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  • 51.
    Bäckström, Johan
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Optimerad värmeleverans från Hedensbyverket2011Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Skellefteå Kraft AB has currently problems with the central district heating network in Skellefteå concerning low pressure difference between the delivering, hot, and returning, cold, pipeline. Cause of this low so called differential pressure, the customers heating requirements in these areas is not fulfilled in a satisfying way. The intent of this project has been, with the use of simulations, to clarify if a solution can be possible by connecting an increasing pressure pump to the district heating network. A pumpstation will be placed in such a way that it improves the ability to control the pressurization of the district heating pipelines and also makes it possible to distribute more heat from Hedensbyn, where the main production of district heat in Skellefteå takes place. Determine if the increase in pressure may result in an increase in electricity production, by lowering the temperature of the outgoing water.

    The result is this project shows that placing a pumpstation at Moröskolan is the most advantageous position. An increasing pressure pump at Moröskolan in Skellefteå would create more favourable conditions in order to control the pressure in the district heating network and maintain a minimum differential pressure. The simulations made shows that with a pumpstation, it is possible to distribute up to 20 MW more heat from the Hedensbyn. A pressure increase in the district heating network would currently allow for an increase in electricity distribution of approximately 4-5,5 GWh/year. Based on these results, the project concerning the pump is planned to begin during spring 2011.

  • 52.
    Bäckström, Lars
    et al.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Guilloux, Tom
    Fusing Kite and Tether into one Unit2017In: Airborne Wind Energy Conference 2017: Book of Abstracts / [ed] Moritz Diehl, Rachel Leuthold, Roland Schmehl, Freiburg, Germany: Albert-Ludwigs-Universität Freiburg; Delft University of Technology , 2017, p. 40-41Conference paper (Refereed)
  • 53.
    Bäfver, Linda
    et al.
    Pöyry SwedPower.
    Renström, Caroline
    Pöyry SwedPower.
    Fahlström, Johan
    Ragn-Sells.
    Enfält, Patrik
    EasyMining Sweden.
    Skoglund, Nils
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Holmén, Erik
    ENA Energi.
    Slambränsleblandningar: Förbränning och fosforutvinning2013Report (Other academic)
    Abstract [en]

    For sustainable phosphorus recycling, the phosphorus in sewage sludge needs to be recovered, as it is a major phosphorus-source. However, all sludge is not suitable for direct recycling on agricultural land, e.g. when the content of heavy metals is too high. To achieve an increased recycling of phosphorus from sewage sludge there is a need of research and development of alternative methods to return the phosphorus from sewage sludge to agricultural land.

    The aim of the project is to show that sewage sludge can be co-combusted with demolition wood in existing boilers, and that the ash can be processed for extraction of phosphorus, together with valuable by-products from the process. Further effects of the project will be the development of new knowledge about combustion with a high sludge to demolition wood ratio in a grate boiler (up to 45 % sludge with respect to wet mixture), which has not been studied in full-scale combustion earlier. The project's goal is to demonstrate mixing and combustion of fuel mixtures of sludge and demolition wood, and subsequent extraction of phosphorus from ash. The target groups for this work are energy companies, suppliers of grate boilers, municipalities, wastewater treatment plants and authorities.

    The project involves the mixing of sewage sludge and demolition wood, combustion-tests of the fuel mixtures and laboratory experiments on bottom ash and fly ash for phosphorus extraction using EasyMining Sweden's method for phosphorus extraction from ash. Extensive analyses have been carried out on fuel, bottom ash and fly ash, as well as thermodynamic equilibrium calculations on the formed compounds containing phosphorus.

    The experience of preparing sludge fuel mixtures shows that the mixtures should be prepared in the near future to when they are to be combusted, to avoid a composting process in the fuel. The project shows that it is possible to combust sludge fuel mixtures with an admixture of up to 45 % sludge relative wet fuel, in an existing grate boiler during one day. However, to combust sludge fuel mixtures over a longer period of time and at a higher load, modifications of the de-ashing system and the flue gas cleaning system are needed. The results indicate a reduced tendency of slagging on the fuel bed at the combustion of sludge mixtures. The analyses of the fly ash showed a trend towards less corrosive ash at combustion of sludge mixtures. The phosphorus content in the ash in this work was 3-4 %. For process economics and from the phosphorus extraction point, as high phosphorus content as possible in the ash is preferable. Higher phosphorus content can be accomplished by mixing sludge with a fuel with lower ash content than demolition wood, co-combustion with a fuel with higher phosphorus content than demolition wood, or by increasing the percentage of sewage sludge in the fuel mixture. Still, a higher proportion of sludge in the mixture would require a higher dry matter content of the sludge in order to get proper combustion conditions. It is primarily bottom ash that is suitable for phosphorus extraction using Easy Mining Sweden's method. If fly ash are to be used for phosphorus extraction, an optimization of the dissolution conditions is required, which was not included in this project. In this project, phosphorus is extracted as ammonium phosphate. The purity of ammonium phosphate is very high, which means that unwanted substances and heavy metals in sewage sludge will not be returned to contaminate fields.

  • 54.
    Carlborg, Markus
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Exposure studies of refractory materials for biomass gasification2013Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Gasification is a technology mostly used to convert fossil feedstock to syngas. Biomass could be used as a feedstock instead but that puts different demands on, among other things, the materials in these reactors.

    In this work, two candidate materials for the inner lining in biomass gasifiers (63 and 85 weight percent Al2O3) have been exposed to three synthetic ashes, K2CO3-CaCO3-SiO2, K2CO3-CaCO3 and K2CO3 at 1050°C in CO2 atmosphere for 7 days in a muffle furnace to reproduce analogous chemical attack that would occur in a real gasifier. Samples were investigated with SEM-EDX for morphological and compositional effects and with XRD for crystalline phases at chosen distances from the exposed surface.

    A heterogeneous melt that prevented deep penetration of alkali was produced when Si was present in the ash composition. In the absence of Si, it turned out that only K was affecting the materials. K attacked the matrix and transported into the material and attacking grains. For the material containing more alumina potassium was found in continuously decreasing amounts down to 7-8 mm from the exposed surface. The other material showed a distinct border between affected and pristine matrix about 5 mm from the exposed surface. The affected part seemed to have been filled out and signs of expansion could be seen. The XRD analysis of the pristine and exposed refractories revealed significant differences. In the exposed ceramics the new phases; Leucite, Kalsilite, Kaliophilite, K(2-x)Al(2-x)SixO4 and Wollastonite were observed.

  • 55.
    Carlborg, Markus
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Refractory corrosion in biomass gasification2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    To stop the net emission of CO2 to the atmosphere, we need to reduce our dependency of fossil fuels. Although a switch to a bio-based feedstock hardly can replace the total amount of fossils used today, utilization of biomass does still have a role in a future in combination with other techniques. Valuable chemicals today derived from fossils can also be produced from biomass with similar or new technology. One such technique is the entrained flow gasification where biomass is converted into synthesis gas. This gas can then be used as a building stone to produce a wide range of chemicals.

    Slagging and corrosion problems are challenges presented by the ash forming elements in biomass during thermochemical energy conversion. The high temperature in the entrained flow process together with ash forming elements is creating a harsh environment for construction materials in the reactor. Severe corrosion and high wear rates of the lining material is a hurdle that has to be overcome to make the process more efficient.

    The objective of this work is to investigate the nature of the destructive interaction between ash forming elements and refractory materials to provide new knowledge necessary for optimal refractory choice in entrained flow gasification of woody biomass. This has been done by studying materials exposed to slags in both controlled laboratory environments and pilot scale trials. Morphology, elemental composition and distribution of refractories and slag were investigated with scanning electron microscopy and energy dispersive X-ray spectroscopy. Crystalline phases were investigated with X-ray diffraction, and thermodynamic equilibrium calculations were done in efforts to explain and make predictions of the interaction between slag and refractory.

    Observations of slag infiltration and formation of new phases in porous materials indicate severe deterioration. The presence of Si in the materials is limiting intrusion by increasing the viscosity of infiltrated slag. This is however only a temporary delay of severe wear considering the large amount of slag that is expected to pass the refractory surface. Zircon (or zirconium) (element or mineral?) based material show promising properties when modeled with thermodynamic equilibrium, but disassembling of sintered material and dissociation of individual grains was seen after exposure to a Si- and Ca-rich slag. Fused cast materials have a minimal slag contact where the only interaction is on the immediate hot face. Dissolution was however observed when exposed to a silicate-based slag, as was the formation of NaAlO2 after contact with black liquor.

  • 56.
    Carleborg, Mattias
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Elanvändning i skolkök2014Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
  • 57.
    Dahlberg, Markus
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Underhåll av Ortvikens gasisolerade 130 kV-brytare2015Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    SCA is experiencing problems with arc-overs inside some of the circuit breakers in their gas insulated 130 kV switchgear at the Ortviken paper mill in Sundsvall. The arc-overs is a result of dust in the breaker chamber. The dust comes from wear, which in turn is a result of that the circuit breakers is operated very frequently in combination with minimal maintenance. When an arc-over occurs there is a production stop at the paper mill and the outcome is associated with great costs. Some maintenance measures is currently being carried out to mitigate the risk of arc-overs, however SCA is interested in other solutions and opportunities.

    This report will examine and present the measures that can be carried out in order to prolong the technical lifetime of the circuit breakers. Relevant information and experience will be collected through interviews and later consolidated and presented as the following three alternative measures;

    1. Audit of the circuit breakers
    2. Rebuilding of the plant
    3. Continued vacuuming

    The preferred option is alternative 1 and 2 combined. Alternative 3 is not preferable but could as a last resort be improved with extended measurements and analysis.

  • 58.
    Dahlin, Jonathan
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Energikartläggning av Palmsundas industrifastighet, Kolen 3.: Energy audit of Palmsundas industrial property, Kolen 32014Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This degree project has been done with the help of TM-konsult AB in Lycksele during the spring of 2014. The course is a concluding moment at 15 hp within the engineering exam, energy technique, at the institution of applied physics and electronics, Umeå University. 

