseringsmodell för kraftvärmeverk2014Independent thesis Advanced level (professional degree), 300 HE creditsStudent thesis
  • 308.
    Lindberg Spiik, Mikael
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Behovsutredning av avfallsavskiljning2014Independent thesis Basic level (professional degree), 180 HE creditsStudent thesis
    Abstract [sv]

    Avfallet från en avdelning på Element Six fabrik i Robertsfors innehåller en mängd av ett ämne.Element Six vill veta huruvida detta ämne bör avskiljas från det övriga avfallet innan det skickasvidare för omhändertagande. Anledningen till att företaget eventuellt borde avskilja ämnet framgårinte av denna rapport. De vill även veta vilken av maskinerna på denna avdelning som ger ifrån sigdetta ämne. Vid användning av vissa av maskinerna på avdelningen spolas avfall ut i ett avlopp. Dåalla maskiner på avdelningen är kopplade till samma avlopp kan ej bestämmas från vilken avmaskinerna detta ämne härrör. En metod för att samla upp avfallet från en specifik maskinframställdes. Material samlades in och renades kemiskt. Därefter analyserades avfallet ielektronmikroskop och annan labboratorieutrustning för att kunna avgöra om det borde avskiljas frånresterande avfall eller ej. Avfallet från maskinen jämfördes även med avdelningens totala avfall för attavgöra huruvida ämne enbart kommer från den undersökta maskinen eller om andra maskiner ocksåkan vara inblandade i tillförseln av ämnet i avfallet. Undersökningen har resulterat i en kvantifieringav den mängd ämne vilken kommer från undersökt maskin, ett antal rekommendationer till företagetsfortsatta arbete har även gjorts. Detta främst gällande huruvida företaget bör avskilja ämnet från restenav avfallet eller ej.

  • 309.
    Lindehag, Samuel
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Rotationsdämpare med integrerad fjäder2014Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This final thesis is carried out at BAE Systems Hägglunds in Örnsköldsvik. The mission was to construct and integrate a new semi-active damping unit in the terrain vehicle BvS10. Questions that came up during the process, among others, was how to mount the damping unit to the vehicle in a flexible way without exposing it to unnecessary wears.

    A generation of the concept is made in 3D using CATIA V5 of a possible solution to the problem. The idea is to weld the unit to the skid girder which is one of the main constructions of the track system. In this way the damping unit will come closer to the track system, which will partly protect it from impacts from below and minimize current problems with breaking forces in the torsion shafts.

    The complete construction was then analyzed, first by theoretical calculations and then with the FEM-tools in CATIA V5. The result of this analysis showed that the construction had a good potential to resist deformation and high tensions. Drawings in 2D of the assemblies were then generated for the left and right damping units separately.

  • 310.
    Linder, Kristofer
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Värmeåtervinning av gruvventilationsluft - LKAB i Kiruna2011Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In order to make underground mining production, large amounts of outdoor air

    must be pushed down to the mining level. At the LKAB facility in Kiruna this is

    done by a number of mining ventilations stations. The air has to be heated before

    it is transported down to the mining levels. This is done in order to prevent icing in

    the shaft. Today, the heating of the air is done by using waste heat from the pellet

    mills and if extra heating is needed, due to lower outdoor air temperatures, oil is

    used.

    The exhaust air from the underground is moist and warm. It is therefore interesting

    to investigate if it is possible to install a heat exchanger in the mine ventilation

    stations and use the heat in the exhaust air to heat the supply air. The heat recovery

    system which has been investigated in this study is a type of coil heat exchanger.

    Heat exchanger manufacturer has submitted a proposal on the type of coil

    heat exchanger that could withstand the specic demands and oer a price for the

    system. The chosen heat recovery system has four supply exchangers with the size

    4500x2000 mm and 3 exhaust exchangers with size 8000x2200 mm. Each Supply

    air coil had a power of 661 kW and each exhaust exchanger was sized at 882 kW.

    Analyses were made to estimate reductions in the use of oil by implementing

    the heat recovery system. In addition, also the amount of waste heat energy that

    could be saved by installing the heat exchangers was calculated. The calculations

    were carried out on a total of 9 mining ventilation stations.

    The energy that the rst installed station could save in form of oil during a

    year has been estimated to 4,7 GWh. If heat exchangers were installed in all the 9

    stations the energy reduction would be approximately 29 GWh per year.

    The energy that could be saved at station 1 in the form of waste heat was 0.6

    GWh per year. If heat exchangers were installed at all the 9 stations, the recoverable

    waste heat was calculated to be approximately 18 GWh per year.

    The nancial analyses were made for two cases. One that was based only on

    prots from the saved oil and, the other also by selling of the saved waste heat to

    TVAB.

    The total installation cost per station was estimated at to around 4.3 million

    skr. Considering the saved amount of oil the payback time for a single station was

    found to be approximately 1.4 years. For all the 9 stations the payback time was

    estimated to be 3.6 years.

    If sale of waste heat is included and added to the analysis, the payback time

    for a single ventilation station is 1,4 years and for an installation in all the stations

    the payback time is 2,4 years.

    The problems that could arise are due to contamination, which could be prevented

    by greater spacing of the battery heat exchangers and protective coating

    with Heresite. Expansion of the exhaust duct must also be made when the exhaust

    air coils are too big to t in the available channel .

    The calculations are based on the assumptions that the temperature of the

    exhaust air is 8

    . and the relative humidity is 100 % in all stations. The same

    kind of coil heat exchanger has therefore been used in the calculation of the dierent

    stations. In the next design step it is proposed that more accurate values for

    each station are provided to the heat exchanger manufacturer to improve design

    performance of the recovery system.

    A futher recommendation is that the rst installation of the heat exchange

    system should be implemented in ventilation station KV10 where there is plenty of

    space available for a heat exchanger system, and KV10 also has the second highest

    exhaust air temperature.

  • 311.
    Lindgren, Andrée
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Transportera torra biofibrer i en luftström: Genom praktiska försök och mätningar2017Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Sliperiet at Konstnärligt campus runs a project called +Project. + Project is runned together with a couple of partners and sponsors. One of the cases with the project is to further improve the biofibres by using the fibers as a filler for 3D-printing. Biofibres today have a very low degree of refinement, when the biofibres that’s a residual product from different industries goes to waste or combustion. 3D-printing works so that a filler material, in this case biofibres, is applied to a surface together with a binder and thus can construct structures. Biofibres are something that is easy to access and from some industries it’s a residual product. One of the problems of transporting biofibres in an air stream is that the biofibres tends to get tangled up in each other and grow larger. This is not desirable if you want a smooth mixing of air and biofibres in the air stream so the binder can be applied to the biofibres as good as possible. In this work, an investigation has been made of existing techniques and ranking of their suitability for the project. The ranking showed that a pipe system with an air stream, generated by a leaf blower would be the most suitable fit. A prototype was drafted through SolidWorks and then manufactured. The prototype was manufactured in plastic from a fire safety perspective. The prototype got a portioning system consisting of a bucket and a funnel that was supposed to bring down the material in the transport pipe and air flow. The prototypes feeding system did not work as planned. Instead of the biofibres dropping into the bucket and further down the feed tube, it threw up the material. The test runs were instead made directly through the air intake on the leaf blower and it was found out that the pipe system worked satisfactorily at low flows of material, higher flows of material was unable to investigate when the portioning system wasn’t working satisfactory.

  • 312.
    Lindgren, Emil
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Förstudieutredning till rationalisering av lyfthjälpmedelsframtagning2017Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    At Volvo GTO in Umeå a large number of lifting tools is used daily in the production. The lifting tools simplify lifting of large and heavy details so the production keeps a good speed without harm the staff’s health.

    Manufacturing takes place in the company’s own workshop with workers that have long experience in construction of lifts. The construction and the CE-marking are performed by Volvo’s staffs or hired consultants. Today takes the documents that Maskindirektivet has as a requirement for CE-marking a lot of resources. The company wants to rationalize that process without breaking the law. Consultants are often hired which generates huge costs because Volvo’s engineers have other tasks.

    By discussing with experts on machine safety and CE-marking with consultation of designers and other staffs involved in the CE mark, some suggestions for change have been presented. If strength calculations are made in advance on parts or whole products the lead time can be shortened. One more suggestion is to found connection between previous risk analysis so risk and risk actions that reduce the damage can be reused. By not producing document that are not a requirement, the entire process can be completed at an earlier stage.

  • 313.
    Lindgren, Lukas
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Integration av bandspänningscylinder: Konceptgenerering för integration av bandspänningscylinder i karossbalk på CV902014Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    På BAE Systems Hägglunds i Örnsköldsvik konstrueras och produceras bandfordonet CV90. För att kunna framföra fordonet i varierande terrängförhållanden sitter en bandspänningscylinder monterad mot ett spännhjul som gör att bandspänningen kan justeras. Vid tuffa terrängförhållanden önskar man kunna öka spänningen på bandet och vid enklare terrängförhållanden vill man kunna minska spänningen.

