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  • 1.
    Antoni, Marc
    et al.
    Linköping University, Department of Mechanical Engineering.
    Forsberg, Torbjörn
    Nilsson, Lars
    Linköping University, The Institute of Technology. Linköping University, Department of Mechanical Engineering, Energy Systems.
    Process orientation: the Swedish experience1999In: Total Quality Management and Business Excellence, ISSN 1478-3363, E-ISSN 1478-3371, Vol. 10, no 45, p. 540-547Article in journal (Other academic)
  • 2.
    Bohlin, Henrik
    et al.
    Linköping University, Faculty of Arts and Sciences. Linköping University, The Tema Institute, Technology and Social Change.
    Henning, Dag
    Linköping University, The Institute of Technology. Linköping University, Department of Mechanical Engineering, Energy Systems.
    Trygg, Louise
    Linköping University, The Institute of Technology. Linköping University, Department of Mechanical Engineering, Energy Systems.
    Energisystemanalys Ulricehamn2004Report (Other academic)
  • 3.
    Carlson, A
    Linköping University, Department of Mechanical Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Energy system analysis of the inclusion of monetary values of environmental damage2002In: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 22, no 3, p. 169-177Article in journal (Refereed)
    Abstract [en]

    This is an analysis of the effect on the technical solution when monetary values of externalities are included in a model for optimising energy systems. The focus of the study is on heating in domestic houses, non-residential premises, multi-dwelling buildings and district heating systems. The included monetary values of damage to the environment and health are those resulting from atmospheric emissions Of CO2, NOx, SO2 and particulates. The estimates are taken from the literature. An optimising method based on linear programming is used and the result is an optimal mix of energy carriers as well as new and existing heating plants that minimise the costs of satisfying a demand for heat. Furthermore, a calculation is made of the externality cost resulting from the energy system. The analysis makes it possible to compare the technical and economic differences of an energy system based on business economics to a system with greater emphasis on socio-economics. Generally speaking, it is cost-effective to take externality costs into consideration at the planning stage instead of correcting the damage later. The results show that by considering externality costs the total discounted cost of the energy system would be approximately 30% lower than today. Furthermore, the use of pellets and wood chips should be substantially larger in all of the studied regions. (C) 2002 Elsevier Science Ltd. All rights reserved.

  • 4.
    Carlson, A
    Linköping University, Department of Mechanical Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Energy systems and the climate dilemma - Reflecting the impact on CO2 emissions by reconstructing regional energy systems2003In: Energy Policy, ISSN 0301-4215, E-ISSN 1873-6777, Vol. 31, no 10, p. 951-959Article in journal (Refereed)
    Abstract [en]

    Global warming is one of the most important environmental issues today. One step for the European Union to fulfil the Kyoto protocol, stating a worldwide decrease of emissions of greenhouse gases, is to treat the environment as a scarce resource by attributing costs for environmental impact. This accompanied with considering the European electricity market as one common market, where coal condensing power is the marginal production, lead to the possibility to reduce CO2-emissions in Europe by reconstructing energy systems at a local scale in Sweden. A regional energy system model is used to study possibilities to replace electricity and fossil fuel used for heating with biomass and how a reconstruction can affect the emissions of CO2. An economic approach is used where cost-effective technical measures are analysed using present conditions and by including monetary values of externalities. The analysis shows that, by acting economically rational, a large amount of electricity and fossil fuel should, in three Out Of four cases, be replaced leading to a substantial reduction of CO2 emissions. (C) 2002 Elsevier Science Ltd. All rights reserved.

  • 5.
    Carlson, Annelie
    Linköping University, Department of Mechanical Engineering, Energy Systems. Linköping University, The Institute of Technology.
    On cost-effective technical measures to avoid environmental damage of regional energy systems2002In: International journal of energy research (Print), ISSN 0363-907X, E-ISSN 1099-114X, Vol. 26, no 12, p. 1103-1115Article in journal (Refereed)
    Abstract [en]

    The production of heat and electricity can cause large environmental impacts and, hence, large costs for society. Those are costs that are seldom taken into consideration. An important question is how the future technical energy systems should be formed if environmental costs were considered as any other good or service, such as raw material, capital and labour. This study comprises cost-effective technical measures when monetary values of external effects are included in an energy system analysis. It is an analysis of how the present energy system can for society be cost-effectively reconstructed to be more sustainable. A regional energy system model has been developed to perform the study and it concentrates upon production of heat in single-family houses, multi-dwelling buildings, non-residential promises and district heating systems. The analysis adopts a business economic perspective, using present prices of energy carriers, and a more socio-economic perspective, in which external costs are included. The result of the analysis is the optimal mix of energy carriers as well as new and existing heating plants that minimizes the costs of satisfying a demand for heat. The results show that it is profitable to invest in new heating plants fuelled with woody biomass. Furthermore, the external costs arising with satisfying the demand for heat can decrease substantially, 60%, by carrying through with the investments that are cost-effective according to the institutional rules valid today. When monetary values of external costs are taken into consideration, this number is additional 5-percentage points lower. It is shown that if environmental costs are included it is more expensive to continue with business as usual than it is to reconstruct and run a more sustainable energy system.

  • 6.
    Danestig, Maria
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Mechanical Engineering, Energy Systems.
    Westerberg, Karin
    Linköping University, Faculty of Arts and Sciences. Linköping University, The Tema Institute.
    Att förändra ett uppvärmningssystem: bilder av framtidens energisystem i Söderköping2005Report (Other academic)
    Abstract [sv]

    Rapporten bygger på en fallstudie i Söderköpings kommu och sätter bilder av framtidens uppvärmningssystem och dessa bilders betydelser för lokalt förändringsarbete i fokus. I fallstudien ingår intervjuer med 4 kommunpolitiker, 4 kommunal tjänstemän samt 2 representater för det privata fjärrvärmeföretaget. Dessutom studeras kommunal protokoll samt massmedierapporteringen kring uppvärmningen i Söderköping. Centrala frågor är: Hur tolkar lokala aktörer tidigare förändringar?; Hur påverkar dessa tolkningar aktörernas bilder av framtidens uppvärmningssystem?; Vilka förhoppningar och farhågor knyts till framtiden?; samt Hur kan lokala framtidsbilder omformas till scenarier och hur kandessa scenarier användas i det kommande energiarbetet i kommunen? Rapportens bärande kategorier är historier, framtidsbilder och scenarier. Med historier menas de berättelser om tidigare förändringar som återfinns i massmedia och kommunala protokoll, men också i informanternas intervjuer. Framtidsbilder utgörs av de förhoppningar och farhågor kring den framtida utvecklingen av uppvärmningssystemet som förmedlats via intervjuerna. Med scenarier menas slutligen de renodlingar och utvecklingar av centrala drag i framtidsbilderna som forskarna stått för och som utvecklats till diskussionsunderlag för kommande energiarbete i kommunen. De scenarier som presenteras och diskuteras är: Centraliserade biobränslesystem Värmepumpskommunen, samt Den decentraliserade självhushållningen