    The aim of this work was to evaluate Palmsundas industrial property, Kolen 3, located on Furuviks industrial area. To perform an energy audit and to come up with energy efficient actions that will lead to a lower energy performance of the building. 

    The work initially started with, by hand calculated the buildings heat energy with the help of A-drawings and design drawings. The method that was used is called degree hours. By making a model in the energy program ViP-Energy which give some sort of backup to the calculations by hand. 

    The inventory of the buildings technical installations has been done by a multiple visits. During the visits there were formed opinions about what actions which could be interesting to examine. The Energy efficient actions that have been examined are: 

    • Assembly of an extra window 

    • Doors and ports 

    • Installations of a new vent system in the older part of the building 

    • Vent systems specific fan power 

    • Redundant windows 

    • Lower the indoor temperature 

    • Radiator system in office staff facilities 

    • The compressed air system  

    • The heat systems circulations pumps 

    • The buildings lightning system 

    The one action that stood out from the rest is to change the entire vent system in the older part of the building. The vent system that’s in the older part of the building are six supply air fans, and also works as a heating system by directly heating the cold outside air. If the inside temperature was lowered by night when no one is present, it was possible to see that a lot of energy was saved. 

    Life cycle assessment has been performed on almost every energy efficient action to determine if the actions are viable or not. 

    To summarize, older industrial properties are in a big need of energy efficiency, even big and small investments are viable in the long haul.

  • 59.
    Demirgok, Berk
    et al.
    Department of Mechanical and Aerospace Engineering, West Virginia University, Morgantown, WV 26506, USA.
    Ugarte, Orlando
    Department of Mechanical and Aerospace Engineering, West Virginia University, Morgantown, WV 26506, USA.
    Valiev, Damir
    Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, NJ 08544, USA.
    Akkerman, V’yacheslav
    Department of Mechanical and Aerospace Engineering, West Virginia University, Morgantown, WV 26506, USA.
    Effect of thermal expansion on flame propagation in channels with nonslip walls2015In: Proceedings of the Combustion Institute, ISSN 0082-0784, E-ISSN 1878-027X, Vol. 35, no 1, p. 929-936Article in journal (Refereed)
    Abstract [en]

    Propagation of premixed flames in narrow channels is investigated by means of extensive numerical simulations of a complete system of combustion and hydrodynamic equations, incorporating transport properties (thermal conduction, diffusion and viscosity) and Arrhenius chemical kinetics. The system includes mass conservation and Navier–Stokes equations as well as those for the energy and species balance. A flame propagates from the closed end of a channel to the open one. An initially planar flame front gets corrugated due to wall friction and thereby accelerates. It is shown that a flame exhibits an exponential state of acceleration only when the thermal expansion coefficient Θ exceeds a certain critical value Θ>Θc. The quantity Θc is tabulated as a function of the Reynolds number related to the flame propagation, Re, being Θc≈6 for Re=5∼20. The major flame characteristics such as the flame propagation speed and acceleration rate are scrutinized. It is demonstrated that the acceleration promotes with Θ   but weakens with Re. In this respect, the present computational results support the theoretical prediction of Bychkov et al  . Physical Review E 72 (2005) 046307 in a wide range of Θ   and Re. While very good quantitative and qualitative agreement between numerical and theoretical results is found for realistically large thermal expansion, Θ>=8, agreement deteriorates with decreasing Θ. Specifically, while the theory and modeling do not quantitatively agree for Θc<Θ<8, they nevertheless demonstrate a qualitative resemblance (the exponential state of acceleration). Finally, no exponential acceleration at Θ<Θc denotes that the theory completely breaks in that case, but this fits other works in the field and thereby allows reconciling various formulations on the flame acceleration.

  • 60. Deng, Na
    et al.
    He, Guansong
    Gao, Yuan
    Yang, Bin
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Zhao, Jun
    He, Shunming
    Tian, Xue
    Comparative analysis of optimal operation strategies for district heating and cooling system based on design and actual load2017In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 205, p. 577-588Article in journal (Refereed)
    Abstract [en]

    Computational load significantly influences energy and cost savings when developing an operation strategy for a district heating and cooling system. In this study, a model was identified to study the effects of the difference between design load and actual load on an optimal operation strategy. The established model is strongly dependent on the economy principle, and the proposed optimal strategy could achieve a dynamic balance between the users' load and the system energy supply. This model was validated at 30% load rate, which demonstrated an obvious cost saving of 63.6% under the actual load and 42.2% under the design load. Based on the current strategy, the optimal strategy at different load rates was analyzed with respect to two characteristics of each subsystem: energy outputs and operation costs. Furthermore, in the optimal strategy, changes in total operation costs and cost savings rates under different load rates are also discussed. The results showed that, when the load rate was changed from 30 to 75%, the savings rates based on the design load were 42.2, 17.9, 2.5, and 12.6%, and the savings rates based on the actual load were 63.6, 49.8, 34.3, and 25.7%, respectively. Based on the actual load, the energy savings advantage of the optimal operation strategy could be maximized, in particular, during the initial stage of project construction. Furthermore, the commercial software MATLAB was used for programming and calculations. The simulation results indicated that the application of the combined cooling, heating, and power system could significantly improve the cost-effectiveness.

  • 61.
    Dion, Claude
    et al.
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Demirgök, Berk
    Dept. Mechanical and aerospace Engineering, West Virginia University.
    Akkerman, Vyacheslav
    Dept. Mechanical and aerospace Engineering, West Virginia University.
    Valiev, Damir
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Bychkov, Vitaly
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Flames in channels with cold walls: acceleration versus extinction2015In: MCS 9, 2015Conference paper (Refereed)
    Abstract [en]

    The present work considers the problem of premixed flame front acceleration in microchannelswith smooth cold non-slip walls in the context of the deflagration-to-detonationtransition; the flame accelerates from the closed channel end to the open one. Recently, anumber of theoretical and computational papers have demonstrated the possibility of powerfulflame acceleration for micro-channels with adiabatic walls. In contrast to the previous studies,here we investigate the case of flame propagation in channels with isothermal cold walls. Theproblem is solved by using direct numerical simulations of the complete set of the Navier-Stokes combustion equations. We obtain flame extinction for narrow channels due to heat lossto the walls. However, for sufficiently wide channels, flame acceleration is found even for theconditions of cold walls in spite of the heat loss. Specifically, the flame accelerates in thelinear regime in that case. While this acceleration regime is quite different from theexponential acceleration predicted theoretically and obtained computationally for theadiabatic channels, it is consistent with the previous experimental observations, whichinevitably involve thermal losses to the walls. In this particular work, we focus on the effectof the Reynolds number of the flow on the manner of the flame acceleration.

  • 62.
    Dyrlind, Johan
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Sänkning av fjärrvärmetemperaturen för ökad elverkningsgrad2012Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Umeå Energi AB provides the majority of Umeå municipality with district heating. In the central district heating system there are two power plants that produce both heat and electricity from waste, Dåva 1, and biofuels in the form of wood chips and peat, Dåva 2.

    Combined Heat and Power (CHP) plants will normally have a better electrical efficiency if district heating supply temperature is lowered; therefore the possibility and profit potential of lowering the supply temperature from the CHP plants and alsothe other heat-producing plants in the network have been investigated.

    The purpose of this thesis has been to investigate the possibility of lowering the supply temperature in Umeå Energi´s district heating network and to calculate the possible income increases if it is done.

    To be able to lower the supply temperature without reducing the heat production, the flow in the district heating network must be increased so that the same amount of heat can be delivered. This thesis examined both the current situation including the current flow constraints and the new constraints that will apply when an additional booster station is plugged into the district heating network.

    A linear fit of the measured values of the flow temperature and the alpha value, the ratio of produced electricity and heat produced, shows that lowering the supply temperature increases the alpha value for both CHP plants according to the equations below:

    α1=0,5834−0,0029∗TF   α2=0,7136−0,0026∗TF

    In addition to the alpha value heat losses from the distribution network also changes with a change in supply temperature.

    A control curve is currently controlling the supply temperature as a function of outdoor temperature, but according to measured values, the control curve is not followed during the majority of the time. This is taken as a further indication that the control curve for the supply temperature should be revised.

    Linked to district heating network is an absorption refrigeration unit that requires a supply temperature of at least 95°C during the summer. When the absorption refrigeration unit is not in operation, the requirement of the flow temperature is 75°C. It should also be investigated how much profit could be made if the absorption chiller did not require a higher supply temperature.

    All calculations have been performed based on measured data from the years 2010 and 2011, data that is considered to be representative also for future years. New control curves have been recommended based on the calculations for optimizing profit with the measured data from the years mentioned above years, calcaulations for the increased income using these control curves have also been done.

    With the current operating condition the potential profit is calculated to be around three million Skr per year with an additional two million in profit if the chiller does not require a higher temperature during the summer.

    With a new booster station the estimated profit differs quite a lot between the years with around 17 million Skr of potential profit in 2010 and 11 million Skr in 2011. The profit if the chiller doesn’t require a higher temperature is basically unchanged, about two million Skr.

    The conclusion of the thesis is that it is both possible and profitable to change control curve and use a lower supply temperature. Since 2010 was a unusually cold year and 2011 was a unusually warm year the calculated profits are considered representative also for coming years. The maximum flow with a new booster station is based entirely on theoretical values and should be considered as more insecure then the other results. It is recommended to try the control curves from this thesis in the production and evaluated the profit in a real situation.

  • 63.
    Ekevärn, David
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Energikartläggning av Martinsons Trä AB2012Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This is a report of a master thesis in energy technology and has been done by mapping energy usage of the company Martinsons Trä AB. Furthermore, this thesis is a part of NV Eko. The purpose of the report is to give a wider image of how energy is used at Martinsons sawmill in Bygdsiljum by mapping specifically and especially the use of electricity in this case. Certain priorities were made, from a production view, and parts of the factory were mapped.

    Measurements were made in order to map the usage of electricity, data has been collected and interviews were conducted.

    The results of this work are statistics over the mapped factories due to the usage of electricity in the these, together with a number of suggestions of improvements. Such suggestions were that some machines need an oversight or replacing.