     

    Bandspänningscylindern sitter för närvarande monterad parallellt med golvet under stolarna inne i stridsrummet på CV90. Detta är inte optimalt då det finns risk att cylindern, vid påkörning av t.ex. en mina eller IED (Improvised Explosive Device), slår in i stridsrummet och utgör på så sätt en skaderisk för besättningen. För att minska skaderisken vill man integrera cylindern i skrovet på vagnen.

    Detta arbete utreder om det är möjligt med en sådan lösning och i så fall, vad det bästa alternativet är.

     

    Under arbetets gång har kontinuerlig kontakt hållits med de inblandade personerna och avdelningarna för att få konstant information och återkoppling på arbetet. Det har även gjorts besök på monteringen för att se problemet med egna ögon.

     

    Arbetet resulterade i fyra olika konceptförslag och det visades på vad dessa koncept har för fördelar och nackdelar. Efter överläggning med inblandade valdes ett förslag ut som analyserades djupare. Resultaten av den fördjupade analysen visar på att det finns möjlighet och utrymme för en lösning där cylindern verkar direkt på spännhjulsaxeln.

  • 314.
    Lindgren, Rickard
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Energikartläggning av en äldre fastighet: En kartläggning kring energiförbrukningen och kostnadsbesparande lösningar för en äldre fastighet2016Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    On the behalf of Norrporten in Umeå have an energy audit been made on an older part of a building. The goal has been to calculate the distribution of energy carriers in the property and to find out what the operating cost for the building is. With that in mind so have different methods to reduce energy and operating costs been examined and its effect on energy consumption. This survey analyzes ventilation, heating, water heating and climate shell of the property. Measures to reduce energy consumption due to operations in the building have not been examined.

    The simulation program IDA ICE was used for energy calculations. The results show that the property currently use about 150 MWh/year of heat and about 104 MWh/year of electricity. This means an annual operating cost of about 200 600 SEK.

    Among the largest energy consuming parts are:

    • Heating of the facility
    • Heating of domestic hot water
    • Ventilating el for fan operation

    The total savings opportunity is apparent to about 14,600 kWh/year of electricity and about 39,600 kWh/year of district heating.

  • 315.
    Lindgren, Simon
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Shaft stability analysis of the RBR S5: Stabilitetsanalys av axel tillhörande RBR S52019Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This bachelor’s thesis work completed for Spinchem intend to calculate and simulate the deflectionof a rotating shaft belonging to the rotating bed reactor S5, RBR S5. The shaft is the part thattransfers the torsion to the RBR S5 and is the part that will behave as a spring due to the rotationalvelocity. This elasticity needs to be evaluated so that Spinchem can, if needed, re-dimension theshaft thickness and profile. The work is needed for Spinchem to make a name for itself in the globalmarket where processing large quantities of liquid is essential.Primarily theoretical calculations and finite element analysis have been utilized, but also a practicalmeasurement with a camera equipped with a macro lens, capable of filming in 50 FPS. The finiteelement analysis has been done with Ansys mechanical modal analysis tool to calculate andsimulate the frequencies and deformation that occurs.The main results show that the currently used 30 mm solid shaft is in fact the optimal choice forthe product. The used shaft and the critical speed of the systems does not coincide too much andwill not cause unnecessarily large vibration amplitudes which in turn will compromise the expectedlife span of the product. There is a possibility that other shaft profiles and dimensions are suitablechoices for the shaft. These are determined by equ (5) and depends on whether the stiffness orthe mass is changed. Another criterion for the selection of the new shaft will be whether thesystem runs under- or -overcritically.The system is working well at the chosen speed, which means that there are no advantages inswitching the system to running over critically. Therefore, the recommendation of this thesis iskeeping the solid 30 mm shaft.

  • 316.
    Lindholm, Kasper
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Analys av renoveringsåtgärder på ett flerbostadshus i samarbete med AB Bostaden2017Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In this project the result of a refurbishment of a multi-family residential was analyzed from an energy perspective.

    The purpose of this project was to show how the different improvement measures that were performed in conjunction with the refurbishment impacted the district heating demand of the building.

    To analyze the building and the improvement measures the simulation program IDA Indoor Climate and Energy was used. In the program the buildings district heating demand before the refurbishment, after the refurbishment and in the seven cases listed below was simulated:

    • If the windows had not been exchanged from double pane to three pane.
    • If the building’s exterior walls had been additionally insulated inwards.
    • In the scenario of where the insulation in the attic had not been exchanged.
    • If neither of the exterior walls had been additionally insulated nor had the insulation in the attic been exchanged.
    • If the buildings airtightness had remained unchanged after refurbishment.
    • If the ventilation system in the building had not been switched to a FTX-system.
    • If the buildings airtightness had remained unchanged and if the ventilation had not been switched to a FTX-system.

    The results of the simulation before the refurbishment, showed that the buildings district heating demand was 160 kWh/m2. The simulation of the building after it was refurbished resulted in the district heating demand being lowered to 71 kWh/m2.

    When simulating the cases listed above, it was determined that the measure that gave the most significant decrease in district heating usage was the installation of the FTX ventilation system. If the building had been renovated without installing the FTX the district heating demand would have risen with 65 kWh/m2.

    The measure that had the second largest impact on the buildings district heating usage was the improvement of the buildings airtightness. The simulation for the case in which in the buildings airtightness remained unchanged resulted in that the district heating usage was increased by 28 kWh/m2.

    The result of the simulation where the windows were not exchanged showed an increase in district heating usage by 24 kWh/m2. The district heating demand increased by 4 kWh/m2 in the simulation where the building’s exterior walls had not been additionally insulated. The results for the case when the insulation in the attic was not exchanged showed an in increase in district heating usage by 3 kWh/m2.

    The conclusion that could be drawn as a result of the simulation results was that the different renovation measures should be prioritized as following, for buildings with similar preconditions:

    1. Install FTX ventilation system
    2. Increase the building's airtightness
    3. Exchange windows
    4. Additionally insulate external walls
    5. Additionally insulate / exchange insulation in the attic.
  • 317.
    Lindmark, Jonas
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Energikartläggning och energieffektivisering av Trinnliden 7:5: Simulering av energibesparande åtgärder i "IDA Indoor Climate and Energy"2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    On behalf of GATE Intelligent Support AB an energy audit has been conducted in the spring of 2015. The project was to develop an energy audit at an industrial premise in Vännäs municipality. Vännäs Fastigheter AB is the owner of this venue and has recently received complaints from tenants about an cold indoor climate in the property. Furthermore, it emerged that the property's future energy supply of heating is uncertain. Therefore a separate project to find an alternative heating sources solution has been initialized. This report will place great emphasis on changes, which lead to an improved indoor climate as to energy savings. To achieve this plan and to make it more understandable the simulation program IDA ICE has been used throughout the whole paper. Additionally, economic calculations for an LCC-analysis including repayment time has been done to compare the measures easier. Results from this project have demonstrated that this industrial premise can when all energy saving measures are carried out, reduce their energy consumption from 299 MWh per year to 129 MWh per year. This means a total decrease of 56.9%. The inspection of the property reveals shortcomings in the existing heating system. The current radiator system was configured wrong which resulted in a significant reduction of the heat outcome. This was not just done by changing settings of the radiator system but as well by adjusting the ventilationsystem to the business conditions of the property. 

  • 318.
    Lindström, Erica
    et al.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics, Energy Technology and Thermal Process Chemistry.
    Larsson, Sylvia H
    Boström, Dan
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics, Energy Technology and Thermal Process Chemistry.
    Öhman, Marcus
    Slagging tendencies during combustion of woody biomass pellets made from  a range of different forestry assortments2010In: Energy & Fuels, ISSN 0887-0624, E-ISSN 1520-5029, Vol. 24, no 6, p. 3456-3461Article in journal (Refereed)
    Abstract [en]

    In this study, multivariate methods were used to select representative raw materials of the pellet assortments prior to combustion. The fuels were selected to form a range of expected slagging tendencies. During combustion, temperatures and O2, CO, NO, and SO2 were measured continuously. The deposits (i.e., slag and bottom ash) were quantified after every experiment and collected for analysis to identify the crystalline phases and to study the morphology and elemental composition respectively. As expected, the slagging was most severe for the whole-tree assortments because of their content of branches, foliage, and twigs. In the most severe case over three-quarters of the total amount of ash melted to form slag. This study indicates that certain concentrations of silicon, inherent in the fuel but also as silicates from contamination, together with alkali metals, mainly potassium, are prerequisites for the initiation of and progress of slag formation. Generally the concentrations of silicon and potassium are low in stemwood but higher in bark, foliage, and living tissues of the tree. Also, the contamination from sand and/or soil is present in the bark and foliage.