  • 7.
    Danestig, Maria
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Mechanical Engineering, Energy Systems.
    Westerberg, Karin
    Linköping University, Faculty of Arts and Sciences. Linköping University, The Tema Institute.
    Lokala aktörers visioner: Framtidens uppvärmningssystem i en kommun2005In: Energitinget,2005, 2005, p. 30-30Conference paper (Other academic)
    Abstract [sv]

    Den situation som olika aktörer Söderköping står inför då det gäller uppvärmningssystemet fokuseras i den studie som presenteras. Huvudsyftet med arbetet har varit att studera aktörernas uppfattning om hur uppvärmningssystemet kan utvecklas samt vilka lokala scenarier som kan skapas. Studien belyser frågor som vilka hinder och möjligheter som finns för uppvärmningssystemets utveckling givet lokala förutsättningar samt hur olika aktörers inflytande skiftar i olika utvecklingsmöjligheter. Presentationen bygger på rapporten "Att förändra ett uppvärmningssystem: bilder av framtidens uppvärmningssystem i Söderköping"

  • 8.
    Eklund, Mats
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Mechanical Engineering, Environmental Technique and Management.
    Söderström, Mats
    Linköping University, The Institute of Technology. Linköping University, Department of Mechanical Engineering, Energy Systems.
    Wolf, Anna
    Linköping University, The Institute of Technology. Linköping University, Department of Mechanical Engineering, Energy Systems.
    Skogsindustriellt ekosystem i Kisa - projektrapport2004Report (Other academic)
  • 9.
    Ekstrand-Tobin, Annika
    Linköping University, Department of Mechanical Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Hälsopåverkan av åtgärder i fuktiga byggnader2004Doctoral thesis, monograph (Other academic)
    Abstract [en]

    The object of this inventory study was to study the effect on the indoor environment and allergy parameters after adequate measures were taken in damp-damaged one-family houses with HDM allergic occupants.

    Moisture may cause damage on building material and increase allergic symptoms. If adequate measures considering moisture are taken in a damaged building this should improve the indoor air quality and thereby reduce the allergic symptoms in allergic patients.

    In this study fifteen patients with allergy to house dust mites (HDM) and living in houses with severe moisture problems were selected. Several technical parameters were measured before and after (one year or more) adequate taken measures. These parameters were e.g. ventilation rate, HDM-content in e.g. mattresses, temperature and moisture conditions in indoor air and in the damaged/damp building structures. In parallel to the technical measurements, questionnaire and medical parameters on each patients including HDM-specific IgE, ECP, symptom score and spirometry were followed.

    The results show a significant reduction of moisture. Improved indoor air quality and odour condition were seen after adequate taken measures. Significant improvements in some clinical data and allergy laboratory tests were noticed. In conclusion this study shows that adequate taken measures in severe moisture damaged houses can improve indoor air quality, well being and may also reduce the conditions for continuing allergy problems in HDM allergic patients.

  • 10.
    Ekstrand-Tobin, Annika
    Linköping University, Department of Mechanical Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Samband mellan astma och inomhusmiljö?: undersökning i 60 unga astmatikers bostäder1993Licentiate thesis, monograph (Other academic)
  • 11.
    Franzén, Thomas
    Linköping University, Department of Mechanical Engineering, Energy Systems. Linköping University, The Institute of Technology.
    EnSAM - EnergiSystemAnalysMetod för industriella energisystem2005Licentiate thesis, monograph (Other academic)
    Abstract [en]

    Traditionally, Swedish industries have been experiencing lower power prices compared with industries in the European continent. The specific power consumption is 2- 3 times higher than other competing industries abroad.

    Since July 2004, the power market is deregulated where industries have the possibility to choose supplier. This could imply a harmonized price level across the continent. This would be disadvantageous for Swedish companies if nothing will be done to reduce power consumption.

    Marginal power production is based on coal-fired condensing power plant in the European power system. Independent of location, reducing the use of electricity would affect the use of expensive and environmentally not favorable plants.

    In this thesis a method that can be used by nearly all industries is presented. The method has been applied on different case studies within different projects like project in Volvo Cars plants in Guthenburg and Gent, Electrolux cooker manufacturing in three European cities, Fredericia in Denmark, Spennymoor in England, Motala in Sweden and in the Oskarshamn area and a similar project ELOST in Östergotland and within program "Uthållig kommun" in Sweden.

    The studies show that the all industries that are considered can reduce their electricity energy use by about 50 %. This would imply significant reduction of carbon dioxide emission in the continent.

    Using top-down approach system failures can be identified and corresponding measures can be taken to improve the system. The use of energy can be reduced through energy avoiding cooling and heating at the same time, controlled operation of compressors and the use of power driven tools instead of compressed air driven tools, the use of efficient lamps and controlled ventilation or totally avoiding ventilation in some manufacturing halls, application of district heating driven absorption chillers and no production use can also contribute to reduced electric energy use.

    Experiences from performed case studies indicate that system failures regarding the electricity use have been detected in nearly all investigated industries.

    Three "laws" are distinguished:

    • 1kWh electricity from a coal fires condensing power plant will give rise to aout 1kg CO2 i.i. : 1 kwh el ≈ 1 kg CO2
    • Low electricity price implicate high electricity use and vice versa i.e: (Electricity price) times (specific use) ≈ constant
    • The efficiency of a coal fired condensing power plant is about 30% which implicate: Electricity price > three times the fuel price
  • 12.
    Gebremedhin, Alemayehu
    Linköping University, Department of Mechanical Engineering, Energy Systems. Linköping University, The Institute of Technology.
    The impact of a widened energy system boundary on cost effectiveness2000Licentiate thesis, monograph (Other academic)
  • 13.
    Gebremedhin, Alemayehu
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Mechanical Engineering, Energy Systems.
    Akkerman, H.
    Ottosson, Hans
    Linköping University, The Institute of Technology. Linköping University, Department of Mechanical Engineering.
    Energy System Analysis: Optimization of the Karlshamn Energy System, in the KEES Project2001Other (Other (popular science, discussion, etc.))
    Abstract [en]

