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  • 51.
    Dahlquist, Erik
    Mälardalen University, School of Sustainable Development of Society and Technology.
    What to consider when developing a simulator for multi purpose usage2006Conference paper (Refereed)
  • 52.
    Dahlquist, Erik
    et al.
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Avelin, Anders
    Mälardalen University, School of Business, Society and Engineering.
    Yan, Jinyue
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Black liquor gasification in a CFB gasifier – system solutions2009Conference paper (Refereed)
    Abstract [en]

    In this paper a new type of black liquor gasification is presented and discussed. It is a CirculatingFluidized Bed process with the addition of TiO2 to the bed material. This gives a directcaustization of Na2CO3 to Na2O.TiO2 which forms NaOH by leaking with water. Thus a lime kilnis not needed. Simultaneously also SO4 is reduced to S2- and stripped off as H2S to a major extent,absorbed in a selective scrubber, giving a separation of OH- and S2- .This makes modifiedcooking possible. The produced synthetic gas can be used to run an efficient Integrated Gas-Combi Cycle (IGCC), up to 37 % electric efficiency, or use the gas for production of differentchemicals like NH3, DME pr Methanol. These aspects are discussed as well in the paper.

  • 53.
    Dahlquist, Erik
    et al.
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Avelin, Anders
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Yan, Jinyue
    Mälardalen University, School of Sustainable Development of Society and Technology.
    CFB Black liquor gasification – Discussions of gasification and system solutions2009In: Proceedings of first International Conference on Applied Energy / [ed] Jinyue Yan, Hong-Kong University , 2009Conference paper (Refereed)
    Abstract [en]

    In this paper a new type of black liquor gasification process is presented and analyzed. It is a Circulating Fluidized Bed (CFB) process with the addition of TiO

    2 to the bed material. This gives a direct caustization of Na2CO3 to Na2O.TiO2 which forms NaOH by leaking with water. Thus a lime kiln is not needed in the process. Simultaneously SO4 is also reduced to S2- and stripped off as H2S to a major extent, absorbed in a selective scrubber, giving a separation of OH- and S2- , which makes modified cooking possible. Performance of integrating black liquor gasification has also been analyzed and discussed for electricity production in an efficient Integrated Gasification Combined Cycle (IGCC) and/or different chemicals such as NH3, DME or methanol in a polygeneration sytem.

  • 54.
    Dahlquist, Erik
    et al.
    Mälardalen University, School of Sustainable Development of Society and Technology. Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Bundschuh, Jochen
    Biomass in different biotopes – an extensive resource2013In: Biomass as Energy Source: Resources, Systems and Applications / [ed] Erik Dahlquist, Taylor & Francis Group, 2013, 1, p. 87-108Chapter in book (Refereed)
    Abstract [en]

    The use of energy is approximately 140 000 TWh per year globally. It is then interesting to note that biomass production is approximately 270 000 TWh/year, or roughly twice as much. This shows that biomass is not a marginal energy resource but more than enough to cover all our needs for both energy and food, if just the biomass is used efficiently. There has been a lot of discussion about using food for energy. This is quite relevant, and if we look at all resources like agricultural and forestry waste, the need to use food for energy is not needed. We can cover all our needs anyhow. The resources we have available and some other aspects like using the energy efficiently is covered in this book. One way of using energy efficiently is to use waste biomass or cellulosic materials in bio refineries, where production of fibers and products from fibers is combined with production of most chemicals we need in our daily life. This includes clothes, soap, perfume, medicines etc. Conventional pulp and paper applications are also covered. But it also includes bio-fuel for vehicles and even fuel for aviation is covered. It also includes production of heat, cool and electricity. That is, biomass can cover all our needs. The difficulty is to use the resources efficiently without harming the productivity long term. This book has the aim to give facts and inspiration to professionals like engineers and researchers, students as well as those working for different type of authorities or societal organizations.

  • 55.
    Dahlquist, Erik
    et al.
    Mälardalen University, School of Sustainable Development of Society and Technology. Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Bundschuh, Jochen
    Pulp and paper industry – trends for the future2013In: Biomass as Energy Source: Resources, Systems and Applications / [ed] Erik Dahlquist, Taylor & Francis Group, 2013, 1, p. 229-234Chapter in book (Refereed)
    Abstract [en]

    The use of energy is approximately 140 000 TWh per year globally. It is then interesting to note that biomass production is approximately 270 000 TWh/year, or roughly twice as much. This shows that biomass is not a marginal energy resource but more than enough to cover all our needs for both energy and food, if just the biomass is used efficiently. There has been a lot of discussion about using food for energy. This is quite relevant, and if we look at all resources like agricultural and forestry waste, the need to use food for energy is not needed. We can cover all our needs anyhow. The resources we have available and some other aspects like using the energy efficiently is covered in this book. One way of using energy efficiently is to use waste biomass or cellulosic materials in bio refineries, where production of fibers and products from fibers is combined with production of most chemicals we need in our daily life. This includes clothes, soap, perfume, medicines etc. Conventional pulp and paper applications are also covered. But it also includes bio-fuel for vehicles and even fuel for aviation is covered. It also includes production of heat, cool and electricity. That is, biomass can cover all our needs. The difficulty is to use the resources efficiently without harming the productivity long term. This book has the aim to give facts and inspiration to professionals like engineers and researchers, students as well as those working for different type of authorities or societal organizations.

  • 56.
    Dahlquist, Erik
    et al.
    Mälardalen University, School of Sustainable Development of Society and Technology. Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Engvall, Klas
    KTH.
    Liliedahl, Trul
    KTH.
    Biomass and black liquor gasification2013In: Technologies for Converting Biomass to Useful Energy: COMBUSTION, GASIFICATION, PYROLYSIS, TORREFACTIONAND FERMENTATION / [ed] Erik Dahlquist, CRC Press, 2013, 1, p. 175-216Chapter in book (Refereed)
    Abstract [en]

    Officially the use of biomass for energy use globally is only 10-13 % of the total energy demand of 140 000 TWh/y. Still, the production of biomass annually is in the range of 270 000 TWh/y. Most of it obviously is not used very efficiently, although some is also used as food. There is thus a need for new methods for converting biomass into refined products like chemicals, fuels, wood and paper products, heat, cooling and electric power. The different type of conversion methods covered is biogas production, bio-ethanol production, torrefaction, pyrolysis, high temperature gasification and combustion. These methods are covered as well as principals for controlling the processes. The suitability for the different methods for different type of biomass as well as different versions of the methods is presented – both existing methods and those being developed for the future. System optimization using modeling methods and simulation is covered as well as analysis of advantages of different solutions. Many key-experts from all over the world are presenting the keys of their specialties to give us an up-to-date view of the situation all over the world. This book has the aim to give facts and inspiration to professionals like engineers and researchers, students as well as those working for different type of authorities or societal organizations.

