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  • 51.
    Blomqvist, Stefan
    et al.
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, Faculty of Science & Engineering.
    La Fleur, Lina
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, Faculty of Science & Engineering.
    Amiri, Shahnaz
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, Faculty of Science & Engineering.
    Rohdin, Patrik
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, Faculty of Science & Engineering.
    Ödlund (Trygg), Louise
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, Faculty of Science & Engineering.
    The Impact on System Performance When Renovating a Multifamily Building Stock in a District Heated Region2019In: Sustainability, ISSN 2071-1050, E-ISSN 2071-1050, Vol. 11, no 8, article id 2199Article in journal (Other academic)
    Abstract [en]

    In Sweden, 90% of multifamily buildings utilize district heat and a large portion is in need of renovation. The aim is to analyze the impact of renovating a multifamily building stock in a district heating and cooling system, in terms of primary energy savings, peak power demands, electricity demand and production, and greenhouse gas emissions on local and global levels. The study analyzes scenarios regarding measures on the building envelope, ventilation, and substitution from district heat to ground source heat pump. The results indicate improved energy performance for all scenarios, ranging from 11% to 56%. Moreover, the scenarios present a reduction of fossil fuel use and reduced peak power demand in the district heating and cooling system ranging from 1 MW to 13 MW, corresponding to 4–48 W/m2 heated building area. However, the study concludes that scenarios including a ground source heat pump generate significantly higher global greenhouse gas emissions relative to scenarios including district heating. Furthermore, in a future fossil-free district heating and cooling system, a reduction in primary energy use will lead to a local reduction of emissions along with a positive effect on global greenhouse gas emissions, outperforming measures with a ground source heat pump.

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  • 52.
    Blomqvist, Stefan
    et al.
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, Faculty of Science & Engineering.
    Rohdin, Patrik
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, Faculty of Science & Engineering.
    Ödlund, Louise
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, Faculty of Science & Engineering.
    Hållbar Region: Ett forskningsprojekt för ökad samverkan mellan energi- och fastighetsbolag. Etapp 2 2016-20182018Report (Other academic)
    Abstract [sv]

    Det är i samverkan mellan energibolag och slutanvändare som effektiva energisystem kan skapas. Med ett systemperspektiv mellan tillförsel- och användarsidan inom energisystemet kan forskningsprojektet Hållbar Region bidra med en pusselbit till framtidens energisystem, med ökad energieffektivitet och minskad klimatpåverkan som resultat.

    Forskningsprojektets syfte är att genom samverkan mellan universitet, energi- och fastighetsbolag arbeta för att skapa en hållbar och resurseffektiv region. Detta delvis genom att utbyta kunskap kring utmaningar och på så vis öka förståelsen för varandras verksamheter, både inom och mellan branscherna.

    Under etapp 1 utvecklades simulerings- och optimeringsmodeller gällande renoveringspaket av fastigheter och energisystemet. Arbetet fortskrider löpande med ytterligare beräkningar och scenarioanalyser. Under etapp 2 har många delstudier genomförts och som vardera ger input och kunskap för vidare utveckling. Några av resultaten uppkomna under etapp 2 är:

    Betong bättre än trä?

    En fallstudie påvisar att ett flerbostadshus med betongstomme har lägre miljöpåverkan än en liknande huskropp av träkonstruktion. Se mer i avsnitt 5.1

    Vikten av utökad och förbättrad kundkontakt!

    En studie av den framtida värmemarknaden visar på vikande efterfrågan. Nya tillämpningsområden, ökad och förbättrad kommunikation är viktiga aspekter för att möta utmaningen. Se mer i avsnitt 5.2

    Tillvarata överskottsvärme!

    Studien undersöker alternativ för att nyttiggöra överskottsvärme i fjärrvärmenätet, som möjliggörs genom samarbete med närliggande verksamheter. Att nyttogöra värmen genom en absorptionsdriven värmepump är det som förordas. Se mer i avsnitt 5.3

    Beräkningar av primärenergifaktorer!

    En studie analysera premiärenergifaktorer för svensk fjärrvärme utifrån flertalet perspektiv och metoder. De beräknade faktorerna blir betydande mindre än Boverkets. Se mer i avsnitt 5.4

    Prismodellens roll för incitament till energieffektivisering!

    Flertalet prismodeller analyseras utifrån ett klimatperspektiv. En modell med säsongsvarierande prissättning förordas och där effektuttaget lyfts fram som en nyckel. Se mer i avsnitt 5.5

    Nyttan av en dynamisk framledningstemperatur!

    Studien undersöker effekt- och flödesutjämnande körstrategier för att möta dygns- och säsongsvariationer av efterfrågan på värme. Studien påvisar ökad elverkningsgrad och ett högre temperaturspann möjliggör bättre effekt- och flödesutjämning. Se mer i avsnitt 5.6

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    Hållbar region : Ett forskningsprojekt för ökad samverkan mellan energi- och fastighetsbolag. ETAPP 2, 2016-2018
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  • 53.
    Borén, Sven
    et al.
    Department of Strategic Sustainable Development, Blekinge Institute of Technology, 37179 Karlskrona, Sweden.
    Nurhadi, Lisiana
    Department of Strategic Sustainable Development, Blekinge Institute of Technology, 37179 Karlskrona, Sweden.
    Ny, Henrik
    Department of Strategic Sustainable Development, Blekinge Institute of Technology, 37179 Karlskrona, Sweden.
    Robért, Karl-Henrik
    Department of Strategic Sustainable Development, Blekinge Institute of Technology, 37179 Karlskrona, Sweden.
    Broman, Göran
    Department of Strategic Sustainable Development, Blekinge Institute of Technology, 37179 Karlskrona, Sweden.
    Trygg, Louise
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, Faculty of Science & Engineering.
    A strategic approach to sustainable transport system development – part 2: the case of a vision for electric vehicle systems in southeast Sweden2017In: Journal of Cleaner Production, ISSN 0959-6526, E-ISSN 1879-1786, Vol. 140, p. 62-71Article in journal (Refereed)
    Abstract [en]

    Electric vehicles seem to offer a great potential for sustainable transport development. The Swedish pioneer project GreenCharge Southeast is designed as a cooperative action research approach that aims to explore a roadmap for a fossil-free transport system by 2030 with a focus on electric vehicles. In the first paper of this tandem publication, the authors propose a new generic process model embedding the Framework of Strategic Sustainable Development. The purpose of applying it in an action-research mode as described in this paper was twofold: (i) to develop a vision for sustainable regional transport and a coarse roadmap towards that vision, and, while doing so, (ii) get additional empirical experiences to inform the development of the new generic process model. Experts from many sectors and organizations involved in the GreenCharge project provided vital information and reviewed all planning perspectives presented in Paper 1 in two sequential multi-stakeholder seminars. The results include a sustainable vision for electric vehicle systems in southeast Sweden within a sustainable regional transport system within a sustainable global society, as well as an initial development plan towards such a vision for the transport sector. The vision is framed by the universal sustainability principles, and the development plan is informed by the strategic guidelines, of the above-mentioned framework. Among other things, the vision and plan imply a shift to renewable energy and a more optimized use of areas and thus a new type of spatial planning. For example, the vision and plan implies a lower built-in demand for transport, more integrated traffic modes, and more multi-functional use of areas for energy and transport infrastructures, for example. Some inherent benefits of electric vehicles are highlighted in the vision and plan, including near-zero local emissions and flexibility as regards primary energy sources. The vision and plan also imply improved governance for more effective cross-sector collaboration to ensure coordinated development within the transport sector and between the transportation sector and other relevant sectors. Meanwhile, the new generic process model was refined and is ready to be applied and further tested in the GreenCharge project and in other projects within the transport sector as well as other sectors. The study confirmed that the new generic process model suggested in support of sustainable transport system and community development is helpful for giving diverse stakeholders, with various specialties and perspectives, a way of working that is goal-oriented and builds on effective, iterative learning loops and co-creation.

  • 54.
    Bringner, Martin
    Linköping University, Department of Management and Engineering, Energy Systems.
    Energianalys av Lavalverkstaden: Siemens Industrial Turbomachinery2009Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In recent years the Swedish electricity price has risen sharply, which resulted in significantly higher energy costs for the companies. Siemens Industrial Turbomachinery in Finspång is one of those companies and for a long time they have seen how the energy usage is increasing every year, mainly due to an increased production. Therefore the company wants to investigate the energy usage and make an energy analysis of Laval workshop, the biggest production plant of the company.

     

    The energy analysis is fundamentally based on measurements to get an overview of the energy usage of the plant. By dividing those in support and production processes, possibilities to energy efficiency measures have been identified and the savings potential quantified. The investment cost is quantified for the two largest investments, in other energy efficiency measures only the saving is taken into account.

     

    The conclusion is that there are great possibilities to increase energy efficiency. A change of general illumination and a new air compressor calls for the greatest investments but also provides the greatest savings. LCC-analysis shows in both cases high profitability and investments are payed back within four and six years respectively. Moreover, a conversion, reduced lighting and idling losses is suggested. Due to the proposed actions, savings of totally 1.6 million SEK a year can be made by reducing

     

    • 1537 MWh (-13 %) of electricity
    • 733 MWh (-15 %) of district heating
    • 261 MWh (-12 %) of district cooling

     

    In addition to the energy efficiency measures that can be concretized there is a great potential to reduce the energy use also in longer term by focusing more of energy use in daily work. By adding routines when purchasing, energy efficient equipment can be promoted and energy use will be reduced even more.

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  • 55.
    Broberg, Nicklas
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Kartläggning och utvärdering av svenska energinätverk: Företagsnätverk och samarbeten inriktade på energi2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

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

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

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

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

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

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

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

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    Kartläggning och utvärdering av svenska energinätverk - Broberg, 2014
  • 56.
    Broberg, Sarah
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Energy efficiency through industrial excess heat recovery-policy impacts2015In: Energy Efficiency, ISSN 1570-646X, E-ISSN 1570-6478, Vol. 8, no 1, p. 19-35Article in journal (Refereed)
    Abstract [en]

    The EU target on energy efficiency implies a 20 % reduction in the use of primary energy by implementation of energy efficiency measures. Not all potential cost-effective measures for improved energy efficiency are implemented. This energy efficiency gap is explained by market barriers. Policy instruments can be used to overcome these barriers. The target could, for example, be obtained through industrial excess heat recovery; but there is a knowledge gap on factors affecting excess heat utilization. In this study, interviews were carried out with energy managers in order to study excess heat utilization from industrys perspective. The study seeks to present how excess heat recovery can be promoted or discouraged through policy instruments, and several factors are raised in the paper. The interviews revealed that excess heat recovery is generally referred to in terms of heat deliveries to the district heating network. One may need to look for innovative recovery solutions, and policies are needed to bring these solutions into action. Due to inefficient conversion for heat-driven electricity generation, a system favoring this implementation could favor an inefficient system. Beyond external instruments, internal goals, visions, and the importance of energy as a priority were shown to be important in the work with improved energy management.

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  • 57.
    Broberg, Sarah
    et al.
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Andersson, Vikor
    Institutionen för energi och miljö, Värmeteknik och maskinlära, Chalmers tekniska högskola.
    Hackl, Roman
    Institutionen för energi och miljö, Värmeteknik och maskinlära, Chalmers tekniska högskola.
    Integrated Algae Cultivation for Biofuels Production in Industrial Clusters2011Report (Other academic)
    Abstract [en]

    Declining fossil resources and the issue of climate change caused by anthropogenic emissions of greenhouse gases make global action towards a more sustainable society inevitable. The EU decided in 2007 that 20 % of the union´s energy use should origin from renewable resources by the year 2020. One way of achieving this goal is to increase the utilisation of biofuels.