  • 319.
    Lindström, Niclas
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Automatisk bollskjutare för innebandyträning2017Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The purpose of the project is to design, develop and evaluate an automatic ball throwing machine for floorball practice. The functions for the machine are automatic aim, shoot with different speeds, ball passing and chip pass. The machine will also supply floorball balls automatically from a storage. This report covers the design of the storage with automatically provider, build a protective frame, design and programming for the pass and the chip pass and overlook possibility to have an automatic detection for the goal. Similar products already exist in other sports like football, tennis and baseball.

    For throwing the ball the machine uses 2 motors that rotate two wheels. The distance between the wheels enable the ball too pass through but just by so much so the wheels get in contact with the ball and can accelerate it. The project has been done in the Umeå University’s facilities with access to workshop and school programs and computers. The system is controlled by a Raspberry PI model 3 and the programing is done in Codesys.

     The tests that were made achieved the requirements and will be seen as successful. The test and evaluations have also been done in the schools facilities. Ideas and inspirations have come from other similar products for other purposes such as tennis, baseball and football. The tests have been evaluated for possible changes and improvements. The project is a first prototype and its purpose is to find functions and possibilities and not build a product. 

  • 320.
    Lingwall, Kim
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Åtgärd för minskad genomloppstid: Förmontering av kranspetsutrustning2018Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Vimek AB is a producer of forestry machinery located in Vindeln, Västerbotten. Their productionis divided in two sections, one preassembly group where standard components are beingassembled and put in stock, and one final assembly group who assembles all parts to a completemachine.By moving elements of assembly from the final assembly section to preassembly section Vimekwant to reduce the throughput time of the Vimek 610 SE forwarder. There is a selection of fivedifferent crane tip tools that comes with the Vimek 610 SE forwarder, where “tilt grapple withbrake linkage” is the most common choice by far.The goal for this project is to the move crane tip equipment “tilt grapple with brake linkage” fromfinal assembly section to preassembly section. A decision basis was formed through interviews,test mountings and a continual dialog with the assemble staff. The best way for Vimek to do thisis by designing a work station containing a mounting fixture. The fixture is constructed andassembled in Vimeks facilities. A new assembling procedure of the crane tip equipment starts totake shape.With the support of Vimeks assembling staff and competent personnel within quality a newconcept of assemble instructions is presented. Standardization, continual improvement andquality control has been the core of this new concept.This project resulted in a new work station for the preassembling section and a reducedthrougput time for the Vimek 610 SE forwarder. The key to this project has been a successfulcollaboration with Vimeks competent assemble staff and designers.

  • 321.
    Ljungberg, Dennis
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Gjutoptimering av svetsat QSD60-fäste: Förstudie för gjutning av ett svetsat redskapsfäste på engcon tiltrotator2016Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Engcon Nordic AB is a company located in Strömsund, Sweden, and is a part of the engcon Group. Engcon is a global leader company in the manufacture of tiltrotators and tool attachment for excavators. The tiltrotators produced at engcon, are manufactured after the customer needs, with the alternative to choose between different sizes, fittings and tool attachments. At this time engcon are developing a new type of hitch for attachment of a integrated grabber, referred to as QSD60-hitch. This QSD60-hitch which allows attachment of a integrated grabber is today planned to be manufactured by welding of a set of pree-cut and machined steel plates, along with a newly developed integrated hydraulic block for control of the gripping claws. This method of manufacturing, with welding of plates, is a very time consuming and expensive method to use for this reason. Engcon Nordic AB has engaged me to investigate whether it is possible to use metal casting of this hitch instead of welding. The purpose of this project is to gather information and put together an early pilot studie of how to manufacture the hitch with casting, based on which of the avalible casting methods that should be used, what materials that are suitable for this purpose and if possible, make suggestions of how to change the shaping and design of the hitch to optimize to the selected casting method. This project is divided into three parts. The very first part consist of gathering information about the various casting methods that are avalible today, and what materials to choose between. Thereafter, the gathered information are used to come up with a proposal of what material and casting method that should be used with consideration of the design and shape of the hitch and the material requirements. The second part of this work is based on finding out how the casting of this object should be done for the chosen method, whether it should be casted in one piece or if separate pieces are necessary, and with respect to the required machining in consideration. Finally the last part of this work consists of making an approximate calculation of the unit price of this hitch, for the alternative casting manufacturing.

  • 322.
    Lodin, Tobias
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Modellering och analys av ventilation i stängda motorutrymmen2016Independent thesis Advanced level (professional degree), 300 HE creditsStudent thesis
    Abstract [en]

    This thesis work, which totally include 30hp, was performed in cooperation with BAE Systems Hägglunds in Örnsköldsvik. They are trying to reduce the cost for their new vehicles, Beowulf, which is constructed for professional civil customers. The engine bay ventilation today utilizing a high rpm military axial fan. The cost for the fan is high because the requirements from the military are high, specially the EMC requirement. Since Beowulf is for civil customers there are no need for those military requirements, therefore is this thesis works focused on are any cheaper solutions for the engine room ventilation.In this work, the heat generation in engine bay and the required air ventilation have been determined through theoretical calculation in Excel. A model has been created, in FloEFD 13, for simulation of the pressure drop in the ventilation system in the engine bay. Another simulation model was created to simulate a solution where the engine bay was ventilated through the cooler fan. A concept generation were also done to find advantages and disadvantage with different ventilation solutions. Finally measurements were made to see how the temperature in the engine bay reacts when the fan is shut off, during amphibian driving and also how the engine after heat affects the temperature.From the results of the simulations and real tests it was shown that the ventilation through the cooler fan would work. In the concept generation it was shown that there are cheap solutions that would reach the requirement ventilation flow if the fan is changed to an electric or hydraulic radial fan.From this reports the conclusion is that there are suitable fan solutions that are a lot cheaper than the fan that is used today. The best solution is reached by using the original cooler fan instead of a separate engine bay fan. This solution would reduce the cost for engine bay ventilation with more than 90 %.

  • 323. Lou, Benyong
    et al.
    Boström, Dan
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics, Energy Technology and Thermal Process Chemistry.
    Velaga, Sitaram P.
    Polymorph control of felodipine form II in an attempted cocrystallization2009In: Crystal Growth & Design, ISSN 1528-7483, E-ISSN 1528-7505, Vol. 9, no 3, p. 1254-1257Article in journal (Refereed)
    Abstract [en]

    The metastable form II of racentic felodipine was obtained in an attempted cocrystallization with isonicotinamide. Its low temperature crystal structure was characterized by a ID hydrogen-bonded chain consisting of four independent felodipine molecules.

  • 324.
    Lund, David
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Rundstyrning i lokalnät: En förstudie i tekniska och ekonomiska konsekvenser för Värnamo Elnät AB2012Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Värnamo Elnät owns and operates a ripple control system which is used to control loadsespecially when the grid is heavily loaded and for control of street lighting. This report aims atclarifying technical and economic aspects of the ripple control system’s future. The system wasinstalled from 1975 and onwards and its use was greater in those days when the controllableloads where greater then today, the current controllable load level is about 3 MW. The reporthighlights three different aspects of the ripple control system’s future – retain the currentsystem, reinvest in a newer system or discontinue the system.In the report the author also discusses relevant connections to Smart Grids and future meteringsystems and tariffs. The author senses a will from the company to discontinue the system on along term, but also a will to be able to control loads on the grid. Therefore the author suggeststhat the system should remain in operation for another 5 to 10 years, under the condition ofanother investigation of the remaining customer base.

  • 325.
    Lundberg, Daniel
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Bergvärme och solenergi i flerbostadshus: En förstudie över Kv. Uppfarten2015Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
  • 326.
    Lundberg, John
    et al.
    Umeå University, Faculty of Science and Technology, Department of Mathematics and Mathematical Statistics.
    Blomström, Victoria
    Umeå University, Faculty of Science and Technology, Department of Mathematics and Mathematical Statistics.
    Produktionsplanering och lagernivåer: En undersökning gällande utjämnad produktion på Jonsson & Paulsson Industri AB2016Independent thesis Advanced level (degree of Master (Two Years)), 300 HE creditsStudent thesis
    Abstract [en]

    Jonsson & Paulsson Industri AB (JP) is a company located in Östersund that manufactures steel-based sub-systems and products. JP is facing a large project that aims to reduce the lead time, reduce the factory floor area and improve their delivery dependability. The master thesis is a subproject of this project with the main objective to eventually raise the company’s delivery dependability by investigating alternative methods to plan JP’s production.  

    The project group’s assignment was to investigate and present proposals for a production plan that was both rate based and leveled, with respect to inventory levels and tied up capital. The purpose of the production plan was to reduce the variation in the flow of the articles. It also increases the possibility of direct feedback concerning whether they follow the production plan of the day or not. The project group also made a sensitivity analysis of the production schedules with the purpose to evaluate which machines and schedules that are most sensitive for disruptions.  Appropriate levels of safety stock were also investigated, so that JP could improve their ability to meet forecasting errors and disruptions in the production. 

