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  • 1.
    Adolfsson, Antonia
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Off grid boende: Dimensionering samt värdering av möjliga system för hantering av avlopp och energiförsörjning2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Bostadsbristen är ett ständigt faktum i Sverige idag och i takt med att boendepriserna ökar så ökar också intresset för att bygga sin egen bostad. Arkitektfirman Tengbom i Karlstad har startat upp ett projekt, Portable Empowerment, som bygger på visionen om att skapa en portabel bostad som ska kunna fungera som en lösning när ett plötsligt behov av bostäder uppstår. För att bostäderna ska kunna flyttas runt krävs det att lösningar för energi- och avloppssystem finns integrerade i bostaden och ska kunna flyttas med för att göra bostaden portabel. För att detta ska vara möjligt krävs det avlopps- och energisystem som är off grid.

    Off grid betyder att systemet inte är kopplat till kommunalt avlopp eller elnät. Det finns sedan länge sätt att lösa både avlopp och energiförsörjning off grid och några exempel där det tillämpas är husvagnen och den klassiska sommarstugan, men de är allt som oftast inte anpassade för bruk året runt. Målet med denna studie är att identifiera samt värdera avlopps- och energisystem som kan tillgodose behoven i en liten bostad som brukas året runt av två personer. Bostaden har sin utgångspunkt i de ritningar som tagits fram av Tengbom för deras projekt Portable Empowerment.

    För att identifiera system som kan tillgodose behoven i bostaden har modeller byggts upp och simuleringar skett där system lämpade för off grid inkluderats. Lösningarna har sedan jämförts med varandra med hjälp av värderingsmatriser där portabilitet, kostnad, miljö och användarvänlighet för varje system värderats.

    Resultatet av studien visar att det finns flera system för både energi och avlopp som kan tillgodose behoven i bostaden året om. Flera av systemen uppfyller kraven för en portabel bostad och det är med andra ord möjligt att uppfylla Tengboms vision om ett fullständigt portabelt boende. Jämfört med en ”vanlig” bostad som är ansluten till vatten- och elnät är dock off grid-lösningarna betydligt mer tidskrävande. Genom att installera ett eget system med lösningar för enbart den egna bostaden tar brukaren också på sig det fulla ansvaret, något som kan tänkas vara en belastning för vissa brukare och en frihet för andra.

    Ur ekonomisk synpunkt visar studien att på energisidan är det svårt att hitta ett off grid-system som är billigare än on grid-systemet där en luftvärmepump installerats. Däremot är anslutningen till ett kommunalt avlopp betydligt dyrare, mellan 100 000-150 000 kronor mer, än att anlägga till exempel en egen infiltrationsanläggning i anslutning till den egna bostaden.

    För att utveckla denna studie bör möjligheten att bygga off grid-byar undersökas. Genom att bygga upp ett samhälle om ett stort bostadsbehov skulle uppstå kan energi- och avloppsanläggningar delas. Anläggningarna har större kapacitet och genom att dela på dessa kan både ansvar och kostnad minskas.

  • 2.
    Almered Olsson, Gunilla
    et al.
    Norges Teknisk-Naturvitenskapelige Universitet, Trondheim, Norge.
    Bladh, GabrielKarlstad University, Division for Social Sciences.Månsson, BengtKarlstad University, Division for Engineering Sciences, Physics and Mathematics.Nyberg, LarsKarlstad University, Division for Environmental Sciences.
    Inte bara träd: hållbart mångbruk av skogslandskapet2004Collection (editor) (Refereed)
    Abstract [sv]

    Skogslandskapen - hur skall vi värdera dem? Ska de betraktas som rekreationsområden och kulturlandskap eller som arena för konflikter och dragkamp om olika resurser? Är skogsregionerna närande eller tärande? Vilka viktiga samband finns mellan skandinaviska och tropiska landskap?Detta är några av de teman som behandlas i denna spänannde bok om de många dimensionerna och resurserna som ryms i skogslandskapen. Boken ger nya och stimulerande aspekter på framtidsmöjligheterna för en hållbar utveckling för boreala skogslandskap. Den tar också upp det nödvändiga mångbruket av skogens resurser liksom den förändrade synen på människans roll i skogen. Och inte minst behandlas den ekologiska paradoxen att störningar behövs för att bevara skogens ekologiska mångfald.Boken är författad av samhällsvetare, miljöteknologer och ekologer inom den tvärvetenskapliga forskargruppen MiljöFocus vid Karlstads universitet.

