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  • 1.
    Ajjan Godoy, Fátima Nadia
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Biohybrid Polymer Electrodes for Renewable Energy Storage2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Daily and seasonally fluctuating energy supply and demand requires adequate energy storage solutions. In recent years electrochemical supercapacitors have attracted considerable attention due to their ability to both store and deliver electrical energy efficiently. Our efforts are focused on developing and optimizing sustainable organic electrode materials for supercapacitors based on renewable bioorganic materials, offering a cheap, environmentally friendly and scalable alternative to store energy. In particular, we are using the second most abundant biopolymer in nature, lignin (Lig), which is an insulating material. However, when used in combination with electroactive and conducting polymers such as polypyrrole (PPy) and poly(3,4-ethylenedioxythiophene) (PEDOT), the biohybrid electrodes PPy/Lig and PEDOT/Lig display significantly enhanced energy storage performance as compared to the pristine conducting polymers without the lignin. Redox cyclic voltammetry and galvanostatic charge/discharge measurements indicate that the enhanced performance is due to the additional pseudocapacitance generated by the quinone moieties in lignin. Moreover, a conjugated redoxpolymer poly(aminoanthraquinone) PAAQ, with intrinsic quinone functions and excellentstability, has been combined with lignin and PEDOT resulting in a trihybrid bioelectrode. PEDOT compensates the low conductivity of PAAQ and provides electrical pathways to the quinone groups. The electrochemically generated quinones undergo a two electron, two protonredox process within the biohybrid electrodes as revealed by FTIR spectroelectrochemistry.These remarkable features reveal the exciting potential of a full organic energy storage device with long cycle life. Therefore, supercapacitor devices were designed in symmetric or asymmetric two electrode configuration. The best electrochemical performance was achieved by the asymmetric supercapacitor based on PEDOT+Lignin/PAAQ as the positive electrode and PEDOT/PAAQ as the negative electrode. This device exhibits superior electrochemical performance and outstanding stability after 10000 charge/discharge cycles due to the synergistic effect of the two electrodes. Finally, we have characterized the response of this supercapacitor device when charged with the intermittent power supply from an organic photovoltaic module. We have designed charging/discharging conditions such that reserve power was available in the storage device at all times. This work has resulted in an inexpensive fully organic system witht he dual function of energy conversion and storage.

    List of papers
    1. Biopolymer hybrid electrodes for scalable electricity storage
    Open this publication in new window or tab >>Biopolymer hybrid electrodes for scalable electricity storage
    2016 (English)In: Materials Horizons, ISSN 2051-6347, E-ISSN 2051-6355, Vol. 3, no 3, p. 174-185Article, review/survey (Refereed) Published
    Abstract [en]

    Powering the future, while maintaining a cleaner environment and a strong socioeconomic growth, is going to be one of the biggest challenges faced by mankind in the 21st century. The first step in overcoming the challenge for a sustainable future is to use energy more efficiently so that the demand for fossil fuels can be reduced drastically. The second step is a transition from the use of fossil fuels to renewable energy sources. In this sense, organic electrode materials are becoming increasingly attractive compared to inorganic electrode materials which have reached a plateau regarding performance and have severe drawbacks in terms of cost, safety and environmental friendliness. Using organic composites based on conducting polymers, such as polypyrrole, and abundant, cheap and naturally occurring biopolymers rich in quinones, such as lignin, has recently emerged as an interesting alternative. These materials, which exhibit electronic and ionic conductivity, provide challenging opportunities in the development of new charge storage materials. This review presents an overview of recent developments in organic biopolymer composite electrodes as renewable electroactive materials towards sustainable, cheap and scalable energy storage devices.

    Place, publisher, year, edition, pages
    ROYAL SOC CHEMISTRY, 2016
    National Category
    Other Environmental Engineering
    Identifiers
    urn:nbn:se:liu:diva-128741 (URN)10.1039/c5mh00261c (DOI)000375296600002 ()
    Note

    Funding Agencies|Knut and Alice Wallenberg Foundation; Wallenberg Scholar grant

    Available from: 2016-05-31 Created: 2016-05-30 Last updated: 2017-11-30
    2. Spectroelectrochemical investigation of redox states in a polypyrrole/lignin composite electrode material
    Open this publication in new window or tab >>Spectroelectrochemical investigation of redox states in a polypyrrole/lignin composite electrode material
    Show others...
    2015 (English)In: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 3, no 24, p. 12927-12937Article in journal (Refereed) Published
    Abstract [en]

    We report spectroelectrochemical studies to investigate the charge storage mechanism of composite polypyrrole/lignin electrodes. Renewable bioorganic electrode materials were produced by electropolymerization of pyrrole in the presence of a water-soluble lignin derivative acting as a dopant. The resulting composite exhibited enhanced charge storage abilities due to a lignin-based faradaic process, which was expressed after repeated electrochemical redox of the material. The in situ FTIR spectroelectrochemistry results show the formation of quinone groups, and reversible oxidation-reduction of these groups during charge-discharge experiments in the electrode materials. The most significant IR bands include carbonyl absorption near 1705 cm(-1), which is attributed to the creation of quinone moieties during oxidation, and absorption at 1045 cm(-1) which is due to hydroquinone moieties.

    Place, publisher, year, edition, pages
    ROYAL SOC CHEMISTRY, 2015
    National Category
    Materials Chemistry
    Identifiers
    urn:nbn:se:liu:diva-120069 (URN)10.1039/c5ta00788g (DOI)000356022800044 ()
    Note

    Funding Agencies|Knut and Alice Wallenberg foundation; Marie Curie network Renaissance; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University [2009-00971]

    Available from: 2015-07-06 Created: 2015-07-06 Last updated: 2017-12-04
    3. High performance PEDOT/lignin biopolymer composites for electrochemical supercapacitors
    Open this publication in new window or tab >>High performance PEDOT/lignin biopolymer composites for electrochemical supercapacitors
    Show others...
    2016 (English)In: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 4, no 5, p. 1838-1847Article in journal (Refereed) Published
    Abstract [en]

    Developing sustainable organic electrode materials for energy storage applications is an urgent task. We present a promising candidate based on the use of lignin, the second most abundant biopolymer in nature. This polymer is combined with a conducting polymer, where lignin as a polyanion can behave both as a dopant and surfactant. The synthesis of PEDOT/Lig biocomposites by both oxidative chemical and electrochemical polymerization of EDOT in the presence of lignin sulfonate is presented. The characterization of PEDOT/Lig was performed by UV-Vis-NIR spectroscopy, FTIR infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy, cyclic voltammetry and galvanostatic charge-discharge. PEDOT doped with lignin doubles the specific capacitance (170.4 F g(-1)) compared to reference PEDOT electrodes (80.4 F g(-1)). The enhanced energy storage performance is a consequence of the additional pseudocapacitance generated by the quinone moieties in lignin, which give rise to faradaic reactions. Furthermore PEDOT/Lig is a highly stable biocomposite, retaining about 83% of its electroactivity after 1000 charge/discharge cycles. These results illustrate that the redox doping strategy is a facile and straightforward approach to improve the electroactive performance of PEDOT.

    Place, publisher, year, edition, pages
    ROYAL SOC CHEMISTRY, 2016
    National Category
    Biological Sciences
    Identifiers
    urn:nbn:se:liu:diva-125323 (URN)10.1039/c5ta10096h (DOI)000368839200035 ()
    Note

    Funding Agencies|Power Papers project from the Knut and Alice Wallenberg foundation; Wallenberg Scholar grant from the Knut and Alice Wallenberg foundation; Marie Curie network Renaissance (NA); European Research Council by Starting Grant Innovative Polymers for Energy Storage (iPes) [306250]; Basque Government

    Available from: 2016-02-23 Created: 2016-02-19 Last updated: 2017-11-30
  • 2.
    Alfredson, Jens
    et al.
    Linköping University, Department of Computer and Information Science. Linköping University, Faculty of Science & Engineering. Saab Aeronaut, Linkoping, Sweden.
    Trabasso, Luís Gonzaga
    Linköping University, Department of Computer and Information Science, Human-Centered systems. Linköping University, Faculty of Science & Engineering. ITA, Brazil.
    Blomstrand, Niklas
    Linköping University, Department of Computer and Information Science. Linköping University, Faculty of Science & Engineering.
    Eckerberg, Maria
    Linköping University, Department of Computer and Information Science. Linköping University, Faculty of Science & Engineering.
    Klamer, Linda
    Linköping University, Department of Computer and Information Science. Linköping University, Faculty of Science & Engineering.
    Ledin, Johanna
    Linköping University, Department of Computer and Information Science. Linköping University, Faculty of Science & Engineering.
    Tarander, Jasmine
    Linköping University, Department of Computer and Information Science, Human-Centered systems. Linköping University, Faculty of Science & Engineering.
    Bång, Magnus
    Linköping University, Department of Computer and Information Science, Human-Centered systems. Linköping University, Faculty of Science & Engineering.
    Engine Failure Induced Task Load Transient for Simulation Based Certification Aiding for Aircraft2018In: ADVANCES IN HUMAN ASPECTS OF TRANSPORTATION, SPRINGER INTERNATIONAL PUBLISHING AG , 2018, Vol. 597, p. 79-86Conference paper (Refereed)
    Abstract [en]

    This study is one of a series of studies, researching various aspects that all aim at enhanced simulation based certification aiding for aircraft. An experimental within-group design study was performed with 10 participants ( 5 male, and 5 female). The results showed a significant difference, F(2,16) = 5.11, p = 0.019, in mental workload between an engine failure condition and an normal condition for eye blink frequency. No effect of speed at the engine failure event on mental workload was found.

  • 3.
    Andersson, Jim
    et al.
    Luleå University of Technology, Sweden.
    Lundgren, Joakim
    Luleå University of Technology, Sweden.
    Malek, Laura
    Lund University, Sweden.
    Hultegren, Christian
    Lund University, Sweden.
    Pettersson, Karin
    Chalmers University of Technology, Gothenburg, Sweden.
    Wetterlund, Elisabeth
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    System studies on biofuel production via integrated biomass gasification2013Report (Other academic)
    Abstract [en]

    A large number of national and international techno-economic studies on industrially integrated gasifiers for production of biofuels have been published during the recent years. These studies comprise different types of gasifiers (fluidized bed, indirect and entrained flow) integrated in different industries for the production of various types of chemicals and transportation fuels (SNG, FT-products, methanol, DME etc.) The results are often used for techno-economic comparisons between different biorefinery concepts. One relatively common observation is that even if the applied technology and the produced biofuel are the same, the results of the techno-economic studies may differ significantly.

    The main objective of this project has been to perform a comprehensive review of publications regarding industrially integrated biomass gasifiers for motor fuel production. The purposes have been to identify and highlight the main reasons why similar studies differ considerably and to prepare a basis for “fair” techno-economic comparisons. Another objective has been to identify possible lack of industrial integration studies that may be of interest to carry out in a second phase of the project.

    Around 40 national and international reports and articles have been analysed and reviewed. The majority of the studies concern gasifiers installed in chemical pulp and paper mills where black liquor gasification is the dominating technology. District heating systems are also well represented. Only a few studies have been found with mechanical pulp and paper mills, steel industries and the oil refineries as case basis. Other industries have rarely, or not at all, been considered for industrial integration studies. Surprisingly, no studies regarding integration of biomass gasification neither in saw mills nor in wood pellet production industry have been found.

    There are several reasons why the results of the reviewed techno-economic studies vary. Some examples are that different system boundaries have been set and that different technical and economic assumptions have been made, product yields and energy efficiencies may be calculated using different methods etc. For obvious reasons, the studies are not made in the same year, which means that different monetary exchange rates and indices have been applied. It is therefore very difficult, and sometimes even impossible, to compare the technical as well as the economic results from the different studies. When technical evaluations are to be carried out, there is no general method for how to set the system boundaries and no right or wrong way to calculate the system efficiencies as long as the boundaries and methods are transparent and clearly described. This also means that it becomes fruitless to compare efficiencies between different concepts unless the comparison is done on an exactly equal basis.

    However, even on an equal basis, a comparison is not a straight forward process. For example, calculated efficiencies may be based on the marginal supply, which then become very dependent on how the industries exploit their resources before the integration. The resulting efficiencies are therefore very site-dependent. Increasing the system boundaries to include all in- and outgoing energy carriers from the main industry, as well as the integrated gasification plant (i.e. total plant mass and energy balance), would inflict the same site-dependency problem. The resulting system efficiency is therefore a measure of the potential improvement that a specific industry could achieve by integrating a biomass gasification concept.

    When estimating the overall system efficiency of industrial biorefinery concepts that include multiple types of product flows and energy sources, the authors of this report encourage the use of electrical equivalents as a measure of the overall system efficiency. This should be done in order to take the energy quality of different energy carriers into concern.

    In the published economic evaluations, it has been found that there is a large number of studies containing both integration and production cost estimates. However, the number of references for the cost data is rather limited. The majority of these have also been published by the same group of people and use the same or similar background information. The information in these references is based on quotes and estimates, which is good, however none of these are publically available and therefore difficult to value with respect to content and accuracy.

    It has further been found that the variance in the operational costs is quite significant. Something that is particularly true for biomass costs, which have a high variance. This may be explained by natural variations in the quality of biomass used, but also to the different markets studied and the dates when the studies were performed. It may be seen from the specific investment costs that there is a significant spread in the data. It may also be seen that the differences in capital employed and process yields will result in quite large variations in the production cost of the synthetic fuels. On a general note, the studies performed are considering future plants and in some cases assumes technology development. It is therefore relevant to question the use of today’s prices of utilities and feedstock’s. It is believed that it would be more representative to perform some kind of scenario analysis using different parameters resulting in different cost assumptions to better exemplify possible futures.

    Due to the surprising lack of reports and articles regarding integration of biomass gasifiers in sawmills, it would be of great interest to carry out such a study. Also larger scale wood pellet production plants could be of interest as a potential gasification based biorefinery.