        

  • 14.
    Gebremedhin, Alemayehu
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Mechanical Engineering, Energy Systems.
    Glad, Wiktoria
    Linköping University, Faculty of Arts and Sciences. Linköping University, The Tema Institute, Technology and Social Change.
    Gustafsson, Stig-Inge
    Linköping University, Department of Mechanical Engineering.
    Energianalys Solna. Forskningsrapport inom programmet Uthållig kommun.2004Report (Other academic)
  • 15.
    Gebremedhin, Alemayehu
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Mechanical Engineering, Energy Systems.
    Gustafsson, Stig-Inge
    Linköping University, The Institute of Technology. Linköping University, Department of Mechanical Engineering, Energy Systems.
    Glad, Wictoria
    Tema T Linköpings Universitet.
    Energisystemanalys Solna2004Report (Other academic)
  • 16.
    Gebremedhin, Alemayehu
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Mechanical Engineering, Energy Systems.
    Henning, Dag
    Linköping University, The Institute of Technology. Linköping University, Department of Mechanical Engineering, Energy Systems.
    Palm, Jenny
    Linköping University, Faculty of Arts and Sciences. Linköping University, The Tema Institute, Technology and Social Change.
    Energianalys Vingåker2006Report (Other academic)
  • 17.
    Gebremedhin, Alemayehu
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Mechanical Engineering, Energy Systems.
    Moshfegh, Bahram
    Linköping University, The Institute of Technology. Linköping University, Department of Mechanical Engineering, Energy Systems.
    Modelling and optimization of district heating and industrial energy system - An approach to a locally deregulated heat market2004In: International journal of energy research (Print), ISSN 0363-907X, E-ISSN 1099-114X, Vol. 28, no 5, p. 411-422Article in journal (Refereed)
    Abstract [en]

    Regions with densely concentration of industries and district heating systems (DHS) could be interesting study object from the light of an integrated heat market on local basis. System analysis with a widened system boundary could be used as an approach to evaluate the benefit of an integrated heat supply system. In this study, an energy system model consisting of totally seven different participants is designed and the optimization results of the system analysis are presented. With applied data and assumptions, the study shows that a significant amount of the heat demand within two sub-systems can be covered by heat supply from the heat market (the entire heat comes from two industries). Shadow prices, which can be used for heat pricing, indicate the advantage of an integrated system. The system cost reduction through integration and the availability of several actors with diverse energy supply system, makes the region under study an interesting area to prove a locally deregulated heat market.

  • 18.
    Gebremedhin, Alemayehu
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Mechanical Engineering, Energy Systems.
    Zinko, Heimo
    Linköping University, The Institute of Technology. Linköping University, Department of Mechanical Engineering, Energy Systems.
    Avoiding high return temperatures with absorption coolers in district heating systems2004In: 9th International Symposium on district heating and cooling,2004, 2004, p. 191-Conference paper (Refereed)
  • 19.
    Gong, Mei
    Linköping University, Department of Mechanical Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Exergy analysis of a pulp and paper mill2005In: International journal of energy research (Print), ISSN 0363-907X, E-ISSN 1099-114X, Vol. 29, no 1, p. 79-93Article in journal (Refereed)
    Abstract [en]

    Different energy and exergy concepts and methods are presented and applied to a Swedish pulp and paper mill. Flow diagrams show that the exergy content is mostly much less than the energy content of the flows. The largest exergy losses appear in the boilers. Heating processes are highly exergy inefficient. A limited Life Cycle Exergy Analysis (LCEA) shows that the exergy output amounts to over 3 times the spent exergy as non-sustainable resources. By replacing the present use of non-sustainable resources, mostly fuel oil, the mill could move towards a truly sustainable process.

  • 20.
    Gong, Mei
    Linköping University, Department of Mechanical Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Using exergy and optimization models to improve industrial energy systems towards sustainability2004Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    With finite natural resources and large energy demands in the world, a sustainable development approach becomes increasingly important in the improvement of energy systems. The concept of sustainability is examined with relation to exergy flows on the earth. The present industrial society is obviously not sustainable. The main aim of this study is to analyze and improve industrial energy systems towards an increased sustainability.

    Exergy analysis is used for evaluating energy systems and for guiding efficiency-improvement efforts. An existing optimization method is improved and applied to an energy system in order to maximize its economic feasibility and profitability. Life cycle analysis based on exergy is applied in order to further guide towards sustainable development. This thesis offers tools to better evaluate energy systems with regard to physical resource use, economy and environment. These tools are particularly useful for decision-making in long-term plarming.

    The concepts and methods presented are useful in the design and optimization of more sustainable energy systems, particularly in industrial processes. A typical Swedish industry, a pulp and board mill, is examined using an improved optimization method together with the exergy method. The main cause of the low exergy efficiency in the mill is irreversibility of combustion and of heat transfer in the steam generator. The change in the price of electricity has a greater effect on the energy cost than the change in the price of fuel, which means a unified European electricity market has large impact on the Swedish industry. Increasing efficiency of processes usually minimizes environmental damage and maximizes economic benefits. In spite of increasing the exergy loss switching from fossil fuel to bio-fuels can decrease the net CO2 emission as well as the energy cost, and is a step towards increased sustainability. The investments in an oil-bark boiler, evaporation plant and recovery boiler give a good supply of sustainable resources, a reduction of environmental impact, and both energy and economical saving. In addition, with replacing the present evaporation plant with the non-conventional one, even more benefits could be achieved. Still, there are more potential for further improvement in the mill.

    List of papers
    1. On exergy and sustainable development - Part 1: conditions and concepts
    Open this publication in new window or tab >>On exergy and sustainable development - Part 1: conditions and concepts
    2001 (English)In: Exergy: An International Journal, ISSN 1634-7803, E-ISSN 1164-0235, Vol. 1, no 3, p. 128-145Article in journal (Refereed) Published
    Abstract [en]

    The future of life on our planet is a matter of great concern. This paper is based on a vision of sustainable development. It is divided into two parts. The first part introduces conditions and concepts that are of importance for sustainable development. Environmental conditions in terms of causes and effects of emissions, the concept of exergy as a physical measure of difference or contrast and a number of different exergy forms common in nature are presented. Emissions and pollutants are differences in the environment, thus effecting the environment. Exergy is a suitable measure of these differences. The concept of sustainability is examined with relation to exergy flows on the earth. Part 2 of this paper introduces methods based on presented concepts and applies these to real systems. Exergy is applied to emissions to the environment by case studies in order to describe and evaluate its values and limitations as an ecological indicator. Exergy is considered as a useful ecological indicator by reference to the literature in the field.