    Today 2nd generation biofuels are being developed. They are seen as a more sustainable solution than 1st generation biofuels since they have a higher area efficiency (more fuel produced per area) and the biomass can be cultivated at land which is not suitable for food crops. One of these 2nd generation biofuels are fuels derived from microalgae.

    In this study a thorough literature survey has been conducted in order to assess the State-of-the-Art in algae biofuels production. The literature review showed the importance of a supplementary function in conjunction with algae cultivation and therefore algae cultivation for municipal wastewater treatment and capturing CO2 emissions from industry was included in the study. It was assumed that all the wastewater of the city of Gothenburg, Sweden, was treated by algae cultivation.

    A computer model of the whole production process has been developed, covering; algae cultivation in conjunction with wastewater treatment, algae harvesting and biofuels production. Two different cases are modelled; a first case including combined biodiesel and biogas production, and a second case investigating only biogas production. Both cases have been evaluated in terms of product outputs, CO2 emissions savings and compared to each other in an economic sense.

    Utilising the nutrients in the wastewater of Gothenburg it is possible to cultivate 29 ktalgae/year. In the biogas case it is possible to produce 205 GWhbiogas/year. The biogas/biodiesel case showed a production potential of 63 GWhbiodiesel/year and 182 GWhbiogas/year. There is a deficit of carbon in the wastewater, hence CO2 is injected as flue gases from industrial sources. The biodiesel/biogas case showed an industrial CO2 sequestration capacity of 24 ktCO2/year while in the biogas case 22.6 ktCO2/year, could be captured. Estimating the total CO2 emissions savings showed 46 ktCO2/year in the biodiesel/biogas case and 38 ktCO2/year for the biogas case. The importance of including wastewater treatment in the process was confirmed, as it contributes with 13.7 ktCO2/year to the total CO2 emissions savings.

    Economic comparison of the two cases showed that biodiesel in conjunction with biogas production is advantageous compared to only biogas production. This is mainly due to the higher overall fuel yield and the high willingness to pay for biodiesel. The total incomes from biodiesel/biogas sales were calculated to 221 million SEK/year and 193 million SEK/year for biogas. It was found that the higher incomes from biodiesel/biogas sales repay the increased investment for the biodiesel process in approximately 3 years.

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    Integrated Algae Cultivation for Biofuels Production in Industrial Clusters
  • 58.
    Broberg, Sarah
    et al.
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Backlund, Sandra
    Linköping University, Department of Management and 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.
    Thollander, Patrik
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Industrial excess heat deliveries to Swedish district heating networks: drop it like it's hot2012In: Energy Policy, ISSN 0301-4215, E-ISSN 1873-6777, Vol. 51, p. 332-339Article in journal (Refereed)
    Abstract [en]

    Using industrial excess heat in District Heating (DH) networks reduces the need for primary energy and is considered efficient resource use. The conditions of Swedish DH markets are under political discussion in the Third Party Access (TPA) proposal, which would facilitate the delivery of firms' industrial excess heat to DH networks. This paper estimates and discusses the untapped potential for excess heat deliveries to DH networks and considers whether the realization of this potential would be affected by altered DH market conditions. The results identify untapped potential for industrial excess heat deliveries, and calculations based on estimated investment costs and revenues indicate that realizing the TPA proposal could enable profitable excess heat investments.

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  • 59.
    Broberg, Sarah
    et al.
    Linköping University, Department of Management and Engineering, Energy Systems.
    Karlsson, Magnus
    Linköping University, Department of Management and Engineering, Energy Systems.
    SYSTEMS ANALYSIS AND CO2 REDUCTIONS USING INDUSTRIAL EXCESS HEAT2013Conference paper (Other academic)
    Abstract [en]

    The adopted Energy Efficiency Directive stresses the importance of using excess heat as a way to reach the EU target of primary energy consumption. Utilization of industrial excess heat may result in decreased energy demand, CO2 emissions reduction, and economic gains. In this study, an energy systems analysis is performed with the aim of investigating how excess heat should be used, and the impact of global CO2 emissions. The manner in which the heat is recovered will affect the system. The influence of excess heat recovery and the trade-off between heat recovery for heating or cooling applications and electricity production has been investigated using the energy systems modeling tool reMIND. The model has been optimized with regard to system cost. The results show that it is favorable to recover the available excess heat in all the investigated energy market scenarios, and that electricity production is not a part of the optimal solution. The trade-off between utilization of excess heat in the heating or cooling system depends on the energy market prices and the type of heat production. The introduction of excess heat also reduces the CO2 emissions in the system for all the studied energy market scenarios.  

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  • 60.
    Broberg, Sarah
    et al.
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Lindkvist, Emma
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Biogas production supported by excess heat - A systems analysis within the food industry2015In: Energy Conversion and Management, ISSN 0196-8904, E-ISSN 1879-2227, Vol. 91, p. 249-258Article in journal (Refereed)
    Abstract [en]

    The aim of this paper was to study the effects on greenhouse gases and economics when a change is made in the use of industrial organic waste from external production and use of biogas (A) to internal production and use (B). The two different system solutions are studied through a systems analysis based on an industrial case. The baseline system (A) and a modified system (B) were compared and analysed. Studies show that industrial processes considered as integrated systems, including the exchange of resources between industries, can result in competitive advantages. This study focuses on the integration of internally produced biogas from food industry waste produced by a food company and the use of excess heat. Two alternative scenarios were studied: (1) the use of available excess heat to heat the biogas digester and (2) the use of a part of the biogas produced to heat the biogas digester. This study showed that the system solution, whereby excess heat rather than biogas is used to heat the biogas digester, was both environmentally and economically advantageous. However, the valuation of biomass affects the magnitude of the emissions reduction. Implementing this synergistic concept will contribute to the reaching of European Union climate targets. (C) 2014 Elsevier Ltd. All rights reserved.

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  • 61.
    Broberg, Sarah
    et al.
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Svensson, Inger-Lise
    Linköping University, Department of Management and 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.
    Thollander, Patrik
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Restenergi inom industrin i Östergötlands och Örebro län: Resultat av enkätundersökning av 85 företag2011Report (Other academic)
    Abstract [sv]

    Bakgrund: Under våren 2011 har Länsstyrelsen Östergötlands län och Länsstyrelsen i Örebro län inventerat restenergin inom industrin i Östergötlands och Örebro län. Enkäten som skickades ut utformades i samarbete med Linköpings Universitet och skickades ut till 85 industrier i länen.

    Syfte: Syftet med undersökningen är att undersöka mängden tillgänglig restenergi i industrin inom Östergötlands och Örebro län. Enkäten syftade till att få fram värmetillgången inom företagen, dels total tillgång i länen och dels spillvärme per län. Syftet med rapporten är också att översiktligt undersöka möjliga användningsområden för den tillgängliga restvärmen. Genom användning av energiinnehållet för uppvärmningsbehov internt eller som när-/fjärr-värme kan användningen av fossila bränslen och el minskas.

    Metod: Metoden som användes för att uppfylla ovanstående syfte är en enkätstudie. Tillsammans med Energisystem vid Linköpings universitet tog Länsstyrelsen fram en lista på frågor inför enkätutskicket. 85 företag inom Östergötlands och Örebro län valdes ut och en enkät sammanställdes av Länsstyrelsen i Östergötlands, Länsstyrelsen i Örebro län och Linköpings Universitet. Företagen är verksamma inom miljö, verkstads-, stål-, glas-, gruv-, kemi-, pappers-, drivmedel- och betongindustrin. Informationen om enkäten skickades ut under våren och sommaren via e-post och svar har inkommit från 28 företag via webbaserade enkätplattformen. Bland de 28 företagen som svarade på enkäten har 9 företag mindre än 50 anställda och ytterligare 15 företag mindre än 500 anställda.

    I den andra delen av studien studeras möjliga användningsområden för användning av den tillgängliga restenergin i länen.

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    Restenergi inom industrin i Östergötlands och Örebro län
  • 62. Order onlineBuy this publication >>
    Broberg Viklund, Sarah
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, Faculty of Science & Engineering.
    System studies of the use of industrial excess heat2015Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Energy, materials, and by-products, can be exchanged between companies, having positive effects in the form of improved resource efficiency, environmental benefits, and economic gains. One such energy stream that can be exchanged is excess heat, that is, heat generated as a by-product during, for example, industrial production. Excess heat will continue to play an important role in efforts to reduce greenhouse gas (GHG) emissions and improve energy efficiency. Using excess heat is therefore currently emphasized in EU policy as a way to reach EU climate targets.

    This thesis examines the opportunities of manufacturing industries to use industrial excess heat, and how doing so can positively affect industry, society, and the climate. Since different parts of the energy system are entangled, there is an inherent complexity in studying these systems and introducing excess heat in one part of the energy system may influence other parts of the system. This analysis has accordingly been conducted by combining studies from various perspectives, by applying both quantitative and qualitative methods and covering a broad range of aspects, such as technical possibilities as well as climate, policy, economics, and resource aspects.

    The results identify several opportunities and benefits accruing from excess heat use. Although excess heat is currently partly used as a thermal resource in district heating in Sweden, this thesis demonstrates that significant untapped excess heat is still available. The mapping conducted in the appended studies identifies excess heat in different energy carriers, mainly low-temperature water. Analysis of excess heat use in different recovery options demonstrated greater output when using excess heat in district heating than electricity production. Optimizing the trade-offs in excess heat used in a district heating network, heat-driven cooling, and electricity production under different energy market conditions while minimizing the system cost, however, indicated that the attractiveness of excess heat in district heating depends on the type of heat production in the system. Viewing excess heat as a low-cost energy source also makes it economically interesting, and creates opportunities to invest in excess heat-recovery solutions. Excess heat is often viewed as CO2 neutral since unused excess heat may be regarded as wasted energy. The GHG mitigation potential of using excess heat, however, was found to be ambiguous. The appended studies demonstrate that using excess heat for electricity production or for applications that reduce the use of electricity reduces GHG emissions. The effects of using excess heat in district heating, on the other hand, depend on the energy market development, for example, the marginal electricity production and marginal use of biomass, and on the type of district heating system replaced. The interviews performed reveal that energy policy does influence excess heat use, being demonstrated both to promote and discourage excess heat use. Beyond national energy policies, internal goals and core values were identified as important for improved energy efficiency and increased excess heat use.

    List of papers
    1. Technologies for utilization of industrial excess heat: Potentials for energy recovery and CO2 emission reduction
    Open this publication in new window or tab >>Technologies for utilization of industrial excess heat: Potentials for energy recovery and CO2 emission reduction
    2014 (English)In: Energy Conversion and Management, ISSN 0196-8904, E-ISSN 1879-2227, Vol. 77, p. 369-379Article in journal (Refereed) Published
    Abstract [en]

    Industrial excess heat is a large untapped resource, for which there is potential for external use, whichwould create benefits for industry and society. Use of excess heat can provide a way to reduce the useof primary energy and to contribute to global CO2 mitigation. The aim of this paper is to present differentmeasures for the recovery and utilization of industrial excess heat and to investigate how the developmentof the future energy market can affect which heat utilization measure would contribute the mostto global CO2 emissions mitigation. Excess heat recovery is put into a context by applying some of theexcess heat recovery measures to the untapped excess heat potential in Gävleborg County in Sweden.Two different cases for excess heat recovery are studied: heat delivery to a district heating system andheat-driven electricity generation. To investigate the impact of excess heat recovery on global CO2 emissions,six consistent future energy market scenarios were used. Approximately 0.8 TWh/year of industrialexcess heat in Gävleborg County is not used today. The results show that with the proposed recoverymeasures approximately 91 GWh/year of district heating, or 25 GWh/year of electricity, could be suppliedfrom this heat. Electricity generation would result in reduced global CO2 emissions in all of the analyzedscenarios, while heat delivery to a DH system based on combined heat and power production frombiomass would result in increased global CO2 emissions when the CO2 emission charge is low.