    By formulating a mathematical model, and implement it in an integer linear programming solver we were able to produce production schedules. The project group then analyzed the sensitivity of these schedules based on their robustness and sensitivity to reduction in capacity. The sensitivity analyses produced different proposals for improvements. The project group collected data of forecasting errors to determine levels for the safety stock. We chose not to proceed with the simulation of multiple reasons. One of them was insufficient data. We therefore recommend JP to collect the missing data that is required for determine the levels of the safety stock, to be able to do this in the future.  

    The project group has developed three different types of production schedules for most welding machines that are leveled and rate based. We have also developed a type of production schedule that is not leveled or rate based, which has been used as a reference. The leveled production schedules are rate based with a weekly production rate. Two of the leveled types of production schedules are a combination of flexible and completely leveled, as they respond to trends in demand to avoid building excessive inventory levels. The third type of leveled production schedule is leveled with respect to batch sizes. JP is likely to improve their delivery dependability if they level and rate base their flows. It helps them to see if the production is in time and act quickly if it is not. The employees’ gets to produce in a more even working pace and knows what is expected to be produced every day. A leveled flow builds higher inventory levels then a flexible production, but costs are also saved since overtime and underemployment is avoided.

    The sensitivity analyses showed that welding machine 304, 302 and 305 are most sensitive to disruptions. Welding machine 303 and 307 can dispose capacity for other, more pressed, welding machines since they are least sensitive. By heightening the gross capacity of welding machine 303, 304, 305 and 307 their sensitivity will be reduced. We have seen a need to level the stress of the welding machines, preferably by shifting an article from machine 302 to 303 or 307. 

  • 327.
    Lundberg, Mattias
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Språkförskolan: En jämförelse mellan CAV- och VAV-system2019Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This report examines the profitability and energy-saving potential of replacing the existing CAV system with a VAV system in Språkförskolan, which is located in Umeå in the Marielund/Olofsdal area. The project is carried out in collaboration with Tyréns in Umeå, which is a consulting company and one of the leading companies in urban management in Sweden.

     

    With the help of IDA ICE, which is an energy calculation program, a model of the preschool could be built in 3D based on floor plan drawings and settings such as the number of people, lighting, ventilation systems and air flows, indoor temperature and so on adjusted so as to be as similar to the actual building as possible. When all values ​​were set, an energy simulation was made in the program, which gave a lot of values ​​such as annual energy consumption for different systems in the building and heat losses through the building envelope. The file was duplicated, and the CAV system was replaced by a VAV system and another simulation was started. Based on the simulation results, energy consumption for the heating system and the fans was compared in both cases.

     

    In AutoCAD, a ventilation solution was designed with the VAV system in one department of the preschool, with associated VAV dampers that automatically adjust the airflow according to the measured load in the room. The CAV system does not adjust the airflow but goes to the maximum dimensioned flow all the time which is not energy efficient in rooms with varying loads (people).

     

    The results from the simulations showed that with variable ventilation, the total annual energy consumption decreased by 20 953 kWh, which is a reduction of 26%. Of this energy saving, the heating system accounted for 67% and the fans for 33%. The investment cost for installing VAV dampers in the building is SEK 192,000, and based on the annual savings the payback time was calculated to 19,7 years. With a lifetime of 25-30 years, an investment of the VAV system is considered to be profitable.

  • 328.
    Lundberg, Petter
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Investigation of the transient nature of rolling resistance on an operating Heavy Duty Vehicle2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    An operating vehicle requires energy to oppose the subjected driving resistances. This energy is supplied via the fuel combustion in the engine. Decreasing the opposing driving resistances for an operating vehicle increases its fuel efficiency: an effect which is highly valued in today’s industry, both from an environmental and economical point of view. Therefore a lot of progress has been made during recent years in the area of fuel efficient vehicles, even though some driving resistances still rises perplexity. These resistances are the air drag Fd generated by the viscous air opposing the vehicles propulsion and the rolling resistance Frr generated mainly by the hysteresis caused by the deformation cycle of the viscoelastic pneumatic tires.

    The energy losses associated with the air drag and rolling resistance account for the majority of the driving resistances facing an operating vehicle, and depends on numerous stochastic and ambient parameters, some of which are highly correlated both within and between the two resistances. To increase the understanding of the driving mechanics behind the energy losses associated with the complexity that is rolling resistance, a set of complete vehicle tests has been carried out. These tests were carried out on the test track Malmby Fairground, using a Scania CV AB developed R440 truck equipped with various sensors connected in one measurement system. Under certain conditions, these parameters can allow for an investigation of the rolling resistance, and a separation of the rolling resistance and air drag via explicit subtraction of the air drag from the measured traction force. This method is possible since the aerodynamic property AHDVCd(β) to some extent can be generated from wind tunnel tests and CFD simulations.

    Two measurement series that enable the above formulated method of separation were designed and carried out, using two separate measurement methods. One which enables the investigation of the transient nature of rolling resistance as it strives for stationarity, where the vehicle is operated under constant velocities i.e. no acceleration, and one using the well established method of coastdown, where no driving torque is applied.

    The drive cycles spanned a range of velocities, which allowed for dynamic and stationary analyses of both the tire temperature- and the velocity dependence of rolling resistance. When analysing the results of the transient analysis, a strong dependence upon tire temperature for given constant low velocity i.e. v ≤ 60 kmh−1 was clearly visible. The indicated dependency showed that the rolling resistance decreased as the tire temperature increased over time at a given velocity, and vice versa, towards a stationary temperature and thereby rolling resistance. The tire temperature evolution from one constant velocity to another, took place well within 50 min to a somewhat stationary value. However, even though the tire temperature had reached stationarity, rolling resistance did not; there seemed to be a delay between stationary tire temperature, and rolling resistance. The results did not indicate any clear trends for v ≥ 60 kmh−1, where the results at v = 80 kmh−1 were chaotic. This suggests that some additional forces were uncompensated for, or that the compensation for air drag was somehow wrongly treated at higher velocities.

    Several factors ruled out any attempts at proposing a new rolling resistance model. These included: the chaotic results for v = 80 kmh−1, the delayed rolling resistance response upon tire temperature stabilization, and the lack of literature support for the observed tendency. The results from the coastdown series on the other hand, showed good agreement with a dynamical model suggested in literature. The stationary temperature behaviour for the considered velocity range at assumed constant condition is also supported in literature.

    Finally, an investigation of the aerodynamic property AHDVCd inspired by ongoing work in ACEA (European Automobile Manufacturers’ Association), was carried out assuming both zero and non-zero air drag at low velocities. The results indicated surprisingly good agreement with wind tunnel measurements, especially when neglecting air drag at low velocities: as suggested by ACEA. 

  • 329.
    Lundegård, Erik
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Energy recovery – Gasification, combustion or plasma?: Competitor or complement?2018Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Abstract

    Energy recovery – Gasification, combustion or plasma?

    -          Competitor or complement?

    The Swedish waste-to-energy system has been developed during many years, and the facilities are well established within the waste management system. Even though the waste volume is significantly reduced by 70 – 80 %, the residues are quite challenging to manage due to high content of pollutants. The air emissions are quite low today, but since waste contains various kinds of contaminants, there is a high need for extensive flue gas cleaning, adding to the residue that must be handled. Today, the main part of residues from flue gas cleaning and fly ash from Swedish waste-to-energy facilities are transported to Langöya, Norway to be used for remedial purposes of an old limestone quarry. However, this option will probably be phased out sometime after the year 2023 – 2025 and other solutions must be considered such as e.g. gasification.

     

    The Plagazi Company has a patented process, including gasification and subsequent production of hydrogen gas, that may be used as a vehicle fuel. Although gasification is a well-known technique, there is still a great distrust in using the method for waste treatment purposes. There is a conception that gasification facilities are high energy consumers, with low operational performance and high investment costs. The present thesis is part of the B.Sc. Programme in Energy Engineering at the University of Umeå. The main thesis objectives are:

     

    • Study and explain significant differences and similarities between waste incineration and gasification;
    • Describe pros-and-cons regarding various methods to produce hydrogen gas;
    • Describe different gasification techniques.

    In addition, the Plagazi-process is described; local plasma gasification with low environmental impact and a second step including production of hydrogen gas. The present study is based on a literature review and interviews with experts in the field. The report excludes biogas production in anaerobic digestion plants.

     

    The present report has proven that there are significant differences between various gasification devices. When making investment decisions regarding gasification as a waste treatment option; fuel quality and utilization of the syngas must be considered.

    The method developed by Plagazi may be suitable in the Swedish waste management system to treat household waste and/or flue gas residues from the combustion plants, for production of hydrogen gas as a vehicle fuel. A full-scale facility in operation is needed to evaluate the Plagazi process with respect to cost efficiency and performance. The Plagazi concept should not be viewed as a competitor to the profitable waste incineration plants, more preferably as a complement. 