    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:liu:diva-86944 (URN)10.1016/S1164-0235(01)00020-6 (DOI)
    Available from: 2013-01-08 Created: 2013-01-08 Last updated: 2017-12-06
    2. On exergy and sustainable development - Part 2: indicators and methods
    Open this publication in new window or tab >>On exergy and sustainable development - Part 2: indicators and methods
    2001 (English)In: Exergy: An International Journal, ISSN 1634-7803, E-ISSN 1164-0235, Vol. 1, no 4, p. 217-233Article in journal (Refereed) Published
    Abstract [en]

    This second part is the continuation of Wall and Gong [Exergy Internat. J. 1 (3) (2001), in press]. This part is an overview of a number of different methods based on concepts presented in the first part and applies these to real systems. A number of ecological indicators will be presented and the concept of sustainable development will be further clarified. The method of Life Cycle Exergy Analysis will be presented. Exergy will be applied to emissions into the environment by case studies in order to describe and evaluate its values and limitation as an ecological indicator. Exergy is concluded to be a suitable ecological indicator and future research in this area is strongly recommended.

    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:liu:diva-86945 (URN)10.1016/S1164-0235(01)00030-9 (DOI)
    Available from: 2013-01-08 Created: 2013-01-08 Last updated: 2017-12-06
    3. Industry and the energy market - optimal choice of measures using the MIND method
    Open this publication in new window or tab >>Industry and the energy market - optimal choice of measures using the MIND method
    2002 (English)In: CRIS Conference on Power Systems and Communications Infrastructures for the future, 2002, China: CRIS, International Institute for Critical Infrastructures , 2002Conference paper, Published paper (Refereed)
    Abstract [en]

    No abstract available.

    Place, publisher, year, edition, pages
    China: CRIS, International Institute for Critical Infrastructures, 2002
    Keyword
    MIND, Industrial energy systems
    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:liu:diva-39960 (URN)51866 (Local ID)51866 (Archive number)51866 (OAI)
    Conference
    Power Systems and Communication Systems Infrastructures for the Future International Conference (CRIS'2002) September 23-27, 2002, Beijing, China
    Available from: 2009-10-10 Created: 2009-10-10 Last updated: 2013-02-11
    4. Optimization of industrial energy systems by incorporating feedback loops into the MIND method
    Open this publication in new window or tab >>Optimization of industrial energy systems by incorporating feedback loops into the MIND method
    2003 (English)In: Energy, ISSN 0360-5442, E-ISSN 1873-6785, Vol. 28, no 15, p. 1655-1669Article in journal (Refereed) Published
    Abstract [en]

    The MIND (Method for analysis of INDustrial energy system) method has been developed for multi-period cost optimization of industrial energy systems. Existing industrial processes can be represented at the desired level of accuracy, i.e. one modeling unit may represent a part of the production process or the whole plant. The optimization method includes both energy and material flows. Nonlinear relations, energy conversion efficiencies and investment costs are linearized by mixed-integer linear programming. A flexible time-scale facilitates the performance of long- and short-term analyses. In order to meet the requirements with regard to sustainable development, the recycling of energy and material flows is becoming more common in many industrial processes. The recycling or reuse of energy and material is managed by feedback loops, which are incorporated into the original MIND method to improve the model and reduce the calculation time. The improved MIND/F method (MIND method with feedback loops) model is applied to a pulp and paper mill in Sweden. A comparison between the original MIND method with manual handling of the feedback loops and the MIND/F method gives highly satisfactory results. Cost optimization using the improved MIND method is well within the given accuracy and computer time and manual calculation time are both reduced considerably. The reuse of energy and material resources is not only an economic advantage, but also implies a reduction of the environmental impact.

    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:liu:diva-46367 (URN)10.1016/S0360-5442(03)00170-1 (DOI)
    Available from: 2009-10-11 Created: 2009-10-11 Last updated: 2017-12-13
    5. Exergy analysis of a pulp and paper mill
    Open this publication in new window or tab >>Exergy analysis of a pulp and paper mill
    2005 (English)In: International journal of energy research (Print), ISSN 0363-907X, E-ISSN 1099-114X, Vol. 29, no 1, p. 79-93Article in journal (Refereed) Published
    Abstract [en]

    Different energy and exergy concepts and methods are presented and applied to a Swedish pulp and paper mill. Flow diagrams show that the exergy content is mostly much less than the energy content of the flows. The largest exergy losses appear in the boilers. Heating processes are highly exergy inefficient. A limited Life Cycle Exergy Analysis (LCEA) shows that the exergy output amounts to over 3 times the spent exergy as non-sustainable resources. By replacing the present use of non-sustainable resources, mostly fuel oil, the mill could move towards a truly sustainable process.

    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:liu:diva-29317 (URN)10.1002/er.1041 (DOI)14614 (Local ID)14614 (Archive number)14614 (OAI)
    Available from: 2009-10-09 Created: 2009-10-09 Last updated: 2017-12-13
    6. Coordination of exergy analysis and the MIND method - applied to a pulp and board mill
    Open this publication in new window or tab >>Coordination of exergy analysis and the MIND method - applied to a pulp and board mill
    2004 (English)In: International Journal of Exergy, ISSN 1742-8297, E-ISSN 1742-8300, Vol. 1, no 3, p. 289-302Article in journal (Refereed) Published
    Abstract [en]

    The MIND (Method for analysis of INDustrial energy systems) method has been developed for cost optimisation of industrial energy systems, mainly with regard to quantities of energy. Exergy analysis reveals losses, efficiencies and possible improvements. These methods can be combined in order to improve industrial energy systems. In this paper, a Swedish pulp and board mill is used as a case study. The efficiencies of the processes in the mill are evaluated using exergy analysis. The most exergy inefficient processes are indicated and some improvements are suggested. This case study shows that it is the boilers and the evaporation plant that are the most inefficient processes, with efficiencies down to 29%. Different investment alternatives for these processes are studied and cost optimisation is achieved using the MIND method. The study shows that the energy costs can be reduced by up to 15 million Euros per year while the exergy efficiency can be improved by up to 14%. The combined approach shows that the energy cost-efficient alternatives are also usually exergy efficient.