    Place, publisher, year, edition, pages
    Elsevier, 2014
    Keywords
    Industrial excess heat; Heat recovery; Electricity generation; District heating; CO2 emission; Energy market scenario
    National Category
    Energy Systems
    Identifiers
    urn:nbn:se:liu:diva-102611 (URN)10.1016/j.enconman.2013.09.052 (DOI)000330494600041 ()
    Funder
    Swedish Energy Agency
    Available from: 2013-12-17 Created: 2013-12-17 Last updated: 2017-12-06Bibliographically approved
    2. Industrial excess heat use: Systems analysis and CO2 emissions reduction
    Open this publication in new window or tab >>Industrial excess heat use: Systems analysis and CO2 emissions reduction
    2015 (English)In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 152, p. 189-197Article in journal (Refereed) Published
    Abstract [en]

    The adopted energy efficiency directive stresses the use of excess heat as a way to reach the EU target of primary energy use. Use of industrial excess heat may result in decreased energy demand, CO2 emissions reduction, and economic gains. In this study, an energy systems analysis is performed with the aim of investigating how excess heat should be used, and the impact on CO2 emissions. The manner in which the heat is recovered will affect the system. The influence of excess heat recovery and the trade-off between heat recovery for heating or cooling applications and electricity production has been investigated using the energy systems modeling tool reMIND. The model has been optimized by minimizing the system cost. The results show that it is favorable to recover the available excess heat in all the investigated energy market scenarios, and that heat driven electricity production is not a part of the optimal solution. The trade-off between use of recovered excess heat in the heating or cooling system depends on the energy market prices and the type of heat production. The introduction of excess heat reduces the CO2 emissions in the system for all the studied energy market scenarios. (C) 2014 Elsevier Ltd. All rights reserved.

    Place, publisher, year, edition, pages
    Elsevier, 2015
    Keywords
    Excess heat; Waste heat; Energy systems modeling; CO2 emission reduction; Heat recovery
    National Category
    Mechanical Engineering
    Identifiers
    urn:nbn:se:liu:diva-120206 (URN)10.1016/j.apenergy.2014.12.023 (DOI)000356745200019 ()
    Note

    Funding Agencies|Swedish Energy Agency

    Available from: 2015-07-21 Created: 2015-07-20 Last updated: 2017-12-04
    3. Biogas production supported by excess heat - A systems analysis within the food industry
    Open this publication in new window or tab >>Biogas production supported by excess heat - A systems analysis within the food industry
    2015 (English)In: Energy Conversion and Management, ISSN 0196-8904, E-ISSN 1879-2227, Vol. 91, p. 249-258Article in journal (Refereed) Published
    Abstract [en]

    The aim of this paper was to study the effects on greenhouse gases and economics when a change is made in the use of industrial organic waste from external production and use of biogas (A) to internal production and use (B). The two different system solutions are studied through a systems analysis based on an industrial case. The baseline system (A) and a modified system (B) were compared and analysed. Studies show that industrial processes considered as integrated systems, including the exchange of resources between industries, can result in competitive advantages. This study focuses on the integration of internally produced biogas from food industry waste produced by a food company and the use of excess heat. Two alternative scenarios were studied: (1) the use of available excess heat to heat the biogas digester and (2) the use of a part of the biogas produced to heat the biogas digester. This study showed that the system solution, whereby excess heat rather than biogas is used to heat the biogas digester, was both environmentally and economically advantageous. However, the valuation of biomass affects the magnitude of the emissions reduction. Implementing this synergistic concept will contribute to the reaching of European Union climate targets. (C) 2014 Elsevier Ltd. All rights reserved.

    Place, publisher, year, edition, pages
    Elsevier, 2015
    Keywords
    Systems analysis; Biogas production; Industrial excess heat; Climate impact; Investment opportunity; Synergies
    National Category
    Mechanical Engineering
    Identifiers
    urn:nbn:se:liu:diva-114983 (URN)10.1016/j.enconman.2014.12.017 (DOI)000348887000025 ()
    Note

    Funding Agencies|Swedish Energy Agency; Linkoping University

    Available from: 2015-03-10 Created: 2015-03-06 Last updated: 2020-04-27
    4. Algae-based biofuel production as part of an industrial cluster
    Open this publication in new window or tab >>Algae-based biofuel production as part of an industrial cluster
    Show others...
    2014 (English)In: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 71, p. 113-124Article in journal (Refereed) Published
    Abstract [en]

    This paper presents a study on the production of biofuels from algae cultivated in municipal wastewater in Gothenburg, Sweden. A possible biorefinery concept is studied based on two cases; Case A) combined biodiesel and biogas production, and Case B) only biogas production. The cases are compared in terms of product outputs and impact on global CO2 emissions mitigation. The area efficiency of the algae-based biofuels is also compared with other biofuel production routes. The study investigates the collaboration between an algae cultivation, biofuel production processes, a wastewater treatment plant and an industrial cluster for the purpose of utilizing material flows and industrial excess heat between the actors. This collaboration provides the opportunity to reduce the CO2 emissions from the process compared to a stand-alone operation. The results show that Case A is advantageous to Case B with respect to all studied factors. It is found that the algae-based biofuel production routes investigated in this study has higher area efficiency than other biofuel production routes. The amount of algae-based biofuel possible to produce corresponds to 31 MWfuel for Case A and 26 MWfuel in Case B.

    Place, publisher, year, edition, pages
    Elsevier, 2014
    Keywords
    Algae; Biofuel; Biogas; Biodiesel; Biorefinery; Industrial excess heat
    National Category
    Mechanical Engineering
    Identifiers
    urn:nbn:se:liu:diva-113047 (URN)10.1016/j.biombioe.2014.10.019 (DOI)000345349500011 ()
    Note

    Funding Agencies|Energy Systems Programme - Swedish Energy Agency

    Available from: 2015-01-09 Created: 2015-01-08 Last updated: 2017-12-05
    5. Industrial excess heat deliveries to Swedish district heating networks: drop it like it's hot
    Open this publication in new window or tab >>Industrial excess heat deliveries to Swedish district heating networks: drop it like it's hot
    2012 (English)In: Energy Policy, ISSN 0301-4215, E-ISSN 1873-6777, Vol. 51, p. 332-339Article in journal (Refereed) Published
    Abstract [en]

    Using industrial excess heat in District Heating (DH) networks reduces the need for primary energy and is considered efficient resource use. The conditions of Swedish DH markets are under political discussion in the Third Party Access (TPA) proposal, which would facilitate the delivery of firms' industrial excess heat to DH networks. This paper estimates and discusses the untapped potential for excess heat deliveries to DH networks and considers whether the realization of this potential would be affected by altered DH market conditions. The results identify untapped potential for industrial excess heat deliveries, and calculations based on estimated investment costs and revenues indicate that realizing the TPA proposal could enable profitable excess heat investments.

    Keywords
    Excess heat; District heating; Third party access (TPA)
    National Category
    Chemical Engineering Economics and Business
    Identifiers
    urn:nbn:se:liu:diva-86547 (URN)10.1016/j.enpol.2012.08.031 (DOI)000312620000035 ()
    Available from: 2012-12-18 Created: 2012-12-18 Last updated: 2017-12-06
    6. Effect of the use of industrial excess heat in district heating on greenhouse gas emissions: A systems perspective
    Open this publication in new window or tab >>Effect of the use of industrial excess heat in district heating on greenhouse gas emissions: A systems perspective
    2015 (English)In: Resources, Conservation and Recycling, ISSN 0921-3449, E-ISSN 1879-0658, Vol. 100, p. 81-87Article in journal (Refereed) Published
    Abstract [en]

    European policy promotes increased use of excess heat as a means to increase the efficiency of resourceuse. By studying possible effects on greenhouse gases, this article aims to analyze and discuss systemaspects of the use of industrial excess heat in district heating. Effects on greenhouse gas emissions arestudied by applying different energy market conditions with different system boundaries in time andspace. First, life cycle assessment is used to assess the introduction of excess heat in district heating in acontemporary system with different geographical system boundaries. Thereafter, future energy marketscenarios for Europe are investigated to explore possible future outcomes. This study concludes that boththe heat production system and the energy market conditions affect the system emission effects of usingexcess heat in district heating. Industrial excess heat in district heating can be beneficial even if it leadsto reduced local electricity production when unused biomass can be used to replace fossil fuels. It isrecommended that a strengthened EU policy should encourage the use of biomass where it has the mostfavorable effects from a systems perspective to ensure emission reductions when industrial excess heatis used in district heating.

    Keywords
    Industrial excess heat, industrial waste heat, district heating, ENPAC, LCA, emission mitigation
    National Category
    Energy Systems
    Identifiers
    urn:nbn:se:liu:diva-118080 (URN)10.1016/j.resconrec.2015.04.010 (DOI)000356750300009 ()
    Funder
    Swedish Energy Agency
    Available from: 2015-05-21 Created: 2015-05-21 Last updated: 2018-09-17
    7. Energy efficiency through industrial excess heat recovery-policy impacts
    Open this publication in new window or tab >>Energy efficiency through industrial excess heat recovery-policy impacts
    2015 (English)In: Energy Efficiency, ISSN 1570-646X, E-ISSN 1570-6478, Vol. 8, no 1, p. 19-35Article in journal (Refereed) Published
    Abstract [en]

    The EU target on energy efficiency implies a 20 % reduction in the use of primary energy by implementation of energy efficiency measures. Not all potential cost-effective measures for improved energy efficiency are implemented. This energy efficiency gap is explained by market barriers. Policy instruments can be used to overcome these barriers. The target could, for example, be obtained through industrial excess heat recovery; but there is a knowledge gap on factors affecting excess heat utilization. In this study, interviews were carried out with energy managers in order to study excess heat utilization from industrys perspective. The study seeks to present how excess heat recovery can be promoted or discouraged through policy instruments, and several factors are raised in the paper. The interviews revealed that excess heat recovery is generally referred to in terms of heat deliveries to the district heating network. One may need to look for innovative recovery solutions, and policies are needed to bring these solutions into action. Due to inefficient conversion for heat-driven electricity generation, a system favoring this implementation could favor an inefficient system. Beyond external instruments, internal goals, visions, and the importance of energy as a priority were shown to be important in the work with improved energy management.