  • 330.
    Lundgren, Linus
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Hållfasthetsanalys på skidbalk och pendelarm BvS 102016Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Denna rapport avser en hållfasthetsanalys på skidbalken och pendelarmen som ingår i bandvagnen BVS 10, tillverkad av BAE Systems Hägglunds, Örnsköldsvik. Syftet med projektet var att utreda om nuvarande balk kan förstärkas så att den klarar av en större vikt på fordonet.

    För att beräkna spänningarna har programmet Catia V5 använts med ett FEM-tillägg. Vid simuleringen av skidbalken som används för närvarande uppkom flera områden som behövdes förstärkas. Förstärkningarna som testades var att öka tjockleken på plåten som skidbalken är tillverkad av, förlänga den befintliga förstärkningen bak på balken, höja tvärsnittet bak, svetsa på plåtar på bakdelen av balken och montera en förstärkningsplåt i mitten på skidbalken. Det gjordes även simuleringar där alla lösningar sattes samman. Simuleringen av pendelarmen visade att den också måste förstärkas men att det krävs förändringar på bussningen som den sitter i för att lösa problemet helt.

    Resultatet av simuleringarna på förstärkningarna var att det endast var skidbalken som var tillverkad med 6 mm tjock plåt som blev godkänd. Skidbalkarna som hade 4 och 5 mm plåttjocklek med alla förstärkningar tillagda låg precis över det gränsvärde som var satt med en säkerhetsmarginal, Om gränsen hade varit satt på samma värde som flytgränsen på materialet så hade dessa balkar blivit godkända.

  • 331.
    Lundholm, Karin
    et al.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics, Energy Technology and Thermal Process Chemistry.
    Nordin, Anders
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics, Energy Technology and Thermal Process Chemistry.
    Backman, Rainer
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics, Energy Technology and Thermal Process Chemistry.
    Trace element speciation in combustion processes: review and compilatons of thermodynamic data2007In: Fuel processing technology, ISSN 0378-3820, E-ISSN 1873-7188, Vol. 88, no 11-12, p. 1061-1070Article in journal (Refereed)
    Abstract [en]

    Chemical equilibrium calculations are often used to determine the fate of trace metals in combustion processes and to study the effects of different process variables and varying fuel compositions. In the present report, thermodynamic data on compounds containing the trace elements As, Cd, Cr, Cu and Pb from different database sources are compared. The results showed significant differences between existing databases in both number of compounds included in the databases and thermodynamic data. The differences also significantly affected the outcome of the equilibrium calculations.

  • 332.
    Lundholm Ljungkvist, Hampus
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Nordstjärnan som nära-nollenergibyggnad2018Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Examensarbetets syfte var att utvärdera hur Umeå kommuns egna energikrav står sig mot det kommande kravet på nära-nollenergibyggnader, NNE-byggnader. Som underlag för utvärderingen på Umeå kommuns kombinerade förskola/äldreboende Nordstjärnan gjordes en energibalansberäkning i simuleringsverktyget IDA ICE. Genom att bestämma byggnadens energiprestanda enligt NNE-kravets författning Boverkets Byggregler, BBR, 26 och enligt tidigare författningar, BBR 24 och 25, kunde utvärdering ske. Byggnadens energiprestanda jämfördes med Umeå kommuns och BBR 24, 25 och 26 krav. Resultatet av utvärderingen visade att Nordstjärnan klarade kraven med kombinerad fjärr- och bergvärme som uppvärmning. Marginalen till BBR 26 krav och Umeå kommuns krav blev 4 % respektive 3 %. Utvärderingen visade också att byggnaden inte hade klarat något av de två kraven om uppvärmningen endast utgjorts av fjärrvärme. Slutsatsen är att Umeå kommuns energikrav är hårdare än BBR 26 krav för byggnader liknande Nordstjärnan. Någon generell slutsats om Umeå kommuns krav mot BBR 26 krav kunde inte dras. Detta på grund av att kraven bygger på olika författningar med olika metoder för bestämning av byggnadens energiprestanda.

    Vidare undersöktes en egen energiproduktions påverkan på Nordstjärnans energiprestanda. En solcellsanläggning simulerades i programmet PV*SOL. Den mängd solel som momentant kunde nyttjas till byggnadens energianvändning och byggnadens nya energiprestanda beräknades. Resultatet visade att den simulerade solcellsanläggningen förbättrade Nordstjärnans energiprestanda enligt BBR 26. Förbättringen blev 12 % vid fjärrvärme och 14 % vid kombinerad fjärr- och bergvärme som uppvärmning. Byggnaden klarade då NNE-kravet vid både fjärrvärme och kombinerad fjärr- och bergvärme med 4 % respektive 16 % marginal.

    Det noterades att byggnadens utformning var bristfällig, sett ur ett energiperspektiv. En enklare undersökning av hur en förbättring av formfaktorn påverkar byggnadens uppvärmningsbehov gjordes. Byggnadens specifika uppvärmningsbehov förbättrades med 5 % samtidigt som byggnadens genomsnittliga värmegenomgångskoefficient, Umedel , försämrades. Slutsatsen av detta blev att energiteknisk kompetens bör kopplas in i ett tidigt skede för att i samråd med arkitekten kunna göra förändringar av byggnadsutformningen. Den visade också på att en byggnads Umedel inte räcker för att bedöma en byggnads konstruktion ur energisynpunkt. Även formfaktorn bör beaktas. 

  • 333.
    Lundin, Mattias
    et al.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Voutilainen, Karl-Oskar
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Vinddataanalys för vindkraft Storfall: behandling och analys av mätdata från sodarmätning samt produktionsberäkning2012Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In recent years the interest in wind power has increased in Västerbotten. The wind resources are generally good while it is sparsely populated. Apoidea is on behalf of the Baltic Group investigating the possibility of establishing a wind farm with about 20 wind turbines northwest of Nordmaling. Wind measurements have been taken for a little more than a year to confirm the wind conditions at the site. The measurements were made with sodar, a kind of remote sensing equipment. The Sodar is an acoustic device which sends out sound signals and then records the rebounding echo to measure wind direction and speed. The technique is based on the Doppler Effect. The signals sent out reflects on temperature stratifications in the air and changes frequency which the sodar registers. Two sodars with support system have been used and they have been placed in different locations around the project area. One sodar has been kept at a location named 006 throughout the entire measure period. While the other sodar during the same period has been moved around to three different locations, each named 071, 072 and 073. The aim of the project was to analyze sodar data to quality check the measurements and calculate the potential energy production. To make this possible the correlation between fixed and mobile sodar was analyzed. This is to receive proof of how well the two measurements align during the period. A long-time correction of 006 has been made and analyzed. As a long-time reference NCEP/NCAR reanalysis data has been used. The areas that were selected to be analyzed includes availability, wind speed, quality and energy production. Most analyses were made in WindPRO or Microsoft Access. The analysis resulted in an estimated availability at between 53 and 86 %. The quality at 120 m is between 90 and 95 % for all measurements. The correlation between sodar 006 and 071 was estimated to 0.90 sector wise weighted average, for sodar 006 and 072, 0.85 and for 006 and 073, 0.86. The correlation between fixed sodar and long-term reference for the time period 2010-06-01 to 2011-10-01 was calculated to 0.64. The statistically corrected average wind velocities were all lower than the 006 measurement and are in the range between 6.54 to 6.67 m/s compared to 6.77 m/s for 006. The method we chose, which included an examination at several measurements in the same area during the same period and the use of the analysis and planning tool WindPRO to analyze these values, is what we understand a common approach. The results of the correlation between measurement sites are high in all locations, which gve a more reliable result, even if two different methods would have been preferred for the validation of the measurement. But this was not possible since there was no mast available in the area. The terrain in the area can be described as complex. Therefore caution was used when the results of the measurements were interpreted. The low availability depended largely on problems with the support system such as the generator. The correlations between the two different sodars are high throughout the entire period and together with the quality results they are validating the measurement. In future projects it would be recommended to include a mast measurement to correlate against. Further comparisons of long-term data would be needed to make reliable production estimates.

  • 334.
    Lundin, Mikael
    et al.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Andersson, Staffan
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Östin, Ronny
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Development and validation of a method aimed at estimating building performance parameters2004In: Energy and Buildings, ISSN 0378-7788, E-ISSN 1872-6178, Vol. 36, no 9, p. 905-914Article in journal (Refereed)
    Abstract [en]

    This paper presents a method for estimating the total heat loss coefficient, the total heat capacity and the gain factor based on measured data for the internal-external temperature difference, the domestic load and the supplied heat. Knowledge of these performance parameters is essential for a reliable energy demand forecast, close guidance and the accurate analysis of efficiency actions in buildings. The method was validated on measurements from a test cell. The values obtained for the performance parameters were in good agreement with a lumped capacitance analysis of the heating and cooling of the test cell. The deviation in the total heat loss coefficient, expressed in terms of the root mean square error, was between 2.5 and 9.4%. The values obtained for the total heat capacity were on average 9.8% higher than the reference value and for the gain factor the average deviation was 12.5%. The method shows promising signs of becoming a robust and accurate tool for extracting both the magnitude and the variation of the performance parameters, based on easily accessible data.