    Keyword
    efficiency; energy; exergy; industrial energy system; optimisation; pulp and paper
    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:liu:diva-22918 (URN)10.1504/IJEX.2004.005558 (DOI)2273 (Local ID)2273 (Archive number)2273 (OAI)
    Available from: 2009-10-07 Created: 2009-10-07 Last updated: 2017-12-13
  • 21.
    Gong, Mei
    et al.
    Linköping University, Department of Mechanical Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Karlsson, Magnus
    Linköping University, Department of Mechanical Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Coordination of exergy analysis and the MIND method - applied to a pulp and board mill2004In: International Journal of Exergy, ISSN 1742-8297, E-ISSN 1742-8300, Vol. 1, no 3, p. 289-302Article in journal (Refereed)
    Abstract [en]

    The MIND (Method for analysis of INDustrial energy systems) method has been developed for cost optimisation of industrial energy systems, mainly with regard to quantities of energy. Exergy analysis reveals losses, efficiencies and possible improvements. These methods can be combined in order to improve industrial energy systems. In this paper, a Swedish pulp and board mill is used as a case study. The efficiencies of the processes in the mill are evaluated using exergy analysis. The most exergy inefficient processes are indicated and some improvements are suggested. This case study shows that it is the boilers and the evaporation plant that are the most inefficient processes, with efficiencies down to 29%. Different investment alternatives for these processes are studied and cost optimisation is achieved using the MIND method. The study shows that the energy costs can be reduced by up to 15 million Euros per year while the exergy efficiency can be improved by up to 14%. The combined approach shows that the energy cost-efficient alternatives are also usually exergy efficient.

  • 22.
    Gong, Mei
    et al.
    Linköping University, Department of Mechanical Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Karlsson, Magnus
    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.
    Industry and the energy market - optimal choice of measures using the MIND method2002In: CRIS Conference on Power Systems and Communications Infrastructures for the future, 2002, China: CRIS, International Institute for Critical Infrastructures , 2002Conference paper (Refereed)
    Abstract [en]

    No abstract available.

  • 23.
    Gong, Mei
    et al.
    Linköping University, Department of Mechanical Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Wall, Göran
    Independent Researcher, Mölndal, Sweden.
    On exergy and sustainable development - Part 2: indicators and methods2001In: Exergy: An International Journal, ISSN 1634-7803, E-ISSN 1164-0235, Vol. 1, no 4, p. 217-233Article in journal (Refereed)
    Abstract [en]

    This second part is the continuation of Wall and Gong [Exergy Internat. J. 1 (3) (2001), in press]. This part is an overview of a number of different methods based on concepts presented in the first part and applies these to real systems. A number of ecological indicators will be presented and the concept of sustainable development will be further clarified. The method of Life Cycle Exergy Analysis will be presented. Exergy will be applied to emissions into the environment by case studies in order to describe and evaluate its values and limitation as an ecological indicator. Exergy is concluded to be a suitable ecological indicator and future research in this area is strongly recommended.

  • 24.
    Gustafsson, Stig-Inge
    Linköping University, Department of Mechanical Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Carpentry factory and municipal electricity loads1998In: Energy Conversion and Management, ISSN 0196-8904, E-ISSN 1879-2227, Vol. 39, no 3-4, p. 343-347Article in journal (Refereed)
    Abstract [en]

    Load management of electricity loads has received more interest in recent years. At least in Sweden, this is natural because of a rather cheap energy price, while at the same time, the demand charge is high. If a company could save the precise kWh that build the peak demand, then these would have a value of more than 200 times the off-peak kWh. This paper deals with monitored electricity data for two carpentry industries and one municipality, both situated in the south of Sweden. The ideal ! situation would be if the industry could reduce their peak demand and, at the same time, reduce the peak for the utility. Both participants would, in that case, save money, and the payback time for load management equipment would decrease substantially. If, however, a load management system at the carpentry transfers kWh to peak hours for the utility, the industry will save money, while the utility gets higher costs. The result of the study is that the Swedish electricity rates in use today are a very poor means of encouraging worthwhile load management, and often, they even aggravate the situation.

  • 25.
    Gustafsson, Stig-Inge
    Linköping University, The Institute of Technology. Linköping University, Department of Mechanical Engineering, Energy Systems.
    Dubbla vinnare med laststyrning av fjärrvärme2004In: Energimagasinet : teknik, ekonomi, miljö, ISSN 0348-9493, Vol. 25, no 6, p. 30-32Article in journal (Other (popular science, discussion, etc.))
  • 26.
    Gustafsson, Stig-Inge
    Linköping University, Department of Mechanical Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Economic benefits from load management in a carpentry factory1996In: Applied Thermal Engineering, ISSN 1359-4311, E-ISSN 1873-5606, Vol. 16, no 10, p. 829-834Article in journal (Refereed)
    Abstract [en]

    As a result of a National Referendum and a subsequent parliament decision Sweden will phase out its nuclear power stations before the year 2010. This source of electricity accounts for about half the total electricity usage and therefore other sources must be constructed, or the country must use less electricity. One way to accomplish this, according to economic theory, is to increase the price of electricity, and we will probably be subject to such actions, at least if there is a risk of a shortage of electricity. Hitherto, most interest for saving energy has been emphasised on space and domestic hot water heating in buildings. The major part of electricity, however, is used in industry, and is therefore worth studying in more detail. One small carpentry plant which manufactures wooden staircases and fibreboard panels for ceilings has been studied. Using monitored data for 1 year of their electricity usage and costs, the amount of money which could be saved by the owner of the factory, if different load management measures had been applied, has been calculated. Thus it was possible to find the maximum cost for equipment that can turn off some processes, such as timber dryers, for short periods.

  • 27.
    Gustafsson, Stig-Inge
    Linköping University, The Institute of Technology. Linköping University, Department of Mechanical Engineering, Energy Systems.
    Energieffektivisering i träindustrin.2004In: Energimagasinet : teknik, ekonomi, miljö, ISSN 0348-9493, Vol. 25, p. 34-37Article in journal (Other (popular science, discussion, etc.))
  • 28.
    Gustafsson, Stig-Inge
    Linköping University, Department of Mechanical Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Finite element modelling versus reality for birch chairs1996In: European Journal of Wood and Wood Products, ISSN 0018-3768, E-ISSN 1436-736X, Vol. 54, no 5, p. 355-359Article in journal (Refereed)
    Abstract [en]

    When chairs and other furniture are designed the work is mostly founded on handicraft experience. Calculations based on solid mechanics theory are almost never used in order to find out optimal solutions for different wood members, or the structure as a whole. We have therefore studied a simple chair, made of birch, where the emphasis is laid on its ability to carry different loads. Using the method of finite elements we have predicted the strain and stress at different points on the chair structure. Further, we have manufactured the chair and exposed it to the same load pattern as used in the finite element calculations. The strain has been monitored and compared to the calculated value at the points of most interest. The result shows that part of the calculations corresponded fairly well with the monitored values but also that much work still remains in order to totally predict the accurate structural behaviour for such a simple frame as a chair. Probably, some of the discrepancies depend on the wood material which exhibits so different response for stress in different directions.