  • 3. Anderson, L. G.
    et al.
    Björk, G.
    Holby, Ola
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Kattner, G.
    Koltermann, P. K.
    Jones, E. P.
    Lindegren, R.
    Rudels, B.
    Swift, J.
    Water masses and circulation in the Eurasien Basin: Results from the Oden 91 expedition1994In: Journal of Geophysical Research, Vol 99, No. C2: 3273-3283Article in journal (Refereed)
  • 4. Anderson, Leif G.
    et al.
    Holby, Ola
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Ohlson, Mats
    Lindegren, Roger
    The transport of anthropogenic carbon dioxid into the Weddell sea1991In: Journal of Geophysical Research, Vol 96, No. C9: 16,679-16,687Article in journal (Refereed)
  • 5.
    Andersson, Ronja
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Energimärkning torktumlare: Utredning av energimärkningen på torktumlare samt möjliga förbättringsåtgärder vid körningar med liten last2016Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    Different parts of the world use energy in different ways and for different purposes. In Sweden the subsector Laundry and Drying represented 6% of the country’s total electricity use in 2007. In the early 80s it was the big household appliances the dominated the increase of energy use in buildings whereas in recent years have been smaller home electronics and small kitchen appliances that have taken the lead. Due to that the need of energy is constantly increasing a more efficient energy use needs to occur. One step in the right direction was made when the publication of the Brundtland Commission and the term ”Sustainable Development” was born.

     

    In Europe the European Union has a goal that in 2020 the energy use shall be reduced by 20% compared to the forecasted use. To reach the goal they have among other things created the eco-design and the energy labelling directives. These directives are designed to improve the products environmental impact during their whole lifecycle and make it easier for the consumers to compare products from an energy perspective with the help of an energy label. For tumble dryers this energy label has been redesigned to more accurately reflect how much energy that is used when the appliances are running.

     

    In this thesis a comparison of the old and the new energy labelling has been made. Beyond this a consumer survey of how the tumble dryers actually are used in the Swedish households has been performed. Based on this, three suggestions of improvement measures when drying small loads have been investigated regarding to energy use, expenditure of time and final moisture content. A tumble dryer has been used to make the comparison between the two labels. Test runs with full and half loads has been run and the results have been used to calculate the energy efficiency classes for both labels. The three improvement measures were run at half load according to the new label, but with changes to external flow adjustment, internal flow adjustment and tennis ball in the drum separately.

     

    The old energy labelling resulted in energy efficiency class D, right on the border to C, and the new labelling in class C. Although the results seem to be equivalent they differ due to the different scales of the labels. According to the old label the dryer resulted at level 4 but according to the new it resulted at level 6 and is therefore less energy efficient when the runs with half load is taken into account.

     

    The consumer survey showed that the load sizes vary a lot from person to person but with an average load of 4,75 kg dry laundry.

     

    The investigation of the suggestions of improved measures showed a very small difference of the energy use, the expenditure of time was better but the textiles got a higher final moisture content compared to the results from the normal method of drying. These three suggestions of improvement are therefore considered to need further investigation or to be replaced.

  • 6.
    Ayedi, Omar
    Karlstad University, Faculty of Technology and Science, Avdelningen för energi-. miljö- och byggteknik.
    Energieffektiv torkning av kläder: en studie av torktumlare med varm- respektive kallvattenanslutning2011Independent thesis Basic level (professional degree), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    Tumble dryers and drying cabinets have to a large extent replaced the traditional way of drying clothes outdoors. They are faster, more convenient, require less space and can be operated regardless of weather conditions. This replacement has significantly increased residential energy consumption, due to the fact that tumbles dryers consume large amounts of electrical energy. In the USA 9 % of the households electric energy is consumed when drying clothes. Over 4 million tumble dryers are sold in Europe each year and 20 % of the residential electricity consumption in Sweden is used drying and washing clothes. Tumble dryers are also utilized in the industrial sector, but industrial dryers are not considered in this study.Increasing energy costs contributes to the public’s awareness and desire to cut their energy consumption. The aim of this study is to increase the energy efficiency and drastically reduce electric power use of tumble dryers.There are two main types of tumble dryers available on the market; the open cycle tumble dryer and the closed cycle tumble dryer. The open cycle tumble dryer is often attached to the ventilation system and thereby it evacuates its exhaust air. The closed cycle tumble dryer condenses the water from the air before it recirculates it.To increase the energy efficiency and reduce electric power use of tumble dryers, two separate studies were made. One on a water cooled closed cycle tumble dryer and one on a hot water heated open cycle tumble dryer. Both tumble dryers where rebuild and originated from the same tumble dryer. The tumble dryer that both studies originated from was a conventional air cooled closed cycle tumble dryer. The tumble dryer is made by Asko Cylinda AB.The results reveal that the water cooled closed cycle tumble dryer does not have greater energy efficiency than the conventional air cooled closed cycle tumble dryer. However the drying time was reduced by 37 %.The result also reveals that the hot water heated open cycle tumble dryer cuts the electric consumption by 93 % and improves the energy efficiency by 53 % compared to the conventional air cooled closed cycle tumble dryer. On the other hand the drying time increases by 9 %.