  • 335.
    Lundin, Mikael
    et al.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Andersson, Staffan
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Östin, Ronny
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Further validation of a method aimed to estimate building performance parameters2005In: Energy and Buildings, ISSN 0378-7788, E-ISSN 1872-6178, Vol. 37, no 8, p. 867-871Article in journal (Refereed)
    Abstract [en]

    A further validation of an earlier developed neural network method for estimating the total heat loss coefficient (K-tot), the total heat capacity (C-tot) and the gain factor (alpha) based on measured diumal data of internal-external temperature difference, supplied heat for heating and "free heat" is presented. The validation was performed in laboratory scale, using a test cell, for three different cases of ventilation, without (constant)-, natural-, and forced ventilation. Earlier measurements from a building was also used in order to simulate a realistic energy use pattern and a rather stochastic behavior of alpha, which also was transformed to represent existing and future buildings in terms of the composition of their energy use. For all three types of ventilation and different types of buildings, the method was capable of estimating the three different performance parameters and their different dependencies. For K-tot, the RMSE was between 3 and 20% and for alpha, the deviation was between 9 and 19%.

  • 336.
    Lundmark, Martin
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Evaluating a high rise building for passive house classifications: Simulating and improving the Slovenian Eco Silver House in European climates using PHPP2015Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    As part of the EU project Energy Efficient Demo Multiresidential highrise Building (EE-highrise), this thesis work evaluates and changes the Slovenian Eco Silver House (ESH) high rise building model in order to see if it can be classifiable as a passive house in different European regions.

    The purpose of this thesis work was to evaluate if the ESH could meet the European and Swedish passive house classification in Sibernik, Ljubljana, Lund, Östersund, Sundsvall and Kiruna. The purpose was also to make a sensitivity analysis of different energy efficiency measures in the energy performance of the building. This analysis was conducted to understand which of the selected energy efficiency measures made the most significant improvements in the results. The measures included in the sensitivity analysis were the building envelopes wall insulation thickness, changing the window frames, altering the ventilation air duct length and width as well as increasing the air duct insulation thickness. Finally, simulations with solar panels on the roof of the ESH were carried out.

    For the European passive house classification, the study involved constructing the model in the Passive House Planning Package (PHPP) and simulating each region and energy efficiency measures separately. PHPP is however made specifically for verifying buildings according to the European passive house standard. So the demands for the Swedish passive house classification cannot be calculated in the PHPP simulations. Because of this, the data available through PHPP was used to manually calculate the Swedish passive house requirements.

    The results showed that the original ESH model, was only passive house certifiable according to the European classification in Sibernik. When including the additional energy efficiency measures it was possible for the ESH to become passive house certifiable in Lund, Ljubljana and Sibernik.

    The Swedish passive house classification results suggests that the ESH may be passive house certifiable in Lund. Also, with additional energy efficiency measures the ESH may meet the passive house requirements in Sundsvall and Kiruna. However, all the passive house classification parameters could not be considered in this study. Accordingly, additional analysis are required to draw final conclusions on whether the ESH building could meet the Swedish passive house certification in the different Swedish climate zones.

    The conclusions drawn were that all the energy efficiency measures contribute to reducing the primary energy demand, heating demand and the heating load. However, these same energy efficiency measures would at the same time increase the cooling demand. Because of this, it was discussed that specific regional models should be made. Because some regional models might benefit from not including the energy efficiency measures used in this thesis at all. They might instead benefit from finding and implementing energy efficiency measures that reduce the cooling demand.

  • 337.
    Lundström, Niklas L.P.
    et al.
    Division of Solid Mechanics, Department of Applied Physics and Mechanical Engineering, Luleå University of Technology.
    Aidanpää, Jan - Olov
    Division of Solid Mechanics, Department of Applied Physics and Mechanical Engineering, Luleå University of Technology.
    Dynamics in large generators due to oval rotorand triangular stator shape2011In: Acta Mechanica Sinica, ISSN 0567-7718, E-ISSN 0459-1879, Vol. 27, no 1, p. 18-27Article in journal (Refereed)
    Abstract [en]

    Earlier measurements in large synchronous generatorsindicate the existence of complex whirling motion,and also deviations of shape in both the rotor and the stator.These non-symmetric geometries produce an attraction forcebetween the rotor and the stator, called unbalanced magneticpull (UMP). The target of this paper is to analyse responsesdue to certain deviations of shape in the rotor and the stator.In particular, the perturbation on the rotor is consideredto be of oval character, and the perturbations of the statorare considered triangular. By numerical and analytical methodsit is concluded for which generator parameters harmfulconditions, such as complicated whirling motion and highamplitudes, will occur. During maintenance of hydro powergenerators the shapes of the rotor and stator are frequentlymeasured. The results from this paper can be used to evaluatesuch measurements and to explain the existence of complexwhirling motion.

  • 338.
    Lundström, Oskar
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Utredning av effektiva elmotorer för fläktdrift2012Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Fläkt Woods is a global manufacturer of fan and air climate systems, they produce the fans and climate systems themselves but they buy the motors from other manufacturers. The objective in this report is to compare the technical differences between the motors and to find where each motor is best used.

    The EC and PMSM-motors are both permanently magnetized and over all they are built very similar. The main difference is shown in the back-EMF, the EC-motor is using a trapezoidal back-EMF while the PMSM-motor uses a sinusoidal back-EMF. The PMSM-motor has a higher degree of efficiency, especially at higher speeds. At lower speeds there are EC-motors showing higher efficiency then the PMSM-motor at around 1300 rpm and below. The second main difference between the motors is the sensors. The EC-motor can use hall-sensors, while the PMSM-motor need more sophisticated sensors because of the sinusoidal current.

    To lower the electric cost of motors a very important part is to dimension it appropriate. If the motor is over dimensioned the efficiency will be lowered because it won’t operate at its optimal speed. Both the EC and PMSM-motor have better efficiency then the older AC-motor, despite this it is still up to the customer to decide what type of product they want to buy. Today the most sold motor for fans is still the AC-motor. This is because of the AC-motors simple construction, the customers high knowledge about the motor and because it is much easier to find spare parts. 

  • 339.
    Lundström, Viktoria
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Virtual Commissioning: Virtual Commissioning of ABB Production cell2016Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The background of the concept, ABB Production Cell, meets the increasing demands from manufacturing industries throughout the world to simplify through standardization and by that reduce investment cost and operating cost throughout the entire lifecycle of the production cell.

    ABB is delivering the production cell as one easy to order, use, and maintain. The production cell is developed for virtual versions and full scale production cells. The different modules shall be utilized and presented in RobotStudio and configured in Automation Builder. With generic templates and hardware it provides e.g. early visualization, standardized systems, shortened design/development phase, and enable virtual FAT(Factory Acceptance Test).

    There is multiple ways of doing a virtual commissioning and it’s a known approach for testing software and hardware together. The method used in this project is known as SIL (Software-In-The-Loop).  This means that the hardware runs as software- e.g. PLC, Drives and HMI- with same properties and behavior as the real hardware.

    This thesis focus on describing phases of an automation system and see how different phases are affected by a virtual commissioning. Benefits will be described and the existing software will be evaluated. Furthermore, an attempt of virtual commissioning has been done with focus on connecting the software for stable communication with the virtual PLC and make a PLC-task with a handshake to the robot controller and the virtual environment. The system is tested in a virtual environment with vFAT and then on the workshop (FAT). This was done to see if the softwares replicated the same behavior as the hardwares. 

    The result for the virtual commissioning is that it is possible to run the virtual PLC (VAC500) with the same time interface, behavior, and signals as the real PLC (AC500).

  • 340.
    Lyxell Lind, Tobias
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Konceptförslag - motorprovbänk: Konceptförslag av chassi och adapterlösning till Indexator AB’s kommande motorprovbänk2012Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Indexator AB, beläget i Vindeln, tillverkar rotatorer och tiltrotatorer för skogs-, transport-, industri och entreprenadbranschen. Själva hydraulmotorn som är en huvudkomponent i rotatorn är av vingmotortyp och egenutvecklad av Indexator. För att Indexator skall kunna fortsätta vara världsledande inom branschen krävs ett ständigt utvecklingsarbete.

    Hos Indexator AB finns ett provningslaboratorium där deras produkter testas och analyseras i bland annat hållfasthet. Till detta laboratorium vill Indexator nu utöka sin testverksamhet. Det vill man göra med hjälp av en specialanpassad motorbänk där rotatorerna kan monteras och köras med dynamisk belastning samtidigt som ett antal data mäts och dokumenteras.