  • 4.
    Andric, Jelena S.
    et al.
    Chalmers University of Technology, Sweden.
    Lindström, Stefan B
    Linköping University, Department of Management and Engineering, Solid Mechanics. Linköping University, Faculty of Science & Engineering.
    Sasic, Srdjan M.
    Chalmers University of Technology, Sweden.
    Nilsson, Håkan
    Chalmers University of Technology, Sweden.
    PARTICLE-LEVEL SIMULATIONS OF FLOCCULATION IN A FIBER SUSPENSION FLOWING THROUGH A DIFFUSER2017In: Thermal Science, ISSN 0354-9836, E-ISSN 2334-7163, Vol. 21, p. S573-S583Article in journal (Refereed)
    Abstract [en]

    We investigate flocculation in dilute suspensions of rigid, straight fibers in a decelerating flow field of a diffuser. We carry out numerical studies using a particle-level simulation technique that takes into account the fiber inertia and the non-creeping fiber-flow interactions. The fluid flow is governed by the Reynolds averaged Navier-Stokes equations with the standard k-omega eddy-viscosity turbulence model. A one-way coupling between the fibers and the flow is considered with a stochastic model for the fiber dispersion due to turbulence. The fibers interact through short-range attractive forces that cause them to aggregate into flocs when fiber-fiber collisions occur. We show that ballistic deflection of fibers greatly increases the flocculation in the diffilser. The inlet fiber kinematics and the fiber inertia are the main parameters that affect fiber flocculation in the predffuser region.

  • 5.
    Angren, Jimmy
    et al.
    Linköping University, Department of Management and Engineering, Environmental Technology and Management. Linköping University, The Institute of Technology.
    Arnoldsson, Joel
    Linköping University, Department of Management and Engineering, Environmental Technology and Management. Linköping University, The Institute of Technology.
    Fjärrvärmens konkurrenskraft: En analys av olika uppvärmningsteknikers kostnadseffektivitet och kunders beslutsfattande2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Historically, the Swedish heat market has been dominated by district heating, which basically has been the only cost effective option where it’s available. Lately, however, the situation has begun to change, partly because of the increased efficiency of heat pumps, but also due to changes in energy policies and increased customer demands - which has led to a more competitive heating market. This study aims to quantitatively and qualitatively analyze the competitiveness of district heating compared to alternative heating technologies, focusing on three segments; apartment buildings, public facilities and other premises.

    After an initial market analysis, heat pumps in combination with electricity or district heating as peak load, as well as pellets in combination with RME, were identified as the most competitive alternatives to district heating. The estimated life cycle cost of the heating systems was then calculated for a number of facilities, as a function of its energy needs and utilization time. These facilities were chosen based on consumption statistics from Vattenfall. Furthermore, several interviews with industry experts were conducted, in parallel with an inquiry that was addressed to energy and climate advisers in Sweden. The survey aimed to get an up-to-date status report of property owners' views on the heat market and thus contribute to the qualitative analysis.

    The result shows, given the assumptions that the authors find reasonable, that there are minor differences between district heating and its competition if viewed from a cost perspective only. For a typical apartment building, district heating is slightly more beneficial, but for a typical public facility/other premise geothermal heat is a marginally cheaper option. Exhaust air heat pump with district heating as peak load is in both cases a cost effective option. However, the sensitivity analysis shows that the life cycle cost can differ by more than a factor of 2,5 for all heating systems depending on what assumptions are made.

    Hence, the choice of heating system is from the property owner's perspective closely related to perceived risk and the extent to which trust towards the heat supplier exists. Effortless and reliable operations appear to be the most important factor besides costs for all customer types. Also, there is uncertainity about future price development among all segments, which can lead to impaired calculations. Thus, the customers’ trust for the existing heat distributor, as well as the relationship between them, may fundamentally affect the choice of heating system. A high investment cost is a crucial barrier since it carries a higher risk while also competing with other efficiency measures about the same budget. Public facility owners are keen about the environmental aspects while this question is of less importance for apartment buildings owners. It may be of importance for other premise owners depending on the owner.

    In summary, it’s difficult to determine the most competitive heating system since the cost effectiveness for all heating systems can vary a lot depending on the assumptions. However, this study indicates that a power based price model will strengthen the competitiveness for district heating among apartment buildings. Among public facilities and other premises it will become more vulnerable to other heating technologies, especially to geological heat pumps.

    To stay competitive it’s important for district heating distributors to be transparent and clear in the communication with their customers, particularly in regards of price development. In the long term it may be necessary to include more than district heating in their offer, for example support in energy efficiency measures, an environmentally certified heat supply or an offer of guaranteed indoor- comfort.

  • 6.
    Apeaning, Raphael Wentemi
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Energy Efficiency and Management in Industries: a case study of Ghana’s largest industrial area.2012Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The judicious use of energy by industries is a key lever for ensuring a sustainable industrial development. The cost effective application of energy management and energy efficiency measures offers industries with an effective means of gaining both economic and social dividend, also reducing the negative environmental effects of energy use. Unfortunately, industries in developing countries are lagging behind in the adoption of energy efficiency and management measures; as such missing the benefits of implementation.

    This study is aims at enhance the knowledge of industrial energy efficiency and management strategies in Ghana, by investigating the present level of energy (and efficiency) management practices in Ghana largest industrial park (i.e. Tema industrial area). The study also incorporates the investigation of also investigation of barriers to and driving forces for the implementation of energy efficiency measure; to shed light on the rationale for both the adoption and non-adoption of cost effective industrial energy efficient technologies in Ghana. This study was carried out using a semi-structure interview due to the explorative nature of the study. The interviews were conducted in sessions, in the first session respondents were asked describe the energy management strategies in used in the respective companies. In the second session, respondents were asked to fill a structured questionnaire covering the various aspects of the study.

    The results reveal that energy is poorly managed in the industrial area and there is an energy efficiency gap resulting from the low implementation energy efficiency measures. In addition the reveals that the important barriers impeding the implementation of cost effective energy efficiency technologies or measures in the surveyed firms principally stems from rational behavior economic barriers, which are deeply linked to the lack of government frameworks for industrial energy efficiency. The study also finds that economic gains related to ‘cost reductions resulting from lowered energy use’ and ‘threats of rising energy prices’ are the most important drivers for implementing energy efficiency measures or technologies.

  • 7.
    Arababadi, Reza
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Energy Use in the EU Building Stock - Case Study: UK2012Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Previous studies in building energy assessmnet have made it clear that the largest potential energy efficiency improvements are conected to the retrofitting of existing buildings. But, lack of information about the building stock and associated modelling tools is one of the barriers to assessment of energy efficiency strategies in the building stocks. Therefore, a methodology has been developed to describe any building stock by the means of archetype buildings.  The aim has been to assess the effects of energy saving measures. The model which is used for the building energy simulation is called:  Energy, Carbon and Cost Assessment for Buildings Stocks (ECCABS). This model calculated the net energy demand aggregated in heating, cooling, lighting, hotwater and appliances.

     

    This model has already been validated using the Swedish residential stock as a test case. The present work continues the development of the methodology by focusing on the UK building stock by discribing the UK building stock trough archetype buildings and their physical properties which are used as inputs to the ECCABS. In addition, this work seekes to check the adequacy of applying the ECCABS model to the UK building stock. The outputs which are the final energy use of the entire building stock are compared to data available in national and international sources.

     

    The UK building stoch is described by a total of 252 archetype buildings. It is determined by considering nine building typologies, four climate zones, six periods of construction and two types of heating systems. The total final energy demand calculated by ECCABS for the residential sector is 578.83 TWh for the year 2010, which is 2.6 % higher than the statistics provided by the Department of Energy and Climate Change(DECC). In the non-residential sector the total final energy demand is 77.28 TWh for the year 2009, which is about 3.2% lower than the energy demand given by DECC. Potential reasons which could have affected the acuracy of the final resualts are discussed in this master thesis. 

  • 8.
    Arfwidsson, Oskar
    et al.
    Linköping University, Department of Management and Engineering, Energy Systems.
    Andersson, Elias
    Linköping University, Department of Management and Engineering, Energy Systems.
    Benchmarking av industriella små och medelstora företags energiprestanda: Presentation av en metod för beräkning av energieffektiviseringsindex2016Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The industrial sector currently accounts for about 30% of the final energy consumption in the western world, but a significant energy efficiency potential has been identified in the sector. Research has shown that there is a great potential for improving energy efficiency in the industrial sector, particularly among small and medium-sized enterprises. However, there are barriers hindering the implementation of cost-effective energy efficiency measures. These barriers include lack of knowledge about the industries own energy end-use.

    A tool that can address this barrier among companies is benchmarking of energy end-using processes that allow the companies to compare their energy performance to other companies. Based on previous research and experiences in the field, a new method was developed for calculating an energy efficiency index, which has the possibility to show each company's energy performance relative to other companies.

    The study began with a literature review of scientific articles and reports on the subject studied. In addition, interviews with government agencies and energy auditing companies that have insight into the companies' work with energy efficiency was conducted. The literature and interview study showed a demand of comparing the energy performance of industrial sites through benchmarking. Benchmarking of energy end-use processes was estimated to have particularly good potential to achieve energy saving potentials through identifying energy efficiency measures.

    The proposed method allows the calculation of an energy efficiency index that is based on individual energy end-using processes in an industrial site. This allows benchmarking of energy end-using processes as well as the entire industrial site. The method was tested and validated with data from Swedish small and medium-sized sawmills compiled by the Swedish Energy Agency in conjunction with the Swedish energy audit support program.

    Validation of the developed method demonstrated that the potential for energy efficiency can be identified by calculating the energy efficiency index. The method assumes that the comparison is conducted for each sector separately, particularly regarding the production processes. To strengthen the reliability of the results, the method should be tested on additional industrial sectors and further quality assurance of the data should be conducted for these sectors.

  • 9.
    Arnoldsson, Joel
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Adsorption Chillers: uptake of Ethanol on Type RD Silica gel2012Independent thesis Basic level (degree of Bachelor), 10,5 credits / 16 HE creditsStudent thesis
    Abstract [en]

    The adsorption cooling technology has the potential to replace all vapor compression based chillers in the future. So, in all over the world immense researches are going on in this field. The purpose of this report is to experimentally investigate whether ethanol could serve as a refrigerant in the technology. Compared to water it has freezing point below 0 °C (-114.1 °C) and can therefore in theory be used in refrigeration applications. The report begins with the theory regarding the adsorption cooling process, describing the cycle and parameters that affect the Coefficient of Performance (COP).In the actual experiment, adsorption between the silica gel and the ethanol vapor is studied at various pressures by maintaining isothermal conditions. An experimental apparatus (Constant Volume Variable Pressure apparatus - CVVP) was fabricated, assembled and tested for this project. After the assembly and testing, volume calibration for the apparatus was carried out as it is essential to know in further experimental calculation. All the data related with the fabrication, assembly and testing of the apparatus and the volume calibrations are presented later in this report in detail.Adsorption experiments are conducted at 301.15K, 311.15K, 321.15K and 331.15K with varying inlet pressure condition to the system and then the uptake data is calculated for each and every experiments using ideal gas equation. Subsequently, the validations of the experimental data with the standard adsorption isotherms are done. Dubinin-Astakhov is found to be the most ideal isotherm to simulate the theoretical data. Its RMSE (Root Mean Square Error) value is found to be 0.506%. It is concluded that ethanol valid option for refrigeration, but further research is needed and recommended.

  • 10.
    Ask, Per
    et al.
    Linköping University, Department of Biomedical Engineering, Physiological Measurements. Linköping University, The Institute of Technology.
    Tibbling, Lita
    Evaluation of a new method for abdominal compression for use in oesophageal investigation.1982In: Scandinavian Journal of Gastroenterology, ISSN 0036-5521, E-ISSN 1502-7708, Vol. 17, no 2, p. 269-272Article in journal (Refereed)
    Abstract [en]

    The use of conventional extra-abdominal compression with a constant cuff pressure was shown to give various pressures intra-abdominally in different subjects. A feedback system was therefore used, in which the extra-abdominal pressure is controlled by the intra-abdominal pressure. For an intra-abdominal pressure increase of 15 mm Hg the external cuff pressure in 20 subjects varied from 21 to 98 mm Hg. There was, however, an almost linear relationship between increased intra-abdominal pressure and cuff pressure. The extra-abdominal pressure required to obtain a certain intra-abdominal pressure also varied with the size of the cuff. To obtain relevant and comparable results in studies of hiatal incompetence and gastro-oesophageal reflux, the feedback system is recommended and the size of the intra-abdominal cuff should be stated.

  • 11.
    Assis Lana e Cruz, Igor
    Linköping University, Department of Management and Engineering, Energy Systems.
    Energy and material balances of wastewater treatment, including biogas production, at a recycled board mill2016Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Challenges surrounding energy have gained increased attention, which is not least reflected in the 2030 Agenda for Sustainable Development and the Sustainable Development Goals (SDGs). Energy issues have also become a pressing matter for most countries in the last decades. The reasons for this are not only related to the effects of the emission of greenhouse gases (GHG) from fossil fuels and their impact in climate change, but also span through other issues such as security of energy supply with geopolitical considerations and competitiveness of industry. To address these issues, a collection of public policies ranging from the international to local levels have been implemented.

    Sweden has historically had lower energy prices than its European counterparts, which has resulted in its industry having a relatively higher share of electricity in the total energy use by industry. The share of electricity accounts for 35% of total energy use in Swedish industry. This has led to efficiency measures being overlooked by industry, and the pulp and paper industry is by far the biggest energy user, with a share of 51% of the total energy use by industry. The variation of energy prices, and particularly electricity prices have obvious implications on the competitiveness of this sector.

    Production of biogas in pulp and paper mills has been gaining attention, and is now the target of an increasing number of scientific studies. The interest for this industry is not only related to security of energy supply and the environmental performance of the biogas itself, but there are also considerations regarding the biogas plant as an alternative to treat the large flows of wastewaters and other waste stream in this sector. There is an estimated biogas production potential of 1 TWh within this industry in Sweden, which accounts for 60% of the current biogas production in the country.

    Pulp and paper mills commonly rely on aerated biological treatment to deal with waste streams with high organic content This biological process has a high energy demand, and the integration of an anaerobic treatment, along with the use of the biogas for heat and electricity can yield a net positive energy recovery for the combined plant.