  • 57.
    Dahlquist, Erik
    et al.
    Mälardalen University, School of Sustainable Development of Society and Technology. Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Hakalehto, Elias
    Silveira, Semida
    KTH.
    Concluding remarks and perspectives on the future of energy systems using biomass2013In: Biomass as Energy Source: Resources, Systems and Applications / [ed] Erik Dahlquist, Taylor & Francis Group, 2013, 1, p. 263-266Chapter in book (Refereed)
    Abstract [en]

    The use of energy is approximately 140 000 TWh per year globally. It is then interesting to note that biomass production is approximately 270 000 TWh/year, or roughly twice as much. This shows that biomass is not a marginal energy resource but more than enough to cover all our needs for both energy and food, if just the biomass is used efficiently. There has been a lot of discussion about using food for energy. This is quite relevant, and if we look at all resources like agricultural and forestry waste, the need to use food for energy is not needed. We can cover all our needs anyhow. The resources we have available and some other aspects like using the energy efficiently is covered in this book. One way of using energy efficiently is to use waste biomass or cellulosic materials in bio refineries, where production of fibers and products from fibers is combined with production of most chemicals we need in our daily life. This includes clothes, soap, perfume, medicines etc. Conventional pulp and paper applications are also covered. But it also includes bio-fuel for vehicles and even fuel for aviation is covered. It also includes production of heat, cool and electricity. That is, biomass can cover all our needs. The difficulty is to use the resources efficiently without harming the productivity long term. This book has the aim to give facts and inspiration to professionals like engineers and researchers, students as well as those working for different type of authorities or societal organizations.

  • 58.
    Dahlquist, Erik
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Hellstrand, Stefan
    Mälardalen University, School of Business, Society and Engineering, Industrial Economics and Organisation. Nolby Ekostrategi, Kil, Sweden.
    Natural resources available today and in the future: How to perform change management for achieving a sustainable world2017Book (Other academic)
    Abstract [en]

    This book focuses on providing an overview of all our available natural resources, considering the sustainability and potential for power generation of each. Energy efficiency prospects of each natural resource are examined in the context of society's key energy needs- Heating/cooling, Electric Power, Transportation and Industrial Production. Geography, climate and demographics are all discussed as key vectors impacting the comparative opportunities for self-sustenance around the globe. The authors provide in-depth coverage of renewable energy upscale and energy efficiency improvements in industry and society within a historical context, including a keen look at the variable effectiveness of different policy tools that have been used to support the transition away from unsustainable resource use. Finally, suggestions for more sustainable futures are provided, from improved policy measures, to new technological horizons in areas from offshore wind and marine energy to biogas and energy storage. © Springer International Publishing AG 2017. All rights reserved.

  • 59.
    Dahlquist, Erik
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Hellstrand, Stefan
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    System perspective2017In: Natural Resources Available Today and in the Future: How to Perform Change Management for Achieving a Sustainable World, Springer International Publishing , 2017, p. 1-56Chapter in book (Other academic)
  • 60.
    Dahlquist, Erik
    et al.
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Hunt, Brian
    Ivergård, Toni
    Chapter 8: Industrial Applications and Case Studies2009In: Handbook of Control Room Design and Ergonomics: A Perspective for the Future / [ed] Toni Ivergård and Brian Hunt, Taylor & Francis Group, 2009, 2nd, p. 203-226Chapter in book (Other academic)
  • 61.
    Dahlquist, Erik
    et al.
    Mälardalen University, Department of Public Technology. IST.
    Jones, Andrew
    International Paper, USA.
    Presentation of a dry black liquor gasification process with direct causticization2005In: TAPPI Journal, Vol. 4, no 6, p. 15-19Article in journal (Refereed)
    Abstract [en]

    In a new black liquor gasification process, black liquor is injected into a circulating fluidized bed, with sodium titanate (Na 2O· (TiO 23) as the fluidizing medium.The organics are gasified mainly by steam reforming because the temperature is relatively low (below 870°C) and the water content of the black liquor is relatively high (>20% water).The black liquor inorganics consist mainly of sodium carbonate and sodium sulfate. In the reactor, sodium carbonate is converted into Na 2O·TiO 2, which is removed from the bed and dissolved in water to give 4 NaOH + Na 2O·(TiO 2)3. After dewatering, this material is reinjected into the fluidized bed.The sulfate is reduced to Na 2S, and most of the sulfur is evaporated as H 2S after Na 2S reacts with CO 2 + H 2O. In a scrubber, the H 2S is selectively absorbed without CO 2. The direct causticization makes the lime kiln unnecessary. The gas is reheated after dust is removed and then combusted in a gas turbine/steam turbine cycle, to produce 2-3 times more electricity than produced in steam cycles with conventional recovery boilers.

  • 62.
    Dahlquist, Erik
    et al.
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Karlsson, Björn
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Lindberg, Eva
    Högskolan i Dalarna.
    Combined solar power and TPV2011In: Conference proceedings WREC 2011 in Linköping, Sweden, May 8-11, 2011 / [ed] Bahram Moshfegh, Linköping: Linköping University Press , 2011, p. 1-4240Conference paper (Refereed)
    Abstract [en]

    In this paper design for a combined TPV and solar power system for local heat and power production is discussed. PV cells are producing electricity when there is light, while TPV cells are used when it is dark. Biomass is combusted and the heat is generating photons for the TPV system. Higher combustion temperature will give higher electric output, but also stronger deterioration of the materials in the combustor. By combining PV-cells that will generate a lot of electric power summer time with TPV-cells that can generate electric power winter time, when we also normally have a higher heat demand, we can achieve a flexible local heat and power system all year round. As both systems generate DC-power, we also can see a potential to use DC components generally, e.g for charging batteries for electrical vehicles, DC-pumps, LED-lamps etc. Design criteria for the systems are discussed in this paper for a house that is principally self sufficient on energy. Both theoretical and practical obstacles are discussed, as there are a number of issues to solve before the technique can be used in ”real life”.

  • 63.
    Dahlquist, Erik
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Mirmoshtaghi, Guilnaz
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Larsson, Eva K.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Thorin, Eva
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Yan, Jinyue
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Engvall, K.
    KTH Royal Institute of Technology, Stockholm, Sweden .
    Liliedahl, T.
    KTH Royal Institute of Technology, Stockholm, Sweden .
    Dong, C.
    North China Electric Power University, Beijing, China.
    Hu, X.
    North China Electric Power University, Beijing, China.
    Lu, Q.
    North China Electric Power University, Beijing, China.
    Modelling and Simulation of Biomass Conversion Processes2013In: Proceedings - 8th EUROSIM Congress on Modelling and Simulation, EUROSIM 2013, 2013Conference paper (Refereed)
    Abstract [en]

    By utilizing biomass gasification, the energy contentof the biomass can be utilized to produce gas to be used forcogeneration of heat and power as well as other energy carrierssuch as fuels for vehicles. The concept is suitable forapplication to existing CHP plants as well as for utilizing spentliqour in small scale pulp and paper mills. The introductionwould enable flexible energy utilization, use of problematicfuels as well as protects the environment by e.g. avoiding therelease of toxic substances. In this paper, the possibilities todevelop this concept is discussed. In this paper we comparedifferent gasification processes with respect to what gas qualitywe get, and how the gasification can be modelled usingdifferent modelling approaches, and how these can becombined. Results from simulations are compared toexperimental results from pilot plant operations in differentscales and with different processes like CFB and BFBTechnologies, athmospheric and pressurized, and using steam,air and oxygen as oxidizing media.