  • 7. Barker Jørgensen, Bo
    et al.
    Nørh Glud, Ronnie
    Holby, Ola
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Oxygen distribution and bioirrigation in Artic fjord sediments (Svalbard, Barents Sea)2005In: Mar. Ecol. Prog. Ser. 292:85-95Article in journal (Refereed)
  • 8.
    Beiron, Jens
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Drifteffektivisering av installationssystem i fastigheter: Förstudie1997Report (Other academic)
    Abstract [sv]

    It is possible to improve the energy efficiency of HVAC (Heating, Ventilation and Air Conditioning) systems with the help of building energy management systems. Through deeper knowledge of the dynamics of the system the staff is able to choose a more effective management strategy. Statistics from the energy management system will inform about the system behaviour. It is possible to collect and present the statistics needed thanks to the fast development of information technology and the introduction of computer based building management system.

    A research project will investigate methods for creation of individual models of HVAC systems based on measurement data. Each system will then be simulated for different operating conditions. As a result of the simulation an optimal management strategy can be chosen. Different performance ratios will be used to evaluate the level of energy efficiency. The performance ratios should be defined so that they can be calculated from measurement data.

    This pilot study presents the background, purpose and method of the project. Some examples will be given to illustrate ineffective use due to a badly chosen management strategy.



    Sammanfattning



    Installationssystem kan drifteffektiviseras genom utnyttjande av driftstatistik. Genom att lära känna sin anläggning kan driftteknikern lättare fatta beslut om optimalaste driftstrategi. Med en förbättrad driftstatistik får teknikern många viktiga upplysningar om anläggningens dynamik och beteende. Som konsekvens av den snabba utvecklingen inom informationsteknologin samt införandet av datorstödda styr- och övervakningssystem finns möjligheter till omfattande datainsamling.

    Ett forskningsprojektet skall undersöka metoder att utifrån insamlad driftstatistik skapa individuella modeller av installationssystem. Modellen skall för varje enskild anläggning senare kunna utnyttjas för att simulera olika driftfall och därmed kunna optimera valet av driftstrategi. Olika nyckeltal kommer att användas för att utvärdera och följa upp effektiviseringsarbetet. Nyckeltalen skall definieras så att de kan beräknas utifrån insamlad driftstatistik.

    Denna förstudie beskriver bakgrund, syfte och metodval för projektet. Ett par exempel från utförda mätningar visar på typiska fall av energiineffektivitet som konsekvens av felaktigt vald driftstrategi.

  • 9.
    Bengtsson, Fredrik
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences.
    Kartläggning av energiförluster: gällande klimatskal och ventilation för Stora Enso Timbers Pelletsfabrik i Grums2013Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
  • 10. Bengtsson, J.
    et al.
    Wikström, Fredrik
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Effects of whole-tree harvesting on the amount of soil carbon: model results1993In: New Zealand Journal of Forest Science 23: 380-389, 1993Article in journal (Refereed)
  • 11.
    Bengtsson, Peder
    et al.
    ASKO Appliances AB, Sockerbruksgatan 3, SE-53140 Lidkoping, Sweden.
    Berghel, Jonas
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences.
    Study of using a capillary tube in a heat pump dishwasher with transient heating2016In: International journal of refrigeration, ISSN 0140-7007, E-ISSN 1879-2081, Vol. 67, p. 1-9Article in journal (Refereed)
    Abstract [en]

    For competitive purposes, manufacturers of household appliances need to produce appliances that use less electricity. One way of doing this for a dishwasher is to add a heat pump system. Previous studies using R134a as refrigerant have shown that the addition of a heat pump can reduce total electricity consumption by about 24%. This paper reports on the use of a capillary tube in a heat pump dishwasher during the transient heating period. Working with an available compressor, the mass of R600a and the length of a 0.9 mm capillary tube were varied in order to find the configuration with the lowest electricity consumption. Three methods of calculating the length of the capillary tube were used to determine five lengths for evaluation. The results show that using a single capillary tube throughout the transient heating period yields similar electricity consumption to a variable expansion device which occurred by switching the capillary tube between two or three different lengths during the heating period.

  • 12.
    Bengtsson, Peder
    et al.
    ASKO Appliances AB, Lidköping, Sweden.
    Berghel, Jonas
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences.
    Renström, Roger
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences.
    Performance Study of a Closed-Type Heat Pump Tumble Dryer Using A Simulation Model and an Experimental Set-Up2014In: Drying Technology, ISSN 0737-3937, E-ISSN 1532-2300, Vol. 32, no 8, p. 891-901Article in journal (Refereed)
    Abstract [en]

    In the interests of competitiveness, manufactures of tumble dryers are seeking to reduce both their electricity use and the drying time. This study examines how the cylinder volume of the compressor and the total heat transfer of the condenser influence the drying time and electricity use in a heat pump tumble dryer. A transient simulation model was developed and compared to an experimental set-up with good similarity. The simulations show that increasing the cylinder volume of the compressor by 50% decreases the drying time by 14% without using more electricity.

  • 13.
    Berghel, Jonas
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Improved Fluidized Bed Drying Technology for Wood Fuels2004Doctoral thesis, monograph (Other academic)
    Abstract [en]

    In this thesis, I discuss experiences from designing, building and evaluating two research plants, which use circulating, atmospheric pressure superheated steam as drying medium for drying sawdust in a fluidized bed.