     

  • 29.
    Gustafsson, Stig-Inge
    Linköping University, The Institute of Technology. Linköping University, Department of Mechanical Engineering, Energy Systems.
    Fjärrvärme i processindustri2005In: Energimagasinet : teknik, ekonomi, miljö, ISSN 0348-9493, Vol. 26, no 4Article in journal (Other (popular science, discussion, etc.))
  • 30.
    Gustafsson, Stig-Inge
    Linköping University, Department of Mechanical Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Indetermined chair frames of ash wood1997In: European Journal of Wood and Wood Products, ISSN 0018-3768, E-ISSN 1436-736X, Vol. 55, no 2-4, p. 255-259Article in journal (Refereed)
    Abstract [en]

    During recent years more interest has been emphasised on wood as a construction material. This is so because wood is a renewable resource and also because problems with waste do not emerge when the wooden structure is taken out of operation. On the contrary this waste is still a resource even if the structure is demolished. Wood could always be used as a biomass fuel which is not expected to contribute to the greenhouse effect. In Sweden most of the interest has been emphasised on our conifers while broad leaved species are much less examined. This paper shows the result from the Finite Element Method applied on indetermined chair frames and compares these findings with actual testing in our laboratory. The conclusion is that there are considerable discrepancies between calculations and real behaviour even for relatively simple structures such as a chair frame. It seems that the real chair is stronger than expected even if the joints between the furniture members must reduce the overall strength found by the FEM calculations.

  • 31.
    Gustafsson, Stig-Inge
    Linköping University, Department of Mechanical Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Load management in municipal electricity systems1997In: International journal of energy research (Print), ISSN 0363-907X, E-ISSN 1099-114X, Vol. 21, no 9, p. 787-791Article in journal (Refereed)
    Abstract [en]

    Load management is one means of reducing maximum electricity load, and hence also the cost of electricity. In Sweden, the amount charged during the maximum load hour might be about 200 times higher than the standard charge for one kilowatt-hour. If the load could be reduced by certain equipment in factories and buildings, the need for new power stations and higher capacity in the grid would also be decreased. Using electricity load data for one full year and a short computer program, this paper shows by how much the load could be reduced by postponing demand. If part of the load could be postponed by only one hour, this part may need to be only very small for maximum benefit. If longer time segments were practicable, larger chunks could be transferred. The main result of the study is, however, that load management in practice is a very subtle task if an optimal solution is to be achieved

  • 32.
    Gustafsson, Stig-Inge
    Linköping University, Department of Mechanical Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Load management measures in a carpentry factory1998In: International journal of energy research (Print), ISSN 0363-907X, E-ISSN 1099-114X, Vol. 22, no 14, p. 1267-1274Article in journal (Refereed)
    Abstract [en]

    The wood manufacturing industry in Sweden is not very often the subject of academic research activities. In certain parts of Sweden, generally in rural areas, this industrial branch is of major importance as a local employer. If the companies could grow and prosper it would lead to a more vivid countryside and decrease migration to larger towns and cities. The council of the European Community has therefore introduced certain funds for research projects in such rural areas. This paper describes the use of electricity and heat in a carpentry factory. The result shows that energy conservation measures and load management might be of significant importance in order to make the company more profitable. Even small savings can be the difference between survival or bankruptcy. For the studied factory it is obvious that much equipment for heating purposes are in a poor state. The steam system which could be useful for decreasing the use of electricity heating suffers from leaking steam traps and other imperfections which lead to severe losses in both kilowatt-hours and money. The steam system is therefore not used in an optimal way

  • 33.
    Gustafsson, Stig-Inge
    Linköping University, Department of Mechanical Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Mechanical properties of some Swedish hard wood species2001In: Proceedings of the Institution of mechanical engineers. Part L, journal of materials, ISSN 1464-4207, E-ISSN 2041-3076, Vol. 215, no L3, p. 125-131Article in journal (Refereed)
    Abstract [en]

    A large part of Sweden is located within the Taiga Area and hence most of the wood species growing there are included in the division of Coniferales. This has also led to major research activities on the needle-leaved types in the Pinaceae family. There are, however, many broad-leaved trees, but because of their relatively low economic importance only a few researchers have had the opportunity to study such woods. For certain branches of the Swedish wood manufacturing industry the Angiosperms are of vital importance, e.g. the furniture factories. In this paper the mechanical properties of two Swedish hard wood genera, namely Betula and Alnus, are revealed. These findings are also compared with those found in the literature.

  • 34.
    Gustafsson, Stig-Inge
    Linköping University, Department of Mechanical Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Mixed integer linear programming and building retrofits1998In: Energy and Buildings, ISSN 0378-7788, E-ISSN 1872-6178, Vol. 28, no 2, p. 191-196Article in journal (Refereed)
    Abstract [en]

    When a building is subject for refurbishment it is important to add only such measures that will reduce the Life Cycle Cost (LCC), for the building. Even better is to add measures that will, not only reduce the cost, but minimise the LCC. One means for such an optimisation is to use the so called Linear Programming (LP), technique. One drawback with LP models is that they must be entirely linear and therefore two variables cannot be, for example, multiplied with each other. The costs for building retrofits are, however, not very often linear but instead ‘steps’ are present in their cost functions. This calamity can, at least to a part, be solved by introducing binary integers, i.e., variables that only can assume 2 values, 0 or 1. In this paper it is described how to design such a Mixed Integer Linear Programming (MILP), model of a building and how different cost elements of the climate shield influence the optimal solution.