  • 64.
    Dahlquist, Erik
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Naqvi, Muhammad
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Thorin, Eva
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Yan, Jinyue
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Kyprianidis, Konstantinos
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Comparison of Gas Quality from Black Liquor and Wood Pellet Gasification Using Modelica Simulation and Pilot Plant Results2017In: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 105, p. 992-998Article in journal (Refereed)
    Abstract [en]

    There is a potential to integrate biomass gasification with pulp & paper and CHP plants in order to complement the existing systems with production of chemicals, such as methane, hydrogen, and methanol etc. To perform system analysis of such integration, it is important to gain knowledge of relevant input data on expected synthesis gas composition by gasifying different types of feed stock. In this paper, the synthesis gas quality from wood pellets gasification (WPG) has been compared with black liquor gasification (BLG) through modeling and experimental results at pilot scale. In addition, the study develops regression models like Partial Least Squares (PLS) made from the experimental data. The regression models are then combined with dynamic models developed in Modelica for the investigation of dynamic energy and material balances for integrated plants. The data presented in this study could be used as input to relevant analysis using e.g. ASPEN plus and similar system analysis tools. 

  • 65.
    Dahlquist, Erik
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Naqvi, Muhammad
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Thorin, Eva
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Yan, Jinyue
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center. Royal Institute of Technology (KTH), Sweden.
    Kyprianidis, Konstantinos
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Hartwell, Philip
    BioRegional MiniMills Ltd, UK.
    Experimental and numerical investigation of pellet and black liquor gasification for polygeneration plant2017In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 204, p. 1066-1064Article in journal (Refereed)
    Abstract [en]

    It is vital to perform system analysis on integrated biomass gasification in chemical recovery systems in pulp and paper and heat and power plants for polygeneration applications. The proposed integration complements existing pulp and paper and heat and power production systems with production of chemicals such as methane and hydrogen. The potential to introduce gasification-based combined cycles comprising gas turbines and steam turbines to utilize black liquors and wood pellets also merits investigation. To perform such analysis, it is important to first build knowledge on expected synthesis gas composition by gasifying at smaller scale different types of feed stock. In the present paper, the synthesis gas quality from wood pellets gasification has been compared with black liquor gasification by means of numerical simulation as well as through pilot-scale experimental investigations. The experimental results have been correlated into partial least squares models to predict the composition of the synthesis gas produced under different operating conditions. The gas quality prediction models are combined with physical models using a generic open-source modelling language for investigating the dynamic performance of large-scale integrated polygeneration plants. The analysis is further complemented by considering potential gas separation using modern membrane technology for upgrading the synthesis gas with respect to hydrogen content. The experimental data and statistical models presented in this study form an important literature source for future use by the gasification and polygeneration research community on further integrated system analysis.

  • 66.
    Dahlquist, Erik
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Naqvi, Muhammad
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center. KTH, Energiprocesser.
    Thorin, Eva
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Yan, Jinyue
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center. KTH, Energiprocesser.
    Kyprianidis, Konstantinos
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Hartwell, Philip
    BioRegional MiniMills Ltd., United Kingdom.
    Modeling of Black Liquor Gasification2016Conference paper (Refereed)
  • 67.
    Dahlquist, Erik
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Naqvi, Muhammad
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center. KTH, Energiprocesser.
    Thorin, Eva
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Yan, Jinyue
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center. KTH, Energiprocesser.
    Kyprianidis, Konstantinos
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Hartwell, Philip
    BioRegional MiniMills Ltd., United Kingdom.
    Modeling of Wood Gasification in an Atmospheric CFB Plant2016Conference paper (Refereed)
  • 68.
    Dahlquist, Erik
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Nordlader, Eva
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Thorin, Eva
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Wallin, Christian
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center. ABB Process Industries AB, Västerås, Sweden.
    Avelin, Anders
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Control of waste water treatment combined with irrigation2019Conference paper (Refereed)
    Abstract [en]

    In waste water treatment using biological treatment processes normally phosphorous, nitrous compounds as well as organic matterare removed.It is also important to remove or kill pathogens that otherwisecould cause diseases. The surplus of bio-sludge is used to produce biogas. In thepaper four different alternatives for system design and operations of systems was discussed. The alternatives integrates thewaste water treatment and irrigation offarmland using the water taken out from different positions in the waste water treatment plant.

  • 69.
    Dahlquist, Erik
    et al.
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Palm, Jenny
    Proceedings of the Scientific Conference on Energy and IT at Alvsjo fair, Stockholm March 11-12, 2009 in connection with the “Energitinget 20092009Collection (editor) (Other academic)
    Abstract [en]

    Editors: Dahlquist E. and Palm J. 2009 Proceedings of the Scientific Conference on Energy and IT at Alvsjo fair, Stockholm March 11-12, 2009 in connection with the “Energitinget 2009” This is a joint scientific conference on Energy and IT between Mälardalen University and the Research School Program Energy Systems in Cooperation with Swedish Energy Agency. The papers are peer reviewed. ISBN number 978-91-977493-4-3.

    Energy savings potentials and social change in the use of residential electricity

    Mats Bladh,

    Adoption of energy efficiency measures in detached houses: Perception of homeowners

    Giresh Nair, Mid Sweden University

    Households, energy use and scenarios of energy efficiency of everyday life activities

    Anna-Lisa Lindén, Lund University

    The role of energy advisors on adoption of energy efficiency measures in detached houses

    Krushna Mahapatra, Mid Sweden University

    Perceptional and socio-economic factors in adoption of low energy houses

    Krushna Mahapatra, Mid Sweden University

    Consumption patterns today and tomorrow with respect to energy and how the energy

    system will be affected by this

    Iana Vassileva, Malardalen University

    CO2 emissions from general district heat use in Sweden – a method for justified

    comparisons in residential energy use

    Magnus Åberg,

    Applying an interdisciplinary perspective on industrial energy efficiency

    Jenny Palm, Dept. of Technology and Social Change, Linköping University and the national

    research school the Energy system Programme

    Markov-Chain Modelling of High-Resolution Activity ,Patterns and Household Electricity

    Demand

    Joakim Widén, Department of Engineering Sciences.Uppsala University

    From electricity to heat – a discourse analytic policy study of energy conversion at national,

    municipal and household level

    Karin Perman, Energi och Miljöteknik, University College Dalarna

    Case study of mobilized energy storages for distributed heating

    Weilong Wang, Mälardalen University and South China University of Technology

    International Scientific Conference on “Energy systems with IT” in connection with the

    Energiting 2009, March 11

    ‐12 at Älvsjö fair, Stockholm.

    Page 3 of 238

    Bio-refinery system of DME or CH4 production from black liquor gasification in pulp mills

    M Raza, Energy Processes, KTH

    Numerical and experimental study of the inclined free fins applied for thermal management

    Bijan Karimpourian, Malardalen University

    Simulation of ambient temperature effect on large-scale power transformer load ability

    Hasan Gholinejad, Malardalen University

    Process control in steel core production to optimize of power dissipation in electrical

    machines and transformers

    Kourosh Mousavi Takami, TDI, Malardalen University

    Evaluation of magnetic aging in transformers and electrical machines cores during

    operation

    Kourosh Mousavi Takami, TDI, ACECR, Malardalen University

    A simple method for removing leakage of metal pipes, like district heating- and NG pipes

    Mohammad Tabatabaeeghomi, Mälardalen University, Vasteras, Sweden also Technology