    This project analyses the current energy and material performance of an anaerobic biological treatment combined with an aerobic biological treatment in a recycled board mill. The anaerobic treatment is performed upstream of the aerobic one and removes most of the chemical oxygen demand of the wastewater.

    Energy and material balances for the plant are presented, and a comparison of the wastewater treatment plant running before and after the start-up of the biogas plant is made. The plant operation with the anaerobic digestion has shown an increased energy use of 9.4% coupled to an increased flow of wastewater of 7.7%. The average biogas production is 72 Nm³/h, which accounts for 440 kWh and is currently being flared. The introduction of AD has largely decrease the organic load in the aerobic treatment, by nearly 50%. This project ends with an optimisation model implemented with the optimisation tool reMIND to investigate potential optimisation strategies for the operation of the combined plant. The model has shown to be adequate to describe electricity use with mean error below 10%. For the biogas production, the mean error was of 16%.

  • 12.
    Bergdahl, Gustav
    et al.
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, Faculty of Science & Engineering.
    Olevik, Jonas
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, Faculty of Science & Engineering.
    En algoritm för automatisk feldetektering och diagnos av ett luftbehandlingsaggregat2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Större byggnader innehåller en mängd installationsteknik för att hålla inneklimatet behagligt. Dessa tekniska system övervakas automatiskt för att större fel och driftavvikelser ska identifieras. Att gå ett steg längre och analysera dessa system på daglig basis är något som kräver både tid och resurser. Det pågår forskning kring att automatisera denna analys, vilken ryms inom den akademiska termen Fault Detection and Diagnosis (FDD). Denna masteruppsats tar avstamp i detta forskningsområde med ambitionen att utveckla en algoritm som automatiskt analyserar ett luftbehandlingsaggregat av FTX-typ för ökad energiprestanda.

     

    Utgångspunkten för algoritmen var att använda de befintliga mät- och styrsignalerna som visas i en driftbild i övervakningssystemet. En litteraturstudie genomfördes för att identifiera möjliga metodval där den kvalitativa metoden expertsystem valdes. I denna tillämpning av expertsystem skapades ett regelverk som detekterar avvikelser från ett förmodat normalfall, sedan analyseras möjliga rotorsaker till avvikelserna genom trädsökning varpå diagnoser kan utfärdas.

     

    För att bedöma hur väl algoritmen fungerade gjordes en fallstudie på delar av universitetssjukhuset i Linköping, där algoritmen testkördes på 8 luftbehandlingsaggregat. Resultatet visade att utfärdade diagnoser är fullt rimliga men för många till antalet, då varje uppmärksammad avvikelse ofta genererar likvärdiga diagnoser. Precisionen bedömdes till 75 % baserat på testningens resultat och begränsas framförallt av antalet tillgängliga sensorer och mätnoggrannhet. En nyckelegenskap för algoritmen är att kvantifiera de uppmärksammade fel som bidrar till en ökad energianvändning. Exempelvis visade resultatet att 6 % av inköpt värme kan ersättas om tilluftsverkningsgraden ökas till 75 %. Här behöver dock hänsyn tas till att beräkningen bakom tilluftsverkningsgraden, som baseras på data från tillgängliga sensorer, dras med en mängd osäkerheter.

     

    Utöver befintliga temperatursensorer undersöktes om ytterligare mätpunkter kunde motiveras för utökad feldetektering och diagnos. En tes var att mindre ventilläckage går att upptäcka genom mätning, vilket inte kunde styrkas. Vidare framkom vikten av att veta temperaturen på uteluften som kommer aggregatet tillhanda, och inte fasad- eller taktemperaturen, för att i efterhand kunna avgöra om systemet körts på ett effektivt sätt.

     

    Fortsatt arbete kan sammanfattas i att minska manuell datahantering och förbättra diagnosmodulen genom att dels införa fel på ett luftbehandlingsaggregat under kontrollerade former, dels genom förfinandet av det grafiska gränssnittet där algoritmens resultat presenteras. 

  • 13.
    Bergek, Anna
    et al.
    Linköping University, Department of Management and Engineering, Project Innovations and Entrepreneurship. Linköping University, Faculty of Science & Engineering. University of Oslo, Norway.
    Mignon, Ingrid
    Linköping University, Department of Management and Engineering, Project Innovations and Entrepreneurship. Linköping University, Faculty of Science & Engineering.
    Motives to adopt renewable energy technologies: evidence from Sweden2017In: Energy Policy, ISSN 0301-4215, E-ISSN 1873-6777, Vol. 106, p. 547-559Article in journal (Refereed)
    Abstract [en]

    The diffusion of renewable energy technologies (RETs) has to speed up for countries to reach their, often ambitious, targets for renewable energy generation. This requires a large number of actors to adopt RETs. Policies will most likely be needed to induce adoption, but there is limited knowledge about what motivates RET adoption. The purpose of this paper is to complement and expand the available evidence regarding motives to adopt RETs through a survey to over 600 non-traditional RET adopters in Sweden. The main finding of the study is that although environmental concerns, technology interest, access to a base resource and prospects to make money are important motives in general, RET adopters is a heterogeneous group with regard to motives: there are many different motives to adopt RETs, adopters differ in how large importance they attach to the same motive and each adopter can have several different motives to adopt. There are also differences in motives between RETs (especially wind power vs. solar power) and between adopter categories (especially IPPs vs. individuals and diversified companies). This implies that a variety of policy instruments might be needed to induce further adoption of a variety of RETs by a variety of adopter categories.

  • 14.
    Bidita, B. S.
    et al.
    Department of Chemical and Environmental Engineering, Faculty of Engineering, University Putra Malaysia, Selangor, Malaysia.
    Suraya, A. R.
    Department of Chemical and Environmental Engineering, Faculty of Engineering, University Putra Malaysia, Selangor, Malaysia; Nanomaterials and Nanotechnology Group, Materials Processing and Technology Laboratory, Institute of Advanced Technology, University Putra Malaysia, Selangor, Malaysia.
    Aziz, Shazed
    Department of Chemical and Environmental Engineering, Faculty of Engineering, University Putra Malaysia, Selangor, Malaysia.
    Salleh, M.A. Mohd
    Department of Chemical and Environmental Engineering, Faculty of Engineering, University Putra Malaysia, Selangor, Malaysia; Nanomaterials and Nanotechnology Group, Materials Processing and Technology Laboratory, Institute of Advanced Technology, University Putra Malaysia, Selangor, Malaysia.
    Idris, A.
    Department of Chemical and Environmental Engineering, Faculty of Engineering, University Putra Malaysia, Selangor, Malaysia.
    Preparation, characterization and engine performance of water in diesel nanoemulsions2016In: Journal of the Energy Institute, ISSN 1743-9671, Vol. 89, no 3, p. 354-365Article in journal (Refereed)
    Abstract [en]

    Water in diesel (W/D) nanoemulsions were prepared by the aid of high energy emulsification method. The formulation was accomplished in the presence of Triton X-100 surfactant. A wide range of surfactant concentration (0.25%–0.40% v/v) with varying amount of water percentage (0.50%–0.90% v/v) was used in the preparation of W/D nanoemulsion fuels. The droplet size of the nanoemulsions at different water:surfactant:diesel ratio increased as surfactant concentration decreased. High kinetic stability was observed in the nanoemulsions. The stability of nanoemulsions with 0.40% surfactant concentration was persisted more than two weeks without phase separation. The droplet size of the nanoemulsions increased with time proving the influence of breakdown processes such as Ostwald ripening. Combustion characteristics of W/D nanoemulsions were studied in terms of different formulating compositions. An engine test bed of diesel engine was used to combust the nanoemulsions to study the exhaust emission concentrations such as CO, CO2, NH3 and NO, and performance parameters include brake power, thermal efficiency. The highest reduction in the exhaust gas emissions concentrations was notified by using surfactant concentration of 0.40% with 0.90% water content. The lowest calorific value of prepared W/D nanoemulsions was achieved 38.48 MJ/kg by using surfactant concentration of 0.40% with 0.90% water. The highest brake power and thermal efficiency was also obtained with 0.40% surfactant concentration and 0.90% water content. In addition, the characteristic evaluation of W/D nanoemulsions was made on the basis of emission characteristics of neat diesel. It has been observed that the use of W/D nanoemulsions in diesel engine has evidently led to the reduction in exhaust emissions, anticipating its application as an alternative eco-friendly fuel in the internal combustion engine.

  • 15.
    Björe Dahl, Emilia
    et al.
    Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics. Linköping University, The Institute of Technology.
    Sjöqvist, Mikaela
    Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics. Linköping University, The Institute of Technology.
    Ökad resurseffektivitet i kraftvärmesystem genom säsongslagring av värme2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Increased resource efficiency in an energy system could result in large economic and environmental benefits. Tekniska verken i Linköping AB (Tekniska verken) is responsible for the district heating network in Linköping. Their vision is to create the world’s most resource efficient region. An important step towards this vision is more efficient usage of produced heat, something which could be achieved through integration of a seasonal heat storage in the energy system. The purpose of the Master’s thesis is therefore to explore the economic and technical potential for a seasonal heat storage in Tekniska verken’s energy system. The investigated technology is borehole thermal energy storage using two different kinds of borehole heat exchangers; u-pipe and annular coaxial heat exchanger.

    To evaluate how Tekniska verken’s energy system changes through integration of a seasonal heat storage a calculation model has been developed in MATLAB. The heat from the seasonal storage needs to be upgraded in order to be used in the ordinary district heating network. Therefore two kinds of heat pumps have been evaluated in the model; absorption heat pumps and compression heat pumps. The main method used for calculations on the heat transfer processes in the storage is the finite difference method. During economic calculations, the economic potential of the investment is expressed solely in relation to the scenario that the storage is not built.

    Four different combinations of borehole heat exchangers and heat pumps have been simulated over a twenty year period. The simulated storages have a depth of 200-250 meters and a radius of approximately 100 meters which relates to1500 boreholes. The result shows small differences between the two types of heat exchangers. The choice of heat pump has though a crucial importance of the economic result. The systems with absorption heat pumps uses drive heat from existing steam production and can cover a major part of the peak load during winter. Meanwhile the compression heat pumps have a large cost for electricity. This causes a negative net present value according to the result, while the systems with absorption heat pumps have a discounted pay-back time of 12 years. Another positive effect of the systems with absorption heat pumps is the decrease in carbon dioxide emissions from the heat production.

    The result of the Master thesis shows that both economic advantages and increased resource efficiency can be achieved through integration of a borehole thermal energy storage with absorptions heat pumps.  To further investigate this potential seems therefore beneficial.  

  • 16.
    Björk, Andreas
    et al.
    Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics.
    Enander, Tobias
    Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics.
    Validering och utveckling av matematisk modell av rökgaskondensering: En undersökning av matematiska modeller avrökgaskondensering samt en studie av hur yttre faktorerpåverkar rökgaskondenseringen i kraftvärmeverk2019Independent thesis Basic level (degree of Bachelor), 10,5 credits / 16 HE creditsStudent thesis
    Abstract [en]

    When burning fuels with high water or hydrogen content, much of the combustion energy follows themoist air that leaves the chimney at the plant. A common example is the combustion of wood fuel orhousehold waste in CHP-plants. In order to increase the plant's efficiency and at the same time clean theair from sulfur dioxide and metals, a flue gas condensation of scrubber-type can be used. Cool water isinjected into a filling bed and meets the hot flue gas. When the flue gases are cooled, energy is released bythe water in the flue gases when vapor turns into liquid form, energy that can be used e.g. to heat thedistrict heating network's return line.

    This work has been carried out on behalf of Hifab DU-teknik, which in the past year has carried outstudies and calculations of the flue gas condensation at the Torsvik CHP plant, which has led to improvedefficiency. Through simulations and calculations in Matlab, this report tries to verify the optimalcondensate flow calculated by DU technology and study how the plant is affected by changed flows andtemperatures in the district heating network’s return line.

    The authors of this work have put a lot of effort into understanding the theory of heat exchangers andenergy in moist air in depth. The theoretical framework we set up can be seen as a thorough introductionto the subjects and an in-depth study compared to the usual course content during the Bachelor's degreeprogram in mechanical engineering at Linköping University.

    The goal of the preparatory method work has been to find expressions of the different temperatures inthe plant that make it possible to simulate changes in the plant. Models have been developed to be able tosimulate and calculate the outgoing temperatures given different mass flows using the ingoingtemperatures in a heat exchanger. The model has proven to work well for the heat exchanger, which isconnected to the district heating network. In the calculations of temperatures out of the filling bed, twomethods have been tested. The authors’ has studied what happens if the condensate temperature out ofthe filling bed is set to the dew temperature of the flue gases. Attempts have also been made to considerthe filling bed as a kind of heat exchanger.

    The result of the authors' calculations of condensate flow differs to a certain extent from the DU-teknik’scalculated condensate flows during a changed boiler load in the plant. To end up at the same result, thehot condensate temperature needed to take a slightly higher temperature than the dew temperature. Theassumption is reasonable to make, but it is difficult to draw any conclusions about the magnitude.

    Regarding the method of considering the filling bed as a heat exchanger, there are both successes andshortcomings. The success lies in that the trend for the different temperatures seems to be in line with thetheory that the authors have presented for heat exchangers and what happens when the massflowsincrease or decrease in a heat exchanger. However, the shortcomings lie in the fact that the method doesnot take into account that heat is released during the condensation, but is based entirely on the fact thatthe fluid in the filling bed do not undergo phase transformations.

    Two important proposals for continued work are highlighted at the end of the report. It would beinteresting to study the possibility of considering the filling bed as two separate heat exchangers, where thedry flue gases encounter a partial current of the condensate and the moisture in the flue gases meetsanother partial current of the condensate. Furthermore, a desire is made to test the flue gas condensationin the future at different condensate flows for a longer period of time in order to achieve stationaryconditions in the temperatures. The data can later be used to produce mathematical expressions of whathappens to the outgoing temperatures of the filling bed when the condensate flow changes or when theingoing temperature of the filling bed increases or decreases.