    The use of electricity in the factories handling the raw material saw processing was calculated to be approximately 30 % of the electricity bought yearly. The factories concerned with the refining process use a corresponding 18 % and the drying facility uses 40 % of the totalt electricity yearly. It was also calculated that in total, Martinsons sawmill in Bygdsiljum uses 23 Gwh.

    The investment of a new moisturising system in the second refining factory (4 in total) needs to be looked into. An oversight of the one of the saw processing factories transformer is needed and the feeding of electricity to the second refining factory needs to be separated from said transformer. Above mentioned measurement needs to be done with transformer 11 as well, separating the second from the third refining factory:s feeding.

    Furthermore an oversight and replacing of certain machines within the refining factories is needed and also a more continuous logging of electricity usage should be implemented.

  • 64.
    Ekman, Joakim
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Energianalys av Romar fastigheter med metodutveckling för ökade incitament för   energieffektivisering hos hyresgäster2012Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Thesis is to work out an examplel of incentivesto motivate tenants to participate and invest in energy efficiency. The workincludes an energy audit of a building to be able to show what kind of savingsthat can be made and the investment costs involved. The property has all theenergy costs embedde in the price which means that tenants do not haveincentives to invest. The energy audit include night patrols to see what wasteenergy att night when there are no working, collection of data from Umeå Energy,an inventory of lighting and the acquisition of information on ventilation andthe compressor. Contact with different companies to get the approximate cost ofthe rationalizations. After the initial work was done the results were compiledand the result was a reduction in electricity consumtion by 354 MWh/year to 211MWh/year. The incentive in this case involves an adjustment of the rental formso that tenants self-pay energy costs and thus become more interested in beinginvolved in investments. An individual measurement of energy consumtion shouldbe as it is possible to assess how much each tenant is using. Investment costscan be split between tenants and landlords and bebefits of the investments canbe divided in the same way. Both parts benefits econonomically andenviromentally on cooperation.

  • 65.
    Emilia, Stjern
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Konsekvenser av ett omfattande elavbrott inom äldrevården2017Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    A long term large-scale power outage would have a big impact on the society, not least for the elderly and sick people. The Swedish hospitals are well prepared for a power outage. How the municipal healthcare chain would cope with a large-scale power outage is not as well investigated.

    The purpose with this report is to increase the knowledge about what consequences a power outage would cause at the elderly care homes and how they could prepare for a scenario like that. The goal is to produce a report to ease the planning of emergency power solutions to the elderly care homes.

    To re-establish the power supply in case of a power outage the most common solution today is a diesel generator. An elderly care home was chosen as a reference to be able to calculate how big efficiency that is needed to supply necessary equipment with enough power. The result showed that the diesel generator need to be able to deliver 640 kVA. A model of the elderly care home was built in the simulation software IDA ICE. A simulation was made to decide how fast the temperature inside the building is sinking in case of an interruption in the district heating system. According to the result the temperature inside the building would be 11 ºC after 48 hours with an outside temperature at almost – 20 ºC. During a day with high temperatures can the inside temperature rise to 29 ºC.

    A power outage could cause big problems for the elderly care homes if there are no access of diesel generators. A diesel generator which would supply an elderly care home with electricity will consume a big amount of diesel. To facilitate the distribution of diesel in case of an emergency is it important to establish a plan for how much diesel that would be consumed over a day and how to secure the delivery to the most important places. 

    If the power outage occurs during a period with unusually hot or cold weather the vulnerability increases because the elderly people appear to be more sensitive of overheating or hypothermia. To know which buildings that would be prioritized in case of an interruption in the district heating system ore cooling system, would it be an advantage to document the buildings time constants.

     

  • 66. Enestam, Sonja
    et al.
    Mäkelä, Kari
    Backman, Rainer
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics, Energy Technology and Thermal Process Chemistry.
    Hupa, Miko
    Occurrence of Zinc and Lead in Aerosols and Deposits in the Fluidized-Bed Combustion of Recovered Waste Wood. Part 2: Thermodynamic Considerations2011In: Energy & Fuels, ISSN 0887-0624, E-ISSN 1520-5029, Vol. 25, no 4, p. 1970-1977Article in journal (Refereed)
    Abstract [en]

    In the present work, which is the second part in a series of two, multi-phase, multi-component equilibrium calculations were used to study the chemistry and deposition behavior of lead and zinc in the combustion of recovered waste wood (RWW). Particular attention was paid to the deposition behavior in different parts of the boiler under varying flue gas and material temperature conditions. In addition, the influence of fuel composition was considered by studying three different fuel compositions. The results from the calculations were compared to experimental results from two measurement campaigns, whose goal was to experimentally determine the distribution and speciation of zinc and lead compounds in aerosol particles and deposits in the fluidized-bed combustion of RWW. The results from the experimental work are presented in part 1 (10.1021/ef101478n) of this work.

  • 67.
    Enevold, Jenny
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Development of light-emitting electrochemical cells for novel applications2011Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The work intended to make progress towards the objective of fiber-shaped light-emitting electrochemical cells (LECs). LECs comprising a film of poly(3,4-ethylenedioxythiophene): poly (styrenesulphonate) (PEDOT:PSS) cast from aqueous dispersion as the sole transparent anode were produced and characterized. It was shown that it is possible to achieve uniform yellow-green light emission at an efficiency of 0.96 cd/A from such LECs fabricated by spin coating at low rotational speed. Implications of using different cathode metals and varying the order of deposition of the films were studied and shown to have significant influence on device performance. Lastly, a novel fiber-like LEC in a coaxial geometry was produced, which promises bright prospects for new applications due to the flexibility of the used materials.

  • 68.
    Englund Sandlund, Emil
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Energibesparingspotential i belysningssystem2014Independent thesis Basic level (university diploma), 180 HE creditsStudent thesis
  • 69.
    Eriksson, Anders
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Energikartläggning av fastigheten Brage 62012Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
  • 70.
    Eriksson, Matias
    et al.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Hökfors, Bodil
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Backman, Rainer
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    The Effects of Oxygen Enrichment and Fuel Composition on Rotary Kiln Lime Production2015In: Journal of Engineering Technology, ISSN 0747-9664, Vol. 32, no 1, p. 30-43Article in journal (Refereed)
    Abstract [en]

    This article discusses the impact of oxygen (O2) enrichment on rotary kiln lump lime production. A predictive simulation tool is utilized to investigate the effect of O2 enrichment on the following key parameters of the lime process: kiln temperature profile, product quality, specific energy consumption and kiln production capacity. Three fuel mixes - 100% coal, 90% coal and 10% waste derived fuel oil, and 90% coal and 10% sawdust - are simulated at three oxygen levels. The oxygen levels represent three scenarios: no enrichment (21% O2), moderate enrichment (23% O2), and moderate-to-high enrichment (25% O2). This work is a part of the on-going efforts to reduce the environmental impact of industrial production. Reducing emissions, utilizing biofuels and waste derived fuels, full utilization of raw materials, and energy efficiency are areas of importance for industry. In the long term, oxyfuel technology, i.e., combustion with recirculated kiln gases and pure oxygen, could allow for near-zero emission production and carbon sequestration from industry and power production. In the short term, emission reductions in lime production must be achieved through other means, such as energy efficiency. As a step on the path to a near-zero emission lime plant, this paper describes an investigation of the influence of oxygen enrichment in rotary kiln lime production. The simulated results show positive effects of O2 enrichment, and the simulation results have been used by the kiln operator for in-house training. Results indicate that oxygen enrichment applied to lime production can reduce energy consumption and emissions.

  • 71.
    Eriksson, Morgan
    et al.
    Umeå University, Faculty of Science and Technology, Applied Physics and Electronics.
    Golriz, M. R.
    Umeå University, Faculty of Science and Technology, Applied Physics and Electronics.
    Radiative Heat Transfer in Circulating Fluidized Beds2005In: International journal of thermal sciences, ISSN 1290-0729, E-ISSN 1778-4166, Vol. 44, p. 399-409Article in journal (Refereed)
    Abstract [en]

     

    A new model for predicting radiation heat transfer in circulating fluidized bed combustors is proposed. The model assumes two phase structure, the flow at the wall dominated by streamers of clusters traveling mostly downward, interspersed with periods where there is upwards flow of a dilute suspension. Also, the model assumes the intensity distribution to be semi-isotropic in the forward and backward direction. The predictions are in good agreement with the experimental results from the literature. Finally, a parametric study is performed to show the effect of different bed parameters on radiative heat transfer. The results indicate that suspension temperature, wall temperature, wall emissivity, particle emissivity, and suspension density have significant influence on the radiation heat transfer coefficient.

     

  • 72.
    Eriksson, Per
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Analys av uppvärmningssystem: En kartläggning och analys av uppvärmningssystem för flygplan med fjärrvärme som energikälla.2017Independent thesis Basic level (university diploma), 180 HE creditsStudent thesis
    Abstract [en]

    When passenger aircrafts are parked during the nights they need warming and ventilation to prevent freezing of critical components, ventilate accumulated moisture and to satisfy the comfort for cabin crew and passengers before takeoff. Smart Climate Scandinavian AB has developed and delivered a climate unit which uses district heating as a thermal energy source instead of electricity. This system is a more energy efficient and environmental sustainable alternative.

    The purpose of the thesis was to chart and analyze parts of the heating system, if possible to state improvements to reduce used energy due to warming passenger aircrafts. The new heating system was compared to the previous one to see which one was more energy efficient.

    To be able to compare the two systems measurements about temperatures and flow has been collected from the control and regulation system. The measurements have been compiled, evaluated and analyzed with focus not to compromise the probability to not affect the energy- and power calculations. Some of the measurements are provided and collected by the energy meter Kamstrup MULTICAL 602 which has good accuracy and precision, these where used as a reference to rate the measurements from other parts of the system.

    Charting of the system proved that the ventilation ducts where equipped with different thickness off insulation. The results of the power calculations proved that if the heating system used ventilation ducts with an insulation thickness of 20 mm instead of 2 mm requires 16 % less power usage.