    Development Institute (TDI), ACECR, Tehran, Iran

    Modeling of Radon Transport trough Building Materials and ventilation

    Keramatollah Akbari, TDI, ACECR, Malardalen University

    Energy efficient window development – Historical overview of the development of energy

    efficient windows in Sweden

    Bernadett Kiss,

  • 70.
    Dahlquist, Erik
    et al.
    Mälardalen University, Department of Public Technology.
    Thorin, Eva
    Mälardalen University, Department of Public Technology.
    Yan, Jinyue
    Mälardalen University, Department of Public Technology.
    Alternative Pathways to a fossil-fuel free energy system in the Mälardalen region of Sweden2006In: Proceedings of the Second International Green Energy Conference, 2006, 2006, p. 822-830Conference paper (Other academic)
    Abstract [en]

    This paper presents a study on alternative pathways to a fossil-fuel free regional energy system in the Mälardalen region of Sweden with a population of 3 million inhabitants. We describe and address how the region can be made independent of fossil fuels by integration of resource management, technology advances, and behavior change in energy use. First we investigate the consumption pattern of the inhabitants. Then we study what resources are available, and how these can be used to fulfill the different demands. If we just use the resources in a pattern of business as usual today without changing the behavior, the balance between demands and resources is difficult to reach. By combining a slightly different behavior and a change of crops it could be possible to fulfill the needs. Some advanced technological solutions have also been proposed. For example, dedicated biomass energy plants such as fodder sugar beats can be used for ethanol production. Also Salix, straw, hemp and some cereals can be used and the residues can be gasified to produce dimethylether (DME), which is good as a replacement for diesel fuel. Still the fuel demand for transport is high, and the vehicle weight could be further reduced. For example, by going back to the car size we had only ten years ago the weight would be 25-30 % less, and fuel consumption would be at least 15 % lower. With diesel engines instead of Otto-engines the fuel consumption could be reduced by 35 %, and with hybrid technology additional 20% fuel reduction could be gained. Improved public transportation will also give a positive effect especially for those commuting between the larger cities and between the cities and the suburbs. The results of our calculations show that it would be possible to accomplish a fossil-free energy system in the Mälardalen region. The results of this study are important since it shows that an energy balance without fossil fuels could be possible for an area with a population in the order of 3 million people, which would also be valuable in studies of other areas in the world.

  • 71.
    Dahlquist, Erik
    et al.
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Thorin, Eva
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Yan, Jinyue
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Alternative Pathways to a Fossil-Fuel Free Energy System in the Mälardalen region of Sweden2007In: International journal of energy research (Print), ISSN 0363-907X, E-ISSN 1099-114X, Vol. 31, no 12, p. 1226-1236Article in journal (Refereed)
    Abstract [en]

    This paper presents a study on alternative pathways to a fossil-fuel free regional energy system in the Mälardalen region of Sweden with a population of 3 million inhabitants. We describe and address how the region can be made independent of fossil fuels by integration of resource management, technology advances, and behaviour change in energy use. First we investigate the consumption pattern of the inhabitants. Then we study what resources are available, and how these can be used to fulfil the different demands. If we just use the resources in a pattern of business as usual today without changing the behaviour, the balance between demands and resources is difficult to reach. By combining a slightly different behaviour and a change of crops we can fulfil the needs and it might even be possible to have a surplus of resources. Some advanced technological solutions have also been proposed. For example, dedicated biomass energy plants such as Salix, straw, hemp and some cereals can be used for ethanol production and the residues can be gasified to produce dimethylether (DME), which is good as a replacement for diesel fuel. Still the fueldemand for transport is high, and the vehicle weight could be further reduced. For example, by going back to the car size we had only 10 years ago the weight would be 25-30% less, and fuelconsumption would be at least 15% lower. With diesel engines instead of Otto engines the fuel consumption could be reduced by 35%, and with hybrid technology additional 20% fuel reduction could be gained. Improved public transportation will also give a positive effect especially for those commuting between the larger cities and between the cities and the suburbs. The results of our calculations show that it would be possible to accomplish a fossil-free energy system in the Mälardalen region. The results of this study are important since it shows that an energy balance without fossil fuels could be possible for an area with a population in the order of 3 million people, which would also be valuable in studies of other areas in the world.

  • 72.
    Dahlquist, Erik
    et al.
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Thorin, Eva
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Yan, Jinyue
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Combined Solar Power, Hydrogen, TPV and Cyanobacter Production2010In: Proceedings of the International Conference of Applied Energy / [ed] Jinyue Yan, 2010, p. 179-188Conference paper (Refereed)
    Abstract [en]

    In this paper we discuss design for a combined TPV and solar power system with production of biomass. During the passage through the solar collector cyanobacters or algae are getting sunshine to drive the photo synthesis. An algae suspension is circulated through a solar panel to drive photo synthesis. The flow rate is varying with solar intensity to balance the temperature increase. This is to avoid inhibition of the cyanobacters/algae growth rate due to too high temperature. PV cells are producing electricity when there is light, while TPV cells are used when it is dark. The biomass produced then is utilized for production of photons for the TPV system. As an alternative a system producing Hydrogen and electricity produced in a fuel cell system is discussed. Design criteria for the systems are discussed in this paper for a house that is principally self sufficient on energy. Both theoretical and practical obstacles are discussed, as there are a number of issues to solve before the technique can be used in ”real life”

  • 73.
    Dahlquist, Erik
    et al.
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Thorin, Eva
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Yan, Jinyue
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Mårtensson, Kenneth
    Enander, Måns
    How to develop a fossil fuel free Malardalen Region2007Conference paper (Refereed)
  • 74.
    Dahlquist, Erik
    et al.
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Tomas-Aparicio, Elena
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Jansson, Johan
    SAPPI South Africa.
    On-line simulations for diagnostics and control2010In: International Control Systems 2010 Proceedings / [ed] Alf Isaksson, Stockholm: SPCI , 2010Conference paper (Refereed)
    Abstract [en]

    The main objective of this project is to develop an application where physical models of fibre lines are run in parallel to the real processes. This application can be useful as a diagnostic tool to detect faults and improve process operations. By running the simulation models continuously, feeding input data from the process data base at a pre-determined time interval, the simulation will show results from the “normal operations”. These simulation results are compared to the measured data and hence faults can be detected e.g. hang-ups in the digester and channelling. NIR-spectra lab measurements of the wood chips fed into the digester can as well be considered. This feature give us the possibility of correlating the quality of the obtained pulp to the raw material used, which can be of help when tuning the process parameters.

    In this paper results from the use of the application described above in several mills in South Africa and results from some preliminary tests in a mill in Sweden are presented. Moreover, the system structure for the interaction between the physical models designed in Modellica language and the real process data is described.

  • 75.
    Dahlquist, Erik
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Vassileva, Iana
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Campillo, Javier
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Lundström, Lukas
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Energy efficiency improvements by renovation actions: in Lagersberg and Råbergstorp, Stoke on Trent and Allingsås2016Report (Other academic)
    Abstract [en]

    This report covers evaluation of some renovation projects and compares energy saving effects versus renovation costs.

    It can be seen that advanced renovation to passive house standard is significantly more expensive than “normal” renovation, but also gives significant improvement by a 62 % reduction of total energy and 85 % reduction in heat demand. The cost associated with the renovation is somewhere in the range of 130–570 €/m2, depending on how the total renovation costs are split between energy and other aspects. Probably somewhere in-between is most correct. This can be compared to mostly better heat control by measuring temperature in every third apartment and controlling heat supply to keep a constant temperature. This gives the possibility to have a significantly lower set point, 21 ºC instead of 24 ºC as earlier. Together with some other actions, 34 % energy savings were achieved at a cost of 28 €/m2. Also renovations with significantly more actions were evaluated, where the cost also is in-between.