    Place, publisher, year, edition, pages
    Springer Verlag (Germany), 2015
    Keywords
    Industrial excess heat; Industrial waste heat; Energy efficiency; Energy policy; Heat recovery; Interviews
    National Category
    Mechanical Engineering
    Identifiers
    urn:nbn:se:liu:diva-114229 (URN)10.1007/s12053-014-9277-3 (DOI)000347554100002 ()
    Note

    Funding Agencies|Energy Systems Programme - Swedish Energy Agency

    Available from: 2015-02-16 Created: 2015-02-16 Last updated: 2017-12-04
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  • 63.
    Broberg Viklund, Sarah
    et al.
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Johansson, Maria
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Technologies for utilization of industrial excess heat: Potentials for energy recovery and CO2 emission reduction2014In: Energy Conversion and Management, ISSN 0196-8904, E-ISSN 1879-2227, Vol. 77, p. 369-379Article in journal (Refereed)
    Abstract [en]

    Industrial excess heat is a large untapped resource, for which there is potential for external use, whichwould create benefits for industry and society. Use of excess heat can provide a way to reduce the useof primary energy and to contribute to global CO2 mitigation. The aim of this paper is to present differentmeasures for the recovery and utilization of industrial excess heat and to investigate how the developmentof the future energy market can affect which heat utilization measure would contribute the mostto global CO2 emissions mitigation. Excess heat recovery is put into a context by applying some of theexcess heat recovery measures to the untapped excess heat potential in Gävleborg County in Sweden.Two different cases for excess heat recovery are studied: heat delivery to a district heating system andheat-driven electricity generation. To investigate the impact of excess heat recovery on global CO2 emissions,six consistent future energy market scenarios were used. Approximately 0.8 TWh/year of industrialexcess heat in Gävleborg County is not used today. The results show that with the proposed recoverymeasures approximately 91 GWh/year of district heating, or 25 GWh/year of electricity, could be suppliedfrom this heat. Electricity generation would result in reduced global CO2 emissions in all of the analyzedscenarios, while heat delivery to a DH system based on combined heat and power production frombiomass would result in increased global CO2 emissions when the CO2 emission charge is low.

    Download full text (pdf)
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  • 64.
    Broberg Viklund, Sarah
    et al.
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, Faculty of Science & Engineering.
    Karlsson, Magnus
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, Faculty of Science & Engineering.
    Industrial excess heat use: Systems analysis and CO2 emissions reduction2015In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 152, p. 189-197Article in journal (Refereed)
    Abstract [en]

    The adopted energy efficiency directive stresses the use of excess heat as a way to reach the EU target of primary energy use. Use of industrial excess heat may result in decreased energy demand, CO2 emissions reduction, and economic gains. In this study, an energy systems analysis is performed with the aim of investigating how excess heat should be used, and the impact on CO2 emissions. The manner in which the heat is recovered will affect the system. The influence of excess heat recovery and the trade-off between heat recovery for heating or cooling applications and electricity production has been investigated using the energy systems modeling tool reMIND. The model has been optimized by minimizing the system cost. The results show that it is favorable to recover the available excess heat in all the investigated energy market scenarios, and that heat driven electricity production is not a part of the optimal solution. The trade-off between use of recovered excess heat in the heating or cooling system depends on the energy market prices and the type of heat production. The introduction of excess heat reduces the CO2 emissions in the system for all the studied energy market scenarios. (C) 2014 Elsevier Ltd. All rights reserved.

    Download full text (pdf)
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  • 65.
    Brolin, Martin
    et al.
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Böhlmark, Erik
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Energikombinat: en studie inom Carpe Futurum2011Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Kraftvärme är en energieffektiv metod att producera både el och fjärrvärme men användningen av denna produktionsform begränsas av att fjärrvärmebehovet vanligtvis är lägre under den varma delen av året. På senare tid har både forskning och nybyggda anläggningar visat på synergieffekter av att samordna produktion av biodrivmedel eller förädling av trädbränslen med kraftvärmeproduktion i en så kallad energikombinatanläggning. Då Vattenfall Värme Uppsala är i behov av att ersätta sitt befintliga kraftvärmeverk utreds i denna studie möjliga ekonomiska och miljömässiga fördelar med att bygga en energikombinatanläggning. I studien utreds ett antal olika tekniker som kan tänkas ingå i energikombinatet och ett antal alternativ väljs ut för vidare analys. Alternativen jämförs sedan med ett referensalternativ bestående av enbart ett nytt biobränsleeldat kraftvärmeverk.

    Studien visar att en energikombinatanläggning bestående av ett kraftvärmeverk i kombination med tillverkning av pellets eller black pellets kan leda till ökad lönsamhet jämfört med enbart ett kraftvärmeverk. Den ökade lönsamheten uppgår till 178 MSEK/år för konventionell pellets samt 281 MSEK/år för black pelletstillverkning. Resultaten visar på ökad lönsamhet även vid ändrade förutsättningar såsom ökade investeringsbehov eller ökade råvarupriser. Den ökade lönsamheten beror dels på stor försäljning av förädlade biobränslen men också på att produktionen av dessa bränslen genererar ett ökat värmeunderlag och drifttid för kraftvärmeverket och därmed en ökad elproduktion. Exempelvis ökade elproduktionen i kraftvärmeverket för alternativet med pelletsproduktion med 117 GWh/år vilket genererar en ökad elförsäljningsintäkt motsvarande 99 MSEK/år.

    Lönsamheten för investeringarna i de olika kombinatalternativen har även bedömts med avseende på alternativens nuvärde, paybacktid samt nuvärdeskvot. Även med dessa metoder visar black pellets

    ‐ samt konventionell pelletstillverkning goda resultat varpå black pelletstillverkning anses som den lönsammaste. Alternativet visar på ett ökat nuvärde jämfört med referensalternativet på 3300 MSEK och alternativets paybacktid är endast drygt 3 år.

    Det är viktigt att poängtera att prognostiserade framtida försäljningspriser för producerad pellets respektive black pellets ligger till grund för beräkningarna då en ny anläggning förväntas tas i drift runt år 2020. Om försäljningspriserna inte utvecklas som prognostiserat utan ligger kvar på dagens nivå så ser resultaten betydligt sämre ut. Endast pelletstillverkning där biobränslet torkas med en bäddtork visar då på lönsamhetspotential.

    För att uppnå lönsamhet i detta fall bör kombinatanläggningen vara i stor skala då den måste förläggas till en ny site vilket medför en extra investering på cirka 700 MSEK. Denna investering undviks vid referensalternativet då enbart ett kraftvärmeverk byggs då detta kan uppföras på den befintliga siten. I alternativen med pellets respektive black pelletsproduktion erfordras cirka 3 TWh biobränsle/år vilket är tre gånger så mycket som för enbart ett biobränsleeldat kraftvärmeverk. Denna storskalighet i råvarutillförseln leder till stora utmaningar beträffande

    I

    logistiken kring råvarutillförseln till anläggningen och vidare studier får visa om dessa frågeställningar kan lösas.

    Tekniken för torrefieringssteget i black pelletstillverkningen är i dagsläget inte kommersiellt tillgänglig. Men en sådan anläggning i kombination med ett kraftvärmeverk kommer att byggas i Örnsköldsvik med start sommaren 2011. Då anläggningen är i drift kan slutsatser dras angående när tekniken kan bli kommersiellt tillgänglig. Vad gäller pelletstillverkningen är det osäkert om en bäddtork kan användas för att uppnå de låga fukthalter som pelleteringen kräver. Att istället använda en ångtork är kommersiellt beprövat, dock erhålls enligt studien en lägre lönsamhet än vid bäddtorkning men fortfarande högre än vid enbart kraftvärme. Vattenfall rekommenderas att noggrant följa teknikutvecklingen inom torrefiering samt utvecklingen av bäddtorkar eller andra torkningsmetoder som använder lågvärdig värme som värmekälla.

    Studien visar även att produktion av drivmedel genom förgasning av biobränsle har en potential för god lönsamhet men att det redan vid små förändringar av det antagna försäljningspriset medför försämrad lönsamhet. Dessutom bedöms det som osannolikt att tekniken finns kommersiellt tillgänglig år 2015 vilket anses nödvändigt, då den nya anläggningen bör stå klar år 2020. Alternativen att torka och lagra oförädlat biobränsle för eget bruk samt att producera syntetisk naturgas för försäljning och eget bruk analyserades i studien. Dessa alternativ visar på försämrad lönsamhet och anses därför inte som konkurrenskraftiga.

    Även produktion av etanol, biogas, biodiesel samt drivmedel genom förvätskning har studerats men har av ekonomiska, tekniska

    ‐ eller miljömässiga skäl inte kunnat ingå i en konkurrenskraftigt kombinatanläggning.

    Beträffande klimatpåverkan visar alternativet med black pelletstillverkning på störst minskning av de relativa koldioxidutsläppen per använd enhet biobränsle samt den totala utsläppsminskningen.

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  • 66.
    Broström, Tor
    et al.
    Uppsala University, Sweden .
    Eriksson, Petra
    Uppsala University, Sweden .
    Liu, Linn
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Rohdin, Patrik
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Ståhl, Fredrik
    SP Technical Research Institute of Sweden.
    Moshfegh, Bahram
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    A Method to Assess the Potential for and Consequences of Energy Retrofits in Swedish Historic Buildings2014In: The Historic Environment: Policy & Practice, ISSN 1756-7505, E-ISSN 1756-7513, Vol. 5, no 2, p. 150-166Article in journal (Refereed)
    Abstract [en]

    The Swedish research project Potential and Policies for Energy Efficiency in Swedish Historic Buildings aims to investigate the interdependency between political energy targets and effects on the built heritage. The first part of this paper presents an iterative and interactive method to assess the potential for and consequences of improving the energy performance in a stock of historic buildings. Key elements in the method are: categorisation of the building stock, identifying targets, assessment of measures, and life-cycle cost optimisation. In the second part of the paper, the method is applied to a typical Swedish building. The selected case study shows how the method allows for an interaction between the quantitative assessment of the techno-economic optimisation and the qualitative assessment of vulnerability and other risks. Through a multidisciplinary dialogue and iteration it is possible to arrive at a solution that best balances energy conservation and building conservation in a given decision context.

  • 67.
    Broström, Tor
    et al.
    Gotland University.
    Eriksson, Petra
    Gotland University.
    Rohdin, Patrik
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Ståhl, Fredrik
    A method to assess the effect of energy saving interventions in the Swedish stock of historic buildings2012In: HERITAGE 2012, Green Lines Institute, 2012Conference paper (Refereed)
  • 68.
    Brunke, Jean-Christian
    et al.
    University of Stuttgart, Germany.
    Johansson, Maria
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Thollander, Patrik
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Empirical investigation of barriers and drivers to the adoption of energy conservation measures, energy management practices and energy services in the Swedish iron and steel industry2014In: Journal of Cleaner Production, ISSN 0959-6526, E-ISSN 1879-1786, Vol. 84, p. 509-525Article in journal (Refereed)
    Abstract [en]

    The Swedish iron and steel industry is focused on the production of advanced steel grades and accounts for about 5% of the countrys final energy consumption. Energy efficiency is according to the European Commission a key element for the transition towards a resource-efficient economy. We investigated four aspects that are associated with the adoption of cost-effective energy conservation measures: barriers, drivers, energy management practices and energy services. We used questionnaires and follow-up telephone interviews to collect data from members of the Swedish steel association. The heterogeneous observations implied a classification into steel producers and downstream actors. For testing the significance, the Mann Whitney U test was used. The most important barriers were internal economic and behavioural barriers. Energy service companies, in particular third-party financing, played a minor role. In contrast, high importance was attached to energy management as the most important drivers originated from within the company. Energy management practices showed that steel companies are actively engaged in the topic, but need to raise its prioritisation and awareness within the organisation. When sound energy management practices are included, the participants assessed the cost-effective energy conservation potential to be 9.7%, which was 2.4% higher than the potential for solely adopting cost-effective technologies.