  • 17.
    Björn, Annika
    et al.
    Linköping University, The Tema Institute, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences.
    Borgström, Ylva
    Pöyry Sweden AB, Norrköping, Sweden.
    Ejlertsson, Jörgen
    Linköping University, The Tema Institute, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences.
    Karlsson, Anna
    Scandinavian Biogas Fuels AB, Stockholm, Sweden.
    Nilsson, Fredrik
    Pöyry Sweden AB, Norrköping, Sweden.
    Svensson, Bo
    Linköping University, The Tema Institute, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences.
    Biogasproduktion inom svensk pappers- och massaporduktion : Syntes av möjligheter och begränsningar samt teknisk utvärdering: Bilaga 2 Etablering/effektivisering av biogasproduktion inom svensk pappers- och massaindustri2016Report (Other academic)
    Abstract [sv]

    Linköpings Universitet har tillsammans med Pöyry och Scandinavian Biogas Fuels drivit projektet ”Etablering/effektivisering av  biogasproduktion inom svensk pappers- och massaproduktion”. Potentialen hos det organiska materialet i avloppsvatten från svensk pappers- och massaindustri (PMI) till biogasproduktion skattades vid projektstart till 100 milj. Nm3 metan per år (1 TWh). Denna rapport är en syntes av resultaten från projektet med syfte att ge visa hur de genererade resultaten kan omsättas i teknisk praktik med tillhörande ekonomiska insatser. Syftet är att ge underlag och stöd till PMI-branschen och externa intressenter, som överväger att implementera biogasproduktion inom PMI.

    Substraten för biogasproduktion som återfinns i pappers- och massaindustrins avloppsvatten och slam kännetecknas av stora volymer med låga COD-halter. Detta kräver rötningstekniker, som tillåter mycket korta uppehållstider jämfört med mer traditionellt utformade biogasanläggningar för att inte tankstorleken ska bli för stor. Två tekniker, som utvecklats inom projektet, klarar detta: EGSB (expanded granular sludge bed) och CSTR (completely stirred tank reactor) med slamåterföring. Dessa tekniker har därför utvärderats för tre olika typbruk, ett CTMP-bruk, ett TMP-bruk och ett sulfatmassabruk. Resultaten från dessa experimentella studier är utgångspunkten för i utvärderingen i föreliggande rapport. För varje processkoncept har en grov kostnadsuppskattning (±20 %) gjorts för den investering som krävs för biogasproduktion.

    En EGSB på ett TMP-bruk med ett totalavlopp på 1500 m3/h, där hela blekeriavloppet från peroxidblekningen och en del av det övriga avloppet behandlas i en 4000 m3 reaktor förväntas ge 2,5 milj Nm3 metan/år. Investeringskostnaden för anläggningen uppskattas till 75 milj. SEK (±20 %).

    En EGSB på ett CTMP-bruk med ett totalavlopp på 170 m3/h där hela avloppet behandlas i en 3000 m3 reaktor förväntas ge 1,8 milj Nm3 metan/år. Investeringskostnaden för anläggningen uppskattas till 64 milj. SEK (±20%).

    En CSTR med slamåterföring som körs på bioslam från ett sulfatmassabruk där ett bioslamflöde på 46 m3/h behandlas i en 4000 m3 reaktor förväntas ge 1,0 milj Nm3 metan/år. I denna design är strategin för den aeroba bioreningen ändrad för att producera ett bioslam optimerat för att ge högsta möjliga biogaspotential. Detta innebär produktion av större mängd slam, som i största mån kan rötas till metan, dvs mängd metan per mängd rötat organiskt material samtidigt som COD-reduktionen i vattenreningen bibehålls. Investeringskostnaden för anläggningen uppskattas till 32 milj. SEK (±20%).

    Baserat på de COD-kvantiteter som når de luftade dammarna inom PMIs vattenreningssystem förbrukas årligen ca 0,8 TWh el. Införande av biogasproduktion i massaindustrins spillvattenrening skulle reducera mängden COD med mellan 30-50%, vilket får till följd att den årliga elförbrukningen i samband med den aeroba reningen går ner med ca 0,2-0,4 TWh. Detta innebär alltså ett energitillskott av 0,9 – 1,1 TWh givet att hela den tillgängliga biogaspotentialen skulle byggas ut. Till detta kommer eventuella vinster relaterade till slamhanteringen.

  • 18.
    Blomqvist, Stefan
    et al.
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, Faculty of Science & Engineering.
    Amiri, Shahnaz
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, Faculty of Science & Engineering. Division of Building, Energy and Environment Technology, Department of Technology and Environment, University of Gävle, Gävle, Sweden.
    Rohdin, Patrik
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, Faculty of Science & Engineering.
    Ödlund, Louise
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, Faculty of Science & Engineering.
    Analyzing the Performance and Control of a Hydronic Pavement System in a District Heating Network2019In: Energies, ISSN 1996-1073, E-ISSN 1996-1073, Vol. 12, no 11, article id 2078Article in journal (Refereed)
    Abstract [en]

    A hydronic pavement system (HPS) is an alternative method to clear snow and ice, which avoids the use of salt, sand, and fossil fuel in conventional snow clearance, and minimizes the risk of accidents. The aim is to analyze the performance of different control strategies for a 35,000 m2 HPS utilizing heat from a district heating and cooling (DHC) system. The key performance indicators are (1) energy performance of the HPS, and (2) primary energy use, (3) electricity production and (4) greenhouse gas (GHG) emissions from the DHC system. The methodology uses a simulation model of the HPS and an optimization model of the DHC system. Three operational strategies are analyzed: A reference scenario based on the current control strategy, and scenarios where the HPS is shut down at temperatures below −10 °C and −5 °C. The study shows that the DHC return temperature is suitable for use. By operational strategies, use during peak demand in the DHC system can be avoided, resulting in reduced use of fossil fuel. Moreover, the energy use of the HPS could be reduced by 10% and the local GHG emissions by 25%. The study emphasizes that the HPS may have positive effects on global GHG emissions, as it enables electricity production from renewable resources.

  • 19.
    Broberg, Nicklas
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Kartläggning och utvärdering av svenska energinätverk: Företagsnätverk och samarbeten inriktade på energi2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The industrial energy use causes carbon emissions that contribute to climate change. Simultaneously within EU and Sweden a competitive industry is pursued. In the aim to achieve both aspects energy efficiency and a reduced energy use is advocated for companies. Although energy efficiency often is cost-effective there exists an energy efficiency gap where cost-effective measures remain unimplemented for different reasons. Energy efficiency networks can in this case be a potential approach for increasing the degree of implementation, resulting in energy efficiency and company development. Financial support is already given from EU and Sweden that could lead to energy efficiency networks, for both small and medium-sized enterprises as well as for large enterprises.

    There exist numerous projects variations in energy efficiency networks with different structures and designs. The knowledge of these networks aimed towards energy efficiency and energy use is very limited. The aim of this work is therefore to identify Swedish energy efficiency networks in order to determine whether they work well by evaluating them from a public perspective.

    To identify energy efficiency networks documents where collected and interviews were held in which random selection was allowed in the form of snowball method. An underlying study has previously been carried out in which a number of networks was identified, which are integrated as a part of the work identification. Overall, this resulted in the identification of 35 different networks projects, which may consist of a single network, multiple networks or stages of a single network. The identified energy networks are divided by larger networks and other networks that have been split into four general networks forms cluster, industrial districts, regional strategic networks and strategic networks as well as alternative network forms for the networks that could not be associated.

    An evaluation has been performed on the underlying policy instrument “Application for financial support to information, education and collaborative projects 2013-2014” which stated that the support allows a wide range of energy efficiency networks and cannot be seen as a particular ruling in the design and implementation of an energy efficiency network. Furthermore it is recommended that a separation is made for collaborative projects in the form of energy efficiency networks in the support system since it would likely lead to more target and specific energy efficiency networks with clearer objectives and follow up. This would still allow a very large variety of network constructions.

    Energy efficiency networks with an efficient information and knowledge sharing has the potential to make enterprises more innovative. However, energy efficiency networks without an initial public financing does not seem to be initialized spontaneously in Sweden. Letters of intent or agreements in the strategic networks are believed to lead into reports with concrete results unlike for the regional strategic networks with no agreements.

    For the larger energy efficiency networks there is a point with being branch-specific because their energy use is more complex to audit. The other energy efficiency networks should instead find interested participants primarily. In combination with this, the participants should have the opportunity to meet and later on branch adapt if possible. This is because several network projects have stated problems with network formation that affects the projects. Furthermore, it appears that the creation of an efficient energy efficiency network sometimes is a maturation process in which several underlying projects can be a reason for an identified network project.

    Finally, we need further research on how the participating enterprises see energy efficiency networks as a supporting and developmental instrument.

  • 20.
    Carlander, Jakob
    Linköping University, Department of Management and Engineering, Energy Systems.
    Att bygga bostäder enligt miljöbyggnadskrav: En fallstudie i området Nya Wahlbecks2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Energy and resource efficiency is an important part in moving towards a sustainable society. In the year 2013, the total energy use in Sweden was 563 TWh and approximately 26 % of the energy was used in the residential and service sector. Within the residential and service sector, nearly 60 % of the used energy is for heating (Energimyndigheten, 2015). The construction of energy efficient buildings is a central part in creating a sustainable society and Nya Wahlbecks is supposed to become a city district which will show that it is possible to increase growth, quality of life and well-being and at the same time decrease the use of non recyclable and non reusable resources.The primary purpose of this master thesis has been to generate suggestions on how to design the residential buildings in the new city district Nya Wahlbecks, which will be built in east Valla in Linköping, so they can be certified in accordance to the environmental certification system Miljöbyggnad. Besides the primary purpose an investigation on how much electricity that can be generated with photovoltaic and how much energy that can be saved by the use of solar heating panels, has also been conducted. Finally a comparison in emissions of CO2-eqvivalents between a building that just meets the criteria´s of Boverkets Byggregler (BBR) and the generated building models was done.The results which the case study has generated, clearly shows that it is possible to build the new residential buildings in Nya Wahlbecks so that they will meet the different criteria’s for grade Silver and Guld from Miljöbyggnad. The requirements from Miljöbyggnad aim to have as low energy use as possible at the same time as a good indoor climate is kept. These two factors can be contradictions to one another, as for instance low energy use can be reached by having thicker insulation, but thicker insulation often results in higher indoor temperature which can then lead to deterioration in indoor climate. The investigations of energy use and indoor climate were conducted through simulations in the building-simulation program IDA-ICE, where several optimizations were done for different parameters to finally meet the requirements from Miljöbyggnad. Simulations with solar panels for heating and generation of electricity were also conducted with IDA-ICE. The results of the study shows that nearly 60 % of the used electricity in the project building can be generated from photovoltaic panels placed on the roof of the building. About 9 % of the buildings heating energy can be produced with solar panels placed in the same way as the photovoltaic ones. When it comes to emissions of CO2-eqvivalents there would be a difference in approximately 19 tons, which is equivalent to about 30 %, if the building meets the requirements of Miljöbyggnad Silver instead of just meeting BBR´s requirements.

  • 21.
    Carl-Erik, Grip
    et al.
    Luleå tekniska universitet.
    Thollander, Patrik
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Söderström, Mats
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Stakeholder study on Barriers to Exergy Analysis2012In: International Conference on Applied Energy ICAE 2012, 2012Conference paper (Refereed)
  • 22.
    Carlsson, Peter
    Linköping University, Department of Management and Engineering, Energy Systems.
    Energiflöden i Motorprovceller: Kartläggning av energiflöden i motorprovceller vid Scania ABs motorproduktion i Södertälje2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Abstract

    Within the Swedish production and industrial enterprises there are constant projects with the aim to increase economical profit and decrease economical losses. At Scania AB’s production facilities these projects are carried out with a great awareness about sustainability, quality and environment.The department of Energy & Media, at Scanias affiliate company Scania Industrial Maintenance AB, have as their main task to investigate and execute projects to increase the efficiency of any energy application at Scanias production sites. A more effective energy use often comes with the potential to cut economical expenses, as well as decrease the environmental impact of the world we live in. As a part of their goal the company wants to clarify the energy flows and use at the engine test cells, which is a final step in most of their engine production.A energy mapping has there for been carried out at the engine testing site in house b150, with the purpose to derive and clarify the energy flows in the test cells there. The mapping is based on gathered data, energy measurements and system analysis, that later have served as a base to the final energy calculations and result compilation.In addition to the energy mapping, the company also wanted to create a substrate for future analysis and mapping of other engine test cells. There for a calculation tool was created to meet this request, which resulted in an Excel-based mapping-template where input data fast generates the test cells energy balance and further can be used for energy investigation.The result of the energy mapping of the test cells in house b150 is presented as a distinct balance of the energy flows, to and from the test cells. Sufficient data is presented to easily derive the energy demand to economical costs and also select those energy flows that can be objects for further energy investigation and hopefully increased efficiency of the test cells.

  • 23.
    Cehlin, Mathias
    et al.
    Högskolan i Gävle, Energisystem.
    Larsson, Ulf
    Högskolan i Gävle, Energisystem.
    Chen, Huijuan
    RISE Research Institutes of Sweden, Division of Built Environment - Energy and circular economy, Borås, Sweden.
    Numerical investigation of Air Change Effectiveness in an Office Room with Impinging Jet Ventilation2018In: Proceedings of the 4th international Conference on Building Energy & Environment / [ed] K. Inthavong*, C.P Cheung, G. Yeoh, J.Y. Tu, Melbourne: Conference On Building Energy & Environment - COBEE2018, Melbourne Australia , 2018, p. 641-646, article id 218Conference paper (Refereed)
    Abstract [en]

    Providing occupant comfort and health with minimum use of energy is the ultimate purpose of heating, ventilating and air conditioning systems. This paper presents the air-change effectiveness (ACE) within a typical office room using impinging jet ventilation (IJV ) in combination with chilled ceiling (CC) under different heat loads ranging from 6.5 - 51 W per square meter floor area. In this study, a validated CFD model based on the v2f turbulence model is used for the prediction of air flow pattern and ACE. The interaction effect of chilled ceiling and heat sources results in a complex flow with air circulation. The thermal plumes and air circulation in the room result in a variation of ACE within the room but also close to the occupant. For all studied cases, ACE is above 1.2 close to the occupants, indicating that IJV is more energy efficient than mixing ventilation.