  • 35.
    Gustafsson, Stig-Inge
    Linköping University, Department of Mechanical Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Municipal thermal and electricity loads: A case study in Linköping1998In: Applied Thermal Engineering, ISSN 1359-4311, E-ISSN 1873-5606, Vol. 18, no 5, p. 257-263Article in journal (Refereed)
    Abstract [en]

    Linear programming models used for optimisation of various energy systems have received increased interest during the last ten years. One reason for this is the use of personal computers. Models with thousands of variables and constraints can now be rapidly optimised. If integers are introduced, which are necessary when increments or steps in cost functions are part of the model, the computing power is of even higher interest. However, many scientific authors do not discuss in detail how the model is designed and what basic data lie behind this design. This paper presents an attempt to study municipal thermal and electricity loads, and further how to divide data for one year into useful segments for linear and mixed integer programming purposes

  • 36.
    Gustafsson, Stig-Inge
    Linköping University, Department of Mechanical Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Optimizing ash wood chairs1997In: Wood Science and Technology, ISSN 0043-7719, E-ISSN 1432-5225, Vol. 31, no 4, p. 291-301Article in journal (Refereed)
    Abstract [en]

    In Sweden, forest research has been emphasised on mainly two species of wood, i.e. pine and spruce. However, we have also a number of hardwoods which could be utilised for furniture manufacturing, cabinets etc. Nowadays, these hardwoods are a slumbering resource in our country. Most of our broad leafed species are found as small stands inside our soft wood forests and hence not utilised in the most profitable way. For example, much of our birch wood is ground to paper fibres even if it would be perfect for high valued veneer. Instead, most of our birch. veneer is imported from Finland. In order to increase the interest for Swedish hardwoods we therefore have started research in this field and have now designed a chair made of ash wood,Fraxinus excelsior. Most chairs are made up of structural elements called indetermined frames which makes it a rather tedious task to analyse the internal forces in the frame. However, by using the Finite Element Method, FEM, it has been possible to reduce this drawback. This paper shows how a chair could be analysed, and designed, by use of methods common in other disciplines than furniture manufacturing. We also present results, in the form of stress-strain diagrams, from tests made on Swedish ash.

  • 37.
    Gustafsson, Stig-Inge
    Linköping University, Department of Mechanical Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Sensitivity analysis of building energy retrofits1998In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 61, no 1, p. 13-23Article in journal (Refereed)
    Abstract [en]

    When a building is refurbished, energy conservation measures might be profitable to implement. The profitability depends, among other things, on the electricity and district-heating tariffs, the unit price for oil, etc. The cost for the retrofit is of course also important as well as the influence of the retrofit on the demand for heat in the building. By the use of a Mixed Integer Linear Programming model of a building, a number of different optimal retrofit strategies are found depending on the energy cost. The result shows that the Life-Cycle Cost for the building is subject only to small changes as long as the optimal strategies are chosen. Most important is the heating system, while building retrofits such as added insulation, are too expensive to take part in the optimal solution.

  • 38.
    Gustafsson, Stig-Inge
    Linköping University, Department of Mechanical Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Solid mechanics for ash wood1999In: European Journal of Wood and Wood Products, ISSN 0018-3768, E-ISSN 1436-736X, Vol. 57, no 5, p. 373-377Article in journal (Refereed)
    Abstract [en]

    Wood is an anisotropic material and, further, because of its natural origin the mechanical properties might significantly differ also between each of the samples tested. Ordinary methods for evaluation of solid mechanic properties often destroy the tested specimens. It is therefore not common practice to evaluate more than one property, e.g. Young's modulus for tension, at the same time using the same sample. Different tests also have different recommendations of how the test specimens should be designed in order to test the property of interest. When calculations are to be made by e.g. the Finite Element Method values for a number of properties must be included and when the resulting construction is examined after this, it is not easy to decide if discrepancies depend on unreliable input data. This paper therefore describes tension, compression and bending tests for one specific detail, namely a wood beam of ash wood. The applied forces are well under those where rupture occurs and hence the material is assumed to be intact during all testing procedures.

  • 39.
    Gustafsson, Stig-Inge
    Linköping University, Department of Mechanical Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Stability problems in optimized chairs?1996In: Wood Science and Technology, ISSN 0043-7719, E-ISSN 1432-5225, Vol. 30, no 5, p. 339-345Article in journal (Refereed)
    Abstract [en]

    Chairs and other furniture are seldom designed by help of structural mechanics and modern computers. Even if the designer uses a sophisticated CAD program, he, or she, will not use for example, finite element programs, FEM, in order to optimise the construction. Most furniture is made of wood or wood composites. Usually, structural mechanics is used for designing wood members in roof constructions and so forth. Because of the consequences of a breakdown, the allowable design stresses must be very low, about one third of the measured breaking strength. Smaller wood details could be chosen with more care and for chairs the result of a break would not necessarily lead to a disaster. However, a lot of the knowledge about how to design small wood structures emanates from the pre-war aeroplane industry. The difference between tensile and compression strength properties in wood also makes ordinary FEM programs hazardous to use because the background theory assumes that these properties are equal in magnitude. In this paper we show how to calculate the internal stresses of an undetermined chair frame and also show some material test results for Swedish alder, Alnus glutinosa.

  • 40.
    Gustafsson, Stig-Inge
    et al.
    Linköping University, Department of Mechanical Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Bojic, Milorad
    University of Kragujevac, Yugoslavia.
    Optimal heating-system retrofits in residential buildings1997In: Energy, ISSN 0360-5442, E-ISSN 1873-6785, Vol. 22, no 9, p. 867-874Article in journal (Refereed)
    Abstract [en]

    The optimal heating-system-retrofit strategy for existing buildings differs due to varying prices of energy, building and installation features, climate conditions, etc. We have examined a test building situated in Linköping, Sweden. By using the OPERA model, we were able to arrive at the optimal retrofit strategy, which includes a ground-coupled heat pump using electricity to run the compressor. Unfortunately, the price of electricity differs according to the time of day, month, etc. These variations are not included in the OPERA model. In OPERA, the price should be divided into 12 segments, one for each month of the year since climate data are divided in this manner. Fine tuning of a dual-fuel system (an oil-fired boiler handles the peak load and a heat pump the base thermal load) is optimized using the Mixed Integer Linear Programming (MILP) method. Adding a hot-water accumulator also makes it possible to use low electricity prices for space and domestic hot-water heating. This system competes in the model with traditional heating devices such as district heating. The optimal method of heating the building was found for using the heat pump alone.

  • 41.
    Gyberg, Per
    et al.
    Linköping University, Faculty of Arts and Sciences. Linköping University, The Tema Institute, Technology and Social Change.
    Karlsson, MagnusLinköping University, The Institute of Technology. Linköping University, Department of Mechanical Engineering, Energy Systems.Ingelstam, LarsLinköping University, Faculty of Arts and Sciences. Linköping University, The Tema Institute, Technology and Social Change.
    System i fokus - uppsatser med teori- och metodexempel från energiområdet: uppsatser från doktorandkursen Systemanalys med metodexempel från energiområdet2005Collection (editor) (Other academic)
  • 42.
    Hedbrant, Johan
    Linköping University, Department of Mechanical Engineering, Energy Systems. Linköping University, The Institute of Technology.
    On the thermal inertia and time constant of single-family houses2001Licentiate thesis, monograph (Other academic)
    Abstract [en]

    Since the nineteen-seventies, electricity has become a common heating source in Swedish single-family houses. About one million smallhouses can use electricity for heating, about 600.000 have electricity as the only heating source.