    From this we can conclude that with more advanced and costly renovations we can achieve very strong reductions, which may be feasible if the renovation demand is high anyhow, while cheap and low cost actions can be good enough for quite good buildings.

    Also behavior with respect to energy use was evaluated. We here can see that the use is very different in different apartments depending on behavior. Energy information actions were giving positive effects on energy demand for the majority of investigated tenants, while approximately 25 % did not reduce or even increased their consumption.

  • 76.
    Dahlquist, Erik
    et al.
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Vassileva, Iana
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Thorin, Eva
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Wallin, Fredrik
    Mälardalen University, School of Sustainable Development of Society and Technology.
    How to save energy to reach a balance between production and consumption of heat, electricity and fuels for vehicles2011In: International Green Energy Conference (IGEC-6) Anadolu University / [ed] Hikmet Karakoc, Eskeshir, 2011Conference paper (Refereed)
    Abstract [en]

    There is a potential to utilize a significant amount of renewable energy in Sweden and EU. Biomass can fulfil some 8 500- 12 500 TWh/y in EU, while the total utilization was 16 084 TWh/y 2009. Even though there is a significant amount of wind power, hydro power and potentially also solar power, it still is most economical to reduce the consumption of heat, electricity and fuels for vehicles. A saved kWh is normally cheaper than to produce one extra. In this paper different opportunities for saving energy will be discussed. This includes manufacturing industries, process industries, power plants and energy systems including distribution of power and smart grids, food production and transportation. There is also a major potential to save energy in buildings, both in the north where it is cold, and in the south where it can be very hot summertime. Here the potential is to avoid cooling instead. Technical solutions as well as economic incentives will be covered. Environmental aspects will be addressed, so that the solutions will be long term sustainable.

     

  • 77.
    Dahlquist, Erik
    et al.
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Vassileva, Iana
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Thorin, Eva
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Wallin, Fredrik
    Mälardalen University, School of Sustainable Development of Society and Technology.
    How to save energy to reach a balance between production and consumptionof heat, electricity and fuels for vehicles2012In: Energy, ISSN 0360-5442, E-ISSN 1873-6785, Vol. 46, no 1, p. 16-20Article in journal (Refereed)
    Abstract [en]

    There is a potential to utilize a significant amount of renewable energy in Sweden and European union(EU). Biomass can fulfil some 8500e12,500 TW h/y in EU, while the total utilization was 16,084 TW h/y2009. Even though there is a significant amount of wind power, hydro power and potentially also solarpower, it still is most economical to reduce the consumption of heat, electricity and fuels for vehicles. Asaved kWh is normally cheaper than to produce one extra. In this paper different opportunities for savingenergy will be discussed. This includes manufacturing industries, process industries, power plants andenergy systems including distribution of power and smart grids, food production and transportation.There is also a major potential to save energy in buildings, both in the north where it is cold, and in thesouth where it can be very hot summer time. Here the potential is to avoid cooling instead. Technicalsolutions as well as economic incentives are covered. Environmental aspects are addressed, so that thesolutions will be long term sustainable.

  • 78.
    Dahlquist, Erik
    et al.
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Vassileva, Iana
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Wallin, Fredrik
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Thorin, Eva
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Yan, Jinyue
    Mälardalen University, School of Sustainable Development of Society and Technology.
    OPTIMIZATION OF THE ENERGY SYSTEM TO ACHIEVE A NATIONAL BALANCE WITHOUT FOSSIL FUELS2011In: International Journal of Green Energy, ISSN 1543-5075, E-ISSN 1543-5083, Vol. 8, no 6, p. 684-704Article in journal (Refereed)
    Abstract [en]

    In this article, the overall energy balance for Sweden and to some extent EU27 is discussed. It deals with the reduction of the total consumption in industrial, transport, and domestic sectors through more efficient vehicles, industrial processes, and buildings and individual behavior. The conclusion is that it should be relatively easy for Sweden to reach a sustainable society if the political will, in the form of policies and incentives, is present. It would also be possible for the EU27 to reach a sustainable society, although it would be more demanding (challenging?).

  • 79.
    Dahlquist, Erik
    et al.
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Vassileva, Iana
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Wallin, Fredrik
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Yan, Jinyue
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Optimization of the energy system to achieve a national balance without fossil fuels2010In: International Green Energy Conference, IGEC-V June 1-3, 2010, Waterlo, Ontario, Canada / [ed] Xianguo Li, Waterloo,Canda: University publications , 2010Conference paper (Refereed)
    Abstract [en]

    In this paper we discuss the overall balance for Sweden and to some extent EU27 with respect to both power and heat production in relation to how the energy is utilized. This includes transportation, where we compare the system of today with a possible future system with hybrid-electric vehicles, renewable fuels and reductions of total consumption, through both better vehicles, as well as better logistics for transportation of goods. Concerning industry use energy improvements through more efficient industrial processes is discussed. For households, offices and manufacturing industries energy efficient buildings and individual behavior with respect to energy use is discussed. New sources for power will be less stable, like wind and solar power. A special focus is on biomass utilization and production. This also includes food. The situation today is compared to the potential balance after implementation of the actions discussed in the paper. The overall conclusion is that it should be relatively easy for Sweden to reach a sustainable society, if just the political will is present. It is also shown that there is a good potential also for the complete EU 27, but the actions are significantly more demanding to reach the balance, although in no way impossible.

  • 80.
    Dahlquist, Erik
    et al.
    Mälardalen University, Department of Public Technology.
    Wallin, Fredrik
    Mälardalen University, Department of Public Technology.
    Dhak, Janice
    Mälardalen University, Department of Public Technology.
    Experiences of on-line and off-line simulation in Pulp and Paper industry2004In: Proceedings of the PTS-symposium, 2004Conference paper (Other (popular science, discussion, etc.))
  • 81.
    Dahlquist, Erik
    et al.
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Wallin, Fredrik
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Karlsson, Björn
    Mälardalen University, School of Sustainable Development of Society and Technology.
    A fossil fuel free Europe need new incentives and a better control to balance power production and demand2011In: SAUPEC 2011 July 13-15 at Cape Town University, South Africa / [ed] SP Chowdrury, Cape Town: Cape Town University Press , 2011Conference paper (Refereed)
    Abstract [en]

    In EU27 today there is a production of approximately 1000 TWh/ electric power from nuclear and 350 TWh/y from hydro power. The solar power potential is probably around 200 TWh/y. The wind power production is approximately 100 TWh/y but with a potential of at least 1000 TWh/y. The total biomass resources available are in the range 8500-12000 TWh/y. This gives a total of 10 000 – 15 000 TWh/y, from which at least 4000 TWh/y as electric power. This can be compared to the present gross energy use in EU 27 that was 16 084 TWh 2009, and 3400 TWh/y electric power. We can also see that there is a potential to save approximately 4 200 TWh/y in households, offices, transportation and industry. The energy balance thus should be possible to obtain with only non-fossil energy resources. Another matter is the power in time and by region. The demand does not always match the production locally at each moment and this demands a robust transmission and distribution network. Therefore we need new business models making it attractive for the users to reduce the load when there is a difficulty to deliver.