     

    För att bänken skall kunna hantera de flesta typer av rotatorer krävs en bänk med stor flexibilitet och adapterlösning för att passa ihop med bänkens motor och drivlina. Två konceptidéer och flertalet detaljlösningar har föreslagits och en slutgiltig konstruktionsmodell över chassi och adapterlösning med tillhörande ritningar har tagits fram. Hållfastheten på konstruktionsmodellerna har analyserats genom FEM-analys och enklare teoretiska beräkningar.

  • 341.
    Löfgren, Erik
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Accuracy of transient versus steady state forces on a rudder operating in a propeller slipstream2015Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In computational fluid dynamics (CFD), a transient simulation is in general more costly than computing the steady state of the system, if such a state exists. The velocity field produced by the propeller blades upstream of a rudder is transient in nature, and rudder design using CFD may therefore become very time-consuming. If a steady solution could accurately predict the performance of the rudder, such an approach would be favourable. The aim of the present study was to assess the possibility to accurately predict the performance of a rudder operating in a propeller slipstream using steady state simulations, e.g. an actuator disk model (ADM). For this reason, the performance of the two-dimensional NACA 0021 rudder section submitted to a sinusoidal transverse gust, representing a transient propeller slipstream, was simulated using ANSYS Fluent. The predicted force coefficients are presented for a number of gust amplitudes, mean angles of attack and reduced frequencies of the transverse gust. The simulations have shown that the modelling error introduced when predicting the performance in a steady state is highly dependent on all these parameters of the actual transient flow, and that the steady result may be a severe over- or under-prediction of the real performance of the rudder. Heavily loaded propellers are suspected to be less suitable for ADM modelling in rudder performance prediction. The predicted unsteady lift coefficient was compared to the linear theories of Horlock and Sears, and the agreement was fair at zero mean angle of attack but poor at a mean angle of attack of 10°. It was also found that the predicted performance of the rudder was significantly altered when the chord based Reynolds number was increased by a factor of 10, which has implications on the validity of model-scale simulations. The effect of including turbulent transition modelling for some of the simulations was also investigated, and the discrepancy in predicted performance was found to be considerable. Due to the formation of a laminar separation bubble the predicted trailing edge separation and viscous stress on the rudder were significantly decreased, leading to better overall performance.

  • 342.
    Löfgren, Helena
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    NOx-reducering vid avfallsförbränning2018Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Waste incineration is used to reduce the volume of waste, destruction of hazardous waste and to extract energy in combined heat and power plants (CHP). Umeå Energi’s CHP Dåva 1 incinerates municipal solid waste (MSW) and other hazardous waste. Nitrogen oxides (NOx) are formed in the combustion process. The emission of NOx is regulated in Sweden’s regulation SFS 2013:253 and law 1990:613. Dåva 1 uses selective non-catalytic reduction (SNCR) with ammonia as flue gas treatment, to reduce NOx in the flue gas. Some of the ammonia in the process remains unreacted (ammonia slip) and it probably contributes to corrosion in the colder economizer. Umeå Energi wants to reduce the NOx emissions without increasing the ammonia related corrosion of the economizer. In the present study, the possibility to reduce NOx formation by SNCR optimization was evaluated. Furthermore an investigation on the use of selective catalytic reduction (SCR) in waste incineration plants in Sweden, and whether it is beneficent to install in Dåva 1, was included. The current efficiency of the SNCR system was tested by switching of the ammonia in short periods of time and measuring and logging the flue gas composition. The efficiency (80 %) proved to be very high if operated at the optimal temperature. ButHowever, the test also showed that the temperature limits for the injection levels could be optimized for improved efficiency. Improved efficiency at all temperatures could reduce both NOx emission and ammonia use. The use of SCR in Swedish waste incineration plants was investigated through interviews. It was found that only five plants are equipped with SCR and they were placed in the clean gas position – after electrostatic precipitatorelectric filter and wet scrubber treatment. The contents of the flue gas was examined monitored at three positions at Dåva 1. The content of SO2, HCl and dust were measured, which in combination with ammonia can cause coating with reduces the efficiency of the catalyst. All three positions were located after the textile filters and had low contents of dust. Position A was located between the textile fabric filters and the economizers and was the hottest position with 205℃. Position B was located after the economizers and had the temperature of 145℃. Position C had the cleanest and thereby the safest position for a catalyst, due to its location after all the flue gas treatments, but the temperature was only 65℃ and requires most re-heating of the flue gas. Since the SNCR system proved to have potential to be more efficient, it should be optimized before considering an investment in a SCR system.

  • 343. Ma, Charlie
    et al.
    Backman, Rainer
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Ohman, Marcus
    Thermochemical Equilibrium Study of Slag Formation during Pressurized Entrained-Flow Gasification of Woody Biomass2015In: Energy & Fuels, ISSN 0887-0624, E-ISSN 1520-5029, Vol. 29, no 7, p. 4399-4406Article in journal (Refereed)
    Abstract [en]

    The potential slag formation behavior during pressurized entrained-flow gasification (PEFG) of woody biomass has been studied from a thermodynamic perspective with respect to compositional, temperature, and pressure variations. An ash transformation scheme was proposed on the basis of the melt formation potential that arises when gaseous K species are present with Si and Ca. Databases and models in FactSage 6.4 were used to carry out thermochemical equilibrium calculations within ChemSheet. It was found that increasing pressure and increasing Si content expanded the range of operating conditions that are conducive of melt formation, while increasing temperature and increasing Ca content diminished the range. The results from the calculations compared qualitatively well to experimental results and provide further information needed in the development of PEFG reactors for woody biomass.

  • 344.
    Madison, Guy
    et al.
    Umeå University, Faculty of Social Sciences, Department of Psychology.
    Paulin, Johan
    Umeå University, Faculty of Social Sciences, Department of Psychology.
    Ratings of speed in real music as a function of both original and manipulated tempo2010In: Journal of the Acoustical Society of America, ISSN 0001-4966, E-ISSN 1520-8524, Vol. 128, no 5, p. 3032-3040Article in journal (Refereed)
    Abstract [en]

    There is an apparent contradiction between the narrow range of tempi optimal for perceptualjudgment and motor synchronization and the wide range of beat tempi found in real music. Therelation between listeners’ perception of speed and beat tempo was therefore investigated, both forreal music excerpts (ME) and metronome sequences. Tempi ranged from 42 to 200 beats per minute (BPM), and some excerpts were further tempo manipulated in four levels from from ±5 to ±20%. Regression analyses showed that speed was a shallower function of original tempo for fast (> 150 BPM) and slow (< 95 BPM) MEs than for MEs with intermediate tempi, describing anon-linear, sigmoid function. Manipulated tempo had twice as large an effect on speed as hadoriginal tempo. In contrast, speed was an almost linear function of tempo for metronome sequences.Taken together, these results show that the non-linearity stems from properties of the musical signal,rather than being a subjective perceptual effect. They indicate an inverse relation between tempo andrelative event density in real music, and demonstrate that the perception of periodic signals isaffected not only by the beat level, but also by faster and slower levels.© 2010 Acoustical Society of America.

  • 345.
    Manchester, Ian R
    et al.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Savkin, Andrey V
    Faruqi, Farhan A
    Method for optical-flow-based precision missile guidance2008In: IEEE Transactions on Aerospace and Electronic Systems, ISSN 0018-9251, E-ISSN 1557-9603, Vol. 44, no 3, p. 835-851Article in journal (Refereed)
    Abstract [en]

    A new precision guidance law is presented for three-dimensional intercepts against a moving target In contrast to previously published guidance laws, it does not require knowledge of the range to the target. This makes it appropriate for use on platforms which have an imaging device, such as a video camera, as a primary sensor. We prove that with idealized dynamic model, the guidance law results in zero miss distance, and a formula is given for impact angle error which tends to zero as does target speed, making this method particularly suitable against slow moving targets. Computer simulations are used to test the law with a more realistic model, with a video camera and optical-flow algorithm providing target information. It is shown to perform well compared with another law from the literature, despite requiring less information.

  • 346.
    Mannberg, Andreas
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Utredning av värmesystem på ICA Kvantum Umeå2012Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The total energy consumption in Sweden reached 457 TWh in the year of 1970, and today is 600 TWh. It shows how our use has increased recently and that we should do something about it. The whole chain from energy production to energy use needs to be more efficient. A study conducted by ICA Fastighet AB shows an average energy use among grocery stores of 421 kWh/m2 year. ICA Kvantum Kronoparken in Umeå has a specific energy use of 658 kWh/m2 year, it shows that the energy use is high and above the mean average.

    The project aims is to conduct a case study at ICA Kvantum Kronoparken in Umeå by mapping the total energy use by the selected energy use categories in the shop. Furthermore, investigate various alternatives to replace the electric boiler which supplies the building with heat today.