    A liberalised European electricity market would most likely raise the Swedish electricity prices during daytime on weekdays and lower it at other times. In the long run, electrical heating of houses would be replaced by fuels, but in the shorter perspective, other strategies may be considered. This report evaluates the use of electricity for heating a dwelling, or part of it, at night when both the demand and the price are low. The stored heat is utilised in the daytime some hours later, when the electricity price is high.

    Essential for heat storage is the thermal time constant. The report gives a simple theoretical framework for the calculation of the time constant for a single-family house with furniture. Furthermore the “comfort” time constant, that is, the time for a house to cool down from a maximum to a minimum acceptable temperature, is derived. Two theoretical model houses are calculated, and the results are compared to data from empirical studies in three inhabited test houses.

    The results show that it was possible to store about 8 kWh/K in a house from the seventies and about 5 kWh/K in a house from the eighties. The time constants were 34 h and 53 h, respectively. During winter conditions with 0°C outdoor, the “comfort” time constants with maximum and minimum indoor temperatures of 23 and 20°C were 6 h and 10 h.

    The results indicate that the maximum load-shifting potential of an average single family house is about 1 kW during 16 daytime hours shifted into 2 kW during 8 night hours. Up-scaled to the one million Swedish single-family houses that can use electricity as a heating source, the maximum potential is 1000 MW daytime time-shifted into 2000 MW at night.

  • 43.
    Henning, Dag
    Linköping University, The Institute of Technology. Linköping University, Department of Mechanical Engineering, Energy Systems.
    The Role of Renewable Energy for a Local Swedich Utility under Varioous Market Conditions, in Renewable Energy - Renewables: The Energy for the 21st Century2001In: World Renewable Energy CongressVI,2000, Brighton: World Renewable Energy Congress , 2001Conference paper (Refereed)
    Abstract [en]

      

  • 44.
    Henning, Dag
    et al.
    Linköping University, Department of Mechanical Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Amiri, Shahnaz
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Holmgren, Kristina
    Linköping University, Department of Mechanical Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Modelling and optimisation of electricity, steam and district heating production for a local Swedish utility2006In: European Journal of Operational Research, ISSN 0377-2217, E-ISSN 1872-6860, Vol. 175, no 2, p. 1224-1247Article in journal (Refereed)
    Abstract [en]

    District heating may help reduce environmental impact and energy costs, but policy instruments and waste management may influence operations. The energy system optimisation model MODEST has been used for 50 towns, regions and a nation. Investments and operation that satisfy energy demand at minimum cost are found through linear programming. This paper describes the application of MODEST to a municipal utility, which uses several fuels and cogeneration plants. The model reflects diurnal and monthly demand fluctuations. Several studies of the Linköping utility are reviewed. These indicate that the marginal heat cost is lower in summer, a new waste or wood fired cogeneration plant is more profitable than a natural-gas-fired combined cycle, material recycling of paper and hard plastics is preferable to waste incineration from an energy-efficiency viewpoint, and considering external costs enhances wood fuel use. Here, an emission limit is used to show how fossil-fuel cogeneration displaces CO2 from coal-condensing plants. © 2005 Elsevier B.V. All rights reserved.

  • 45.
    Henning, Dag
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Mechanical Engineering, Energy Systems.
    Hrelja, Robert
    Linköping University, The Tema Institute.
    Trygg, Louise
    Linköping University, The Institute of Technology. Linköping University, Department of Mechanical Engineering, Energy Systems.
    Energisystemanalys Örnsköldsvik2004Report (Other academic)
  • 46.
    Henning, Dag
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Mechanical Engineering, Energy Systems.
    Palm, Jenny
    Linköping University, Faculty of Arts and Sciences. Linköping University, The Tema Institute, Technology and Social Change.
    Energitillförsel och energihushållning i samverkan2006Report (Other academic)
  • 47.
    Johansson, Sten
    et al.
    Linköping University, Department of Mechanical Engineering, Engineering Materials. Linköping University, The Institute of Technology.
    Hedbrant, Johan
    Linköping University, Department of Mechanical Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Kursskal eller aktiv kurshemsida: Sammanfattning av några erfarenheter av kursskali teknologkurser2001Report (Other academic)
    Abstract [sv]

    Möjligheten att kommunicera med hjälp av datorer har funnits i mer än 20 år och ur denna möjlighet har ett antal idéer om hur en sådan kommunikation kan utnyttjas vid undervisning realiserats. Istället för att ersätta konventionella brev med elektroniska varianter blev det istället vanligt att skicka korta meddelanden eller att man tog i anspråk de datorstödda sk konferenssystem som utvecklades. Centrala funktioner i dessa system innebar att man inte bara kunde utbyta meddelanden med kort svarstid utan även kunde skapa möten eller aktiviteter, nyhetskontroll och organisation av lästa och olästa meddelanden i en struktur [1]. Dessa konferenssystem kan kompletteras med funktioner som formellt behövs för att kunna bedriva distansundervisning elektroniskt. Exempel på sådana funktioner är:

    • Elektroniska gruppdiskussioner
    • Databaser där elever kan söka, läsa och kopiera information och ävenladda ner undervisningsprogram
    • Datorstöd där läraren växelverkar med studenten
    • Datorstöd för distanstentamen
  • 48.
    Karlsson, Fredrik
    Linköping University, The Institute of Technology. Linköping University, Department of Mechanical Engineering, Energy Systems.
    Experimental Evaluation in a Low-Energy Building2006In: The International Journal of Ventilation, ISSN 1473-3315, E-ISSN 2044-4044, Vol. 5, p. 239-248Article in journal (Refereed)
  • 49.
    Karlsson, Fredrik
    Linköping University, The Institute of Technology. Linköping University, Department of Mechanical Engineering, Energy Systems.
    Varaktighetsdiagram för "Hus utan värmesystem"2004Report (Other academic)
  • 50.
    Karlsson, Fredrik
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Mechanical Engineering, Energy Systems.
    Ruud, Svein
    SP Sveriges Provnings- och Forskningsinstitut .
    "Husen utan värmesystem" halverar energianvändningen2004In: VVS Teknik & Installation, Vol. okt. 2004, p. 10-14Article in journal (Other (popular science, discussion, etc.))
12 1 - 50 of 88
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