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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.
    Aldaron, Mattias
    Karlstad University, Division for Engineering Sciences, Physics and Mathematics.
    Anaerob rening vid StoraEnso Skoghalls Bruk2009Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    An analysis of a specific application of anaerobic wastewater treatment at a pulp and board mill, Stora Enso Skoghall, was carried out. A literature study was done and effluent wastewater from CTMP pulp production was analyzed. The analysis consisted of a broad constituent analysis and an anaerobic treatment trial. Results from these test where used to calculate the treatment effectiveness and resulting energy potential at the mill.

    The literature study and constituent analysis showed that toxicity of the water to be treated, due to wood extractives and sulphur content, was of concern. Detoxification chemicals targeting these constituents where used in the anaerobic treatment trial. The trial consisted of a two chamber upflow reactor and aerobic post treatment. The result of the trial is that the water of concern has about 50% anaerobically degradable content. A full scale implementation of anaerobic wastewater treatment would result in a methane production of 3,76 to 7,76 GWh/yr. An application of anaerobic wastewater treatment will also result in electricity savings, in aerated pond, and increase the capacity margin on current sludge handling techniques.

  • 3.
    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.

  • 4. 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)
  • 5. 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)
  • 6. Andersson, Johan
    Energieffektiv torkning av blåmusslor2013Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
  • 7.
    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.

  • 8.
    Anukam, Anthony
    et al.
    Univ Ft Hare, South Africa.
    Meyer, Edson
    Univ Ft Hare, South Africa..
    Okoh, Omobola
    Univ Ft Hare, South Africa..
    Mamphweli, Sampson
    Univ Ft Hare, South Africa..
    Gasification characteristics of sugarcane bagasse2012In: PROCEEDINGS OF SAIP2012: THE 57TH ANNUAL CONFERENCE OF THE SOUTH AFRICAN INSTITUTE OF PHYSICS / [ed] J. J. VanRensburg, SOUTH AFRICAN INST PHYSICS , 2012, p. 464-471Conference paper (Refereed)
    Abstract [en]

    Sugarcane bagasse is a residue that results from the crushing of sugarcane in the sugar industry. Among the various agricultural crop residues, sugarcane bagasse is the most abundant lignocellulosic material in tropical and sub-tropical countries including South Africa. Bagasse is a renewable feedstock that can be used for power generation and manufacturing cellulosic ethanol In the sugarcane industries the bagasse is mainly burnt inefficiently in boilers that provide the heating for the industry. This project seeks to investigate the possibility of gasifying sugarcane bagasse as an efficient conversion technology. Proximate and ultimate analysis of sugarcane bagasse was conducted after which the results were used to conduct computer simulation of the mass and energy balance during gasification. This paper presents the proximate and ultimate analysis as well as the computer simulation results.

  • 9.
    Axelsson, Tobias
    Karlstad University.
    Stöd till energi- och klimatrådgivnin: Solceller samt energilagring med batterier och svänghjul2019Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    There are many paths towards a more sustainable future. One way is to be more efficient with the use of energy in our daily lives. Another way is to work towards an increasing share of renewable energy in the energy mixture. The municipalities in Sweden has since the late 70s employed experts to provide the citizens with energy advice. This study was performed to provide additional information and inspiration for the benefit of these energy and climate advisors. In this article the author has conducted a literature compilation/review regarding the subject solar PV since the advisors deal with a lot of questions regarding this subject. The literature compilation also includes the subject energy savings and energy storage. An internet-based survey and a focus group discussion are also included to improve understanding of how the respondents think and feel about solar PV and their energy habits. It turns out to be hard to find information that eases the purchase and installation of solar panels. The advisors should make use of the people who already uses solar power in the municipally. These people can provide information regarding dealers and contractors as well as provide exposure for solar PV itself. The results also show that a lot of people cannot afford to invest in solar power. Therefore, it is important not to neglect advice regarding energy savings. Especially since it turns out that most respondents care about their environmental footprint and are willing to make changes, but are not always sure of what to do. This seems to indicate that general energy saving tips that reaches a lot of people would be effective. As an energy and climate advisor you should also try to help people to help themselves get more and better feedback regarding their energy usage. To remind the inhabitance of the municipally that regular maintenance should be performed on the home itself as well as on certain devices seems to be an effective strategy. Lastly people would benefit from simple statistics to help them get a better understanding for which devices uses the most energy. This would give them a knowledge foundation that would ease future device investments. To add further to this paper, a life-cycle costing analysis for a typical Swedish home equipped with solar PV and energy storage is used to determine if a hybrid energy storage system (mechanical and chemical) can rival more traditional storage solutions. The most promising hybrid system is 30 kWh divided in a 3:17 ratio between flywheel and batteries. However, from an economic standpoint battery storage still outperformed the system with a small margin.