    The increased use of pellets has created a demand for new drying equipment at the Swedish pellet plants. The underlying cause is that almost all of the available dried material, such as wood shavings, is already in use. The remaining biofuel materials, primarily wet sawdust need drying before entering the pellet process.



    The primary demands on the drying process were an uncomplicated design and efficient energy use. A key aim was to improve the drying technique used in the Swedish wood fuel system with specially interest on the control system.



    Sawdust has been tested in both a full scale and a laboratory scale dryers. The tests were done in a spouted bed. The product of the steam mass flow and the enthalpy difference limits the drying capacity. The tests showed that it is possible to use the temperature after the dryer as a control parameter for the outgoing moisture content in a spouted bed dryer. The results and conclusions can be very useful when designing a similar full scale drying system.

  • 14.
    Berghel, Jonas
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Increased Capacity in an Existing Spouted Dryer Using a Heating Tube2008Conference paper (Refereed)
  • 15.
    Berghel, Jonas
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    The Effect of Using a Heating Tube in an Existing Spouted Bed Superheated Steam Dryer2011In: Drying Technology, ISSN 0737-3937, E-ISSN 1532-2300, Vol. 29, no 2, p. 183-188Article in journal (Refereed)
  • 16.
    Berghel, Jonas
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    The gas to Particle Heat Transfer and Hydrodynamics in Spouted Bed Drying of Sawdust2005In: Drying Tecnology, Vol. Vol.23(5)Article in journal (Refereed)
  • 17.
    Berghel, Jonas
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    The Heat Transfer Coefficients Dependency on Spouted Bed Heights, Material Flow and Mean Residence Time2002Conference paper (Refereed)
  • 18.
    Berghel, Jonas
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Beiron, Jens
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Olin, Malin
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Renström, Roger
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Individuell Examination i en Projektbaserad Kurs2000Conference paper (Other (popular science, discussion, etc.))
  • 19.
    Berghel, Jonas
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Brunzell, L.
    Bengtsson, P.
    Performance Analysis of a Tumble Dryer2004Conference paper (Refereed)
  • 20.
    Berghel, Jonas
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Eriksson, Bengt
    Biobränsletorkning: - torkning av rörflen1996Report (Other academic)
  • 21.
    Berghel, Jonas
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences.
    Frodeson, Stefan
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Granström, Karin
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Renström, Roger
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Ståhl, Magnus
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Nordgren, Daniel
    Innventia, Box 5604, SE-11486 Stockholm, Sweden.
    Tomani, Per
    Innventia, Box 5604, SE-11486 Stockholm, Sweden.
    The effects of kraft lignin additives on wood fuel pellet quality, energy use and shelf life2013In: Fuel processing technology, ISSN 0378-3820, E-ISSN 1873-7188, Vol. 112, no 0, p. 64-69Article in journal (Refereed)
    Abstract [en]

    In 2011, the total consumption of pellets in Sweden amounted to 1.9 million tons, which represents an energy value of 9 TWh. The pellets are used in large-scale as well as in small-scale applications, and increased demands on pellet quality are likely to force pellet producers to improve on the pellet properties. One way of increasing pellet quality is by using additives. The purpose of this article, therefore, is to examine kraft lignin as an additive. Pelletswere produced in a small industrial pellet press located at KarlstadUniversity, Karlstad, Sweden, and 1–4% of kraft lignin was added to the pellets. The results indicate that the addition of an increased amount of kraft lignin to the pellets increases their mechanical durability and their lengths. The results also indicate that dry kraft lignin yields pellets with higher durability as compared to wet kraft lignin. The energy demand was unaffected by the increased use of kraft lignin. The general results presented in this paper are useful for producers of lignin, pellet producers and end-users of pellets, who are interested in developing their products and/or improving the production processes.