  • 82.
    Dahlquist, Erik
    et al.
    Mälardalen University, School of Business, Society and Engineering.
    Widarsson, B.
    Lilja, R.
    Avelin, Anders
    Mälardalen University, School of Business, Society and Engineering.
    Dynamisk dataåterförening: Kvalitetssäkring av signaler2008In: Varmeforsk project publication series, no 1050Article in journal (Other academic)
  • 83.
    Dahlquist, Erik
    et al.
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Widarsson, Björn
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Avelin, Anders
    Mälardalen University, School of Business, Society and Engineering.
    MODELBASED DIAGNOSTICS, MAINTENANCE ON DEMAND AND DECISION SUPPORT ON BOILERS2009In: SIMS, Scandinavian Modelling and Simulation  Society 50, conference in Fredrice, Denmark, October 7-8 (2009)), Fredrice: SIMS electronic , 2009Conference paper (Refereed)
    Abstract [en]

    At a CFB boiler a system has been tested based on a Modelica model together with a decision support system. The model is a physical model including energy and material balances, chemical reactions like combustion and gasification reactions. For the combustion system we primarily consider equilibrium conditions while for gasification the kinetics is important and thus PLS-models built on experimental data in a pilot plant are combined with literature data and a physical model. The simulation model is first developed in Modelica, but then placed as an object in Simulink/Matlab, from which data is communicated to and from the data base through OPC-server. Measured data are collected from the process data base and inserted as initial data into the simulation model, including the boiler, separator, heat exchangers and steam system. A simulation during 300 seconds is performed and the data after this is compared to the initial data. If we have steady state conditions, the values after the simulation will be the same as the initial data, while if the data are not balanced, the difference will correspond to a balanced state between all measured data and the physical correlations in the boiler. This procedure is repeated on a regular basis and the trend of the difference between the measured and the balanced data is plotted and analyzed with respect to slope respectively variance. These data are combined with other type of information like standard deviation of sensors, which corresponds to noise; is the data value changing at all? Input of manual information like lab-data, unexpected events like noise; maintenance actions; activities like how many times a valve has been opening and closing; combination of data like Energy and Mass balances combined with conductivity in blow down from steam drum to detect possible leakages in piping or boiler systems;

    All this information is introduced into a BN, Bayesian Net, which has been built from known relations, but where the quantitative data is built from experience and statistics. In this way we can then detect possible faults or probable faults coming up. This information is used by both the operators and maintenance staff. The mathematical simulation model over the CFB boiler and results from the utilization is presented in this paper.

  • 84.
    Dahlquist, Erik
    et al.
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Yan, inyue
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Thorin, Eva
    Mälardalen University, School of Sustainable Development of Society and Technology.
    How to become independent of fossil fuels in Sweden2008In: quist / [ed] Lui Ronghou, Shanghai: SJTU press , 2008Conference paper (Refereed)
    Abstract [en]

    Sweden has got the toughest demand in the whole of Europe recently. In 2020 minimum 49 % of the energy should be renewable energy. To achieve the goal biogas production is being optimized, utilizing organic wastes and crops, to produce methane for cars and buses. In Vasteras a 200 MW waste gasification plant will be built to replace coal in an existing 600 MW PC-boiler with biogas. The plant will start up 2011. There will be co-firing with also peat, aside of the biogas. In Sweden 120 TWh/y of biomass is consumed, which is almost 1/3 of the total 400 TWh energy utilized annually. Most of it is used in co-generation (CHP) or pulp and paper industry. Now the plan is to increase production of liquid fuels for vehicles. Energy balances for production of bio ethanol in Sweden will be discussed. This can be an interesting part of poly-generation systems. Plug-in hybrid car are foreseen to be introduced on a large scale within the next 10 years. Here liquid fuels are used in a combustor with e.g. a turbine and generator primarily to produce electricity, while electric engines fed by electricity from batteries drive the vehicle. Today 60 % of the new cars are "environmental", that is low consuming diesel, ethanol or biogas. Seven years ago it was only 5 % of the new cars! Cities, county authorities and government are working together with companies and universities to drive the transfer away from fossil fuels.

  • 85.
    Dahlquist, Erik
    et al.
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Yan, Jinyue
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Norstrom, Christer
    Lundin, Sune
    Entrepreneurship and sustainability perspective in engineering education2006Conference paper (Refereed)
  • 86.
    Dhak, Janice
    et al.
    Mälardalen University, Department of Mathematics and Physics.
    Dahlquist, Erik
    Mälardalen University, Department of Mathematics and Physics.
    Holmström, Kenneth
    Mälardalen University, Department of Mathematics and Physics.
    Ruiz, Jean
    Mälardalen University, Department of Mathematics and Physics.
    Generic methods for paper mill optimisation2004In: PTS-COST Symposium Simulation and Process Control for the Paper Industry, (Munchen, Germany, March 9-10, 2004), 2004Conference paper (Refereed)
  • 87.
    Dhak, Janice
    et al.
    Mälardalen University, Department of Mathematics and Physics.
    Dahlquist, Erik
    Mälardalen University, Department of Mathematics and Physics.
    Holmström, Kenneth
    Mälardalen University, Department of Mathematics and Physics.
    Ruiz, Jean
    Centre Technique du Papier, Domaine Universitaire, France.
    Belle, Jurgen
    Papiertechnische Stiftung, Germany.
    Goedsch, Frank
    Papiertechnische Stiftung, Germany.
    Developing a generic method for paper mill optimization2004In: Proceedings of the PAPTAC Control Systems 2004 Conference, (Quebec City, Canada, June 14-18), 2004, p. 207-214Conference paper (Refereed)
    Abstract [en]

    A generic method for formulating pulp and paper optimization problems is presented. Two ongoing projects in the framework of the DOTS project illustrate the method: optimization of sizing quality at a specialty paper mill, and optimization of the water and broke systems at a coated paper mill. Explicit and implicit formulations are compared, and different usages of external simulators in conjunction with optimization are discussed. The problems are solved using MATLAB/TOMLAB. Some results from different optimization algorithms are also presented.

  • 88.
    Farrokh, Mohammad
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Mahmoudi, Jafar
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Dahlquist, Erik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Modeling and Simulation of a DiasporeTubular Digestion Process2013In: International Journal of Simulation and Process Modelling, ISSN 1740-2123, E-ISSN 1740-2131, Vol. 33, no 2, p. 126-133Article in journal (Refereed)
    Abstract [en]

    A simulation model is developed to predict the performance of a tubular digestion process of a low alumina/silica ratio diaspore bauxite type. The electrolyte - NRTL property method is used to calculate the equilibrium and thermodynamic properties of the slurry. The Aspen Plus simulator has been employed to solve the reaction and thermodynamic submodels. The model was validated with several sets of the industrial experimental data in terms of the flash tanks temperatures and close agreement was found. The simulation model has been utilized by the R&D department to predict the digestion process behaviour at various operation conditions. One practical output of this work is suggestion for a new design to increase the vapour and thermal energy recovery in the digestion process unit. As a result, the exhaust vapour from the last flash tank was directed to a new pre-heater section. The industrial output has been confirmed by the energy department that has decreased 8% in the furnace fuel consumption and leads to an increase of water recovery in the digestion unit.