    From the analysis of energy calculations, a linear equation which calculate the energy use dependent on outside temperature was determined.

    The results of using the new heating system instead of the previous saves 9200 kWh energy per year and pound. That the new system is more energy effective considers to be likely because its uses regulation of the demand by inside temperature of the aircraft, previous system only used regulation dependent of outside temperature.

    The conclusions of this project are:

    • The sizing of the system is good enough to deliver the required demand.
    • Adjust the active time for preheating.
    • Night time reduction results in marginally less energy use.
    • Use ventilation ducts with insulation thickness of 20 mm.
    • The new heating system is more energy efficient compared to previous.
    The full text will be freely available from 2020-06-01 00:00
  • 73.
    Eriksson, Simon
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Spillvärme för SSAB EMEA Luleå: En utredning av koksverkets förutsättningar att utnyttja spillvärme i det befintliga värmesystemet2013Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Rising energy prices and better environmental awareness are two reasons that make waste heat utilization increasingly relevant. In Sweden, we have a leading position when it comes to use of waste heat, which amounts to 4 TWh. An investigation by the Swedish District Heating Association, in cooperation with Statistics Sweden shows that there is an unused waste heat potential of 10 TWh. The problems of utilizing waste heat are caused by everything from high investment costs to problems with concluding agreements with district heating companies that benefit both parties.This thesis presents the opportunities for SSAB coke plant to integrate waste heat into the existing heating system and thereby reducing the energy costs.The reports aim is to find out what temperatures and flows that occur in the heating system and optimize it to the appropriate level for heat exchange with waste heat. The goal is also to propose a suitable way of linking the two systems and ensure their mutual functions are not affected.The annual consumption of the coke plant heating system amounts to 16 GWh. Temperature difference over the heat exchanger shows a poor heat exchange in the system, which is mainly caused by unregulated equipment and an oversized pump. Proposed measures with payback periods shorter than one year are presented in the report. Economic conditions for integrating waste heat are also favorable and turned out to be completely dependent on the amount of heat exchange that can be achieved in the heating system.

  • 74.
    Eriksson Stephanopoulos, Antonios
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Komfortkylsystems installationskostnader och energiförbrukning i kontor2011Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    On behalf of Creanova AB this master thesis has been implemented in the autumn 2010. The aim with the project was to analyze how installation and energy costs for comfort cooling in office buildings depends on different design conditions. The conditions that have been examined is particularly the design indoor temperature, but also sun protection in terms of louvers and blinds as well as LED lighting.

    All the varied parameters have been simulated in four different directions with both CAV (Constant Air Volume) systems with conventional baffle and VAV (Variable Air Volume) systems with active diffuser TTD-160 from Lindinvent.

    The calculations for the office have been simulated in climate simulation program IDA ICE 4.0. After that two different solutions were developed for the office, one with CAV ventilation and one with VAV ventilation. Finally installation cost of each simulation and its energy consumption was calculated.

    The calculations show that the installation costs for an office space will increase by about 50% when the design indoor temperature is lowered from 26 to 22 ° C for the CAV system with supply air baffle. The corresponding figure for the VAV system with inlet diffuser is about 40%. Energy costs for air conditioning and heating will increase by about 114% for the CAV system and approximately 127% for VAV solution in which the same design temperature drop is implemented.

    By attaching different types of sunscreen on the office window, the need for comfort cooling for offices with south, east, or west facade is greatly reduced, which is clearly reflected in the costs for both installation and energy. To attach sunscreen on offices with north facades are not necessary, because the solar radiation on north facades is already very low. The installation costs for the VAV solution has proven to be about 10-15% lower than the CAV solution with the same conditions and energy costs for the VAV solution is between 20-27% lower than for the CAV solution

    But designing VAV systems are not always appropriate, since the ducts and installations take up more space because of the ventilation ducts increased size. When very exclusive buildings are constructed the ventilation ducts increased shaft area may lead to that the lost rental income is greater than the savings that the lower energy consumption generates.

  • 75.
    Eriksson, Tommy
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Övertoner i kemisk industri: Harmonics in chemical industry2016Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Disturbance in the power grids is a problem that is spread worldwide and have negative effect

    on the power quality. It also gives unwanted costs for consumers as well as producers of

    electrical power. The main reason to problems with the power quality is the increasing use of

    non-linear loads connected to the power grid. The term “Power quality” is used to define the

    quality present in the power system. The typical disturbances in the power system are

    harmonics, change in voltage and transients. By measuring and analysing a result can be

    given to see what arrangements might be necessary to increase the power quality.

    Akzo Nobel Pulp & Performance Chemicals AB is an industry who mainly

    produces bleaching chemicals. In the process a large amount of electrical energy is needed

    and problems in the power quality have occurred multiple times. The main issue is the

    generation of harmonics which is spread to the connected power grid. They want to minimize

    the spread of harmonics to help increasing the power quality in the internal system and the

    external grid. The plant is connected to 70 kV incoming voltage which supplies the loads via

    the switchgear. The loads mainly consist of rectifiers and variable frequency drives.

    The reason this study has been conducted is to gather information and measurements as an

    initial start for a larger investigation for larger study for an installation of a harmonic filter.

    This report will show measurements of the harmonic’s being presence, filtering methods

    available and some proposals for the larger study and how to minimize the harmonic

    generation.

    To get an understanding on harmonics studies has been done on theories on the topic such as

    Power quality, Fourier analysis and filtering methods being available. Some studies on the

    type of non-linear loads connected in the plant such as rectifiers and variable frequency drives

    has been done as well. Measurements in the main switchgear of the three supplying phases in

    the point of common coupling have been done.

    The results show that the level of harmonics exceeds the given limit at many times. And the

    given limit is only fulfilled with reduced use of power by the plant. The main harmonic that

    contributes in exceeding the given limit is the 7:th harmonic, which makes sense with the

    theory in harmonic generation given by rectifiers and variable frequency drives. The 5:th

    harmonic should be more present based on the same theories, but they are not. This is

    considered to be because of a phase shift between the loads connected. The even harmonics is

    seen in the system as well which indicates a non-symmetrical case for the system. The nonsymmetrical

    case are within acceptable limits. Filtering are necessary to keep the level of

    harmonics under the limit. A planning in locating the loads should also be considered with the

    harmonics in mind for future changes in the system.

  • 76.
    Eskills, Jonathan
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Betydelsen av en byggnads planlösning vid energieffektivisering: Enligt simulering i IDA ICE2018Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The residence and service sector stand for 40 % of the total energy use in Sweden. 90 % of that energy is used for households and facilities, which means that its energy use is only surpassed by that of the industry

    An appropriate solution for a national reduction in use of energy is therefore to streamline the energy efficiency for existing and planned buildings.

    The aim for this academic work is to examine how different methods of streamlining energy use is affected by building planning. Two real life buildings are to be compared and analysed. The buildings have identical outer dimensions and construction, and one of them has a comparatively more open building plan.

    Five different streamlining solutions are going to be simulated in the software EQUA IDA ICE; a lowering of the room temperature, an increased efficiency on the heat exchanger in the air handling unit, a decreased U-value (a Swedish building standard in energy transmission) for the windows, a decreased U-value for the roof and lastly a change from a proportional control system to a proportional integrating on the heating and cooling system.

    The results show that:

    A lowering of the room temperature by 2 ˚C, lessens the heating load for the air handling unit by 42,5 % in the building with a more open building plan, whilst the less open building sees a decrease of 35,8 %.

    The effect of an increased efficiency from 0,6 to 0,9 on the heat exchanger in the air handling is unaffected by a buildings planning.

    A lowered U-value for the windows from 1,8 to 1,1 W/m2,K increases the cooling load for the air handling unit by 130 % on the building with the more open planning. And at the same time the building with the less open planning is unaffected by the streamlining.

    A lowered U-value for the roof from 0,09 to 0,05 W/m2,K gives an increased performance on the heating load for both the heating system and air handling unit on the building with the more open planning, compared to that of the less open building.

    If the control system of the heating and cooling systems changes from a proportional integrating to a proportional one, the cooling load for the cooling system increases by 4,1 % on the building with the more open planning, whilst it increases by 17,1 % on the less open building.

    Streamlining the energy use of ventilation, cooling and heating systems has a bigger impact on buildings with a more open planning compared to those with a less open building plan.

    A less open building plan is better affected by the streamlining of the energy transmission trough the construction compared to a more open planning.

  • 77.
    Fagerström, Jonathan
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Fine particle emissions and slag formation in fixed-bed biomass combustion: aspects of fuel engineering2015Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    There is a consensus worldwide that the share of renewable energy sources should be increased to mitigate climate change. The strive to increase the renewable energy fraction can partly be met by an increased utilization of different biomass feedstocks. Many of the "new" feedstocks puts stress on certain challenges such as air pollution emissions and operation stability of the combustion process. The overall objective was to investigate, evaluate, and explain the effects of fuel design and combustion control - fuel engineering - as primary measures for control of slag formation, deposit formation, and fine particle emissions during biomass combustion in small and medium scale fixed-bed appliances. The work in this thesis can be outlined as having two main focus areas, one more applied regarding fuel engineering measures and one more fundamental regarding the time-resolved release of ash forming elements, with particular focus on potassium.

    The overall conclusion related to the abatement of particle emissions and slag formation, is that the release of fine particle and deposit forming matter can be controlled simultaneously as the slag formation during fixed-bed biomass combustion. The methodology is in this perspective denoted “fuel engineering” and is based on a combined approach including both fuel design and process control measures. The studies on time-resolved potassium release showed that a Macro-TG reactor with single pellet experiments was a valuable tool for studying ash transformation along the fuel conversion. The combination of dedicated release determinations based on accurate mass balance considerations and ICP analysis, with phase composition characterization by XRD, is important for the understanding of potassium release in general and time-resolved data in particular. For wood, the results presented in this work supports the potassium release mechanism from "char-K" but questions the previously suggested release mechanism from decomposition of K-carbonates. For straw, the present data support the idea that the major part of the potassium release is attributed to volatilization of KCl. To further explore the detailed mechanisms, the novel approach developed and applied in this work should be complemented with other experimental and analytical techniques.