  • 22.
    Berghel, Jonas
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Nilsson, Lars
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Renström, Roger
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Particle mixing and residence time when drying sawdust in a continuous spouted bed2008In: Chemical Engineering and Processing, ISSN 0255-2701, E-ISSN 1873-3204, Vol. 47, no 8, p. 1252-1257Article in journal (Refereed)
  • 23.
    Berghel, Jonas
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Renström, Roger
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Analysis of Superheated Steam Drying of Sawdust in Spouted Bed From Design Perspective2010Conference paper (Refereed)
  • 24.
    Berghel, Jonas
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Renström, Roger
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Basic design criteria and corresponding results performance of a pilot-scale fluidized superheated atmospheric condition steam dryer2002In: Biomass and Bioenergy, Vol. Vol.23(2), p. 103-112Article in journal (Refereed)
  • 25.
    Berghel, Jonas
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Renström, Roger
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Controllability of Product Moisture Content when Non-Screened Sawdust is Dried in a Spouted Bed2004In: Drying Tecnology, Vol. Vol.22(3)Article in journal (Refereed)
  • 26.
    Berghel, Jonas
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Renström, Roger
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Design Criteria, Key Parameters and Performance Results of a Fluidized Bed1999Licentiate thesis, monograph (Other academic)
  • 27.
    Berghel, Jonas
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences.
    Renström, Roger
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Shi yong dao liu guan dui lian xu pen dong gan zao qi de ying xiang: (Effects of using draft tubes in a continued spouted bed)2013In: Drying Technology & Equipment, ISSN 1727-3080, Vol. 1727-3080, no 3, p. 9-18Article in journal (Refereed)
  • 28.
    Berghel, Jonas
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Renström, Roger
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Technical presentation of a 200kW Superheated Steam Dryer1998Conference paper (Other (popular science, discussion, etc.))
  • 29.
    Berghel, Jonas
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Renström, Roger
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Temperature Measurement as Indicators of the Quality of the Spouting Bed when Non-screened Sawdust is Dried2004Conference paper (Other (popular science, discussion, etc.))
  • 30.
    Berghel, Jonas
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Renström, Roger
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    The Use of Temperature after The Spouting Bed as a Control Parameter of Outgoing Moisture Content When Sawdust is Dried2002Conference paper (Refereed)
  • 31.
    Berghel, Jonas
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Renström, Roger
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Usefulness and significance of energy and mass balances of a superheated steam dryer2001In: Drying Tecnology, Vol. Vol.19(6), p. 1083-1098Article in journal (Refereed)
  • 32.
    Berghel, Jonas
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Renström, Roger
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Kullendorff,, Anders
    Biobränslen: - utvärdering av fluidiserad ångtorkprojektet fluidtork1997Report (Other academic)
  • 33.
    Berghel, Jonas
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Renström, Roger
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Kullendorff, Anders
    Biobränsletorkning - en lägesrapport projektet Fluidtork1996Report (Other academic)
  • 34.
    Berghel, Jonas
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Renström, Roger
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Kullendorff,, Anders
    Biobränsletorkning: - en lägesrapport projektet fluidtork1996Report (Other academic)
  • 35.
    Berghel, Jonas
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Renström, Roger
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Stawreberg, Lena
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Integrating tumble dryer in the heating systems in block of flats2009Conference paper (Other (popular science, discussion, etc.))
  • 36.
    Berghel, Jonas
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Renström, Roger
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Stawreberg, Lena
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Utveckling av energieffektivare kondenstumlare för en- och flerfamiljshus2008Report (Other academic)
  • 37.
    Beri, George
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Prediktering och styrning av värmesystem i flerbostadshus: Utvärdering av egenutformad MPC-regulator2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In 2012, 30% of the total energy consumption was used by apartments and buildings. Heating of apartment buildings and commercial buildings represents 60% (79.5 TWh) of that energy consumption. There is thus great potential for reducing energy use in the residential sector. Part of the overall efficiency work is to review the control of heating systems. Today's control often involves simple on / off systems where an upper and lower limit controls when to start and stop a process. This form of control is therefore best suited to systems where the change of state occurs quickly. When it comes to homes with high mass however, it takes time before a change takes effect. In some cases, it can take up to 24h before a change is noticed for buildings with high thermal inertia. An alternative to the traditional temperature based control is the so-called MPC controller which stands for Model Predictive Control. MPC is a control method that can take into account the thermal inertia and the dynamics of buildings. MPC controller also controls the system proactive rather than retroactive, which is the technique most of current control methods use. One problem with the MPC controller thou is that it requires large computational resources and technical knowledge of the building where it will be implemented. The aim of the thesis was to design a simple MPC controller and evaluate its performance. This was done by constructing a bench test model that can evaluate the function of the MPC controller. In addition to constructing a simple MPC-controller, a study has been done on how the current control method can be more energy efficient without having to invest in new equipment. The goal was to reduce the variations in indoor temperature and improve operating economics of the building. The study was conducted at Karlstad Bostads Aktiebolag (KBAB) that owns and manages 7,300 apartments in Karlstad. The Bench test model calculated indoor temperature using the weather conditions as solar radiation, cloud cover, outside temperature and wind speed. The study presents a number of simple MPC controllers that can be used to minimize indoor temperature variations and improving operating economy. It is estimated, however, that the MPC controller that only takes into account the outside temperature in its prediction is the most appropriate. The MPC controller has the potential to reduce heating requirements by 3.12 MWh (-4%) and reduce indoor temperature variations with 96%. The mean annual temperature would be 21.1 ° C and the energy consumption 113 kWh/m2 for the building. The study also presents an alternative to current control method that does not require any additional resources or investments. It has the potential to reduce heating requirements by 8.3 MWh (10%) and reduce indoor temperature variations by 65%. The energy consumption would then be 106 kWh/m2.

  • 38.
    Bock, Patricia
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Energianalys vid sprängmedelsfabriken Orica Sweden AB: Möjligheter att minska energibehovet i byggnad 2100 och 2100A2012Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    Reducing the energy of a building is a way to reach the parliament aims to reduce energy use by 20% by 2020. This will also result in reduced emissions of greenhouse gases which is part of sustainable development. Orica Sweden AB in Gyttorp manufactures explosives and igniters to the civilian market. A survey on the energy usage performed by Sweco concludes that energy savings can be made, especially in the buildings located on the eastern parts of Oricas industrial area. This is where the buildings 2100, with the extension 2100A are situated.