  • 89.
    Ghaviha, Nima
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Bohlin, M.
    RISE SICS, Västerås, Sweden.
    Holmberg, C.
    Bombardier Transportation, Västerås, Swede.
    Dahlquist, Erik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Skoglund, Robert
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Jonasson, Daniel
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    A driver advisory system with dynamic losses for passenger electric multiple units2017In: Transportation Research Part C: Emerging Technologies, ISSN 0968-090X, E-ISSN 1879-2359, Vol. 85, p. 111-130Article in journal (Refereed)
    Abstract [en]

    Driver advisory systems, instructing the driver how to control the train in an energy efficient manner, is one the main tools for minimizing energy consumption in the railway sector. There are many driver advisory systems already available in the market, together with significant literature on the mathematical formulation of the problem. However, much less is published on the development of such mathematical formulations, their implementation in real systems, and on the empirical data from their deployment. Moreover, nearly all the designed driver advisory systems are designed as an additional hardware to be added in drivers’ cabin. This paper discusses the design of a mathematical formulation and optimization approach for such a system, together with its implementation into an Android-based prototype, the results from on-board practical experiments, and experiences from the implementation. The system is based on a more realistic train model where energy calculations take into account dynamic losses in different components of the propulsion system, contrary to previous approaches. The experimental evaluation shows a significant increase in accuracy, as compared to a previous approach. Tests on a double-track section of the Mälaren line in Sweden demonstrates a significant potential for energy saving.

  • 90.
    Ghaviha, Nima
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Bohlin, Markus
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Dahlquist, Erik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Speed profile optimization of an electric train with on-board energy storage and continuous tractive effort2016In: 2016 International Symposium on Power Electronics, Electrical Drives, Automation and Motion, SPEEDAM 2016, 2016Conference paper (Refereed)
    Abstract [en]

    Electric traction system is the most energy efficient traction system in railways. Nevertheless, not all railway networks are electrified, which is due to high maintenance and setup cost of overhead lines. One solution to the problem is battery-driven trains, which can make the best use of the electric traction system while avoiding the high costs of the catenary system. Due to the high power consumption of electric trains, energy management of battery trains are crucial in order to get the best use of batteries. This paper suggests a general algorithm for speed profile optimization of an electric train with an on-board energy storage device, during catenary-free operation on a given line section. The approach is based on discrete dynamic programming, where the train model and the objective function are based on equations of motion rather than electrical equations. This makes the model compatible with all sorts of energy storage devices. Unlike previous approaches which consider trains with throttle levels for tractive effort, the new approach considers trains in which there are no throttles and tractive effort is controlled with a controller (smooth gliding handle with no discrete levels). Furthermore, unlike previous approaches, the control variable is the velocity change instead of the applied tractive effort. The accuracy and performance of the discretized approach is evaluated in comparison to the formal movement equations in a simulated experimented using train data from the Bombardier Electrostar series and track data from the UK.

  • 91.
    Ghaviha, Nima
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Bohlin, Markus
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Dahlquist, Erik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Wallin, Fredrik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Optimal Control of a Battery Train Using Dynamic Programming2015Conference paper (Other academic)
    Abstract [en]

    Electric propulsion system in trains has the highest efficiency compared to other propulsion systems (i.e. steam and diesel). Still, electric trains are not used on all the routes, due to the high setup and maintenance cost of the catenary system. Energy storage technologies and the battery driven trains however, make it possible to have the electric trains on the non-electrified routes as well. High energy consumption of the electric trains, makes the energy management of such trains crucial to get the best use of the energy storage device. This paper suggests an algorithm for the optimal control of the catenary free operation of an electric train equipped with an onboard energy storage device. The algorithm is based on the discrete dynamic programming and Bellman’s backward approach. The objective function is to minimize the energy consumption, i.e. having the maximum battery level left at the end of the trip. The constraints are the trip time, battery capacity, local speed limits and limitations on the traction motor. Time is the independent variable and distance, velocity and battery level are the state variables. All of the four variables are discretized which results in some inaccuracy in the calculations, which is discussed in the paper. The train model and the algorithm are based on the equations of motion which makes the model adjustable for all sorts of electric trains and energy storage devices. Moreover, any type of electrical constraints such as the ones regarding the voltage output of the energy storage device or the power output can be enforced easily, due to the nature of the dynamic programming. 

  • 92.
    Ghaviha, Nima
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center. Mälardalen University.
    Bohlin, Markus
    Research Institutes of Sweden RISE SICS Västerås.
    Holmberg, Christer
    Bombardier Transportation.
    Dahlquist, Erik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Speed Profile Optimization of Catenary-free Electric Trains with Lithium-ion BatteriesManuscript (preprint) (Other academic)
    Abstract [en]

    Catenary-free operated electric trains, as one of the recent technologies in railwaytransportation, has opened a new field of research: speed profile optimization and energy optimaloperation of catenary-free operated electric trains. A well-formulated solution for this problem shouldconsider the characteristics of the energy storage device using a validated model and method. This paper,discusses the consideration of the battery behavior in the problem of speed profile optimization ofcatenary-free operated electric trains. We combine the single mass point train model with an electricalbattery model and apply a dynamic programming approach to minimize the charge taken from thebattery during the catenary-free operation. The models and the method are validated and evaluatedagainst experimental data gathered from the test runs of an actual battery driven train tested in Essex,UK. The results show a significant potential in energy saving. Moreover, we show that the optimumspeed profiles generated using our approach consume less charge from the battery compared to theprevious approaches.

  • 93.
    Ghaviha, Nima
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Bohlin, Markus
    SICS - swedish institute of computer science, Sweden.
    Wallin, Fredrik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Dahlquist, Erik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    AN ALGORITHM FOR OPTIMAL CONTROL OF AN ELECTRIC MULTIPLE UNIT2014In: Proceedings from The 55th Conference on Simulation and Modelling (SIMS 55),21-22 October, 2014. Aalborg, Denmark, Linköping: Linköping University Electronic Press, 2014Conference paper (Refereed)
    Abstract [en]

    This paper offers a solution for the optimal EMU train (Electric Multiple Unit) operation with the aim of minimizing the energy consumption. EMU is an electric train with traction motors in more than one carriage. The algorithm is based on dynamic programming and the Hamilton-Jacobi-Bellman equation. To model the train, real data has been used, which was provided by experts from Bombardier Transportation Västerås. To evaluate the model, some experiments have been done on the energy saving in exchange for the increase in the trip time. Moreover a simple accuracy factor is introduced to evaluate the accuracy of the model. The final goal is to use this approach as a base for a driver advisory system, therefore it is important to have the amount of calculations as minimum as possible. The paper also includes the studies done on the calculation time. The solution can be used for driverless trains as well as normal trains. It should be mentioned that this paper is a part of a research which is still in progress and the final model will also be used by Bombardier Transportation Västerås as an evaluation tool for the propulsions systems and trains.

  • 94.
    Ghaviha, Nima
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Bohlin, Markus
    SICS Swedish ICT, Sweden.
    Wallin, Fredrik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Dahlquist, Erik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Optimal Control of an EMU Using Dynamic Programming2015In: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 75, p. 1913-1919Article in journal (Refereed)
    Abstract [en]

    A model is developed for minimizing the energy consumption of an electric multiple unit through optimized driving style, based on Hamilton-Jacobi-Bellman equation and Bellman's backward approach. Included are the speed limits, track profile (elevations), different driving modes and the train load. This paper includes aspects like the power loss in the auxiliary systems, time management, validation of the model regarding energy calculations and a study on discretization and the accuracy of the model. The model will be used as a base for a new driver advisory system. 