  • 24.
    Celander, Filip
    et al.
    Linköping University, Department of Management and Engineering, Environmental Technology and Management. Linköping University, The Institute of Technology.
    Haglund, Johan
    Linköping University, Department of Management and Engineering, Environmental Technology and Management. Linköping University, The Institute of Technology.
    Energy and nutrient recovery from dairy manure: Process design and economic performance of a farm based system2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This thesis assessed the technical and economic premises for installing systems that process manure in order to recover nutrients and inherent energy. The main purpose of recovering nutrients was to extract phosphorus from the manure, so as to be able to distribute more of the manure on the farm without exceeding the phosphorus regulation. Three other scenarios were included as reference; conventional manure handling, solid-liquid separation only and solid-liquid separation including energy recovery. Since most important parameters for modeling scenarios in agriculture are site-specific (e.g. soil type, crop rotation and manure composition), the thesis results were based on a case farm. The case farm is a 675 ha dairy farm with approx. 1400 milking cows, located in Östergötland, Sweden.

    As for the results, it was first concluded that the central characteristics of manure were the content of dry matter (DM), nitrogen (N), phosphorus (P) and potassium (K). The higher the DM content, the more fuel for energy recovery, and the higher the N:P-ratio, the more on-farm N can be utilized before having to consider the P regulation. The technical premises for farm-scale nutrient recovery were limited to commercial techniques from companies operating in Sweden, and included various possible processing methods, such as; pH modification, anaerobic digestion, coagulation-flocculation, precipitation, filtration and reverse osmosis. However, most methods were either too costly or simply not realistic to install on stand-alone farms, resulting in only two feasible options; struvite precipitation and secondary solid-liquid separation with a decanter centrifuge.

    The comparison in economic performance for all scenarios resulted as follows: nutrient recovery by struvite precipitation was the most profitable scenario of all, if struvite was allowed to replace mineral P fertilizer (i.e. end-product on-farm utilization). If not, it was more profitable to invest in only energy recovery, as nutrient recovery by secondary solid-liquid separation or struvite precipitation with end-product sales were not as profitable. However, the absolutely largest increase in profitability lies within investing in a primary solid-liquid separation. As for the case farm, this investment reduced costs by more than 2 MSEK, while any of the latter scenarios reduce costs by 0,1-0,2 MSEK. Furthermore, the possible utilization of the waste heat from energy recovery increased profitability by a factor of ten.

  • 25.
    Chen, Huijuan
    et al.
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology. Department of Building, Energy and Environmental Engineering, University of Gävle, Sweden.
    Janbakhsh, Setareh
    Linköping University, Department of Management and Engineering. Linköping University, The Institute of Technology. Department of Building, Energy and Environmental Engineering, University of Gävle, Sweden.
    Larsson, Ulf
    Department of Building, Energy and Environmental Engineering, University of Gävle, Sweden.
    Moshfegh, Bahram
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology. Department of Building, Energy and Environmental Engineering, University of Gävle, Sweden.
    Numerical investigation of ventilation performance of different air supply devices in an office environment2015In: Building and Environment, ISSN 0360-1323, E-ISSN 1873-684X, Vol. 90, p. 37-50Article in journal (Refereed)
    Abstract [en]

    Abstract The aim of this study was to compare ventilation performance of four different air supply devices in an office environment with respect to thermal comfort, ventilation efficiency and energy-saving potential, by performing numerical simulations. The devices have the acronyms: Mixing supply device (MSD), Wall confluent jets supply device (WCJSD), Impinging jet supply device (IJSD) and Displacement supply device (DSD). Comparisons were made under identical set-up conditions, as well as at the same occupied zone temperature of about 24.2 °C achieved by adding different heat loads and using different air-flow rates. Energy-saving potential was addressed based on the air-flow rate and the related fan power required for obtaining a similar occupied zone temperature for each device. Results showed that the WCJSD and IJSD could provide an acceptable thermal environment while removing excess heat more efficiently than the MSD, as it combined the positive effects of both mixing and stratification principles. This benefit also meant that this devices required less fan power than the MSD for obtaining equivalent occupant zone temperature. The DSD showed a superior performance on heat removal, air exchange efficiency and energy saving to all other devices, but it had difficulties in providing acceptable vertical temperature gradient between the ankle and neck levels for a standing person.

  • 26.
    Dahl, Elin
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Energy companies becoming energy service providers: A comparative study between Denmark and Sweden2012Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Energy efficiency is important – but an energy saving potential has yet to reach its full range. Energy services are means to reach that potential and energy companies are stressed as important actors into creating an established market for energy services. Energy services are tools that include providing in-direct services such as energy statistics, audits, declarations, consultations and analysis. It also includes a number of more complex and direct services, for example energy efficiency measurements or service contracts.

    This report is a result of a study on Danish and Swedish energy companies offering energy services, based on the market they act upon. It aims to find their driving forces for providing energy services. It also looks closer into whether publically and privately owned energy companies differ and if there exist contradictions to both supply energy and energy services at the same time. It also looks into how energy companies are affected and feel about national regulatory instruments.

    Energy companies in both countries offering energy services are reaching a wide spectrum of client segments and energy services. They often have the possibility to combine and package energy supply with energy services and they can reduce many of the theoretical barriers to energy efficiency by offering energy services. They are driven by a client demand and a closer client relationship, both leading to a decreased supply client fluctuation. A new business opportunity and a green profile strategy are also driving factors. Energy services also help energy companies to decrease heavy investment on existing equipment by having more control over their clients’ energy use and reducing energy utilization tops.

    Danish energy companies are tied to an energy saving obligation scheme, providing them with conditions, which their market is based, whilst Swedish energy companies offering energy services act on a market that is created by them and their competitors derive from different business backgrounds. There exist an assertive regulatory instrument in Denmark affecting driving factors for public and private energy companies and clients. In Sweden regulatory instruments, such as energy efficiency programmes, subsidises for energy audits and voluntary agreements for industries affect energy companies in a less way than in Denmark, mostly increasing a client demand for energy services. The regulatory instruments in Denmark increase a trust for energy companies as energy service providers as in Sweden they are trusted upon their existing substantial role on the energy market, a reputation of knowledge and experience and a strategy aiming towards visualisation, motivation and education for the clients.

    Public energy companies feel a responsibility towards their public owners to offer an efficient energy supply and by having a local connection to the municipality they are able to increase competiveness in the region by offering energy services. Private companies are substantially larger than public companies and have a great potential to reach out to a larger number of clients through their existing supply client stock. This is of substantial higher relevance in Sweden than Denmark. 

  • 27.
    de Vries, Frank
    Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics .
    Inverkan av värme på lagerlägets cylindricitet i ett lagerhus2010Independent thesis Basic level (university diploma), 10,5 credits / 16 HE creditsStudent thesis
    Abstract [sv]

    Det här examensarbetet har utförts hos och med stöd av SKF Mekan i Katrineholm. Grundfrågeställningen som innebar upphovet till examensarbetet är om värme påverkar lagerlägets cylindricitet hos ett lagerhus. Detta avgränsas senare till att gälla enbart värmepåverkan under produktion för en typ av lagerhus i en storlek men tre olika materialval. Därmed koncentreras arbetet på gjuterilinan för de mindre lagerhusen samt den bearbetningslina som kallas ”Robot line”.

    Inledningsvis ges en presentation vad lager och lagerhus är samt vilken funktion de fyller. Därefter ges en överblick av gjuteriet samt bearbetningen. Berörda linor betraktas mer ingående men även övriga linor ges en övergripande bild av. Övriga resurser såsom mätrum samt testlabb presenteras också.

    De tre olika materialen granskas för att se vilka avgörande skillnader som finns dem emellan. Detta med hjälp av litteratur samt intervjuer med medarbetare hos SKF Mekan, personal vid Linköpings universitet samt SWEREA.

    Två test som genomförts under arbetets gång beskrivs, varav det ena lyckat men det andra misslyckat. Dock fick det andra testet ett överraskande resultat.

    Befintliga kontroller längs med produktionskedjan omtalas.

    Slutligen sammanfattas vilka moment inom gjuteri- samt bearbetningsprocessen där toleransen för cylindriciteten hos lagerläget riskerar att under-/överskridas samt vad som då är orsaken.

  • 28.
    Dermentzis, Georgios
    et al.
    Unit for Energy Efficient Building, University of Innsbruck, Innsbruck, Austria.
    Ochs, Fabian
    Unit for Energy Efficient Building, University of Innsbruck, Innsbruck, Austria.
    Gustafsson, Marcus
    Linköping University, Department of Management and Engineering, Environmental Technology and Management. Linköping University, Faculty of Science & Engineering.
    Calabrese, Toni
    Unit for Energy Efficient Building, University of Innsbruck, Innsbruck, Austria.
    Siegele, Dietmar
    Unit for Energy Efficient Building, University of Innsbruck, Innsbruck, Austria.
    Feist, Wolfgang
    Unit for Energy Efficient Building, University of Innsbruck, Innsbruck, Austria; Passive House Institute, Darmstadt, Germany.
    Dipasquale, Chiara
    EURAC Research, Bolzano, Italy.
    Fedrizzi, Roberto
    EURAC Research, Bolzano, Italy.
    Bales, Chris
    Energy Technology, Dalarna University, Falun, Sweden.
    A comprehensive evaluation of a monthly-based energy auditing tool through dynamic simulations, and monitoring in a renovation case study2019In: Energy and Buildings, ISSN 0378-7788, E-ISSN 1872-6178, Vol. 183, p. 713-726Article in journal (Refereed)
    Abstract [en]

    An energy auditing tool (PHPP) was evaluated against a dynamic simulation tool (TRNSYS) and used for the assessment of energy conservation measures in a demo case study. The comprehensive comparison of heating and cooling useful demands and loads included three building types (single-, multi-family house, and office), three building energy levels (before renovation and after renovation with a heating demand of 45 and 25 kWh/(m²·a)) and seven European climates.

    Dynamic simulation results proved PHPP (monthly energy balance) to be able to calculate heating demand and energy savings with good precision and cooling demand with acceptable precision compared to detailed numerical models (TRNSYS). The average deviation between the tools was 8% for heating and 15% for cooling (considering climates with a relevant cooling load only). The higher the thermal envelope quality was, i.e. in case of good energy standards and in cold climates, the better was the agreement. Furthermore, it was confirmed that PHPP slightly overestimates the heating and cooling loads by intention for system design.

    The renovation design of a real multi-family house was executed using PHPP as energy auditing tool. Several calculation stages were performed for (a) baseline, (b) design phase, and (c) verification with monitoring in order to calculate the corresponding heating demand. The PHPP model was calibrated twice, before and after the renovation. The necessity for tool calibration, especially for the baseline, was highlighted increasing the confidence with respect to a number of boundary conditions.

    In this study, PHPP was tested as an energy auditing tool aiming to be a versatile and less error-prone alternative to more complex simulation tools, which require much more expert knowledge and training.

  • 29.
    Dipasquale, Chiara
    et al.
    EURAC.
    Fedrizzi, Roberto
    EURAC.
    Bellini, Alessandro
    EURAC.
    Gustafsson, Marcus
    Linköping University, Department of Management and Engineering, Environmental Technology and Management.
    Ochs, Fabian
    University of Innsbruck.
    Bales, Chris
    Högskolan Dalarna.
    Database of energy, environmental and economic indicators of renovation packages for European residential buildings2019In: Energy and Buildings, ISSN 0378-7788, E-ISSN 1872-6178, Vol. 203, article id 109427Article in journal (Refereed)
    Abstract [en]

    Increasing the energy efficiency with a vast impact in the residential building stock requires retrofit so- lutions that can be exploited with respect to a wide range of different building typologies and climates. Several tools and methodologies are nowadays available both for the assessment of building demands and for the individuation of optimum retrofit solutions. However, they are usually either too complex to be adopted by professionals or, on the contrary, oversimplified to account for the full complexity of a deep envelope and HVAC system retrofit. In this context, this paper describes a methodology developed to generate reliable information on retrofit solutions for typical buildings in different climatic conditions. Detailed numerical models are used to simulate a number of combinations of envelope and HVAC systems retrofit measures and renewable energy integration. Energy performance results are gathered in a database that allows comparing solu- tions, spanning over a range of more than 250,0 0 0 combinations of building types, age of construction, climates, envelope performance levels and HVAC systems configurations. Economic feasibility is also de- rived for each of the combinations. In this way, the accurateness of a detailed and validated calculation is made available to assist during the decision making process, with minimum computational effort being required by professionals: the variety and density of evaluated combinations allows to easily assess the performance of a specific case by interpolating among instances previously assessed. The applicability of the results to different climates and similar building typologies is verified by a comparison of the database results with a specific case dynamic simulation.

  • 30.
    Elez, Stefan
    Linköping University, Department of Management and Engineering, Energy Systems.
    Framtida energilösning för tillvaratagande av överskottsvärme med värmepump: Ett examensarbete utfört på Händelöverket, E.ON2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    E.ON has set a goal to deliver 100% renewable and recycled energy year 2025. To achieve this goal at E.ON’s combined heat-and power plant, Händelö in Norrköping, the coal driven Boiler 12 and the biofuel driven Boiler 11 must be replaced with a new renewable and recycled solution to produce heat. A solution that is being discussed at E.ON is replacing these two boilers with a single heat water boiler, Boiler 16 which will be producing heat. In the Händelö area there are some enterprises with residual flows in form of excess heat that is not being used today. By using the excess heat, the greenhouse emissions can be reduced and the national energy system can become more efficient. Another solution is therefore replacing the boilers with an energy solution that uses the excess heat and with the help of a heat pump producing heat.

    The aim of this project has been to investigate the possibilities of a future energy solution with heat pump and how it can be used in cooperation with the Händelö plant to decrease the investment-and marginal costs of the heat production to the district heating network of Norrköping. The objective of this project has therefore been, creating a model in the modelling tool remind and VBA Excel that can calculate the profitability of the future heat pump solution in comparison to the new Boiler 16 with different scenarios of the electricity price.