  • 10.
    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 %.

  • 11. Azcarate, Juan
    et al.
    Haas, Jan
    Karlstad University.
    Mörtberg, Ulla
    Balfors, Berit
    Dilemmas for green infrastructure and accessibility to ecosystem services in compact cities: Stockholm case studiesManuscript (preprint) (Other academic)
  • 12. Azcarate, Juan
    et al.
    Mörtberg, Ulla
    Haas, Jan
    Balfors, Berit
    Reaching compact green cities: A study of the provision of and pressure on cultural ecosystem services in Stockholm2015Other (Other academic)
  • 13. 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)
  • 14.
    Beckius, Tobias
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Fjärranalys av vegetationsförändring efter branden i Västmanland 2014: Vegetationsskador och återväxt efter en av de mest omfattande skogsbränderna i Sverige2018Independent thesis Basic level (university diploma), 180 HE creditsStudent thesis
  • 15.
    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.

  • 16.
    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
  • 17. 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)
  • 18.
    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.

  • 19.
    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.

  • 20.
    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.

  • 21.
    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)
  • 22.
    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)
  • 23.
    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)
  • 24.
    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)
  • 25.
    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.))
  • 26.
    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)
  • 27.
    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)
  • 28.
    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.

  • 29.
    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)
  • 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.
    Analysis of Superheated Steam Drying of Sawdust in Spouted Bed From Design Perspective2010Conference 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.
    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)
  • 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.
    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)
  • 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.
    Design Criteria, Key Parameters and Performance Results of a Fluidized Bed1999Licentiate thesis, monograph (Other academic)
  • 34.
    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)
  • 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.
    Technical presentation of a 200kW Superheated Steam Dryer1998Conference 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.
    Temperature Measurement as Indicators of the Quality of the Spouting Bed when Non-screened Sawdust is Dried2004Conference paper (Other (popular science, discussion, etc.))
  • 37.
    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)
  • 38.
    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)
  • 39.
    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)
  • 40.
    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)
  • 41.
    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)
  • 42.
    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.))
  • 43.
    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)
  • 44.
    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.

  • 45.
    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.

     

     

     

     

     

  • 46.
    Brici, Ecaterina
    et al.
    Karlstad University, Faculty of Technology and Science.
    Bergstedt, Ksenia
    Karlstad University, Faculty of Technology and Science.
    Kemisk modifiering av avloppsvatten för effektivare syresättning2006Independent thesis Basic level (professional degree), 15 points / 22,5 hpStudent thesis
    Abstract [en]

    Biological wastewater treatment processes consume large quantities energy in the aeration processes. The biological treatment is responsible for 80 % of the total consumption of electricity and thereby responsible for the biggest part of the energy costs. Today when the energy prices increase the energy efficiency of the wastewater treatment is a question of high priority.

    The aim with this study is to study oxygen transfer in to the wastewater from paper industry with the intention to make the biological wastewater treatment more energy efficient. Studies are limited to wastewater from Gruvöns mill.

    The study has been carried out in lab scale. The oxygenation has been conducted by using a surface aerator of the type airTURBO from Eden Aquatech. The company strives for innovative technology for aeration, oxygen involvement and mixing of waters. This company is interested to further develop technology for these processes and to make products more energy efficient.

    The study was carried out with clean water, industrial wastewater and modified industrial wastewater. The modification of industrial wastewater has been done by adding salts and by changing the pH.

    It is realized that chemical modification of wastewater by adding salts has important impact of the aeration. The addition of salts into wastewater results in a reduction of energy consumption for the aeration.

    Quantification of energy consumption for aeration has been carried out.

    The quantification shows a reduction of 17% for aeration of chemical modified wastewater with salts compared to unmodified wastewater.