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  • 69. Buchanan, M
    et al.
    Aas, G M
    Moshfegh, Bahram
    Linköping University, The Institute of Technology. Linköping University, Department of Management and Engineering, Energy Systems.
    Enchancing efficiency in PV systems: A New Solar Cooling Module2007In: Solar Energy applications,2007, 2007Conference paper (Refereed)
  • 70.
    Carlander, Jakob
    Linköping University, Department of Management and Engineering, Energy Systems.
    Att bygga bostäder enligt miljöbyggnadskrav: En fallstudie i området Nya Wahlbecks2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

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

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  • 71.
    Carlander, Jakob
    et al.
    University of Gävle, Gävle, Sweden.
    Trygg, Kristina
    Linköping University, Department of Thematic Studies, Technology and Social Change. Linköping University, Faculty of Arts and Sciences.
    Moshfegh, Bahram
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, Faculty of Science & Engineering.
    Integration of Measurements and Time Diaries as Complementary Measures to Improve Resolution of BES2019In: Energies, ISSN 1996-1073, E-ISSN 1996-1073, Vol. 12, no 11, p. 1-29, article id 2072Article in journal (Refereed)
    Abstract [en]

    Building energy simulation (BES) models rely on a variety of different input data, and the more accurate the input data are, the more accurate the model will be in predicting energy use. The objective of this paper is to show a method for obtaining higher accuracy in building energy simulations of existing buildings by combining time diaries with data from logged measurements, and also to show that more variety is needed in template values of user input data in different kinds of buildings. The case studied in this article is a retirement home in Linköping, Sweden. Results from time diaries and interviews were combined with logged measurements of electricity, temperature, and CO2 levels to create detailed occupant behavior schedules for use in BES models. Two BES models were compared, one with highly detailed schedules of occupancy, electricity use, and airing, and one using standardized input data of occupant behavior. The largest differences between the models could be seen in energy losses due to airing and in household electricity use, where the one with standardized user input data had a higher amount of electricity use and less losses due to airing of 39% and 99%, respectively. Time diaries and interviews, together with logged measurements, can be great tools to detect behavior that affects energy use in buildings. They can also be used to create detailed schedules and behavioral models, and to help develop standardized user input data for more types of buildings. This will help improve the accuracy of BES models so the energy efficiency gap can be reduced.

    Download full text (pdf)
    fulltext
  • 72.
    Carl-Erik, Grip
    et al.
    Luleå tekniska universitet.
    Thollander, Patrik
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Söderström, Mats
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Stakeholder study on Barriers to Exergy Analysis2012In: International Conference on Applied Energy ICAE 2012, 2012Conference paper (Refereed)
  • 73.
    Carlsson, Peter
    Linköping University, Department of Management and Engineering, Energy Systems.
    Energiflöden i Motorprovceller: Kartläggning av energiflöden i motorprovceller vid Scania ABs motorproduktion i Södertälje2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Abstract

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

    Download full text (pdf)
    fulltext
  • 74.
    Carlén, Albin
    et al.
    Energimyndigheten.
    Rosenqvist, Marie
    Energimyndigheten.
    Paramonova, Svetlana
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, Faculty of Science & Engineering.
    Thollander, Patrik
    Municion, Susana
    CIT Industriell Energi AB, Gothenburg, Sweden.
    Energy effiency networks for small and medium sized enterprises: bosting the energy efficiency potential by joining forces2016In: ECEEE Industry Summer Study 2016, 2016Conference paper (Refereed)
    Abstract [en]

    Small –and medium-sized enterprises (SMEs) remain a cornerstone in individual economies. In terms of improved energy efficiency potentials, the relative potential for SMEs is larger than for energy-intensive companies. However, the level of deployment, due to various barriers such as lack of information and high transaction costs in general remains low among industrial SMEs. The most common policy activity towards industrial SMEs are energy audit policy programs. Deployment levels from the Swedish energy audit program is roughly 50 percent of the detected cost-effective energy efficiency measures, which goes in line with results from the world’s largest program, the American IAC (Industrial Assessment Center). In order to enhance deployment levels, the Swedish Energy Agency has recently started up a national energy efficiency network program for SMEs, funded by the European Regional Development Fund. The aim of this paper is to present an ex-ante evaluation of the Swedish energy efficiency networks (EENet). The paper adds value to the growing scientific literature on energy efficiency network policy evaluation in order to further enhance scientific knowledge on energy efficiency network operationalization and evaluation. Including costs for the program administration, the subsidy effectiveness varied between 1.75 and 2.03 kWh/SEK for the different analyzed scenarios. The outcome of the paper results was that the Swedish Energy Agency reduced threshold for participation in the EENet from 2 GWh/year to 1 GWh/year in annual energy use.

  • 75.
    Cehlin, M.
    et al.
    University of Gävle.
    Moshfegh, Bahram
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Numerical modeling of a complex diffuser in a room with displacement ventilation2010In: Building and Environment, ISSN 0360-1323, E-ISSN 1873-684X, Vol. 45, no 10, p. 2240-2252Article in journal (Refereed)
    Abstract [en]

    A micro/macro-level approach (MMLA) has been proposed which makes it possible for HVAC engineers to easily study the effect of diffuser characteristics and diffuser placement on thermal comfort and indoor air quality. In this article the MMLA has been used to predict the flow and thermal behavior of the air in the near-zone of a complex low-velocity diffuser. A series of experiment has been carried out to validate the numerical predictions in order to ensure that simulations can be used with confidence to predict indoor airflow. The predictions have been performed by means of steady Reynolds Stress Model (RSM) and the results have good agreement both qualitatively and quantitatively with measurements. However, measurements indicated that the diffusion of the velocity and temperature was to some extent under-predicted by the RSM, which might be related to high instability of the airflow close to the diffuser. This effect might be captured by employing unsteady RSM. The present study also shows the importance of detailed inlet supply modeling in the accuracy of indoor air prediction.

  • 76. Cehlin, M
    et al.
    Moshfegh, Bahram
    Linköping University, The Institute of Technology. Linköping University, Department of Management and Engineering, Energy Systems.
    Karlsson, Fredrik
    Linköping University, The Institute of Technology. Linköping University, Department of Management and Engineering, Energy Systems.
    Larsson, Ulf
    Högskolan i Gävle .
    Analysis on Comfort and Indoor Climate for a Hospital Building by Multizone Modeling2008In: Analysis on Comfort and Indoor Climate for a Hospital Building by Mujltizone Modeling,2008, 2008Conference paper (Refereed)
  • 77.
    Cehlin, Mattias
    et al.
    Högskolan i Gävle.
    Moshfegh, Bahram
    Linköping University, The Institute of Technology. Linköping University, Department of Management and Engineering, Energy Systems.
    Visualization of isothermal low-Reynolds circular air jet using computed tomography2005In: 6th World Conference on Experimental Heat Transfer, Fluid Mechanics, and Thermodynamics,2005, 2005Conference paper (Refereed)
  • 78. Order onlineBuy this publication >>
    Chen, Huijuan
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Experimental and numerical investigations of a ventilation strategy – impinging jet ventilation for an office environment2014Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    A well-functioning, energy-efficient ventilation system is of vital importance to offices, not only to provide the kind of comfortable, healthy indoor environment necessary for the well-being and productive work performance of occupants, but also to reduce energy use in buildings and the associated impact of CO2 emissions on the environment. To achieve these goals impinging jet ventilation has been developed as an innovative ventilation concept.

    In an impinging jet ventilation system, a high momentum of air jet is discharged downwards, strikes the floor and spreads over it, thus distributing the fresh air along the floor in the form of a very thin shear layer. This system retains advantages of mixing and stratification from conventional air distribution methods, while capable of overcoming their shortcomings.

    The aim of this thesis is to reach a thorough understanding of impinging jet ventilation for providing a good thermal environment for an office, by using Computational Fluid Dynamics (CFD) supported by detailed measurements. The full-field measurements were carried out in two test rooms located in a large enclosure giving relatively stable climate conditions. This study has been divided into three parts where the first focuses on validation of numerical investigations against measurements, the second addresses impacts of a number of design parameters on the impinging jet flow field and thermal comfort level, and the third compares ventilation performance of the impinging jet supply device with other air supply devices intended for mixing, wall confluent jets and displacement ventilation, under specific room conditions.

    In the first part, velocity and temperature distributions of the impinging jet flow field predicted by different turbulence models are compared with detailed measurements. Results from the non-isothermal validation studies show that the accuracy of the simulation results is to a great extent dependent on the complexity of the turbulence models, due to complicated flow phenomena related to jet impingement, such as recirculation, curvature and instability. The v2-f turbulence model shows the best performance with measurements, which is slightly better than the SST k-ω model but much better than the RNG k-ε model. The difference is assumed to be essentially related to the magnitude of turbulent kinetic energy predicted in the vicinity of the stagnation region. Results from the isothermal study show that both the SST k-ω and RNG k-ε models predict similar wall jet behaviours of the impinging jet flow.

    In the second part, three sets of parametric studies were carried out by using validated CFD models. The first parametric study shows that the geometry of the air supply system has the most significant impact on the flow field. The rectangular air supply device, especially the one with larger aspect ratio, provides a longer penetration distance to the room, which is suitable for industrial ventilation. The second study reveals that the interaction effect of cooling ceiling, heat sources and impinging jet ventilation results in complex flow phenomena but with a notable feature of air circulation, which consequently decreases thermal stratification in the room and increases draught discomfort at the foot level. The third study demonstrates the advantage of using response surface methodology to study simultaneous effects on changes in four parameters, i.e. shape of air supply device, jet discharge height, supply airflow rate and supply air temperature. Analysis of the flow field reveals that at a low discharge height, the shape of air supply device has a major impact on the flow pattern in the vicinity of the supply device. Correlations between the studied parameters and local thermal discomfort indices were derived. Supply airflow rates and temperatures are shown to be the most important parameter for draught and stratification discomfort, respectively.

    In the third part, the impinging jet supply device was shown to provide a better overall performance than other air supply devices used for mixing, wall confluent jets and displacement ventilation, with respect to thermal comfort, heat removal effectiveness, air exchange efficiency and energy-saving potential related to fan power.

    List of papers
    1. Numerical investigation of the flow behavior of an isothermal impinging jet in a room
    Open this publication in new window or tab >>Numerical investigation of the flow behavior of an isothermal impinging jet in a room
    2012 (English)In: Building and Environment, ISSN 0360-1323, E-ISSN 1873-684X, Vol. 49, p. 154-166Article in journal (Refereed) Published
    Abstract [en]

    The impinging jet concept has been proposed as a new ventilation strategy for use in office and industrial buildings. The present paper reports the mean flow field behavior of an isothermal turbulent impinging jet in a room. The detailed experimental study is carried out to validate the numerical simulations, and the predictions are performed by means of the RNG k-ε and SST k-ω model. The comparisons between the predictive results and the experimental data reveal that both of the tested turbulence models are capable of capturing the main qualitative flow features satisfactorily. It is found that the predictions from the RNG k-ε model predicts slightly better of the maximum velocity decay as jet approaching the floor, while the SST k-ω model accords slightly better in the region close to the impingement zone.

    Another important perspective of this study is to investigate the influence of different flow and configuration parameters such as jet discharge height, diffuser geometry, supply airflow rate and confinement from the surrounding environment on the impinging jet flow field with the validated model. The obtained data are presented in terms of the jet dimensionless velocity distribution, maximum velocity decay and spreading rate along the centerline of the floor. The comparative results demonstrate that all the investigated parameters have certain effects on the studied flow features, and the diffuser geometry is found to have the most appreciable impact, while the supply airflow rate is found to have marginal influence within the moderate flow range. 