    The research in this thesis has explored some of the challenges related to the combined phenomena of fuel conversion and ash transformation during thermochemical conversion of biomass, and has contributed with novel methods and approaches that have gained new knowledge to be used for the development of more effective bioenergy systems.

  • 78.
    Fahlén, Albin
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Småskalig vattenkraft vid Olofsfors bruksmuseum: Med faunapassage2013Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In Sweden there are 1894 small-scale hydropower plants in operation, which together generate 4.3 TWh of electricity per year according to Swedish hydropower compound (SVKF, 2011). This corresponds to the annual consumption of about 860,000 Swedish households (based on an annual consumption of 5000 kWh). In the mid-1950s there were around 4000 small-scale hydropower plants in operation in Sweden before cheap fossil fuels and uranium competed with them, in the current situation only 1,894 of these are in use. If slumbering small hydropower plants once again would be taken into use and some new ones are built, we would be able to extract about 7 TWh of renewable electricity from these annually in Sweden, representing about 1.4 million households.

    The thesis intends to calculate and construct a hydroelectric power plant at the existing dam in Olofsfors and give suggestions on how the power station should run during the time that fish migration is greatest in Leduån.

    The turbine and generator to the station in Leduån at Olofsfors is designed by the height of the fall and the water flow through the dam. The turbine selected for the station is a CK-1000RM turbine with a 4-pole 250 kW generator from Cargo & power turbine Sweden AB, which is expected to deliver 1.2 GWh per year. To facilitate the fish migration from the birth- and breeding place to the sea, the plan is to put down a 1.5 m high plate at the intake to prevent the surface water to flow through the turbine. Then you reduce the flow through the turbine to increase the flow of water through the fish ladder. This is done because the fish during their migration often swims at depth of 1 m and the fish also follows the main stream of the water. Fish migration is solely controlled by the temperature in the water. This means that you can predict when the migration takes place and perform the actions to reduce water flow through the turbine and prevent surface water passing through the turbine with the plate.

  • 79.
    Falk, Joel
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Engineering.
    Skoglund, Nils
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Grimm, Alejandro
    Swedish University of Agricultural Sciences, Department of Forest Biomaterials and Technology.
    Boström, Dan
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Öhman, Marcus
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Engineering.
    Difference in phosphate speciation between sewage sludge and biomass ash from fluidized bed combustion2018In: 27th International Conference of Impacts of Fuel Quality on Power Production and the Environment, September 23–28 September, 2018, Lake Louise, Canada, 2018Conference paper (Refereed)
    Abstract [en]

    The role of phosphorus in biomass combustion is a topic that has become increasingly relevantin recent years. Due to the demand for new sources of renewable energy and recovery of phosphorus from waste streams such as sewage sludge, research into the behavior of phosphorus during combustion is necessary for a continued development. This study aims to investigate potential differences in phosphate behavior during co-combustion of sewage sludge compared to other phosphorus-rich biomass or additives. The investigation was carried out in a bench scale bubbling fluidized bed, co-combusting six biomass blends of similar ash composition and combustion conditions but with different phosphorus association (logging residues (LR) or wheat straw (WS) with sewage sludge (SS), dried distiller’s grain (DG), or phosphoric acid (PA)). After combustion, bed ash samples, fly ash deposits and cyclone ash were collected and analyzed for elemental composition (SEM-EDS) and phase composition (XRD). Based on the XRD phase analyses, a significant difference in phosphate speciation were foundbetween biomass blends containing SS compare to DG or PA. Only two phosphate phases were identified in the ash from SS blends compared to a large variety of phosphates in ash from DG or PA blends. The difference in speciation could not be explained by a difference in ash fractionation as the elemental composition of the analyzed ash fractions were similar. Rather, the results indicate that the behavior of phosphorus in SS may be different to that in DG or PA.

  • 80.
    Finell, Fredrik
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Energiberäkningar för olika lösningar av VVS-system vid Hjältarnas Hus i Umeå.: Jämförelse av olika systemlösningar för VVS genom simuleringar i IDA ICE.2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
  • 81.
    Fjellstedt, Emelie
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Energiåtervinning ur kylluft: Svenska Lantmännens foderfabrik i Holmsund i samarbete med Umia AB2015Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

     Lantmännen i Holmsund tillverkar pelleterat djurfoder till gris, nöt, ren och höns. På fabriken finns tre stycken presslinjer som pressar råvarorna till pellets. Vid tillverkning av pellets blandas råvarorna med ånga som håller ca 75-78°C. Ångan gör att pelletsen blir varm och fuktig efter tillverkningen. För att pelletsen ska kunna hålla en god kvalité vid transport och förvaring torkas denna med luft i pelletskylar. Varje presslinje har en egen pelletskyl. Kylluften som lämnar pelletskylarna är relativt varm och fuktig. En del av energin som finns i kylluften tas idag tillvara på i ett återvinningssystem som ger värme till fabriken och melassanläggningen. Trots den nuvarande återvinningen är kylluftluftflödet fortfarande varmt när den lämnar byggnaden. En del av målet i arbetet har varit att reda på vilken energi som finns i den utgående kylluften och vilken kvalité denna har. Den andra delen av syftet har varit att utreda hur denna energi kan tas tillvara. Mätningar visar att kylluften från press 1 och 2 håller en medeltemperatur på ca 45°C och ett medel volymflöde på 7,5 m3 /s när den lämnar byggnaden. Från presslinje 3 håller luften en något högre temperatur och volymflödet är ungefär hälften. Möjliga avsättningsområden för energin är fabriksvärmesystemet, melassanläggningen samt tappvarmvatten.

    Ungefärligt energibehov för dessa områden är:

    Melassanläggning 133 MWhFabriksvärme 68 MWhTappvarmvatten 15,6 MWh

    För att dessa områden ska kunna tillgodogöra sig energin som finns i kylluften behöver temperaturerna in i systemen vara högre än vad som finns tillgängligt i kylluften. För detta ändamål föreslås att två stycken värmepumpar installeras på fabriken. En värmepump för att värma melassanläggningen och en värmepump som kan förse fabriksvärmesystemet och tappvarmvattenberedning med värme. Det finns ett stort energiöverskott från kylluften kontra avsättningsområdena. Energitillgången från frånluften är dock inte konstant utan styrs efter produktionen i fabriken. Genom att installera en ackumulatortank visar beräkningar att värmepumparna skulle kunna täcka 80 % av energiförbrukningen. Ekonomiska beräkningar visar att Lantmännen i Holmsund kan göra en besparing på 130 000 kr/år om de föreslagna åtgärderna införs. Återbetalningstiden för anläggningen beräknades till 8,1 år.

  • 82.
    Fjellstedt, Johan
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Energioptimering av tryckluft: Genom värmeåtervinning och driftoptimeringar för industriella tillämpningar på Volvo Trucks i Umeå2019Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Volvo Trucks in Umeå use large amounts of compressed air and the air compressors at Volvo use large amounts of energy every year. The majority of the energy supplied to the compressors goes to heat losses cooled to the Ume River and groundwater.

    The purpose of this project was to develop a new heat recovery system where a larger part of the compressor heat is used and various suggestions for optimizations on the compressed air system.

    Lack of digital control systems on the compressed air system has led to various operating problems and difficulties in diagnosing them while making optimizations difficult. The absence of logged data led to lack of various critical compressor data that instead had to be estimated with different calculation methods.

    The report resulted in a number of measures that were proposed, such as an investment in a variable speed drive compressor with heat recovery to the district heating system, various operating optimizations and a reworking of the current heat recovery system. The heat recovery systems showed to have great saving potential with a short payback period.

    The heat recovery systems that were developed in the project was to recycle heat from a new air compressor to the return line on the district heating at a station inside the factory and a heat exchange on three current compressors towards a nearby district heating line. It was thus possible to show significant reductions in the amount of purchased district heating and energy costs without affecting other processes.

    An outdated compressed air system showed higher future costs due to increased service costs and a future need for renovations on compressors. This means that Volvo probably would have reduced costs by investing in a new air compressor. 

  • 83.
    Flygare, Kristoffer
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Energisimulering av Fortifikationsverkets Kontorsbyggnad 1: Energisimulering och utvärdering av renovering2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The purpose of this project is to analyze an upcoming renovation of an office building in Boden, owned by Fortifikationsverket. The project makes use of the software IDA Indoor Climate and Energy and Revit to simulate the building as it will function after completed renovation. This way Fortifikationsverket has a reference value to use when evaluating the actual performance of the building.

    The project introduces the reader to Revit as well as to the simulation program IDA ICE and shows how energy consumption may be simulated when one wishes to renovate a building. Drawings, an energy report and measured energy consumption act as the basis for the simulation and where values are not available assumptions are made. The upcoming renovation consists of a new HVAC system and rules set forth by Fortifikationsverket which are to be followed when a building under their regime is renovated. These rules consists of reducing air leakage, lowering room temperature and installing more effective lightning, fans, heat exchangers and air cooling.

    The project finds that the upcoming renovation lowers the yearly energy consumption of the building by approximately 31 %, heating and electricity are included in this energy consumption and are lowered by approximately 29 % and 33 % respectively. The yearly use of heating and electricity is found to be 409 009 kWh and 446 905 kWh respectively.

    Of the various measures taken by the renovation the heat recovery is found to be the most effective. The electricity consumption was lowered most by more effective lightning and fans.

  • 84.
    Fredriksson, Petter
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Beräkning av värmeförluster och energieffektivisering av elbussar2012Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The ”civilized” world is in need of fossil fuel in order to function. Hybricon AB is a company in Umeå that is developing a technology that hopefully can reduce parts of this need. They are currently testing their two electrical busses (with Hybrid backup) in city traffic on the roads of Umeå in cooperation with the county of Umeå.

                                   

    The busses are originally diesel-busses, but the diesel motor has been replaced with two electrical hub-motors with a power of 145 kW each that are powered by batteries.