    A dimensioning of a compressor heat pump has been performed to investigate the technical-and operation qualifications for a heat pump. Furthermore, different models have been created in remind and VBA Excel for a compressor heat pump and an absorptions heat pump. The absorption heat pump has not been dimensioned, a heat pump supplier has provided different values based on the technical- and operating qualifications.

    The result shows that an energy solution with an absorption heat pump is considerably more profitable than a solution consisting of a single Boiler 16. The investment cost of an absorption heat pump became 30

    – 42 MSEK cheaper than the corresponding investment cost for the Boiler 16. In addition, the marginal cost of the absorption heat pump became 79 -102 MSEK more profitable than Boiler 16’s marginal cost considering an economical life span of 20 years and different electricity price scenarios. The total profitability of the absorption heat pump became 110 – 140 MSEK. The compressor heat pump did not become profitable in comparison to Boiler 16. The investment cost for the compressor heat pump became 14 – 24 MSEK more expensive than the corresponding investment cost of Boiler 16 and the marginal cost was only 0 – 5 MSEK less expensive than considering different electricity price scenarios.

    The conclusion of the project is that E.ON should continue investigating the possibilities of investing in an absorption heat pump. The compressor heat pump is not considered being worth investigating further.

  • 31.
    Emilsson (Gustafsson), Sara
    et al.
    Linköping University, Department of Management and Engineering, Environmental Technology and Management. Linköping University, Faculty of Science & Engineering.
    Ivner, Jenny
    Region Östergötland.
    Implementing the global sustainable goals (SDGs) into municipal strategies applying an integrated approach2018In: Handbook of Sustainability Science and Research / [ed] Walter Leal Filho, Springer, 2018, p. 301-316Chapter in book (Refereed)
    Abstract [en]

    The UN emphasises the importance of collaboration and integrated approaches to effectively implement the SDGs. Much of the action will have to take place locally where municipalities will play an important role in coordinating the efforts towards SDG fulfilment. They are constant local actors close to citizens and they can also influence other actors through their strategies. This paper reflects on how the SDGs can be integrated into existing strategies in order to avoid parallel non-effective processes and to avoid the risk of the SDGs to become marginalised. Furthermore, the paper discusses roles and preconditions of municipalities in the SDG implementation process. This study focuses the implementation of the SDGs into a regional municipality’s strategic planning and management, Region Östergötland, Sweden. The challenges and opportunities connected to implementing the SDGs will be problematized, and the paper gives recommendations on how this type of organisations can implement the SDGs taking advantage from qualities in already existing management and working procedures.

  • 32.
    Eriksson, Fredrik
    Linköping University, Department of Management and Engineering.
    Optimering av ventilationsbehovet till tvättapparat2011Independent thesis Basic level (university diploma), 10,5 credits / 16 HE creditsStudent thesis
    Abstract [sv]

    Syftet med detta examensarbete är att undersöka om det går att minska frånluftsventilationen till tvättapparater för pappersmassaindustrin. Genom att mäta flödet för frånluftsventilationen och mätinstrument vid ångläckaget har undersökningar gjorts om det går att minska frånluftsventilationen. 

    Examensarbetet har utförds för företaget Metso i Sundsvall som bl.a. tillverkar hela systemlösningar till pappersmassaindustrin. Mätningarna har gjorts på SCA Östrand i Timrå som är en pappersmassa tillverkare. 

    Inledningsvis ges en presentation över hur pappersmassatillverkning går till och sedan ges en mera genomgående beskrivning av hur Twinroll tvättapparat, spädskruv och standpipe fungerar.

    I teori delen tas det upp vilka saker som påverkar ångläckaget för tvättapparaten. Det som påverkar är sambanden i ideala gaslagen, fukt och avdunstning. För att beräkna hastigheten med pitotrör har Bernoullis ekvation härleds i teoridelen.  

    Mätningarna gick ut på först att fastställa frånluftsventilationsflödet från tvättapparaten. Dessa mätningar gav problem i början eftersom frånluften hade hög temperatur och ånghalt men sedan kunde flödet mätas. För mätningarna användes pitotrör och vinghjulsmätare.

     För att fastställa vilket det minsta frånluftsventilationsflöde är innan det bildas ångläckage från tvättapparaten användes för det mänskliga ögat. Det visade att det inte gick att visa hur ångläckage ändrades genom tiden. Mätningar av temperatur- och RH-givare gav dåliga värden förutom när en tillfällig produktionsstörning inträffade. Då fastställs att när produktionen, temperaturen på pappersmassan- och spritsen går ner minskas ångläckaget. RH-givaren visade felvärden pga att inte synbart ångläckage inträffar och att spritsen går i intervaller. 

    Konceptgeneringen visade att minskade av kåpansluftvolym och ångläckagearean troligtvis är dem bästa lösningarna. Dem andra lösningarna kan testas om energipriserna går upp och då lär dem bli lönsamma. 

  • 33.
    Eriksson, Robert
    et al.
    Linköping University, Department of Management and Engineering, Solid Mechanics. Linköping University, Faculty of Science & Engineering.
    Simonsson, Kjell
    Linköping University, Department of Management and Engineering, Solid Mechanics. Linköping University, Faculty of Science & Engineering.
    Leidermark, Daniel
    Linköping University, Department of Management and Engineering, Solid Mechanics. Linköping University, Faculty of Science & Engineering.
    Moverare, Johan
    Linköping University, Department of Management and Engineering, Engineering Materials. Linköping University, Faculty of Science & Engineering.
    Evaluation of notch effects in low cycle fatigue of alloy 718 using critical distances2018In: 12TH INTERNATIONAL FATIGUE CONGRESS (FATIGUE 2018), E D P SCIENCES , 2018, Vol. 165, article id 15001Conference paper (Refereed)
    Abstract [en]

    Gas turbine disks contain many notch-like features acting as stress raisers. The fatigue life based on the notch root stress may be overly conservative as the steep stress gradient in front of the notch may give rise to so-called notch support. In the current work, the theory of critical distances was applied to the prediction of the total fatigue life of low cycle fatigued, notched specimens made from alloy 718. The fatigue tests were performed at 450 degrees C and 550 degrees C. It was found that, for lives shorter than 5000-10000 cycles, the notched specimens had longer lives than would have been expected based on the notch root strain. For lives longer than 5000-10000 cycles, there were no notch support. The life prediction for notched specimens could be significantly improved by basing the prediction on the strain chosen some distance from the notch (the critical distance). An expression for calculating the critical distance based on the notch root strain was suggested.

  • 34.
    Ewerbring, Carl-Arvid
    Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics. Linköping University, The Institute of Technology.
    Konsumentvänlig Energibesparingsmodell: Ett verktyg som hjälper småhusägare att sänka sina energikostnader2012Independent thesis Basic level (degree of Bachelor), 10,5 credits / 16 HE creditsStudent thesis
    Abstract [en]

    Energy awareness is growing among the Swedish population and a one­‐to­‐two-family dwelling can save energy. The purpose of this paper is to design a tool that helps these home owners reduce their energy costs.

    The paper develops a model that gives them an indication of how much energy they can save. For the majority of homeowners, the next step in the quest to reduce theirs is most likely an energy audit. Therefore, information to help home owners to get a good energy audit performed is included in the model.

    A prototype running the operating system iOS is created and validated against existing models, as well as an energy audit. 

  • 35.
    Faghani, Farshad
    Linköping University, Department of Science and Technology, Physics and Electronics.
    Thermal conductivity Measurement of PEDOT:PSS by 3-omega Technique2010Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Conducting polymers (CP) have received great attention in both academic and industrial areas in recent years. They exhibit unique characteristics (electrical conductivity, solution processability, light weight and flexibility) which make them promising candidates for being used in many electronic applications. Recently, there is a renewed interest to consider those materials for thermoelectric generators that is for energy harvesting purposes. Therefore, it is of great importance to have in depth understanding of their thermal and electrical characteristics. In this diploma work, the thermal conductivity of PEDOT:PSS is investigated by applying 3-omega technique which is accounted for a transient method of measuring thermal conductivity and specific heat.

    To validate the measurement setup, two benchmark substrates with known properties are explored and the results for thermal conductivity are nicely in agreement with their actual values with a reasonable error percentage. All measurements are carried out inside a Cryogenic probe station with vacuum condition. Then a bulk scale of PEDOT:PSS with sufficient thickness is made and investigated. Although, it is a great challenge to make a thick layer of this polymer since it needs to be both solid state and has as smooth surface as possible for further gold deposition.

    The results display a thermal conductivity range between 0.20 and 0.25 (W.m-1.K-1) at room temperature which is a nice approximation of what has been reported so far. The discrepancy is mainly due to some uncertainty about the exact value of temperature coefficient of resistance (TCR) of the heater and also heat losses especially in case of heaters with larger surface area. Moreover, thermal conductivity of PEDOT:PSS is studied over a wide temperature band ranging from 223 - 373 K.

  • 36.
    Fakhri, Akram
    Linköping University, Department of Management and Engineering, Environmental Technology and Management.
    Possibility of Integrated Product Service Engineering for a Swedish Utility Supplier toward Economic and Environmental Sustainability2011Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The energy demand of today, with increasing population and the price of fossil fuels in one hand and consequent environmental issues such as climate change and global warming on the other hand, has resulted in global consideration concerning increasing energy efficiency in distribution network. Integrated product/service engineering (IPSE) has been frequently applied to propose integrated product/service offering at different physical product manufacturing companies. However, it has not been utilized at utility providers. Therefore, this project applies IPSE, at a Swedish utility provider to introduce new ideas of business models with the aims of increasing energy efficiency in the distribution network with means of new technologies and energy policy instruments.

    Literature survey on IPSE methods to choose the most appropriate method was followed by literature review on smart grid and new technologies as means for utility provider to increase energy efficiency in distribution network. Different IPSE methods has been discussed and investigated recently. For this thesis, however, PSS Layer method was applied to answer the research questions such as customer needs, new technologies, involved actors, the flow of information and service between actors, life cycle activities, associated services, contracts and finances.

    Then, interviews with experts at Göteborg Energi AB were implemented to investigate customer demands, available new technologies, economic and technical opportunities and barriers.

    Five different integrated product/service proposals by providing the nine dimension of PSS Layer method were designed. In each model, new actors and technologies were introduced to increase value for both customer and utility provider.

    As discussion, first, it was shown that the findings in designing new business models at GBE could be generalized to the most of Swedish utility providers. Second, the five proposals with their impacts on GBE were presented and the main aspects of each integrated product/service proposals were discussed. Then, the keys to tackle the problem by designers were described. Finally, the feasibility of the results by PSS layer method was assessed by comparing the method with theory.

    Organizing workshops with the attendance of involved actors was recommended to add more details to the proposed business models. For further research, cost-benefit analysis and life cycle assessment were important to analyze the feasibility of proposals.

  • 37.
    Falk, Karolina
    et al.
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Forsberg, Joel
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Adapting to the Changes Enforced by EU’s Network Codes for Electricity: The Consequences for an Electricity Company from a Distribution System Operator’s Perspective2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    To reach EU’s climate and energy target an integrated electricity market is considered to be required (Klessmann, et al., 2011; Boie, et al., 2014; Becker, et al., 2013). As a result the European Commission decided to form a set of rules, named the Network Codes, to create a single European market (ENTSO-E, 2013b). The Network Codes will affect Distribution- and Transmission System Operators, grid users and production units as well as all the other actors on the electricity market (Eurelectric, n.d.a). Concerns regarding what the Network Codes’ actual consequences are have been expressed within the line of business (Swedish Energy, 2013a). Therefore the purpose of this master’s thesis was to determine and furthermore illustrate the consequences the Network Codes will have, in current version, for a Swedish non-transmission system connected electricity company and determine what actions need to be taken.

    The purpose has been addressed by conducting interviews, document studies and by utilizing a change management model, the Intervention Strategy Model, introduced by Paton & McCalman (2000). The structured approach that is the nature of the model was used when determining the consequences the Network Codes enforce and what actions a non-transmission system connected electricity company has to take to cope with them. To further facilitate the determination of these actions this study was conducted on a non-transmission system connected electricity company, in this thesis named Electricity Company A.

    The investigation of the concerns expressed within the line of business illustrated that the concerns were diverse but a majority of them might be incorporated into either of the following groups, simulation models, demand side aggregator and information handling. Out of these groups information handling was by far the area of greatest concern with issues primarily connected to the Distribution System Operator. Consequently this thesis focused on the Distribution System Operator’s perspective.

    The analysis of the area of greatest concern, presented in two flow charts, clearly showed the increased amount of communication enforced by the Network Codes. This increased information handling results in numerous possible organisational consequences for the Distribution System Operator, for example might new systems be required and some existing systems be used with or without adaption. Furthermore, the extra workload could possibly be handled by the existing personnel, in some cases after complementary education, but it might also require new personnel. Finally the Network Codes open up for the possibility for the Distribution System Operator to define certain details which may be conducted individually or in cooperation with other Distribution System Operators. Which of these possible consequences that will affect a specific company is, however, dependent on its preconditions.

    The study on Electricity Company A reveals that the numerous actions required to handle the new communication were not as significant as the line of business might have feared. For Electricity Company A, primarily a new system is needed to handle the real-time values and some of the existing systems need to be updated. Additionally the combined extra work load might require extra personnel for Electricity Company A even though the individual work assignments are fairly small. The actions required should be fairly similar for companies of approximately equal size but might be more extensive for smaller non-transmission system connected electricity companies. All companies need, however, to conduct an individual analysis to determine which specific actions are required for them.

    The conclusions of this thesis aspired, and partly succeeded, to be generalizable on a European level. One example of this is the usage of the Intervention Strategy Model which proved applicable for determining which specific actions are required for all European electricity companies. Furthermore the concerns presented and the possible consequences of the increased information handling found, are generalizable but not complete for all European electricity companies. This thesis focused on one part of the complex Network Codes’ consequences and consequently further research is needed to fully understand the consequences for the electricity business in total.