    Place, publisher, year, edition, pages
    Elsevier, 2012
    Keywords
    Impinging jet ventilation, Measurement, Numerical simulation, Parametric study
    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:liu:diva-71471 (URN)10.1016/j.buildenv.2011.09.027 (DOI)000298200600016 ()
    Note
    Funding agencies|KK Foundation||Fresh Air AB||Formas||Ny Kraft Sverige AB||University of Gavle||Linkoping University||Available from: 2011-10-19 Created: 2011-10-19 Last updated: 2017-12-08
    2. Comparing k-ε Models On Predictions Of An Impinging Jet For Ventilation Of An Office Room
    Open this publication in new window or tab >>Comparing k-ε Models On Predictions Of An Impinging Jet For Ventilation Of An Office Room
    2011 (English)In: Proceedings of Roomvent 2011, 11th International Conference on Air Distribution in Rooms 19 - 22 June 2011 Torendheim, Norway, 2011Conference paper, Published paper (Refereed)
    Abstract [en]

    The objective of this study is to compare the performance of different k-ε models, i.e. the Standard k-ε, the Renormalization Group (RNG) k-ε, and the Realizable k-ε, with a two-layer model for the prediction of the mean velocity field and the temperature pattern from a newly designed impinging jet supply device for ventilation of an office room. The numerical predictions are validated against the detailed experimental measurements. The experimental investigation was performed in a test room with the dimensions 4.2×3.6×2.5 m, as a mock-up of a single-person office. Detailed velocity and temperature field measurements including the comfort zone and the jet developing region along the floor were carried out. The in-house made single-sensor hot-wire probe and the thermocouple are measuring instruments used to investigate the mean velocity, turbulence intensity and temperature. The boundary conditions for Computational Fluid Dynamics (CFD) study are obtained from the same set-up measurement. The results mainly consist of the flow field presentation, i.e., the velocity and temperature profiles in the comfort zone and the jet developing region along the floor. The comparisons between the results from the three versions of the k-ε models and measurements show generally satisfactory agreement, and better consistency is observed at the free jet region and the wall jet region that farther from the impingement zone. Among the three tested turbulence models, RNG shows the best overall performance.

    Keywords
    CFD, Impinging jet ventilation, Turbulence model, Wall jet, Measurement
    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:liu:diva-71470 (URN)
    Conference
    11th International Conference on Air Distribution in Rooms 19 - 22 June 2011 Torendheim, Norway
    Available from: 2011-10-19 Created: 2011-10-19 Last updated: 2014-05-19
    3. Investigation on the flow and thermal behavior of impinging jet ventilation systems in an office with different heat loads
    Open this publication in new window or tab >>Investigation on the flow and thermal behavior of impinging jet ventilation systems in an office with different heat loads
    2013 (English)In: Building and Environment, ISSN 0360-1323, E-ISSN 1873-684X, Vol. 59, p. 127-144Article in journal (Refereed) Published
    Abstract [en]

    This paper presents the flow and temperature field within an office using impinging jet ventilation (IJV) under different heat loads ranging from 17 to 65 W per square meter floor area. The measurement was carried out in a full-scale test room to verify the reliability of three turbulence models, i.e., the RNG k-epsilon, SST k-omega and (nu(2)) over bar - f models. It is found that all the tested models show good agreements with measurements, while the (nu(2)) over bar - f model shows the best performance, especially on the overall temperature prediction. less thanbrgreater than less thanbrgreater thanThe (nu(2)) over bar - f model is used further to investigate a number of important factors influencing the performance of the IJV. The considered parameters are: cooling effect of chilled ceiling, external heat load as well as its position, number of occupants and supplied air conditions. The interaction effect of chilled ceiling and heat sources results in a complex flow phenomenon but with a notable feature of air circulation. The appearance and strength of the air circulation mainly depends on the external heat load on window and number of occupants. It is found that with higher external heat load on window (384 W and 526 W), the air circulation has a strong tendency towards the side wall in the opposite direction to occupant, while with lower power on window (200 W) the air circulation has a strong tendency in the center of the room and extends to a larger area. When two occupants are present, two swirling zones are formed in the upper region. The effects of air circulation consequently alter the temperature field and the level of local thermal comfort.

    Place, publisher, year, edition, pages
    Elsevier, 2013
    Keywords
    Impinging jet ventilation, Chilled ceiling, Heat sources, Air movement, Turbulence models, Measurement
    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:liu:diva-89812 (URN)10.1016/j.buildenv.2012.08.014 (DOI)000314371900014 ()
    Note

    Funding Agencies|KM Foundation|2007/0289|Formas|242-2008-835|Fresh Air AB||Kraft and Kultur AB||University of Gavle|7216-7438-181-81|Linkoping University||

    Available from: 2013-03-07 Created: 2013-03-07 Last updated: 2017-12-06Bibliographically approved
    4. Computational investigation on the factors influencing thermal comfort for impinging jet ventilation
    Open this publication in new window or tab >>Computational investigation on the factors influencing thermal comfort for impinging jet ventilation
    2013 (English)In: Building and Environment, ISSN 0360-1323, E-ISSN 1873-684X, Vol. 66, p. 29-41Article in journal (Refereed) Published
    Abstract [en]

    Impinging jet ventilation (IJV) has been proposed to achieve an effective ventilation of an occupied zone in office and industrial buildings. For IJV systems, draught discomfort is the issue of most concern since it supplies cooled air directly to the occupied zone. This study investigated a number of factors influencing draught discomfort and temperature stratification in an office environment equipped with IJV. The factors considered were: shape of air supply device, discharge height, supply airflow rate and supply air temperature. The Response Surface Methodology (RSM) was used to identify the level of the significance of the parameters studied, as well as to develop the predictive models for the local thermal discomfort. Computational fluid dynamics (CFD) was employed to perform a set of required studies, and each simulation condition was determined by the Box – Behnken design (BBD) method. The results indicated that at a low discharge height, the shape of air supply device had a major impact on the flow pattern in the vicinity of the supply device because of the footprint from impinging jet, which consequently affected the draught risk level in the occupied zone. A square-shaped air supply device was found to result in lower overall draught discomfort than rectangular and semi-elliptic shapes. The RSM analysis revealed that the supply airflow rate had a significant impact on the draught discomfort, while the shape of air supply device and discharge height had moderate effects. The temperature stratification in the occupied zone was mostly influenced by the supply air temperature within the range studied.

    Place, publisher, year, edition, pages
    Elsevier, 2013
    Keywords
    Computational fluid dynamics (CFD), Response Surface Methodology (RSM), Draught discomfort, Temperature stratification, Impinging jet ventilation
    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:liu:diva-92744 (URN)10.1016/j.buildenv.2013.04.018 (DOI)000321423500004 ()
    Available from: 2013-05-20 Created: 2013-05-20 Last updated: 2017-12-06
    5. Comparisons of ventilation performance of different air supply devicesin in an office environment
    Open this publication in new window or tab >>Comparisons of ventilation performance of different air supply devicesin in an office environment
    (English)Manuscript (preprint) (Other academic)
    Abstract [en]

    The aim of this study was to compare ventilation performance of four different air supply devices in an office environment with respect to thermal comfort, ventilation efficiency and energy-saving potential, by performing numerical simulations. The devices have the acronyms: Mixing supply device (MSD), Wall confluent jets supply device (WCJSD), Impinging jet supply device (IJSD) and Displacement supply device (DSD). Comparisons were made under identical set-up conditions, as well as at the same occupied zone temperature of about 24.2°C achieved by adding different heat loads and using different air-flow rates. Energy-saving potential was addressed based on the air-flow rate and the related fan power required for obtaining a similar occupied zone temperature for each device.

     

    Results showed that the IJSD could provide an acceptable thermal environment while removing excess heat more efficiently than the MSD, as it combined the positive effects of both mixing and stratification principles. This benefit also meant that this device required less fan power than the MSD for obtaining equivalent occupant zone temperature. The WCJSD studied in this paper behaved somewhat like the MSD, but caused higher draught discomfort at ankle level because of very high supply velocities, which was might due to small nozzle diameter of the supply device. Further studies are required for the WCJSD to make these conclusions applicable for general conditions. The DSD showed a superior performance on heat removal, air exchange efficiency and energy saving to all other devices, but it had difficulties in providing acceptable vertical temperature gradient between the ankle and head levels for a standing person.

    Keywords
    Ventilation performance, air supply devices, thermal comfort, energy-saving
    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:liu:diva-106491 (URN)
    Available from: 2014-05-09 Created: 2014-05-09 Last updated: 2014-05-15
    Download full text (pdf)
    Experimental and numerical investigations of a ventilation strategy – impinging jet ventilation for an office environment
    Download (pdf)
    cover
  • 79.
    Chen, Huijuan
    et al.
    Linköping University, Department of Management and Engineering, Energy Systems.
    Janbakhsh, Setareh
    Linköping University, Department of Management and Engineering, Energy Systems.
    Larsson, Ulf
    university of Gavle.
    Moshfegh, Bahram
    Linköping University, Department of Management and Engineering, Energy Systems.
    Comparisons of ventilation performance of different air supply devicesin in an office environmentManuscript (preprint) (Other academic)
    Abstract [en]

    The aim of this study was to compare ventilation performance of four different air supply devices in an office environment with respect to thermal comfort, ventilation efficiency and energy-saving potential, by performing numerical simulations. The devices have the acronyms: Mixing supply device (MSD), Wall confluent jets supply device (WCJSD), Impinging jet supply device (IJSD) and Displacement supply device (DSD). Comparisons were made under identical set-up conditions, as well as at the same occupied zone temperature of about 24.2°C achieved by adding different heat loads and using different air-flow rates. Energy-saving potential was addressed based on the air-flow rate and the related fan power required for obtaining a similar occupied zone temperature for each device.

     

    Results showed that the IJSD could provide an acceptable thermal environment while removing excess heat more efficiently than the MSD, as it combined the positive effects of both mixing and stratification principles. This benefit also meant that this device required less fan power than the MSD for obtaining equivalent occupant zone temperature. The WCJSD studied in this paper behaved somewhat like the MSD, but caused higher draught discomfort at ankle level because of very high supply velocities, which was might due to small nozzle diameter of the supply device. Further studies are required for the WCJSD to make these conclusions applicable for general conditions. The DSD showed a superior performance on heat removal, air exchange efficiency and energy saving to all other devices, but it had difficulties in providing acceptable vertical temperature gradient between the ankle and head levels for a standing person.

  • 80.
    Chen, Huijuan
    et al.
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology. Department of Building, Energy and Environmental Engineering, University of Gävle, Sweden.
    Janbakhsh, Setareh
    Linköping University, Department of Management and Engineering. Linköping University, The Institute of Technology. Department of Building, Energy and Environmental Engineering, University of Gävle, Sweden.
    Larsson, Ulf
    Department of Building, Energy and Environmental Engineering, University of Gävle, Sweden.
    Moshfegh, Bahram
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology. Department of Building, Energy and Environmental Engineering, University of Gävle, Sweden.
    Numerical investigation of ventilation performance of different air supply devices in an office environment2015In: Building and Environment, ISSN 0360-1323, E-ISSN 1873-684X, Vol. 90, p. 37-50Article in journal (Refereed)
    Abstract [en]

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

  • 81.
    Chen, Huijuan
    et al.
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Moshfegh, Bahram
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Comparing k-ε Models On Predictions Of An Impinging Jet For Ventilation Of An Office Room2011In: Proceedings of Roomvent 2011, 11th International Conference on Air Distribution in Rooms 19 - 22 June 2011 Torendheim, Norway, 2011Conference paper (Refereed)
    Abstract [en]

    The objective of this study is to compare the performance of different k-ε models, i.e. the Standard k-ε, the Renormalization Group (RNG) k-ε, and the Realizable k-ε, with a two-layer model for the prediction of the mean velocity field and the temperature pattern from a newly designed impinging jet supply device for ventilation of an office room. The numerical predictions are validated against the detailed experimental measurements. The experimental investigation was performed in a test room with the dimensions 4.2×3.6×2.5 m, as a mock-up of a single-person office. Detailed velocity and temperature field measurements including the comfort zone and the jet developing region along the floor were carried out. The in-house made single-sensor hot-wire probe and the thermocouple are measuring instruments used to investigate the mean velocity, turbulence intensity and temperature. The boundary conditions for Computational Fluid Dynamics (CFD) study are obtained from the same set-up measurement. The results mainly consist of the flow field presentation, i.e., the velocity and temperature profiles in the comfort zone and the jet developing region along the floor. The comparisons between the results from the three versions of the k-ε models and measurements show generally satisfactory agreement, and better consistency is observed at the free jet region and the wall jet region that farther from the impingement zone. Among the three tested turbulence models, RNG shows the best overall performance.