    The batteries are charged at the end station after each route. In case the batteries should run low on capacity during driving, they can be recharged by the so called genset. The genset consists of a diesel-engine with a generator.

     

    A general problem with electrical vehicles is their lack of waste heat for compartmental heating, due to higher efficiency of the electrical engine and the fact that the energy conversion doesn’t involve combustion. An ordinary diesel-buss can use the waste heat from the engine for compartmental heating, but even that is not enough to satisfy the need of heat to keep the bus warm in for example northern Sweden, where the climate is very cold during winter.

     

    The purpose of this thesis is to help Hybricon investigate how big the heat losses are for the electrical busses and thereby calculate the maximum need of heating power, and also investigate what different energy efficient actions can contribute to lowering the need of heating power. The goal for Hybricon is to be independent of fossil fuels for the heating of their busses, after future energy efficient actions.

     

    The power for heating in the bus at its original manufactured state is between 40-50 kW when the doors are closed and between 100-500 kW depending on the number of doors open simultaneously (one, two or three).

     

    Through energy efficient actions in the climate shell, the maximum heating power for the bus can be lowered by 22,4 % when the doors are closed and about 3,5 % when doors are open.

    It is shown that the biggest heat loss occurs when one or more doors are open. Many energy efficient actions must be made and especially the heat loss through the doors must be lowered significantly, if the busses are to be heated in an energy efficient way and without need of fossil fuels.

  • 85.
    García López, Natxo
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Biomass utilization for energy purposes in Kenya: Fuel characteristics and thermochemical properties2016Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    About forty percent of the world´s population, mostly inhabitants of countries with developing economies, rely on the traditional usage of biomass for energy purposes. The major negative consequences are environmental and health effects. Additionally, the most remarkable social consequence is rural poverty which is directly linked to lack of access to electricity. This places the questions related to biomass utilization for energy production at the core of global welfare.The present work was performed as a part of a larger research project funded by Formas and which involves Swedish and Kenyan partners. The aim of this study was to gather basic knowledge about the characteristics of relevant biomass from sub-Saharan Africa, more specifically from Kenya. Eight different types of biomass, including agroforestry trees, agricultural residues and water hyacinth, were evaluated according to fuel characteristics and thermochemical properties. Ultimate and proximate analyses of the collected biomass were carried out, in addition to heating values analyses. Moreover, the biomass was pelletized and a thermogravimetric analysis was performed in a single pellet reactor. Finally, the composition of the residual ashes was determined. The results show that there was a large variation in the fuel characteristics and thermochemical behaviour of the studied agricultural residues and water hyacinth biomass types, whereas agroforestry trees had rather similar properties and thermochemical behaviour when combusted at the same temperature. In addition, results from the ash composition analyses showed large differences among the studied biomass types, which can be used to better predict and solve problems related to the combustion of these biomass types.

  • 86.
    Glim, Fredrik
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Rangordning av projekt inom Vattenfall Eldistribution2011Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
  • 87.
    Grahnström, Robert
    et al.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Langendahl, Truls
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Verkningsgradsförluster på kaplanturbin vid primärreglering2012Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In the Nordic electric power system the power output must always, instantaneous be consumed. This is upheld by the load frequency regulation.

    In E.ON hydropower this type of regulation is partly produced by the Kaplan turbine. This means that the turbine is constantly in regulation. Because the different construction of the Kaplan compared with for example Francis and Pelton, the Kaplan has a regulation system for the runner blade. This regulation system and the system for the guide vanes react individually and differently on a regulation change, with the result that the guide vanes and the runner blades will be unsynchronized. The purpose of this exam work is to examine this reaction and how big lost in efficiency this carry. To four fill this purpose a method in three steps is created, divided into pre-study, data collection and analysis & results.

    The pre-study includes a study in the variation of the electric power system and how the Kaplan will react to these.  Later, under the data collection phase this variation is simulated while the data is collected by specially made measurement equipment. From the data collected under the data collection phase, an analysis and result calculation can be made.

    The data is collected from Edensforsens hydro power plant and the result is that the runner blade and the guide vanes are almost always wrongly synchronized during load frequency regulation. But this fault is not mainly caused by different regulation speed but due to hysteres in the runner blade regulation system. The highest point of error is 0,54°, which is considered a lot. . Unsynchronized runner blades leads to an efficiency loss of 0,3 % compared with fully synchronization. The results are not statistically significant.  

    The report also makes suggestion on how the method can be improved, an alternative method and how the regulation errors can be avoided.

  • 88.
    Granholm, Mikael
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Översyn och optimering av kylsystem vid Norrlands Universitetssjukhus2013Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Västerbottens Läns Landsting arbetar kontinuerligt för att minimera sin verksamhets negativa påverkan på miljön. För att göra detta har de satt upp mål för 2020. Detta examensarbete kommer att försöka hjälpa dem att uppnå sina mål om en minskning med 17 procent av den specifika elanvändningen och en minskning med 22 procent av den specifika värmetillförseln jämfört med nivån år 2009.

    Syftet med detta projekt har varit att bidra till en ökad kunskap om hur kylsystemet för närvarande används och undersöka möjligheterna för en mer effektiv drift. Detta arbete fokuserar på tre huvudaspekter, driftsäkerhet, ekonomisk vinning och energieffektivitet. Målet med projektet har varit att undersöka tre eller fyra förbättringsförslag relaterade till de ovan nämnda aspekterna.

    Arbetet har delats upp i två delar för att uppnå projektets syfte och mål. Till att börja med en allmän översyn av kyltillförseln till Norrlands universitetssjukhus, och därefter en undersökning av de förslag som tagits fram. Granskningen har bestått av bearbetning av ritningar, driftkort och befintliga data. Data fanns främst tillgängligt för 2012. Översynen resulterade i en lista med nio förslag. De metoder som har använts är dels energiberäkningar i Excel, simuleringar av driftfall, riskanalys och stokastisk analys.

    Det viktigaste resultatet av översynen ligger i potentialen att minska den abonnerade maxeffekten från fjärrkyla. För att erhålla tillräckligt underlag för en investering bör en kylmaskin i byggnad 10B loggas. Tre förslag har undersökts utförligare, optimerad reglering av energitillförsel med en uppskattat sänkning av toppeffekten på 400 kW, energilager för kyla med en sänkning på ca 0,2 kW/kWh lagerkapacitet samt en sammankoppling av två kylnät som främst ökar redundansen i systemet.

  • 89.
    Granlund, Alexander
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Frostskyddsreglering i batterivärmeväxlare: Utvärdering av värmeväxlare av modell Ecoterm och Econet2018Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This master’s thesis was written in collaboration with Fläkt Woods in order to evaluate the frost protection control of two run-around coil heat exchangers, their older model Ecoterm and their newer model Econet. The frost protection of Ecoterm is only reliant on the temperature of the liquid circuit whereas Econet also regards the dewpoint temperature of the exhaust air, as to not activate the frostprotection unnecessarily. Ecoterm uses bypass control for frost protection and defrosting whereas Econet first increases the liquid flowrate before initiating bypass control. The evalutation is built upon data collected from the university hospital in Umeå, NUS, mainly during february 2018, with a minimum outside temperature of -23°C. Ecoterm starts defrosting when the liquid temperature reaches -5°C, which correlates to an outside temperature of -14°C irregardless if there is any risk of frost growth, which there was not during the measuring period. For Econet the results were more difficult to interpret, but imply that bypass control only was nescessary at two occasions during the whole measuring period. This is partly due to the design of Econet, which integrates the additional heating, normally reserved for a separate battery, into the heat exchangers liquid circuit. The results for Ecoterm show the limitations of single parameter controlled frost protection and why better frost protection control is necessary for highly efficient heat exchangers. For quantifiable results further studies are required.

  • 90.
    Granqvist, Daniel
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Klimatberäkningar för grundförstärkningsmetoden KC-pelare hos programmet Geokalkyl2017Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Vid projektering av väg- och järnväg är det viktigt att i ett tidigt skede som möjligt få en uppfattning om hur kostnaden kommer vara samt vilken klimatpåverkan arbetet kommer medföra.

    Det finns olika beräkningsprogram som utför både en kostnad och klimatkalkyl vid byggnation av väg- och järnväg. Exempel på beräkningsprogram är Geokalkyl och Klimatkalkyl.

    Tidigare har en fallstudie utförts mellan Klimatkalkyl och Geokalkyl där det visade på att vid användningen av grundförstärkningsmetoden kalkcement-pelare beräknar Geokalkyl klimatpåverkan 30 gånger så högt som klimatkalkyl.

    Syftet med det här projektet är att undersöka och vidareutveckla beräkningssättet för kalkcement-pelare hos programmet Geokalkyl.

    Grundförstärkningsmetoden kalkcement-pelare används bland annat för att stabilisera väg- och järnvägsbankar. Nedsättningen för pelarna är med hjälp av en maskin, blandningsbärare samt en tank förvarar blandningen. Vid nedsättning borrar maskinen ned till önskat djup. Då borren nått önskat djup roterar den upp samtidigt som blandning mängden släpps ut. Blandningen bildar tillsammans med jorden de fasta pelarna som stabiliserar marken.

    Geokalkyl gör beräkningarna i ett Excelverktyg där hänvisningar sker mellan olika blad i Excel. Ekvationen som gör beräkningen finns under fliken Indata. Alla arbetsmoment för kalkcement-pelare beräknas i samma ekvation där hänvisningar sker till separata informationsbilagor. Maskinförbrukningarna hänvisas till en dold Excelflik, Hagert. De justerbara parametrarna finns under fliken In parametrar. De parametrar som är justerbara är transportlängd och vilken klimatpåverkan pelarna har per längdmeter. Klimatpåverkan mäts i använda kWh och mängden koldioxidekvivalenter.

    För att uppnå syftet valdes följande utförande. Först inläsning på området, därefter tolkning av tidigare beräkningssätt och till sist uppbyggnad av nya beräkningssättet.

    Avgränsningarna för projektet är att endast se över specifika arbetsmoment som tillkommer vid användning av grundförstärkningsmetoden kalkcement-pelare hos Geokalkyl.