    This study focuses on opportunities to reduce energy demand in buildings 2100 and 2100A at Orica Sweden AB in Gyttorp. The energy demand today is analyzed, and several proposed measures to reduce energy use are evaluated. The following measures are investigated:

    • A reduction in the supply air temperature in ventilation
    • Adapting runtime for ventilation
    • Connection of existing equipment for heat recovery
    • Investment of new air handling units with higher heat recovery efficiency of the recycling system and evaporative cooling where possible
    • A technical solution for heat recovery from the condenser of a chiller
    • A technical solution for heat recovery from two air compressors

    Detailed measurements and calculations underlying the suggestions result. Measurements of air flow in ducts were performed by hot wire thermometer. The volume flow of the condenser where measured by flowmeters and measurement of current was logged by an ampermeter. The total energy demand for heating, humidification, cooling and dehumidification of ventilation air for all handling units is calculated 2118 MWh / year. The measures introduced can reduce the energy demand to 1057 MWh /year, which represents 50% of the estimated energy needs today.

     

     

     

     

     

  • 39.
    Brunzell, Lena
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Reducing the Energy Use for Textiles in a Closed Cycle Tumble Dryer2006Manuscript (preprint) (Other academic)
  • 40.
    Calles, Olle
    et al.
    Karlstad University, Faculty of Social and Life Sciences, Department of Biology.
    Österling, Martin
    Karlstad University, Faculty of Social and Life Sciences, Department of Biology.
    Gustafsson, Pär
    Karlstad University, Faculty of Social and Life Sciences, Department of Biology.
    Nyberg, Lars
    Karlstad University, Faculty of Social and Life Sciences, Centre for Climate and Safety.
    Forsberg, Jan
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Hebrand, M
    Olsson, M
    Renöfält, B
    Karlsson, H
    Johansson, M
    Biokanalers egenskaper och möjligheter2009Report (Other academic)
  • 41.
    Dahlén, Pär
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences.
    Underlag till en standard för teknisk isolering2014Independent thesis Basic level (professional degree), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [sv]

    Vid upphandling inom offentlig sektor eller större företag kan användandet av standarder vara ett viktigt redskap för att säkerställa att en produkt eller tjänst uppfyller de krav som verksamheten ställer när det gäller exempelvis kvalitet, kostnader och effekter på miljön. Stigande priser på energi och en ökad insikt om samhällets negativa inverkan på miljön gör att energieffektiviseringar blivit ett viktigt inslag i de allra flesta verksamheter och här kan användandet av standarder spela en viktig roll.Syftet med det här examensarbetet är att utreda hur isolering av varma och kalla rör samt ventilationskanaler kan dimensioneras optimalt så att energiförluster från dessa minimeras. Hur olika faktorer och förutsättningar påverkar vad som är en optimerad isolering måste därmed även att utredas så att konsekvenser av olika val kan kartläggas.Målet är att ta fram ett underlag som kan fungera som hjälpmedel då en ny standard för dimensionering av teknisk isolering skall tas fram av Landstingsfastigheter i Värmland. Underlaget kommer att utgöras av en beräkningsmodell som skall kunna ge tillförlitliga uppgifter om hur olika yttre faktorer samt val av isoleringsmaterial dels kan påverka vilken den nödvändiga isoleringstjockleken blir och dels visa de ekonomiska konsekvenserna. En livscykelkostnadsanalys gjordes därför för olika dimensioneringsalternativ.Arbetet resulterade i en beräkningsmodell som kan användas för att beräkna olika isoleringstjocklekar för olika typer av fall. Grundprincipen för beräkningsmodellen är att det skall gå att undersöka vilken isoleringstjocklek som behövs då en bestämd energiförlust eller temperatur på isoleringens yta skall uppnås. Isoleringen till varma rör dimensioneras för en reducerad energiförlust medan isolering till kalla rör och ventilationskanaler dimensioneras för en önskad temperatur på isoleringens yta. Livscykelkostnadsanalysen visade att dimensioneringen bör göras för en så liten energiförlust som möjligt.Ett antal olika fall undersöktes med hjälp av beräkningsmodellen. Beräkningarna visade att val av material och ytskikt kan få en betydande inverkan på hur isoleringen måste dimensioneras för att de mål som sätts för den skall uppnås. Att välja en produkt med något lägre värmeledningsförmåga kunde exempelvis minska isoleringsbehovet med nästan 20 % på större rördimensioner. Huruvida isoleringen prioriteras i ett tidigt skede av en projektering eller ej kan också få stora konsekvenser för hur stor ett systems energiförlust blir eftersom en avgörande faktor ofta är om isoleringen får plats i utrymmet. Dimensionering av isolering för kalla system som syftar till att motverka kondensutfällning på isoleringens yta visade sig innebära förhållandevis stora energiförluster. Detta tyder på att isolering av kalla installationer istället borde dimensioneras mot energiförluster.