    To modifying wastewater by raising pH-value to 11 shows no positive impact on the system, it requires more energy.

  • 47.
    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)
  • 48.
    Calles, Olle
    et al.
    Karlstad University, Faculty of Social and Life Sciences, Department of Biology.
    Karlsson, Simon
    Vezza, Paolo
    Politecnico di Torino.
    Comoglio, Claudio
    Politecnico di Torino.
    Tielman, Johan
    E.ON Vattenkraft.
    Success of a low-sloping rack for improving downstream passage of silver eels at a hydroelectric plant2013In: Freshwater Biology, ISSN 0046-5070, E-ISSN 1365-2427, Vol. 58, p. 2168-2179Article in journal (Refereed)
    Abstract [en]

    1. The European eel (Anguilla anguilla) is a critically endangered species, and one major threat is thesurvival of silver eels migrating downstream towards the sea from lake and river rearing areas. Duringthis migration, many eels are impinged and die on intake racks, or are injured or killed whenpassing through turbines.2. Intake racks at a hydroelectric plant were modified to avoid impingement and to collect eels withoutinjury; high mortality on both racks and in turbines was previously documented. Modificationsconsisted of reducing the rack gap width from 20 to 18 mm, decreasing the rack slope from 63 to 35degrees, increasing the rack surface area by 58% and installing six openings in the rack leading totraps.3. Downstream passage conditions for silver eels at the hydroelectric plant were significantlyimproved, reducing mortality from >70% at the old steep 20 mm racks to <10% at the modified18 mm rack collection facility. No tagged eels were impinged and killed on the racks, and 80%entered the collection facility.4. Survival can probably be improved even more, as the individuals that passed the facility mostlikely escaped through holes in the traps. Moreover, injured untagged eels were still encountered atthe modified racks, illustrating the need for rehabilitative measures to be implemented at all obstaclesbetween the main eel rearing areas and the sea.

  • 49.
    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)
  • 50.
    Carlson, Carl-Johan
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Johansson, Albin
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Simulering av ett värmeåtervinningbatteri med avseende på det svenska klimatet: Effekter av att reglera vätskeflöde efter utetemperatur2019Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    A growing population and need for energy in all forms is a fact, and with the justification for making a large amount of energy-related products more effective, the directive Eco-design was developed. Section 6 in the directive covers ventilation units, and specific requirements are set for different components within the unit. Eco-design oversees the entire European Union and the requirements that come with the directive create special problems, frost formation and freezing, for climates that, by comparison with the rest of Europe, are naturally colder. The purpose of this study is to investigate and evaluate whether the Ecodesign directive is suitable as a design method for the Swedish climate with regard to recycled energy, for liquid-coupled heat recovery systems. In collaboration with the company Aircoil, which specializes in various cooling systems, goal formulation was set, and the objective of this study was to focus on recovering as much energy as possible, by regulating the liquid flow in a liquid-coupled recycling system according to the current outdoor temperature and investigating what effects this flow control may have on temperature efficiency, total pressure drop and specific fan power (SFP). To reach the objective, the group got access to the software AC MasterSelection, which is the software used by Aircoil to make dimensioning calculations for liquid-coupled heat recovery systems. The software is certified and approved by Svensk Ventilation, which is the organization that represents the Swedish ventilation industry vis-à-vis authorities, government and the European Union - in terms of legislation and regulations. The software was used to obtain a large amount of data which was then compiled in Microsoft Excel to take flow variation profiles that generate higher recycling effect for the locations Malmö, Stockholm and Kiruna. The same profiles were then simulated in Matlab SimuLink to investigate the effect that a varying fluid flow has over the period of one year. Five different airflows for the heat recovery system were tested, 1 to 5 m3/s. According to the results, an estimated annual heat energy saving potential could be derived by utilizing a varying liquid flow for Malmö to be between 0.9 to 8.7%, for Stockholm between 1.1 to 4.4% and for Kiruna 3.3 to 15.8%. The results indicate that Eco-design and the regulations and requirements that come with the directive are not the most efficient design-wise from an energy recovery aspect for the Swedish climate, especially for the coldest locations, and that the electrical energy supplied to the system for the extra pump work is recovered in thermal energy to a much greater extent.

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