  • 82.
    Chen, Huijuan
    et al.
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Moshfegh, Bahram
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Cehlin, Mathias
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Computational investigation on the factors influencing thermal comfort for impinging jet ventilation2013In: Building and Environment, ISSN 0360-1323, E-ISSN 1873-684X, Vol. 66, p. 29-41Article in journal (Refereed)
    Abstract [en]

    Impinging jet ventilation (IJV) has been proposed to achieve an effective ventilation of an occupied zone in office and industrial buildings. For IJV systems, draught discomfort is the issue of most concern since it supplies cooled air directly to the occupied zone. This study investigated a number of factors influencing draught discomfort and temperature stratification in an office environment equipped with IJV. The factors considered were: shape of air supply device, discharge height, supply airflow rate and supply air temperature. The Response Surface Methodology (RSM) was used to identify the level of the significance of the parameters studied, as well as to develop the predictive models for the local thermal discomfort. Computational fluid dynamics (CFD) was employed to perform a set of required studies, and each simulation condition was determined by the Box – Behnken design (BBD) method. The results indicated that at a low discharge height, the shape of air supply device had a major impact on the flow pattern in the vicinity of the supply device because of the footprint from impinging jet, which consequently affected the draught risk level in the occupied zone. A square-shaped air supply device was found to result in lower overall draught discomfort than rectangular and semi-elliptic shapes. The RSM analysis revealed that the supply airflow rate had a significant impact on the draught discomfort, while the shape of air supply device and discharge height had moderate effects. The temperature stratification in the occupied zone was mostly influenced by the supply air temperature within the range studied.

  • 83.
    Chen, Huijuan
    et al.
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Moshfegh, Bahram
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Cehlin, Mathias
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Numerical investigation of the flow behavior of an isothermal impinging jet in a room2012In: Building and Environment, ISSN 0360-1323, E-ISSN 1873-684X, Vol. 49, p. 154-166Article in journal (Refereed)
    Abstract [en]

    The impinging jet concept has been proposed as a new ventilation strategy for use in office and industrial buildings. The present paper reports the mean flow field behavior of an isothermal turbulent impinging jet in a room. The detailed experimental study is carried out to validate the numerical simulations, and the predictions are performed by means of the RNG k-ε and SST k-ω model. The comparisons between the predictive results and the experimental data reveal that both of the tested turbulence models are capable of capturing the main qualitative flow features satisfactorily. It is found that the predictions from the RNG k-ε model predicts slightly better of the maximum velocity decay as jet approaching the floor, while the SST k-ω model accords slightly better in the region close to the impingement zone.

    Another important perspective of this study is to investigate the influence of different flow and configuration parameters such as jet discharge height, diffuser geometry, supply airflow rate and confinement from the surrounding environment on the impinging jet flow field with the validated model. The obtained data are presented in terms of the jet dimensionless velocity distribution, maximum velocity decay and spreading rate along the centerline of the floor. The comparative results demonstrate that all the investigated parameters have certain effects on the studied flow features, and the diffuser geometry is found to have the most appreciable impact, while the supply airflow rate is found to have marginal influence within the moderate flow range. 

  • 84.
    Chen, Huijuan
    et al.
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology. Department of Building, Energy and Environmental Engineering, Faculty of Engineering and Sustainable Development, University of Gävle, Gävle, Sweden.
    Moshfegh, Bahram
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology. Department of Building, Energy and Environmental Engineering, Faculty of Engineering and Sustainable Development, University of Gävle, Gävle, Sweden.
    Cehlin, Mattias
    Department of Building, Energy and Environmental Engineering, Faculty of Engineering and Sustainable Development, University of Gävle, Gävle, Sweden.
    Investigation on the flow and thermal behavior of impinging jet ventilation systems in an office with different heat loads2013In: Building and Environment, ISSN 0360-1323, E-ISSN 1873-684X, Vol. 59, p. 127-144Article in journal (Refereed)
    Abstract [en]

    This paper presents the flow and temperature field within an office using impinging jet ventilation (IJV) under different heat loads ranging from 17 to 65 W per square meter floor area. The measurement was carried out in a full-scale test room to verify the reliability of three turbulence models, i.e., the RNG k-epsilon, SST k-omega and (nu(2)) over bar - f models. It is found that all the tested models show good agreements with measurements, while the (nu(2)) over bar - f model shows the best performance, especially on the overall temperature prediction. less thanbrgreater than less thanbrgreater thanThe (nu(2)) over bar - f model is used further to investigate a number of important factors influencing the performance of the IJV. The considered parameters are: cooling effect of chilled ceiling, external heat load as well as its position, number of occupants and supplied air conditions. The interaction effect of chilled ceiling and heat sources results in a complex flow phenomenon but with a notable feature of air circulation. The appearance and strength of the air circulation mainly depends on the external heat load on window and number of occupants. It is found that with higher external heat load on window (384 W and 526 W), the air circulation has a strong tendency towards the side wall in the opposite direction to occupant, while with lower power on window (200 W) the air circulation has a strong tendency in the center of the room and extends to a larger area. When two occupants are present, two swirling zones are formed in the upper region. The effects of air circulation consequently alter the temperature field and the level of local thermal comfort.

  • 85.
    Dahl, Elin
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Energy companies becoming energy service providers: A comparative study between Denmark and Sweden2012Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

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

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

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

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

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

    Download full text (pdf)
    Energy companies becoming energy service providers - Master thesis, 2012 - Elin Dahl
  • 86. Order onlineBuy this publication >>
    Danestig, Maria
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Efficient heat supply and use from an energy-system and climate perspective2009Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The aim of this thesis is to illustrate whether the heat demand in district heating systems can be seen as a resource that enables efficient energy utilization, how this can be achieved and to discuss consequences of this assumption. Based on the answers to posed research questions and on the studies included in this thesis, it is concluded that the hypothesis “A common system approach for energy supply and heat demand will show climate and economic efficient solutions” is true.

    In cold-climate countries, energy for heating of buildings is essential and heating options that interplay with the power system through electricity use or generation have potential for efficiency improvements. In Sweden, district heating is used extensively, especially in large buildings but to a growing extent also for small houses. Some industrial heat loads and absorption cooling can complement space heating demand so that the production resources may be more evenly utilised during the seasons of the year.

    Rising electricity prices in recent years cause problems for the extensive use of electric heating in Sweden and further switching to district heating should be a possible option. To be economically favourable, district-heating systems require a certain heat load density. New low-energy houses and energy-efficiency measures in existing buildings decrease the heat demand in buildings and, thus, in district heating systems. Optimisation models have been used in several studies of large, complex energy systems. Such models allow scenarios with changing policy instruments and changed consumer behaviour to be analysed. Energy efficiency measures as well as good conditions for efficient electricity generation, which can replace old, inefficient plants, are needed to reduce carbon dioxide emissions from the energy sector.

    Results when having a European energy perspective to studies of changes in Sweden differ from when having for example a Swedish energy system perspective The effects on global carbon dioxide emissions, when studying combined heat and power electricity generation in Sweden, are greater than it is on local emissions.

    List of papers
    1. Stockholm CHP potential: opportunity for CO2 reductions?
    Open this publication in new window or tab >>Stockholm CHP potential: opportunity for CO2 reductions?
    2007 (English)In: Energy Policy, ISSN 0301-4215, E-ISSN 1873-6777, Vol. 35, no 9, p. 4650-4660 Article in journal (Refereed) Published
    Abstract [en]

    The potential for combined heat and power (CHP) generation in Stockholm is large and a total heat demand of about 10 TWh/year can be met in a renewed large district heating system. This model of the Stockholm district heating system shows that CHP generation can increase from 8% in 2004 to 15.5% of the total electricity generation in Sweden. Increased electricity costs in recent years have awakened an interest to invest in new electricity generation. Since renewable alternatives are favoured by green certificates, bio-fuelled CHP is most profitable at low electricity prices. Since heat demand in the district heating network sets the limit for possible electricity generation, a CHP alternative with a high electricity to heat ratio will be more profitable at when electricity prices are high. The efficient energy use in CHP has the potential to contribute to reductions in carbon dioxide emissions in Europe, when they are required and the European electricity market is working perfectly. The potential in Stockholm exceeds Sweden's undertakings under the Kyoto protocol and national reduction goals.

    Place, publisher, year, edition, pages
    Elsevier, 2007
    Keywords
    District heating, CHP, CO2
    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:liu:diva-17211 (URN)10.1016/j.enpol.2007.03.024 (DOI)
    Available from: 2009-03-11 Created: 2009-03-11 Last updated: 2017-12-13Bibliographically approved
    2. Energy policies for increased industrial energy efficiency: Evaluation of a local energy programme for manufacturing SMEs
    Open this publication in new window or tab >>Energy policies for increased industrial energy efficiency: Evaluation of a local energy programme for manufacturing SMEs
    2007 (English)In: Energy Policy, ISSN 0301-4215, E-ISSN 1873-6777, Vol. 35, no 11, p. 5774-5783 Article in journal (Refereed) Published
    Abstract [en]

    The most extensive action targeting the adoption of energy efficiency measures in small- and medium-sized manufacturing industries in Sweden over the past 15 years was project Highland. This paper presents an evaluation of the first part of this local industrial energy programme, which shows an adoption rate of more than 40% when both measures that have already been implemented and measures that are planned to be implemented are included. A comparison between this programme and another major ongoing programme for the Swedish energy-intensive industry indicates that the approach used in project Highland aimed at small- and medium-sized industries is an effective way to increase energy efficiency in the Swedish industry. The major barriers to energy efficiency among the firms were related to the low priority of the energy efficiency issue.

    Place, publisher, year, edition, pages
    Elsevier, 2007
    Keywords
    Energy efficiency, Energy audits, Industrial energy programmes
    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:liu:diva-12512 (URN)10.1016/j.enpol.2007.06.013 (DOI)
    Note
    Original publication: Patrik Thollander, Maria Danestig and Patrik Rohdin, Energy policies for increased industrial energy efficiency - Evaluation of a local energy programme for manufacturing SMEs, 2007, Energy Policy, (35), 11, 5774-5783. http://dx.doi.org/10.1016/j.enpol.2007.06.013. Copyright: Elsevier B.V., http://www.elsevier.com/Available from: 2008-09-30 Created: 2008-09-10 Last updated: 2017-12-12Bibliographically approved
    3. Increased use of district heating in industrial processes - Impacts on heat load duration
    Open this publication in new window or tab >>Increased use of district heating in industrial processes - Impacts on heat load duration
    2009 (English)In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 86, no 11, p. 2327-2334Article in journal (Refereed) Published
    Abstract [en]

    Current knowledge of the potential for an increased use of industrial district heating (DH) due to conversions of industrial processes to DH is limited. In this paper, a Method for Heat Load Analysis (MeHLA) for exploring industrial DH conversions has been developed. This method can be a helpful tool for analyzing the impact different industrial processes have on the local DH system, when processes that utilize electricity and other fuels, convert to utilizing DH instead. Heat loads for different types of industries and processes are analyzed according to characteristics such as temperature levels and time dependency. MeHLA has been used to analyze 34 Swedish industries and the method demonstrates how conversion of industrial processes to DH can result in heat load duration curves that are less outdoor temperature-dependent and more evenly distributed over the year. An evenly distributed heat load curve can result in increased annual operating time for base load DH plants such as cogeneration plants, leading to increased electricity generation. In addition to the positive effects for the DH load duration curve, the conversions to DH can also lead to an 11% reduction in the use of electricity, a 40% reduction in the use of fossil fuels and a total energy end-use saving of 6% in the industries. Converting the industrial processes to DH will also lead to a potential reduction of the global carbon dioxide emissions by 112,000 tonnes per year.