  • 42.
    De Magistris, Federica
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Chemical Engineering. Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Germgård, Ulf
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences.
    Beghello, Luciano
    Karlstad University, Faculty of Technology and Science, Department of Chemical Engineering. Karlstad University, Faculty of Technology and Science, Paper Surface Centre.
    Järnström, Lars
    Karlstad University, Faculty of Technology and Science, Department of Chemical Engineering. Karlstad University, Faculty of Technology and Science, Paper Surface Centre. Karlstad University, Faculty of Technology and Science, Materials Science.
    Lestelius, Magnus
    Karlstad University, Faculty of Technology and Science, Department of Chemical Engineering. Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences, Paper Surface Centre. Karlstad University, Faculty of Technology and Science, Materials Science.
    Effect of calendering on the compressibility of papers made with fibre of various properties2010Conference paper (Other (popular science, discussion, etc.))
    Abstract [en]

    The surface and bulk compressibility of a given paper influence its calendering, coating, surface sizing and printing properties. This study aims at a deeper knowledge of which variable affects the compressibility of paper sheets and how calendering effect different sheet properties. The pulps were characterized by their chemical compositions and physical properties. The bulk compressibility, the surface compressibility and the thickness were evaluated both before and after calendering

  • 43. De Magistris, Federica
    et al.
    Germgård, Ulf
    Karlstad University, Faculty of Technology and Science, Department of Chemical Engineering.
    Svedinger-Andersson, Maria
    Pulping to different xylan contents and its impact on the pulp quality2008Conference paper (Other (popular science, discussion, etc.))
  • 44.
    Denker, Richard
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics.
    Dimensioning and control for heat pump systems using a combination of vertical and horizontal ground-coupled heat exchangers2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    A model has been developed which simulates a system consisting of a horizontal and vertical ground-coupled heat exchanger connected in parallel to the same heat pump. The model was used in computer simulations to investigate how the annual minimum and mean fluid temperatures at the heat pump varied as several parameters of the combined system were changed. A comparison was also made between different control settings for fluid flow rate distribution between the two exchangers. For the case when the flow rate distribution was not controlled, the effect of viscosity differences between a colder and warmer exchanger was investigated. The short term effects of letting the vertical heat source rest during the warm summer months was then tested. Lastly, the results of the model was compared to a simple 'rule of thumb' that have been used in the industry for this kind of combined system. The results show that using a combined system might not always result in increased performance, if the previously existing exchanger is a vertical ground-coupled heat exchanger. The effects of viscosity differences on the flow distribution seems to be negligible, especially for high net flows. Controlling the fluid flow rates seems to only be worth the effort if the the pipe lengths of the two combined exchangers differ heavily. Letting the vertical ground-coupled heat exchanger rest during summer was shown to in some cases yield an increased short-term performance in addition to the already known positive long term effects. The rule of thumb was shown to recommend smaller dimensions for combination systems than the more realistic analytical model.

  • 45.
    Edin, Oscar
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Modellering och simuleringar för att analysera förbättringsmöjligheter av värmeöverföring från kondensor i en diskmaskin med värmepump2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Today, the world is faced with major challenges when dealing with environmental problems and their consequences. The most critical issue on a global scale has been identified as greenhouse gas (GHG) emissions that contribute to the enhanced greenhouse effect through elevated average temperatures around the globe. A large part of GHG emissions is linked to fossil-based electricity production. Within the EU, almost half of all electricity is produced by combustion of fossil fuels such as natural gas and coal. It is therefore of great importance that this type of production is phased out, but also that the consumption of electricity by consumers is reduced.

    In the domestic appliances industry, continuous development towards more energy-efficient solutions has been happening in response to climate change threats and stiff competition in the global marketplace. In the field of dishwasher development, ASKO Appliances AB investigates the possibilities of reducing electricity consumption by their machines. A suggested solution is to supplement the machines with a heat pump for heating the wash water instead of only a conventional electrical element. Studies have shown that this method of water heating can reduce electricity consumption by up to 24%.

    The solution means that a coil-shaped condenser is placed in the bottom-well of the machine to deliver heat to the bypassed water. In this work, focus is placed on the condenser unit in the heat pump system and its geometry, with the purpose of evaluating the possibilities for improved heat transfer to the water by simulating different geometries on the condenser. In this work, the COMSOL Multiphysics software is used to create a 3D model over the system and simulate different geometries and conditions. The model is validated by comparison with experimental data. Flow simulations evaluates the emitted power of the component when changing the diameter of the condenser, pipe diameter, and increased distance between the turns (pitch) and number of turns in the coil.

    Results presented in this study show that it is possible to improve the condenser-performance in comparison to the original design, if the pipe diameter is increased. One alternative means that the number of turns on the condenser is maintained according to the original design and the diameter is increased by 3 mm, which generates a 22 % increase of heat transfer rate. A second option is to remove one turn on the condenser and increase the diameter by 4.5 mm, resulting in a 24% increased heat transfer rate.