  • 95.
    Ghaviha, Nima
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Bohlin, Markus
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Wallin, Fredrik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Dahlquist, Erik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Optimal Control of an EMU Using Dynamic Programming and Tractive Effort as the Control Variable2015In: Proceedings of the 56th SIMS, Linköping University Electronic Press, Linköpings universitet, 2015, p. 377-382Conference paper (Refereed)
    Abstract [en]

    Problem of optimal train control with the aim of minimizing energy consumption is one of the old optimal control problems. During last decades different solutions have been suggested based on different optimization techniques, each including a certain number of constraints or different train configurations, one being the control on the tractive effort available from traction motor. The problem is previously solved using dynamic programming for trains with continuous tractive effort, in which velocity was assumed to be the control variable. The paper at hand presents a solution based on dynamic programming for solving the problem for trains with discrete tractive effort. In this approach, tractive effort is assumed to be the control variable. Moreover a short comparison is made between two approaches regarding accuracy and ease of application in a driver advisory system.

  • 96.
    Ghaviha, Nima
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Campillo, Javier
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Bohlin, Markus
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Dahlquist, Erik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Review of Application of Energy Storage Devices in Railway Transportation2017In: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 105, p. 4561-4568Article in journal (Refereed)
    Abstract [en]

    Regenerative braking is one of the main reasons behind the high levels of energy efficiency achieved in railway electric traction systems. During regenerative braking, the traction motor acts as a generator and restores part of the kinetic energy into electrical energy. To use this energy, it should be either fed back to the power grid or stored on an energy storage system for later use. This paper reviews the application of energy storage devices used in railway systems for increasing the effectiveness of regenerative brakes. Three main storage devices are reviewed in this paper: batteries, supercapacitors and flywheels. Furthermore, two main challenges in application of energy storage systems are briefly discussed. 

  • 97.
    Ghaviha, Nima
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Holmberg, C.
    Bombardier Transportation, Västerås, Sweden.
    Bohlin, M.
    RISE SICS, Västerås, Sweden.
    Dahlquist, Erik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Modeling of Losses in the Motor Converter Module of Electric Multiple Units for Dynamic Simulation Purposes2017In: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 142, p. 2303-2309Article in journal (Refereed)
    Abstract [en]

    Simulation of power consumption in electric trains is categorized in two categories: electrical power simulation and mechanical power simulation. The mechanical power is calculated as speed times tractive effort and it gives an overall view on the total energy consumption of the train during different driving cycles. Detailed calculation of losses in different components in the propulsion system is however done using complex electrical models. In this paper, we introduce a nonlinear regression model generated from validated electrical equations for the calculation of the power loss in the motor converter module of electric trains. The function can be used instead of efficiency maps to evaluate the trains’ performance during the operation or dynamic simulations.

  • 98.
    Gholinejad, Hassan
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Mousavi Takami, Kourosh
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Dahlquist, Erik
    Mälardalen University, School of Sustainable Development of Society and Technology. Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Estimation of electricity losses by numerical approach to present a solution for losses reduction2014In: International Journal of Advanced Engineering Applications, ISSN 2321-7723, Vol. 7, no 4, p. 30-40Article in journal (Refereed)
    Abstract [en]

    Electricity losses are one of the big anxieties for utilities. Electricity loss in Iran network according to Tavanir report is over 15% but individual researchers have different comments. Also, the lack of sufficient information is a network problem. To overcome on the problems authors used Top-Down/Bottom-Up method to estimate of losses in Iran’s electricity network. To achieve the model, at a certain moment measurements of input complex power in the feeder and voltages in the farthest network node and power flow calculation has been done. Using the estimated losses, authors suggest a strategy to losses reduction in every different part of distribution networks. Due to different culture, climate and network topology, losses are different and separate solution is needed. Proposed method was carried out by performing tests on a feeder with 88+35 nodes according to the IEEE 123 node test feeder. An economical investigation showed the benefits for utilities and improved the proposed plan. The main innovation in the presented paper is to combine a forecasting approach with experimental data to define a model for networks with unknown parameters.

  • 99.
    Gholinejad, Hassan
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Mousavi Takami, Kourosh
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Mousavi Takami, Amin
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Dahlquist, Erik
    Mälardalen University, School of Sustainable Development of Society and Technology. Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    To promote electricity smart grid performances by numerical modeling applications2014In: Proceedings of the 55th Conference on Simulation and Modelling(SIMS 55): “Modelling, Simulation and Optimization” / [ed] Alireza Rezania Kolai, Kim Sørensen & Mads Pagh Nielsen, Linköping: Linköping University Electronic Press, 2014, p. 347-355Conference paper (Refereed)
    Abstract [en]

    Wide world’s utilities are generating, transmitting and distributing of electricity throughout the country andare responsible to its quality.Distributed automated distribution system has been proposed for planning to reduce losses, optimize capacityand load balancing in electricity networks. The world electricity average loss is about and outage percustomer time is about min/ year. The indices are needed to optimize in developing countries.This paper deals on a modeled distribution system in Sari distribution region and evaluates three mentionedparameters on network quality. Restoration, maneuvers to achieve the minimum loss, reactive powercontrolling, load balancing etc are investigated.Modeling performs by MATLAB software, EMTP for transient modeling and Digsilent with real data bySari Distribution Company. In this paper, a new approach by rearrangement aimed at reducing losses andimproving of load balancing in distribution networks was presented.

    Keywords: Modelling, smart grid, electricity network

  • 100.
    Hakalehto, E.
    et al.
    Finnoflag Oy, Kuopio and Siilinjärvi, Finland.
    Dahlquist, Erik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    A microbiological approach to the ecosystem services2018In: Microbiological Environmental Hygiene, Nova Science Publisher Inc. , 2018, p. 433-474Chapter in book (Other academic)
    Abstract [en]

    Man has always exploited the environment for securing human life and culture. This “tradition” is both embedded into our instincts as well as a mode of behavior and a learnt method of survival in our societies. However, alongside with the globalization of the economy, internationalization, industrialization and population growth, the consequences of the one-sided approach of the past have become unbearable for the environment. Consequently, in order to maintain life on earth in its current form, we should establish new thinking and modes of action. Therefore, the survival strategies for Mankind should inherently contain the strive for sustainability, as well as the tendency to avoid past mistakes, and to repair them instantaneously whenever possible. The agricultural tradition of different nations leans on the centuries old wisdom of human civilization in a good sense. For example, the East Asian agricultural societies have learnt to handle each piece of land in their possession in an individual manner, taking into account the local environmental conditions. These principles are now more and more unanimously accepted, at least in theory. Also, the industrial ecosystem needs to be functioning in the natural way, and in balance with the environment. This is a necessity in the reversion or prevention of any developing environmental catastrophes that could wait behind the corner. As the major vehicles for the circulation of matter, microbes are in a key position and provide means for finding the solutions to serve the global ecosystems. In the aftermath of a vast environmental crisis, namely the oil leakage from the “Deepwater Horizon” oil platform well in the Mexican Gulf in the year 2010, it was noticed that the dramatic consequences of the spill were mitigated and the worst scenario of destruction avoided thanks to the cleaning actions of the marine micro-organisms. This was a positive result both ecologically and in economic sense. It further encouraged the scientists to find and isolate microbial strains which could be used for such operations. Although the natural microflora compensated and mitigated the effects of the Deepwater Horizon accident surprisingly well in 2010, there have been observations and concerns about the long term effects of this ecocatastroph (Geggel, 2015).

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