    Tidigare beräkningssättet hade bristfälliga hänvisningar till informationsbilagorna, samt felaktiga och bortglömda arbetsmoment. De beräkningarna som var felaktiga var dels att beräkningen tog hänsyn till en dimension men enligt informationsbilagorna skall den variera. Det var även en felaktig volym i pelarna, detta sågs genom att framställningsvärden per längdmeter pelare var med felaktig beräkning på dimension. Exempel på arbeten som tidigare beräkning ej tog hänsyn till var arbetet kring nedsättning, det vill säga förbrukning för maskinen och bäraren samt dess maskintransporter.

    För att bygga upp det nya beräkningssättet identifierades samtliga arbetsmoment kring kalkcement-metoden. Där respektive arbetsmoment fick en separat ekvation. Samtidigt så lyftes beräkningarna från Hagert till samma Excelblad som resterande beräkning. Alla antaganden från informationsbilagorna lyftes även in till Excelbladet. Genom att alla antaganden och beräkningar nu sker på samma Excelblad gör det beräkningen väldigt följsam. Förutom att beräkningen är följsam så är den lätt att justera genom att alla antaganden syns och att samtliga arbetsmoment har en separat ekvation. De arbeten som är utöver detta arbete måste ses över för att beräkningssättet skall kunna ersätta det befintliga i Geokalkyl.

  • 91.
    Granström, Jonas
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Effektivare fjärrvärmeanvändning med bättre exergiprestanda i fjärrvärmecentralen2011Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    District heating is today considered, one of the most important ways to increase our energy efficiency and reduce environmental damages with less emission from carbon dioxide. In Sweden around half of the homes and premises are connected to district heating and the numbers are increasing. 

    A lot of investigations during the 1990s have shown that return temperatures in the circulating system generally are too high. Along with this knowledge the importance and economical benefits has been spoken out but so far the overall work of cooling has gone slowly. 

    This being the point of view, focus is on reduced temperature of water in the primary circuit. Function and design of the district heating substations are investigated as one of the keys. Simulations and calculations have been made to compare an entirely parallel connection with a partially serial connection with focus on better exergy qualities of the substation. 

    The results show that the principle for how a substation is connected and the design of internal heat distribution can have an effect on the characteristics of the return temperature. It is possible to get a decrease in return temperature as outdoor temperature is falling instead of having an increased temperature, being the norm today. 

    The complete parallel connection figures as reference. Simulations show that the compared connection “Ventilation med återvinning” gives a flow rate weighted difference in return temperature of 5,1ºC. For the same connection but with the possibility of input mass flow from the return of the hot water before primary water the difference was 11,6ºC. 

    It is realistic to believe that this would have a corresponding effect on the system in larger scale. If so there is a possibility of better economy in the production of combined power and heat and also a need of system development to reach lower return temperatures. Dimensioning software for district heating substations to minimize destruction of exergy will also be needed.

  • 92.
    Grenbäck, Albin
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Utredning av potentiell installation av bergvärme2019Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    A housing society in the municipality of Umeå have under a period found interest in lowering their heating costs for the property. The property consists of 4 buildings in total with 3 of them being a multi-family residential containing 36 apartments in total and one of the buildings is an office building. The housing society was interested in knowing what a geothermal heating system would cost and how long the payback time would be.

    With the help of the old drawings the property was drawn in Revit and used to calculate the heat loss from different layers of the climate barrier and heat loss from the ventilation system. The internal heat generation was calculated by using standard values. When the total heat losses were calculated, and the internal heat generation was known the yearly energy needs were calculated by using a duration diagram.

    Then the yearly energy needs were compared to the actual yearly energy consumption of district heat and the software Nibe Dim was used to simulate three different alternatives.

    The investment that showed best result showed that the total cost for the investment would be 1 800 000 SEK and the annual saving 75 000 SEK/year. The payback time for the investment would however be as high as 24 years.

  • 93. Grimm, Alejandro
    et al.
    Etula, Jarkko
    Salh, Roushdey
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Kalén, Gunnar
    Segerström, Markus
    Brücher, Jörg
    Söderberg, Christer
    Soukup, David
    Pfeifer, Christoph
    Larsson, Sylvia H.
    Slagging and fouling characteristics during co-combustion of Scots pine bark with low-temperature dried pulp and paper mill chemical sludge2019In: Fuel processing technology, ISSN 0378-3820, E-ISSN 1873-7188, Vol. 193, p. 282-294Article in journal (Refereed)
    Abstract [en]

    This paper shows how chemical sludge (CS) generated during wastewater treatment at a paperboard mill can be quickly dried at low-temperature and employed in bark-fired boilers to reduce slagging and corrosion problems. By using a cyclone-dryer operated at an inlet-air velocity of 110 m/s and a temperature of 90 degrees C, the dry-matter content of CS was increased from approximately 19 to 82%. The residence time of CS inside the cyclone was approximately 2 s when using the inlet-air velocity mentioned above. Disaggregation of the feedstock caused by collisions with the cyclone wall and between particles played a crucial role in enhancing the efficiency of heat and mass transfer. Three co-pelletized mixtures of Scots pine bark (SPB) and dried-CS were combusted in a 40 kW fixed-bed burner. Flue gas analysis was performed with a gas analyser. Coarse and fine ash were analysed by SEM-EDS and XRD. NO,, and SO2 emissions increased with increasing amount of CS in the mixtures. Mono combustion of SPB resulted in a large quantity of slag (i.e., molten ash) with a high degree of sintering (i.e., hardness of the slag), and ash deposits formed on heat transfer surfaces were rich in K2SO4 and KCI. Mixtures of SPB and CS were less prone to slagging, and the amount of alkali chloride in the deposits was reduced in favour of alkali sulphate formation.

  • 94. Grimm, Alejandro
    et al.
    Ohrnan, Marcus
    Lindberg, Therese
    Fredriksson, Andreas
    Boström, Dan
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics, Energy Technology and Thermal Process Chemistry.
    Bed Agglomeration Characteristics in Fluidized-Bed Combustion of Biomass Fuels Using Olivine as Bed Material2012In: Energy & Fuels, ISSN 0887-0624, E-ISSN 1520-5029, Vol. 26, no 7, p. 4550-4559Article in journal (Refereed)
    Abstract [en]

    The bed agglomeration characteristics during combustion of typical biomass fuels were determined in a bench-scale bubbling fluidized-bed reactor (5 kW) using olivine and quartz sand as bed material. The fuels studied include willow, logging residues, wheat straw, and wheat distiller's dried grain with solubles (wheat DDGS). Bed material samples and agglomerates were analyzed by means of scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM-EDS), for morphology and elemental composition. Furthermore, bed ash particles were separated by sieving from the bed material samples and analyzed for elemental composition by SEM-EDS and for determination of crystalline phases by powder X-ray diffraction (XRD). Chemical equilibrium calculations were performed to interpret the experimental findings of layer formation and reaction tendencies in both bed materials. Significant difference in the agglomeration tendency between olivine and quartz was found during combustion of willow and logging residues. These fuels resulted in inner layers that were more dependent on the bed material composition, and outer layers that have a composition similar to the fuel ash characteristics. The elemental composition of the inner layer formed on the quartz bed particles was dominated by Si, K, and Ca. In the olivine bed, the inner layer consisted mainly of Mg, Si, and Ca. Chemical equilibrium calculations made for both bed materials showed a low chemical driving force for K to react and be retained by the olivine bed particles, which is in accordance to the experimental findings. For the quartz case, the inner layer was found responsible for the initiation of the agglomeration process. The composition of the fewer and more porous agglomerates found after the experiments in the olivine bed showed neck composition and characteristics similar to the individual bed ash particles found in the bed or outer bed particle coating composition. For DDGS (rich in S, P, K, and Mg) and wheat straw (rich in Si and K), no significant differences in the bed agglomeration tendency between olivine and quartz bed materials were found. The results show that the bed particle layer formation and bed agglomeration process were associated to direct adhesion of bed particles by partly molten fuel ash derived K Mg phosphates for DDGS and K-silicates for wheat straw.

  • 95.
    Gulliksson, Thomas
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Jämförelse av energiberäkningsprogram för byggnader2015Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The aim of this work was to determine differences between the building energy simulation softwares IDA Indoor Climate and Energy (IDA ICE), VIP-Energy (VIP) and IES Virtual Environment (IES) with respect to functions, user experience and results from simulations.

    Of the three options for comparison the focus of this work was put on simulation results. A building was modelled in the softwares with identical input parameters where it was possible. Simulation results of the buildings total energy usage were analyzed. Sensitivity analyses of input parameters such as U-values, air flows, room temperature etc. were also performed.

    The results of the simulations showed that both IDA ICE and VIP calculated a total energy usage of 129 MWh per year for the building. IDA ICE calculated a specific energy usage, defined by Boverkets Byggregler (BBR), to 101.4 [kWh/(m2 year) heated area] while VIP calculated a usage of 102.9 [kWh/(m2 year) heat area]. The reason for the different results was that VIP calculated a smaller part of the heat recovered from the ventilation heat exchanger which led to a higher addition from the heating system.

    The sensitivity analysis showed that the U-value of walls, floor and roof were significant parameters. The reason for that was because they each stood for about 30 % of the total envelope area. The specific energy usage changed about 5 % when the room temperature changed with . Other significant settings and parameters were ventilation flow, shadow calculation settings in VIP and settings for the thermal bridges in IDA ICE.

    IDA ICE is an energy and climate simulation software well suited for calculation of power demand for heating and cooling, yearly energy demand, climate simulations etc. The software is user-friendly even though it is quite complex.

    VIP is an energy simulation software well suited for calculation of yearly energy demand. The software is easy to use but suffers from a few major disadvantages such as no graphical view of the building, poor compatibility with certifications etc.

    IES is an energy and climate simulation software. The software has a high learning curve and poor usability and had to be excluded from the simulations due to the time limitation of this work.

    It was concluded that for engineering consultants that works with energy and climate simulations of buildings, IDA ICE is the best choice.