  • 38.
    Farhanieh, Arman
    et al.
    Siemens Ind Turbomachinery AB, Sweden.
    Mau, Christoph
    Siemens Ind Turbomachinery AB, Sweden.
    Annerfeldt, Mats
    Siemens Ind Turbomachinery AB, Sweden.
    Nadali Najafabadi, Hossein
    Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics. Linköping University, Faculty of Science & Engineering.
    Karlsson, Matts
    Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics. Linköping University, Faculty of Science & Engineering. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    UNSTEADY EFFECTS IN THE HEAT LOAD PREDICTIONS FOR A TWO-STAGE COMPRESSOR TURBINE2016In: PROCEEDINGS OF THE ASME TURBO EXPO: TURBINE TECHNICAL CONFERENCE AND EXPOSITION, 2016, VOL 5A, AMER SOC MECHANICAL ENGINEERS , 2016, no UNSP V05AT13A025Conference paper (Refereed)
    Abstract [en]

    Heat load analysis play an important role in the estimation of hot gas components lifetime. To achieve a high level of accuracy in heat load analysis, predicting the temperature distribution on the vane and blades is one area where further development is needed. Due to strong flow unsteadiness and mixing effects from blade row interactions and cooling injections, accurate heat load predictions have become an engineering challenge. This study uses both steady and time-accurate computational fluid dynamics (CFD) simulations to investigate the unsteady and mixing effects in a two-stage compressor turbine. The commercial code ANSYS CFX-15 is utilized to evaluate the performance of the steady state, mixing plane (MP) method, versus time-accurate, profile transformation (PT) and time transformation (TT) methods. The presence or absence of the rotor-stator cavities from which purge or cooling air is entering the main flowpath can also play an important role in the unsteadiness and mixing properties. Therefore the unsteady effects have been examined for two cases; a simplified model without any cavity and a detailed geometry with all the cavities included. In the simplified case, the cooling has been implemented as local patches. The results are then compared with gas temperature measurements from the real engine tests using thermo-crystals. The measurements include temperature profiles in front of the leading edge of each stator and rotor for both stages. The findings suggest that including cooling cavities may not improve the results in steady state simulations, however their presence in transient simulations can lead to mixing prediction improvements. Moreover, the results indicate that the transient simulations will improve the mixing predictions mainly in the second stage of the turbine. The results also indicate that in transient simulations, number of passages and pitch ratio between the stators of consecutive stages directly affect the results regardless of which transient method is used.

  • 39.
    Fenton, Paul
    et al.
    Linköping University, Department of Management and Engineering, Environmental Technology and Management. Linköping University, Faculty of Science & Engineering.
    Kanda, Wisdom
    Linköping University, Department of Management and Engineering, Environmental Technology and Management. Linköping University, Faculty of Science & Engineering.
    Barriers to the diffusion of renewable energy: studies of biogas for transport in two European cities2017In: Journal of Environmental Planning and Management, ISSN 0964-0568, E-ISSN 1360-0559, Vol. 60, no 4, p. 725-742Article in journal (Refereed)
    Abstract [en]

    The diffusion of renewable energy – particularly in transport – in cities may facilitate the transition away from fossil fuels, improve air quality and reduce greenhouse gas emissions. Past studies on this topic have focused on system modelling of diffusion pathways, technology characteristics and also estimations of future availability of renewable energy, whilst neglecting the agency of producers and users. This article assesses barriers to the diffusion of biogas for transportation in cities from a system and actor perspective. Using document studies and interviews in the cities of Basel, Switzerland, and Odense, Denmark, we identify the presence of conflicting political priorities and shifting strategic objectives, resulting in mixed signals concerning the role and viability of biogas for transportation. This underlines the importance of public sector support and coherent design and implementation of strategy and policy enabling the diffusion of renewable energy.

  • 40.
    Fjellborg, Anders
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Energieffektiv ventilation2012Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Syftet med detta examensarbete är att konkretisera och visa på de grundläggande problemen med inomhusklimatet i Brogårdsfabriken i Vetlanda, för att utifrån detta komma fram med åtgärdsförslag för att minska dem. Detta samt att utreda möjligheterna att ta till vara den i fabriken internt genererade överskottsvärmen och minska energianvändningen.

    Arbetet har skett i ett top-down-perspektiv, vilket betyder att fabriken ses som ett slutet system där tillförd energi in i systemet ställs mot bortförd energi ut ur systemet. Stor del av arbetet har bedrivits i simuleringsprogrammet IDA – Indoor Climate and Energy till vilket data samlats in genom fysiska mätningar i fabriken och genom intern dokumentation på företaget.

    Problemen med inomhusklimatet för de anställda ute i produktionen är av olika karaktär i olika delar av fabriken och varierar även i intensitet beroende på vilken tid på året som studeras. Dock är de bakomliggande orsakerna till problemen alltid desamma. Det handlar bland annat om bristfällig processventilation, stora öppna lokaler som är svårkontrollerade, problem med infiltration genom portar och andra öppningar i klimatskalet.

    Förslag att återskapa en tidigare befintlig vägg rekommenderas för att lösa problemet med kalldrag i packhallen. Väggen skulle förhindra luftrörelser i områden där problemen upplevs och nästintill eliminera dem.

    Fokus på att minska energianvändningen har skett genom att titta på en optimering av ventilationsdriften vilket har resulterat i en kostnadsbesparing på cirka 370 tkr/år vid reducering av driften under enbart helger. Det finns ytterligare potential till kostnadsbesparingar för ventilationsdriften under andra tillfälliga driftstopp eller semesterstängningar av fabriken, om ventilationsdriften anpassas efter detta.

  • 41.
    Gorur, Murat
    Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics.
    ECC-D4 Electostatic Oil Cleaner Design for Heavy-Duty Gas Turbine Applications2010Independent thesis Advanced level (degree of Master (Two Years)), 30 credits / 45 HE creditsStudent thesis
    Abstract [en]

    The turbine technology improvements from 1980 onwards have considerably increased mechanical and thermal stresses on turbine oils which, cause oil oxidation and thereby turbine oil degradation (Livingstone et al., 2007; Sasaki & Uchiyama, 2002). If the oil degradation problem is ignored, this might result in serious turbine system erratic trips and start-up operational problems (Overgaag et al., 2009). Oil oxidation by-products, in other words, sludge and varnish contaminants, lead stated turbine operation-tribological problems. Hence, sludge and varnish presence in turbine oil become a major reason for declining turbine reliability and availability.

    In the power generation industry, heavy-duty gas turbines as well as steam turbines have been lubricated with mineral based turbine oils for many decades (Okazaki & Badal, 2005). First, generally Group I oils (mineral base oils produced by solvent extraction, dewaxing) were used. Nevertheless, this group of oils has lower oxidation resistance. Therefore, modern gas turbines demand oils which have better oil oxidation resistance, and lower sludge and varnish contaminants tendency (Hannon, 2009).

    Today, there are many turbine lubricants available on the market. Besides Group I oils, more and more Group II oils (mineral base oils produced by hydro cracking and hydro treating) are selected in service, and having increased oil oxidation resistance. However field inspections demonstrate that Group II oils also experience sludge and varnish problems as well as Group I oils. Primary reason for these phenomena is the antioxidant additive packages that are used in Group II oils (Overgaag et al., 2009). In any case with recent oil formulations, oil degradation products still exist in current turbine oils, and will continue to do so in natural process. These sludge and varnish contaminants are less than 1 micron in size. Thus, they can pass turbine oil system standard mechanical filters without obstruction. With regard to keep the turbine systems in best operational conditions, external turbine oil cleaning practices became crucial to remove these less than 1 micron size oil degradation products from turbine oils. Current effective method for removing the sludge and varnish is to use electrostatic oil cleaners (Moehle & Gatto et al., 2007).

    Since the majority of turbine user and operator population have been shifted to use Group II based oils to counter the increased sludge and varnish problems, traditional oil cleaners became insufficient to remove sludge and varnish from Group II. (Due to Group II oils have different oil characteristics such as oil oxidation stability and solvency capability). With this awareness, thesis project is looking for ways to introduce and develop an Advanced Electrostatic Oil Cleaner to increase the availability and reliability figures of heavy-duty gas turbines against the rising amount of oil degradation products in modern formulated turbine oils.

    ECC (Electrostatic Cooled Cleaner) is an electrostatic oil cleaner device to clean and cool mineral based turbine oils for heavy-duty gas turbine applications by removing the sludge and varnish - oil contaminants from turbine oils. The basic principle of the ECC is based on the electrostatic force produced by parallel positioned electrodes which are charged with a high D.C. voltage. Oil contaminants- sludge and varnish have polar nature. Therefore, they are attracted by electrostatic forces whose intensity is proportional to the voltage applied. With the oil flowing in parallel to these electrodes, the polar particles in the oil (which is only neutral /no polar) are caught by filter media positioned between these electrodes.

    Small investments on advanced oil cleaner result in big savings on turbine system performance. Increased turbine availability and reliability predominantly reduce maintenance costs and risks besides, and thus maximizing revenue by extending heavy-duty gas turbine operational life.

    An introduced prototype of the ECC-D4 model was tested using two Group II and one Group I oils. The amounts of 200 liter (each) test oils were circulated approximately 300 times through the ECC-D4. In each 3 oil cleaning test sessions, it is proved that the oil insolubles content decreased approximately 40% in tested turbine oils within about 240 ECC-D4 operating hours.

    With taken base of heavy-duty gas turbine characteristics such as 400 MW power production capacity, annually 8000 operating hours, and 15000 liter oil reservoir volume; it is estimated that the ECC-D4 can extend the oil service-life from 24000 to 48000 operating hours (which is approximately the oil service end-life). In addition to that, assuming the ECC-D4 investment cost as 30k€, about 15k€ savings per year through the new turbine oil and component replacement costs, besides turbine operation profit losses. Moreover, the ECC-D4 returns on investment with a rate of 39 % for defined heavy-duty gas turbine.

    In general perspective of ECC-D4, it makes heavy-duty gas turbine infrastructure innovative, fully integrated and committed to fulfilling the need for clean, efficient, reliable power production practices in an environmental manner.

     

  • 42.
    Gustafsson, Daniel
    et al.
    Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics.
    Larsson, Isak
    Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics.
    Solvärme i Singapore2015Independent thesis Basic level (degree of Bachelor), 10,5 credits / 16 HE creditsStudent thesis
    Abstract [en]

    The world faces big issues regarding its energy supply and its impact on the environment. Something has to be done in order to stop this. One way to do that is to make energy generation more sustainable by shifting from fossil fuels to renewable energy sources. Solar energy is one of them, and this report covers hot water produced from it.

    A country that should have good conditions to harvest solar power is Singapore. The country has a very limited land area and almost no natural resources. Because of this, most of its energy is supplied by imported natural gas. In this report, a case has been created to evaluate the performance and profitability of a hot water solar system in a villa in Singapore. In order to do this, literature about the sun, solar heating systems and Singapore has been looked into. Further, thermodynamical correlations have been studied and used in calculations to draw conclusions.

    The result of this report is that an installation of a solar water heating system in a villa in Singapore is feasible and profitable. Other applications of solar thermal power have been evaluated qualitatively and the conclusion is that these also have big potential in Singapore. Ultimately, this could lead Singapore to be less relying on imported energy and also reduce its impact on the environment.

  • 43.
    Gustafsson, Marcus
    et al.
    Linköping University, Department of Management and Engineering, Environmental Technology and Management. Linköping University, Faculty of Science & Engineering.
    Cruz, Igor
    Linköping University, Biogas Research Center. Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, Faculty of Science & Engineering.
    Svensson, Niclas
    Linköping University, Department of Management and Engineering, Environmental Technology and Management. Linköping University, Faculty of Science & Engineering.
    Karlsson, Magnus
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, Faculty of Science & Engineering.
    Technologies for production of liquefied biogas for heavy transports: Energy, environmental, and economic analysis2019Conference paper (Refereed)
    Abstract [en]

    The heavy transport sector is facing a growth within technology and infrastructure for use of natural gas. This opens an opportunity for the biogas market to grow as well, especially in the form of liquefied biogas (LBG). This study presents an investigation of the energy balance, environmental impact and economic aspects of current technologies for production of LBG: mixed refrigerant cycle, nitrogen cycle, pressure reduction and cryogenic liquefaction. Calculations are based on a review of recent literature and data from the biogas industry. The results show that mixed refrigerant cycle is the most economic and energy efficient technology for liquefaction of upgraded biogas, followed by nitrogen cycle. The lowest electricity use and environmental impact is achieved if the liquefaction process is preceded by amine scrubber upgrading. Pressure reduction liquefaction is inexpensive and can be an alternative in areas connected to a high-pressure gas grid, but as a method for liquefaction it is not very efficient as only about 10% of the incoming gas is liquefied and the rest remains in its gaseous form. Moreover, addition of propane for distribution in the natural gas grid increases the environmental impact compared to other distribution pathways. The cryogenic technology has a higher energy use than other liquefaction technologies but compensates by also including CO₂ separation, which could make it suitable if there is no existing upgrading facility in place. However, there are technical difficulties to overcome and it is not widely implemented.