    Today, the property has a total energy use of 2 237 MWh/year in a heated area of 3 400 m2. The analysis was conducted by separating the total energy use in seven main categories. By doing that it is easy to find the categories of high energy efficiency potential. Separation as follow:

    • Lights
    • Ventilation
    • Heating
    • Food cooling
    • Comfort cooling
    • Hot water
    • Operational electricity

    After completing the case study it showed that food cooling is responsible for approximately 42 % of total energy use, and also there you have the highest potential in saving energy and money. Other major users are area operational electricity which accounts for 21 % and includes all other equipment and use in addition to the above categories. The areas where energy efficiency measures were possible are lights, ventilation and cooling food. After these measures a given potential of the total energy use reduction by 20 % from 2 237 MWh/year down to 1 818 MWh/year.

    District heating and geothermal heating are the heat sources which best could replace the existing electric boiler. District heating has a lower investment cost and higher annual cost than geothermal heat, which is the opposite. Both have a payback period of 4-6 years which is considered as viable.

    The project focused on the property heating system, which only represents 7 % of total use. That compares to cooling food which represent 42 %. If the project was focused on food cooling rather than the heating system greater savings may has become possible. A recommendation for the future is to explore the cooling food system more, and also study and explore if free cooling is possible in winter. Today is not used, and it may be one of many factors that make the property’s energy use so high. 

  • 347.
    Manoraj Pettersson, Daniel
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Plåtformning av längsgående kanter på solfångare: Prototyputveckling av maskinmodul för bockning av plåtkanter2016Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Using solar energy is clearly an important part of creating a sustainable future. Thats exactly what the small company Absolicon Solar Collectors placed in Härnösand thinks and carries through. By developing and manufacturing concentrated solarcollectors with a complete runningcentral for producing steam intended for industrial purpose are they pushing the technology and industry forward. They have so far manufactured small volumes of pilot plants but will now have the ability to manufacture larger volumes. To accomplish that they will have to be able to speed up the manufacturing process regarding some of the processes in the manufacturing line.

    As a part of the first station in the line will they need a method to semi automatically bend the two longest edges of the collector. It is this method this thesis is all about. A functional prototyp is also a part of the desired result.

    Roll forming became the method of choice. After choosing method was a small research around the subject accomplished containing visits at companies and literature studying. The demands of the curvature of the bends were also more closely investigated to get a better grip of the demands on the roll forming mill.

    Rollforming is an effective way to change the profile of steel plates and strips. The higher rollspeed the faster rollforming. By calculating tension and elongation of the steel or by testing can the number of passes and the length of the mill be determined.

    In the part theory of the report is essential theory and rules regarding roll forming compiled for simple calculations and general understanding of some of aspects in roll and mill design.

    In the part method of the report is the work regarding planning and contructing the two hand made prototypes. Prototype one is manufactured for the purpose of testing stands, shafts and rolls. Derived from the results of testing prototype one is the final prototype constructed and made.

    The work is resulting in a final prototype containing two passes which is not producing the desired final bend angle but the function of the roll forming as a method can still be validated and presented. The steel strip is easily by hand dragged trough the mill and no defects or other problem were encountered. The final prototype is not fully meeting the demands of the final bend angle due to the short deadline it was made in. Two more passes are still needed do be added for the final angle.

    As a conclusion is roll forming as a method really suitable for this bending operation because of its simplicity, low cost, small physicall measurments and high forming speed.

  • 348.
    Marcusson, Carl
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Analys och omkonstruktion av CamTool Solid2015Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Söderhamn Eriksson AB har producerat och levererat utrustning till sågverksindustrin i över 150 år. Företagets uppgift är att förse sågverksnäringen med effektiva maskiner och system för bästa utnyttjande av råvaran. En av Söderhamn Erikssons viktigaste produkter är barkningsmaskinerna Cambio. Den komponent i barkningsmaskinen som till stor del avgör barkningsresultatet är barkverktyget. Barkverktyget finns i två utföranden, CamTool och CamTool Solid. Detta examensarbete behandlar endast det sistnämnda. Barkverktygets huvudsakliga uppgift är att avlägsna barken från veden utan att orsaka oacceptabla fiberskador, genom verktygets barkkant som ligger an mot stockens mantelyta med en lämplig kraft och skjuvar av barken. CamTool Solid ger bra barkresultat vid höga hastigheter och under svåra förhållanden som till exempel under savperioden vid barkning av gran, därför vill företaget fortsätta utveckla den verktygsvarianten.

    Projektets mål är optimera verktygets design och genom finita element metoden (FEM) analysera befintligt verktyg. Optimeringen görs genom omkonstruktion av verktygets ingående delar för att minimera spänningar och fördela de koncentrationer som uppstår vid olika lastfall. Ett mål är även att minska det tryck som krävs från rotorns luftbälgar att hålla verktygets barkkant mot stockens mantelyta.

    Syftet är att resultatet av detta arbete ska användas vid framtagning av en ny verktygsdesign i framtiden.

    All nödvändig indata för analysen har införskaffats genom studiebesök på sågverk, egna sökningar i företagets dokumentation, litteraturstudier och kommunikation med företagshandledarna samt två av företagets kunder.

    För att uppfylla examensarbetes mål och kravspecifikation har ett flertal faser genomförts, där konstruktionsfasen upptagit en stor del av tiden.

    Arbetet har resulterat i en ny verktygsdesign med lägre spänningskoncentrationer i det område där de flesta brott sker i nuvarande verktyg. Den nya konstruktionen ger enligt beräkningar även en skonsammare arbetssituation för barkmaskinen. Det krävs lägre tryck från luftbälgarna på grund av att verktyget väger mindre och har tyngdpunkten på ett mer fördelaktigt ställe. 

  • 349.
    Marklund, Daniel
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Analys av smörjmedel samt skapande av affärsplan2018Independent thesis Basic level (professional degree), 180 HE creditsStudent thesis
    Abstract [en]

    This bachelor thesis is written for Ålö AB in Umeå. A company that is a world leading manufacturer and developer of front loader and associated gear. Ålö wants to introduce a lubricant optimized for its products in its product portfolio. The lubricant refers to lubrication of the front loader pivot pins to reduce abrasion. Through increased understanding of the tribological factors that affect wear between bushing and pivot pins, analyzes and assumptions have been established. The report presents "Analysis of lubricants for Ålö's products and the creation of business case" for the purpose of conducting a technical analysis and giving a recommendation on which lubricant is suitable for the company's products. The specified goals was also to compile a business plan for possible product development after results and tests from work.Through abrasion tests in lab, different grease fats have been tested and analyzed for its impact on abrasion. The tests conducted relate to components used in production and with conditions that should resemble to actual conditions as closely as possible. The result showed that greases containing "Extreme Pressure" additives created the highest resistance to abrasion in the bushings where the most suitable lubricant also included "Anti-Wear" additives.The assessment is that, based on completed work, the potential for Ålö to launch a new after-sales product in the form of its own lubricating grease is great.

  • 350.
    Markus, Nyberg
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Utvecklingsmodell för hydrauliska svivlar2014Independent thesis Basic level (professional degree), 180 HE creditsStudent thesis
    Abstract [sv]

    Indexator Rototilt Systems erbjuder tiltrotatorer och systemlösningar för anläggningsmaskiner till sina kunder. Tiltrotatorerna kan oftast ses på grävmaskiner. Dessa är placerade mellan grävmaskinens grävarm och skopa. I tiltrotatorn sitter det en viktig komponent, kallad svivel. Sviveln gör att tiltrotatorn kan roteras obehindrat runt den egna axeln samtidigt som en kontinuerligt hydraulisk förbindelse upprättahålls mellan redskapet och hydraulsystemet. Svivelns främsta uppgift i tiltrotatorn är att försörja redskapsfästets låscylinder med hydraulolja samt i förekommande fall uttag för diverse hydrauliska redskap som är kopplade under tiltrotatorn.

    Detta arbete har utförts för att ta fram en modell som tar hänsyn till de parametrar som är viktiga för en svivel, för utvecklingsstöd vid framtagning av svivlar. Arbetet har utförts genom att samla in och sammanställa information om hur svivlarnas ingående komponenter fungerar rent teoretiskt. Detta till hjälp av erfarna personer inom Indexator AB och tätningsleverantörer. Utifrån modellerna har problemet med att inte ha någon standardiserad testmetod lösts. Med CAD-programmet Solidworks 2010 har en testrigg konstruerats för att kunna verifiera bland annat de tätningar som erhålls ur modellerna och svivlarnas egenskaper.

    Denna informationsinsamling resulterade i mycket information om svivlarna och deras egenskaper. Informationen spaltades upp i en generell modell och en tätningsmodell. En verklighetstrogen testmetod har även tagits fram för att kunna testa svivlar och deras egenskaper.

    Avslutningsvis diskuteras hur dessa utvecklingsunderlag fungerar, tankar och funderingar kring dessa och hur man ska ta vara på dem. Samt vad som kommer att krävas utav Indexator Rototilt Systems om de ska fortsätta att utveckla dessa modeller, testmetoden och testriggen.

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