  • 96.
    Gunnarsson, Per
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Förstärkning av utsatta delar av elnätet med lokala energisystem: En undersökning om lokala energisystem kan implementeras i elnätet för att öka leveranssäkerheten av el till öar2017Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Det svenska elnätet har en mycket hög leveranssäkerhet på den el som skickas till kunderna och på många ställen kan elen levereras från flera håll till samma punkt. I utkanterna av elnätet som exempelvis öar, har inte elnätet samma säkerhet längre och om ett avbrott uppstår kan det vara vid dåligt väder. Framkomligheten blir svår och det kan ta tid att få dit en reparatör som kan laga felet.

    Syftet med det här arbetet var att undersöka om Umeå Energi Elnät (UEEN) skulle kunna använda sig av lokala energisystem för att motverka svåravhjälpta avbrott på öar och områden som är utsatta för den typen av avbrott, samt undersöka vilka komponenter som skulle krävas i en sådan lösning. Målet var att skapa ett lösningspaket som kan skalas om till olika antal abonnenter.

    Lösningen togs fram genom att först undersöka vilka komponenter som vanligtvis används i lokala energisystem. Därefter undersöktes och jämfördes komponenternas styrkor och svagheter med hjälp av fakta och resultat från vetenskapliga artiklar. De komponenter som inte var lämpade för den här typen av applikation eller som inte var tillräckligt bra, valdes successivt bort tills den bäst lämpade lösningen kvarstod. Den bästa lösningen blev ett litiumjonbatteri som laddas direkt av elnätet då den kräver lite underhåll, kan leverera höga effekter utan att ta skada och har en låg kapacitetsförlust. Anledningen till varför ingen lokal elproduktionsanläggning var med i lösningen beror på att ingen lösning är tillräckligt pålitlig för att kunna användas vid uppladdning av batterilagret och blir för stora om de ska användas till att göra ön självförsörjande. Detta beror på att de lösningar som är bäst lämpade som lokala elproduktionsanläggningar är för väderberoende och de lösningar som inte beror av vädret blir för stora och dyra för att vara rimliga alternativ.

    Storleksdimensioneringen av batterilagret skedde utifrån avbrottsstatistik för Umeås landsbygdsnät. Genom att göra en täthetsfördelning över landsbygdsnätets avbrottsstatistik kunde sedan den bästa fördelningsfunktionen passas in till det datat. Den fördelning som passade bäst till datat var en weibullfördelning som visade i sin kumulativa täthetsfunktion att drygt 80 % av alla avbrott som sker i ett område, pågår i tre timmar eller mindre. Genom att anta att avbrotten på öar också följer den här funktionen sånär som på att deras avbrott blir längre, kunde en dimensioneringsmetod tas fram. Metoden gick ut på att energilagret dimensioneras efter de tre på varandra följande timmar med högst energiförbrukning i ett givet område under ett år, vilket garanterar att strömförsörjningen kan täckas i tre timmar. Med tanke på att energiförbrukningen varierar mycket beroende på årstid och tid på dygnet kan batterilagret därför också klara mycket längre avbrott än tre timmar. Anledningen till varför just tre timmar valdes beror på att ett större energilager inte täcker upp så många procent fler avbrott än ett energilager på tre timmar och ett mindre energilager skulle inte klara tillräckligt långa avbrott. Det finns teknologier som inom några år kan ha mognat tillräckligt för att vara en bättre lösning än den som presenteras i den här rapporten, men den här lösningen är fortfarande tillräckligt bra för att kunna användas till att motverka långa avbrott och är en lösning som troligen skulle fungera länge efter att den installerats.

  • 97.
    Gustavsson, Isak
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Energikartläggning och energioptimering av bergtunnel: Ett arbete i Umeå Energis regi kring bergtunnelns energianvändande samt optimering av ventilationen.2015Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Umeå Energi is a company that will be needed to map the use of energy in their facilities. This thesis is an indication of how this mapping will be like and what the result of the tunnel will show. Together with Umeva, Umeå Energi has a 3,5 kilometres long tunnel where the district heating and district cooling pipes goes. There are also pipes for sewer and drinking water. More thoroughly the thesis shows the energy use of the tunnel and also problem solving for better energy efficient considering ventilation. The quality of air in the tunnel is also analysed where the relative humidity of air is the most studied. The aims of the work are that Umeå Energi can reduce their electrical energy use and that they will get a better knowledge about the air quality in the tunnel. Measurements that where done was for some of the electric devices in the tunnel and there were also previously measurements done for the relative humidity of air, temperature and radon. The payments that has been for the tunnel under 2014 comes from an electrical energy use at 180000 kWh. An investigation about the electricity to the tunnel is done in the thesis and the conclusion is that the real electrical energy use of the tunnel should be 200000 kWh for 2014. The total energy use of the tunnel for 2014 is 460000 kWh, where heating and electricity are included. The analysis of the humidity problem results in that the inlet temperature of air is too high in relation to the air temperature of the tunnel and also that there is an inflow of small water amounts on several parts of the tunnel. Through these factors the relative humidity of air gets more worse and gets as high as 83-84 % in the tunnel. It also comes forward that one of the fans may bring polluted air to the tunnel. If the old fans are replaced by new EC-fans the electrical energy use will reduce. If all the fans would be replaced it gives a positive annuity of 10100 SEK/year but if the fan at Uminova not is replaced it gives a positive annuity of 11200 SEK/year. The payback time of the later choice is approximately 4 years. 

  • 98.
    Gårdbro, Gustav
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Techno-economic modeling of the supply chain for torrefied biomass2014Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Torrefaction and densification of biomass can provide an important piece in the puzzle of phasing out fossil fuels in favor of renewable alternatives. This new energy carrier shares many of the advantages with fossil coal in terms of energy density, hydrophobicity and burner feeding but is carbon neutral and renewable. It also lacks the challenges of many other renewable alternatives, especially irregular availability.

    A model was developed in Excel as sales support for BioEndev, one of the leading actors in the process of taking torrefaction to a commercial market, assessing the black pellet supply chain from feedstock to end user and comparing it to white pellets. Data was obtained from literature, industry and BioEndev. The model can be used for different parameters for price of feedstock, capital and operating expenditures, transport and handling costs and analyze 28 different cases. It also includes simplified calculations for energy input and greenhouse gas emissions.

    A case study for two different supply chains was performed with the model. One assessed a production facility in northern Sweden with distribution to a consumer in Denmark. The other a torrefaction plant in southeastern USA with distribution to a consumer in the Netherlands.

    The cost for delivering black and white pellets from Sweden to Denmark was found to be 33.0 €/MWh and 35.3 €/MWh respectively. For the case of delivering from USA to the Netherlands, the total supply chain cost was 27.6 €/MWh for white pellets and 24.7 €/MWh for black pellets.

    Suggestions for further work are to 1) develop the model outside this study’s limitations, for example by adding integration options for the torrefaction facility or by different end user configurations, and 2) expand the scope to also comparing black pellets to coal to see how big the gap is and which political incentives that could shrink this gap. 

  • 99.
    Gåsste, Filip
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Energieffektivisering av byggnad M7 i Umedalen: Energikartläggning med förslag till energieffektiviserande åtgärder ur en ekonomisk synvinkel2016Independent thesis Basic level (university diploma), 180 HE creditsStudent thesis
    Abstract [en]

    In Sweden, housing and services use about 40 % of all energy in which households and other premises stand for 90 % of these. The Parliament has decided that energy consumption must be reduced by 20 % to year 2020 and by 50 % to year 2050. Due to energy efficiency there are great savings to be found in costs, indoor climate and energy. The purpose has been to recommend cost efficient measures to lower the energy consumption. An energy survey has been made in a building, M7, located in Umedalen, Umeå belonging to Balticgruppen AB. The energy performance is 136 kWh/m2*year according to the energy declaration. The calculations of the energy measures result in a drop of energy usage by 66 % to an energy performance of 46 kWh/m2*year and a payback period of 8,5 years. The most cost efficient measures are made in the ventilation with the lowest payback period of only 3 days.

  • 100.
    Gåsste, Filip
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Uppföljning av energikartläggning: Hedbergska skolan i Sundsvall2018Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The world faces major challenges to cope with global warming and climate change. As a step in limiting temperature rise by two degrees, the UN Climate Change Conference in Paris 2015 decided on a binding climate agreement to begin in 2020.

    In order to achieve the energy goals of the municipality of Sundsvall in reducing energy consumption by 20%, a number of projects with high energy savings in municipal property are being implemented. WSP Systems was contacted in 2014 and preformed an energy survey in the school “Hedbergska skolan” to identify measures for reducing energy usage, resulting in the pre-study report "Förstudie energieffektivisering". The result of the energy audit resulted in the energy saving project "Hedbergska Energispar" which includes various types of measures and renovations.

    The purpose of this work is to evaluate the potential of energy savings and the cost-effectiveness in the measures recommended in the report Förstudie energieffektivisering.

    In order to improve future energy projects, this work will present different kind of suggestions of improvements in the approach of energy surveys.

    In 2013 the energy use of Hedbergska skolan was 2250 MWh of which 1600 MWh where district heating and 650 MWh where electricity. The energy performance of the school was 241 kWh/m2/year in 2013.

    The recommended energy measures in Förstudie energieffektivisering where calculated to decrease energy consumption by 35,5% and to result in an energy performance of 157 kWh/m2/year. These energy savings where obtained by actions including; changing windows, new ventilation system and new indoor lightning system.

    The project, Hedbergska energispar will have a decrease of energy usage by 41,3% and an energy performance of 143 kWh/m2/year when finished, without changing the windows. However, this comes with high costs.

    There are some difficulties in comparing the result of the energy savings project to the energy audit report since the project differs in some ways from the pre-study. Therefore, it is difficult to draw conclusions from this. As a consequence, the calculation presented in the pre-study energy audit are affected by this and can no longer be used as a basis for actions. Recommendations based on the work with the evaluation are to clarify what the purpose of the energy audit is and what costs for actions are acceptable for the client. Energy calculations should be focused on more extensive calculations for indoor lightning and ventilation using the latest climate data.  

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