  • 44.
    Gustafsson, Olle
    et al.
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, Faculty of Science & Engineering.
    Karlsson, Johan
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, Faculty of Science & Engineering.
    Resurseffektiv energieffektivisering av flerbostadshus: Frånluftsvärmepumpar i kombination med fjärrvärme2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Fjärrvärme täcker i dagsläget cirka 56 procent av energibehovet för uppvärmning och varmvatten i svenska bostadssektorn. Denna siffra förväntas minska i och med ökade energieffektiviseringsåtgärder och installationer av alternativa värmekällor. Det har blivit allt vanligare att både fastighetssektorn och olika miljöklassningssystem fokuserar på att minska mängden inköpt energi och ett sätt att göra detta på är att installera frånluftsvärmepumpar som ett komplement till fastighetens primära uppvärmningssystem. Det kommunalägda bostadsbolaget AB Stångåstaden planerar att utföra detta i flerbostadshus där FTX-system av flera anledningar inte är möjligt att installera. Installationen är aktuell i fastigheter som i dagsläget har frånluftsventilation och självdrag samt är högre än tre våningar.Installationen kommer att påverka den lokala fjärrvärmeleverantören Tekniska verken AB och då även de är kommunalägda finns det ett intresse i att utreda de effekter som frånluftsvärmepumparna kommer att ha på de båda företagen samt på kommunen i stort. Därför ämnar denna rapport till att påvisa effekterna av installationen av frånluftsvärmepumpar som komplement till fjärrvärme ur ett ekonomiskt, miljö- och resursmässigt perspektiv. I den här rapporten syftar resurs till den primärenergianvändning som sker till följd av förändrad fjärrvärme- och elanvändning vid installation av frånluftsvärmepumpar.Detta har gjorts genom att undersöka två befintliga fastigheter där frånluftsvärmepumpar nyligen installerats och modellera dem i programmet BV2. Där undersöks hur värmeanvändningen förändras då frånluftsvärmepumpen tillåts att drivas utifrån följande sex driftfall;

    1. Frånluftsvärmepumpen går året runt 2. Frånluftsvärmepumpen går mellan december och februari 3. Frånluftsvärmepumpen går mellan oktober och april 4. Frånluftsvärmepumpen startar då utetemperaturen understiger -4˚C 5. Frånluftsvärmepumpen startar då utetemperaturen understiger +1˚C 6. Frånluftsvärmepumpen startar då utetemperaturen understiger +5˚C

    Dessa är framtagna med avseende på Tekniska verkens säsongsbaserade fjärrvärmepris samt på ungefärliga utetemperaturer då marginalproduktionen för fjärrvärmen skiftar bränsle. Dessa kommer även att jämföras med ett referensfall då enbart fjärrvärme täcker fastigheternas värmebehov.Förändringen i fastigheternas fjärrvärmebehov simulerades sedan i Tekniska verkens energiplaneringssystem för att se hur värme- och elproduktionen påverkades. Genom detta erhölls underlag för att kunna ta fram de ekonomiska, miljö- och primärenergimässiga effekterna som uppkommer i och med frånluftsvärmepumpens drift.Utifrån detta kan det konstateras att frånluftsvärmepumpar inte är en lönsam energieffektiviseringsåtgärd för Tekniska verken, Stångåstaden eller Linköpings kommun. Prisbilden och bränslesammansättningen för fjärrvärme i Linköping ger inte frånluftsvärmepumparna potential till att vara lönsam utifrån något av de tre kriterierna ekonomi, miljö och resurs. De mest fördelaktiga driftfallen fås för alla parter då frånluftsvärmepumpen får starta mellan en och minus fyra grader. Detta ger som bäst kommunen en ekonomisk förlust på cirka 1,6 Mkr för Fastighet A och 2,8 Mkr för Fastighet B över en tidsperiod på tjugo år, vilket bedöms vara värmepumpens ekonomiska livslängd. Förlusten beror till störst del på de höga investeringskostnaderna som frånluftsvärmepumparna medför, men också på den prisbild som är satt för fjärrvärme i Linköping.Genom att temperaturstyra frånluftsvärmepumpen ges också störst potential till att minska utsläppsintensiv marginalproduktion av fjärrvärme och genom det också ge minskade globala växthusgasutsläpp i jämförelse med att enbart använda fjärrvärme. Merparten av driftfallen ger dock ökade utsläpp i jämförelse med referensen. Anledningen är till stor del den höga andel avfallsbränsle som finns i Tekniska verkens produktionsmix. Minskad fjärrvärmeproduktion minskar även Tekniska verkens elproduktion vilken antas täckas upp av en mer utsläppsintensiv europeisk marginalproduktion.iiDet finns inget av de valda driftfallen som minskar användningen av den primärenergi som krävs vid värmeproduktionen och anledningen är återigen att den ökade elanvändningen värderas med en högre faktor än vad avfallsbaserad fjärrvärme gör.Frånluftsvärmepumparna är på båda fastigheterna installerade på fastighetens radiatorretur och trots den bevisat förhöjda returtemperaturen som sker på fjärrvärmenätet så bedöms detta inkopplingsalternativ som det mest effektiva sätt att utföra installationen på för att erhålla bäst värmefaktor, driftkostnad och grundinvestering.Trots att inget av de analyserade driftfallen gav en entydig förbättring ur kriterierna ekonomi, miljö och resurs i jämförelse med referensfallet lyckades ändå mängden inköpt energi minskas i samtliga fall. Detta kan ses som en indikation på att de mål om minskad inköpt energi som sätts inom branschen kan behöva revideras, då exempelvis en av de primära anledningarna till dessa mål är att minska koldioxidutsläppen.

  • 45.
    Gyberg, Per
    et al.
    Linköping University, The Tema Institute, Technology and Social Change. Linköping University, Faculty of Arts and Sciences.
    Galis, Vasilis
    Linköping University, The Tema Institute, Technology and Social Change. Linköping University, Faculty of Arts and Sciences.
    Palm, Jenny
    Linköping University, The Tema Institute, Technology and Social Change. Linköping University, Faculty of Arts and Sciences.
    Hushållens energibeteende - en arena för förändring2007In: Energianvändning i vardagen idag och i framtiden, 2007Conference paper (Other academic)
  • 46.
    Hadera, Hubert
    et al.
    ABB Corporate Research, Ladenburg, Germany;Technische Universität Dortmund, Germany.
    Ekström, Joakim
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Sand, Guido
    ABB Corporate Research, Ladenburg, Germany.
    Mäntysaari, Juha
    ABB Oy Industry Solutions, Helsinki, Finland.
    Harjunkoski, Iiro
    ABB Corporate Research, Ladenburg, Germany.
    Engell, Sebastian
    Technische Universität Dortmund, Dortmund, Germany.
    Integration of production scheduling and energy-cost optimization using Mean Value Cross Decomposition2019In: Computers and Chemical Engineering, ISSN 0098-1354, E-ISSN 1873-4375, Vol. 129, article id UNSP 106436Article in journal (Refereed)
    Abstract [en]

    The integration of the optimization of the cost of the procurement of electric energy with production planning and scheduling is increasingly considered in various industries. The traditional approach to integrate production scheduling and energy procurement in industry is production driven, i.e. the production is scheduled first, after which the energy supply optimization is performed to find the best available energy portfolio. This will usually not lead to the optimum of the overall problem. The combined scheduling and energy procurement optimization can be formulated as an integrated monolithic optimization model, but the resulting problems are very hard to solve. Moreover, solutions to the two isolated problems may be available. In this paper, we propose to use Mean Value Cross Decomposition for solving the combined problem by iterating between energy-aware production scheduling and energy-cost optimization, possibly building on existing solutions. We apply the approach to two industrial use cases: a pulping process and a steel production process. MILP-based models are employed for the two scheduling problems and for the energy cost optimization a minimum-cost flow network model is used. Good quality solutions can be obtained within reasonable computation times for the two use cases.

  • 47.
    Hallberg, Björn
    Linköping University, Department of Management and Engineering, Energy Systems.
    Spillvärmeåtervinning ur kylvattensystemet ismältverket på Sapa Profiler AB i Sjunnen2011Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The smelting process at Sapa Profiler AB in Sjunnen generates large quantities of waste heat which is absorbed by the cooling water when the aluminum is cooled down. This paper is the result of a Master’s Degree Project aiming to present the conditions for recycling the waste heat. The cooling water absorbs the heat from the aluminum at an average rate of 600 kW and the paper shows that it can be used to replace electrical power consumption for heating the production plant’s facilities. The total savings potential comes to 464 000 SEK/year which represents a yearly reduction of 10-420 tons in CO2 emissions. Measures were taken already during the ongoing project in order to improve the possibilities of recycling the waste heat, which is suffering from discontinuous flows and low temperatures. In the paper a model is presented of how relatively high temperatures and continuous flows can be attained with the help of a warm water tank. Once he continuous flow is created, the waste heat can be exchanged to a separate flow which serves to transport the waste heat to the local heat distribution systems. Despite the significant savings potential, the  necessary investment of 3 650 000 SEK makes for a pay-back time of at least eight years.

  • 48.
    Hermansson, Henrik
    Linköping University, Department of Management and Engineering, Energy Systems.
    Kryogen uppgradering av biogas med kyla från värmedriven absorptionskylmaskin2009Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This is a master thesis that has been carried out at Göteborg Energi AB. It refers to investigate ifcryogenic upgrading of biogas with advantage can be done by producing necessary cold with a heatdriven absorption cooling machine. Göteborg Energi is one of three actors that together will build abiogas plant in Lidköping that will be up and running in 2010. The plant will produce 30 GWhliquefied biogas annually.

    This thesis investigastes whether it is advantageous, to upgrade biogas with heat driven cooling, in aperspective of economy, energy use and environment. It compares cryogenic upgrading with coldproduced by electricity, but also by other techniques. Two different process simulation softwares havebeen used as support to this thesis; Hysys and DESIGN II.

    The result shows that energy usage increases when the necessary cold is produced with heat instead ofelectricity; 0,47 kW/Nm3 rawgas for cryo upgrade with absorptions cooling and 0,29 kW/Nm3 rawgaswith cold produced by electricity. If it’s possible to use the waste heat to warm the digester, the energyconsumption for the upgrading can be reduced to 0,29 kW/Nm3 for the system with heat-driven cold,and 0,15 kW/Nm3 rawgas for cold produced by electricity. In comparison with other techniques forupgrading, 0,47 kW/Nm3 rawgas is a high value while 0,29 kW/Nm3 rawgas is among the lowestvalues for energy use.

    The impact on the climate emerges from the use of electricity and when methane slips out from theupgrading plant. The result shows that the impact on the climate is slightly decreased for cryogenicupgrading when the cold is produced with a heat driven absorption machine instead of electricity. Theresult varies a lot due to how one calculate the emission of carbon dioxide from the electricity on themargin. In comparison with other upgrading techniques, the climate impact from cryogenic upgradingis less, other than the COOAB-technique that is superior because of its low methane slip and lowdemand of electricity.

    An economical comparison shows that the cost for energy usage is about the same for cryogenic as forother techniques; approximately 0,03 SEK/kWh upgraded gas. If one can utilize the waste heat, thecost would be decreased to 0,024 and 0,02 SEK/kWh upgraded gas for the system with cryogenicupgrading with cooling from absorption machine respectively cooling produced with electricity.

    My conclusion is that the utilization of the waste heat is essential if one wishes to get good economyand low energy use for the upgrading of biogas with cryogenic methods. A slightly increasedenvironmental improvement can be received if one change the cold production from electricity to heat,otherwise it is always more advantageous to use electricity for cryogenic methods.

  • 49.
    Holm, Björn
    et al.
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Göransson, Mikael
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Analys av energikartläggningar och framställning av metodik för Dalkia AB2013Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    During the last decade, the awareness of energy usage has increased in Sweden, especially within the industrial sector. This is most likely the cause of ever increasing energy prices, increased taxation and regulations and a focus on negative environmental factors associated with energy usage.

    It is also to be noted that Swedish industry has previously enjoyed comparatively low electricity prices, in comparison to her European neighbors (outside of Scandinavia where the situation is similar to that of Sweden). This has led to a situation in which Swedish industries have evolved with limited awareness of their own energy usage and with a low overall effectiveness (again in comparison to European neighbors outside of Scandinavia).

    Energy optimization is now a high priority for many industrial companies in order to lower costs and remain competitive on the international market. This has led to an excellent business opportunity for the company Dalkia AB, the Swedish branch of the multinational French company Dalkia.

    Dalkia AB performs various services all related to the usage, optimization and supply of energy. In order to optimize energy usage an energy audit is usually performed in order to map a company’s current energy use and recommend energy efficiency measures.

    At the request of Dalkia AB this master thesis had the goal of analyzing their energy audit method in order to find weaknesses and thereafter suggest improvements. All the steps involved in Dalkia AB ́s energy audit method where investigated.

    From the analysis it was discovered that they lacked experienced and capable auditors to audit industrial processes, that there were no relevant programs within the company to calculate the total energy usage of an audited object and finally that the reports presenting results from the audit left the salesmen confused as to how the results were calculated and what estimations they were based upon. The confusing reporting was potentially complicating the final sale to the customer.

    In order to rectify the problems development started on the following components which were to be eventually taken over by the engineers at Dalkia; a guide to follow for industrial audits, a program to use to calculate energy usage and a report structure to use to present results from the energy audit in a clearer fashion.

  • 50.
    Hultgren, Elin
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Making renewable electricity a reality: Policies and challenges when transforming Germany´s electricity system2013Independent thesis Basic level (degree of Bachelor), 10,5 credits / 16 HE creditsStudent thesis
    Abstract [en]

    Germany is to undertake a speedy phase-out of nuclear energy and at the same time move into the age of renewable energy. The policy basis for the transformation of the electricity system is the Renewable Energy Sources Act (EEG). The aim of this report is to investigate the transformation of the German electricity system: popularly called the Energiewende. The report will introduce and analyze the Renewable Energy Sources Act as a policy instrument, and how the electricity grid needs to be developed in order to handle the increasing shares of electricity from renewable sources. The history, main regulations, and the success of the EEG will be investigated. Furthermore, the ways in which the EEG needs to be revised will be given attention. The imperfections of today’s electricity grid when implementing a dominating share of renewable electricity, and ways in which Information and Communication Technology can be used in solving those imperfections will be analyzed. The basis for this thesis is a literature study. Since this is a current topic changing frequently, up-to-date research is used as the main reference. The EEG is based on a feed-in tariff system. The main concern when implementing a dominating share of renewable electricity is the fluctuation over time. It is difficult to know how much power will be produced and when. The future challenge of the electricity grid is to keep meeting demand and supply in a secure way. To succeed with the transformation, the EEG not only needs to be revised but a solution to the system stability is also necessary. The EEG is considered a successful policy instrument but what it is missing today is incentives for balancing demand and supply, energy efficiency, and technology innovation. In order to deal with fluctuating sources, the main focus when upgrading the grid should be to improve the forecasting issues. The success of making RES a significant part in electricity generation could become strong proof for the global community that an electricity system based on renewable energy sources is possible.

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