    The analysis of increasing the distance between the turns shows that the condenser’s heat transfer decreases as the distances increase. By analyzing the flow distribution around the condenser, it has been found that this effect occurs due to the nature of the outlet, which causes large areas with low velocities around the condenser. Discussion has been made on how this can be prevented and there is good potential to conduct further studies in the matter.

  • 46. Eriksson, Karl-Erik
    et al.
    Lindgren, Kristian
    Månsson, Bengt
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Structure, Context, Complexity, Organization: Physical Aspects of Information and Value1987Book (Refereed)
    Abstract [en]

    Our universe, as a closed system, obeys the second law of thermodynamics, i.e., its entropy, its disorder, increases. Still, in the midst of this we are wit- nessing an opposite process, in which order is emerging. The picture we have is that the universe has evolved from a totally unstructured state of matter and radiation to a highly structured state. On the surface of our Earth, some of this structure takes highly sophisticated forms in living organisms and their complex interaction and in the social as well as material organization of human societies. What makes all this possible, thermodynamically, is, of course, the fact that over the universe as a whole the entropy increase is large enough to compensate for local creation of order. The aim of this book is to sketch a perspective and to present a set of concepts, which can be useful in order to describe and understand processes in which structure emerges. The word describe gives a hint that information is an important concept. Information is a general concept, which can be applied not only to the description of a system but also to the described system as well. We shall use the concept as it was introduced by Shannon in information theory. Then one may ask for the origin of structure (measured in terms of information) in the universe; one may ask how it is being transformed and how creative and destructive processesstructure formation and entropy productionare related to each other. Many ideas and concepts have been developed which make information a very flexible and versatile theoretical tool. In this book we deal with concepts and methods belonging to the lower levels in a hierarchy of information theory concepts. These concepts take into account some necessary aspects of life, including human life, but they are far from sufficient to capture the full concept of life. The ideas used in this book have been collected from many fields, but we have no ambition to review the fields from where we have picked our material, and our collection of references is not systematic. We have mixed old material with new material, elementary discussions with more advanced, in order to make the book as a whole more self-contained. Since the book has not been written for a well-defined category of readers, we hope that in this way it will be more useful. Our aim has been to sketch a perspective on the great process of structure formation going on all the time around us, and to convey some of the most basic theoretical ideas which are useful for work in this perspective.

  • 47. Eriksson, K.-E.
    et al.
    Islam, S.
    Karlsson, S.
    Månsson, Bengt
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Optimal Development of an Economy with a Bounded Inflow of one Essential Resource Input1984In: Resources and Energy, 6, 235-258Article in journal (Refereed)
  • 48. Eriksson, K.-E.
    et al.
    Månsson, Bengt
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Exergi (Exergy)1991In: Nationalencyklopedien, Vol. 6,Article in journal (Other academic)
  • 49. Eriksson, K.-E.
    et al.
    Månsson, Bengt
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Termodynamik1992In: Miljö från A till Ö, Höganäs: Bra Böckers Förlag , 1992Chapter in book (Other academic)
  • 50.
    Eriksson, Linnea
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    The impact of calculation methods on the gap between predicted and actual energy performance of buildings: Using a thermal simulation model of a building2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The building sector is responsible for almost a quarter of the total carbon dioxide emissions. The urgency to reduce the emissions is reflected in the stricter guidelines which have been set all over the world. To reduce the building sector’s emissions the energy consumption need to be reduced, which can be done in two ways: building new energy efficient buildings or retrofitting of current buildings. Due to the life expectancy of current building stock the largest savings before 2030 will be made through retrofits. For this reliable computational tools are required, and currently there is a gap between the predicted and actual performance of retrofitted buildings. This thesis is going to look into how the computational method is contributing to the performance gap. A building at the RMIT campus in Melbourne, Australia, which is going to be retrofitted through retrofits designed by Siemens, is used. A thermal simulation model of the building was built, and tuned to reflect the pre-retrofit building, and compared against the measured energy performance of the building. The retrofits were then implemented in the simulation model and the gap in the predictions between the simpler computational method used by Siemens in designing the retrofits, and the extensive simulation model was compared. The gap between the computational methods were analysed in order to see how Siemens calculation method contribute to the performance gap. The conclusions which have been drawn are that the simulation model is reflecting the energy use of the building well considering the access of data available during the study. Especially the electricity use is reflected well both in the total annual use, approximately 4 % gap to measured value, and the monthly variation over the year. The total natural gas use is under predicting the annual use, approximately 40 % gap to the measured value, but shows a good correlation to the monthly variation. The electricity use is relatively stable in the simulation model, where the natural gas was sensitive for direct changes to the heating system. The input parameters which have the largest impact in the electricity use are internal gain profiles and the electrical internal gains energy use. Siemens calculation method are contributing to the performance gap through the lack of interaction between the different retrofits, the light retrofit have a noticeable impact on the heating and cooling system of the building. To only use one single period in the regression models can also easily lead to incorrect predictions. The strength of the simulation model is its ability to see the retrofits influence on each other and the possibility for scenario analysis.

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