    Keywords
    District heating, heat load duration curve, industrial heat load, global CO2
    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:liu:diva-17212 (URN)10.1016/j.apenergy.2009.03.011 (DOI)
    Available from: 2009-03-11 Created: 2009-03-11 Last updated: 2017-12-13Bibliographically approved
    4. Increased system benefit from cogeneration due to cooperation between district heating utility and industry
    Open this publication in new window or tab >>Increased system benefit from cogeneration due to cooperation between district heating utility and industry
    2004 (English)In: Proceedings of the 9th international symposium on district heating and cooling, Espoo, Finland, 30-31 August., 2004, p. 97-104Conference paper, Published paper (Refereed)
    Abstract [en]

    District heating and steam supply in the town Örnsköldsvik in northern Sweden is in focus for this study. Low temperature waste heat from pulp manufacturing in the Domsjö mill is now utilised for district heating production in heat pumps, which dominate district heating supply. Based on this traditional cooperation between the local district heating utility and the pulp industry, the parties discuss a partial outsourcing of the industrial steam supply to the utility, which may enable beneficial system solutions for both actors. The local utility must find a new location for a heating plant because a railway line is being built at the heat pump site. Planning for a new combined heat and power production (CHP) plant has started but its location is uncertain. If the plant can be situated close to the mill it can, besides district heating, produce steam, which can be supplied to adjacent industries. The municipality and its local utility are also considering investing in a waste incineration plant. But is waste incineration suitable for Örnsköldsvik and how would it interact with cogeneration?

    Alternative cases have been evaluated with the MODEST energy system optimisation model, which minimises the cost for satisfying district heating and steam demand. The most profitable solution is to invest in a CHP plant and a waste incineration plant. Considering carbon dioxide emissions, the results from applying a local or a global perspective are remarkably different. In the latter case, generated electricity is assumed to replace power from coal condensing plants elsewhere in the North-European power grid. Therefore, minimum global CO2 emissions are achieved through maximal electricity production in a CHP plant. From this viewpoint, waste incineration should not be introduced because it would obstruct cogeneration. The study is carried out within the program Sustainable municipality run by the Swedish Energy Agency.

    Keywords
    District heating, cogeneration, optimisation, waste incineration, industrial steam supply
    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:liu:diva-17213 (URN)TKK-ENY--20 (Local ID)TKK-ENY--20 (Archive number)TKK-ENY--20 (OAI)
    Available from: 2009-03-11 Created: 2009-03-11 Last updated: 2009-05-08Bibliographically approved
    5. Modelling the impact of policy instruments on district heating operations: experiences from Sweden
    Open this publication in new window or tab >>Modelling the impact of policy instruments on district heating operations: experiences from Sweden
    2006 (English)In: 10th International Symposium on District Heating and Cooling, Hanover, Germany, 2006Conference paper, Published paper (Refereed)
    Abstract [en]

    Emission allowances aim at reducing carbon dioxide emissions in the European Union. Feed-in tariffs and green certificates increase renewable electricity generation in some countries. Undesired energy carriers, such as fossil fuels, can be taxed to decrease consumption. In Sweden, monetary policy instruments have been used for many years, which has influenced district-heating utilities’ operations and investments.

    The energy system optimisation model MODEST may help elucidating the impact of policy instruments on choices of fuels and plants. The model can minimise operation and investment costs for satisfying district heating demand, considering revenues from electricity sales and waste reception. It has been used to analyse heat and electricity production for 50 local Swedish utilities. This paper shows how some plants, systems and policy instruments have been modelled and results from some case studies. It may help analysts who face policy instruments, which probably will have a growing influence on district heating operations.

    Policy instruments should reflect external costs and induce behaviour that is beneficial from an overall viewpoint. Swedish fossil-fuel taxes hampered cogeneration during many years. Earlier, fuel input could be freely allocated to output energy forms and wood was often used for heat production and coal for electricity generation to minimise taxes. Now, lower taxes promote fossil cogeneration but green certificates make it more profitable to invest in renewable electricity generation.

    Carbon dioxide emission allowances can reduce local emissions due to districtheating and electricity production significantly at current price levels but the impact depends on allowance price. With emission trading, investment in a natural-gas-fired cogeneration plant may be beneficial for some utilities due to high electricity prices in the European electricity market, partly caused by emission allowances.

    District-heating demand can enable utilisation of resources that otherwise would be of no value. A landfill ban now increases waste incineration, which may reduce industrial waste heat utilisation and heat disposal from cogeneration plants and thereby decrease electricity production. A tax on incinerated waste may reduce the profitability of investing in waste incineration.

    Keywords
    Energy policy, taxes, green certificates, emission allowances, CHP
    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:liu:diva-14204 (URN)
    Available from: 2007-01-04 Created: 2007-01-04 Last updated: 2009-05-18Bibliographically approved
    6. Local development possibilities for sustainable energy supply and use in Sweden
    Open this publication in new window or tab >>Local development possibilities for sustainable energy supply and use in Sweden
    2007 (English)In: In B. Frostell, Å. Danielsson, L. Hagberg, B.-O. Linnér, E. Lisberg Jensen (eds., Science for Sustainable Development - The Social Challenge with emphasis on conditions for change, Proceedings from the 2nd VHU Conference, Linköping 6-7 September, Uppsala: VHU, 2007Conference paper, Published paper (Other academic)
    Abstract [en]

    Large structural changes are necessary to reduce the resource use in industrialised countries to a sustainable level. Modifications of municipalities’ normal operations can contribute to a more ecologically, economically and socially sustainable society through, for example, promotion of measures concerning energy conservation and renewable energy supply. In the Swedish Energy Agency’s Sustainable municipality programme, it is developed how spatial plans of ground use and building development can promote local renewable energy sources and efficient energy utilisation. Energy issues can be integrated in spatial planning through scenarios of future energy supply and use, which are discussed by local stakeholders. It can be shown how wall insulation, solar heating and heat recovery can reduce primary energy demand and that switching from electricity to biofuel can reduce CO2 emissions. The indicator heat load density depends on building structure and shows, for instance, preconditions for district heating, which often is a favourable heating option. If the local energy utility is involved in spatial planning, it may facilitate the introduction of temporary solutions, such as pellets boilers, to make more customers chose district heating in areas where the network is delayed. District heating systems enable efficient electricity generation in combined heat and power (CHP) plants, which can be elucidated by an optimisation model that considers economy and environment. Strategic spatial planning can promote establishment and expansion of district heating networks.

    Keywords
    District heating, energy conservation, heat load density, municipality, renewable
    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:liu:diva-17216 (URN)
    Available from: 2009-03-11 Created: 2009-03-11 Last updated: 2009-03-11Bibliographically approved
    7. Efficient heat resource utilisation in energy systems
    Open this publication in new window or tab >>Efficient heat resource utilisation in energy systems
    2008 (English)In: Energy in Europe: Economics, Policy and Strategy, Filip Magnusson and Oscar W. Bengtsson (eds.) / [ed] Oscar W. Bengtsson,Filip L. Magnusson, Nova Publishers , 2008, 1, p. 315-359Chapter in book (Other academic)
    Abstract [en]

    Energy constitutes the motive force of the civilisation and it determines, in a high degree, the level of economy development as a whole. Despite the increase use of different type of energy, particularly, renewable energy sources, fossil fuels will continue dominating the energy combinations in the world near future. However, oil reserves are declining and this situation would have a negative impact in the future economic development of many countries all over the world. In Europe, the import energy dependency is rising. Unless Europe can make domestic energy more competitive in the next 20 to 30 years, around 70% of the European Unions energy requirements, compared to 50% today, will be met by imported products some of them from regions threatened by insecurity. Now, the energy requirements of the different countries are so high that, for the first time in the humanity's history, there is a need to consider different types of available energy sources and their reserves to plan the economic development of the countries. At the same time, there is also a need to use these sources in the most efficient possible manner in order to sustain that development. The EU leads the world in demand management, in promoting new and renewable forms of energy. If the EU backs up a new common policy with a common voice on energy questions, Europe can lead the global search for energy solutions. However, EU must act urgently because it takes many years to bring innovation on stream in the energy sector, as well as to make productive the investments that are need to update the energy infrastructure in the region. This book provides leading-edge research on this field of study from around the globe.

    Place, publisher, year, edition, pages
    Nova Publishers, 2008 Edition: 1
    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:liu:diva-17217 (URN)978-1-60456-829-5 (ISBN)1-604-5682-9-1 (ISBN)
    Available from: 2009-03-11 Created: 2009-03-11 Last updated: 2013-05-24Bibliographically approved
    8. A multidisciplinary and interactive method for exploring energy systems in municipalities
    Open this publication in new window or tab >>A multidisciplinary and interactive method for exploring energy systems in municipalities
    2009 (English)Article in journal (Other academic) Submitted
    Abstract [en]

    Due to environmental concerns and changed market conditions in the energy system, the preconditions for energy use and production in Sweden have changed in recent years. To be able to manage these new demands on a local level, municipalities need to adopt new methods to deal with unstructured and complex situations. This article presents a method for multidisciplinary and interactive exploration of energy systems at the local level. The method creates opportunities for local actors to discuss and negotiate the necessary actions within the local energy system.

    Keywords
    Energy, local, multidisciplinary, interactive, method
    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:liu:diva-17218 (URN)
    Available from: 2009-03-11 Created: 2009-03-11 Last updated: 2009-03-11Bibliographically approved
    Download full text (pdf)
    Efficient heat supply and use from an energy-system and climate perspective
    Download (pdf)
    Cover
  • 87.
    Danestig, Maria
    et al.
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Gebremedhin, Alemayehu
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Karlsson, Björn
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Stockholm CHP potential: opportunity for CO2 reductions?2007In: Energy Policy, ISSN 0301-4215, E-ISSN 1873-6777, Vol. 35, no 9, p. 4650-4660 Article in journal (Refereed)
    Abstract [en]

    The potential for combined heat and power (CHP) generation in Stockholm is large and a total heat demand of about 10 TWh/year can be met in a renewed large district heating system. This model of the Stockholm district heating system shows that CHP generation can increase from 8% in 2004 to 15.5% of the total electricity generation in Sweden. Increased electricity costs in recent years have awakened an interest to invest in new electricity generation. Since renewable alternatives are favoured by green certificates, bio-fuelled CHP is most profitable at low electricity prices. Since heat demand in the district heating network sets the limit for possible electricity generation, a CHP alternative with a high electricity to heat ratio will be more profitable at when electricity prices are high. The efficient energy use in CHP has the potential to contribute to reductions in carbon dioxide emissions in Europe, when they are required and the European electricity market is working perfectly. The potential in Stockholm exceeds Sweden's undertakings under the Kyoto protocol and national reduction goals.

  • 88.
    Danestig, Maria
    et al.
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Henning, Dag
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Efficient heat resource utilisation in energy systems2008In: Energy in Europe: Economics, Policy and Strategy, Filip Magnusson and Oscar W. Bengtsson (eds.) / [ed] Oscar W. Bengtsson,Filip L. Magnusson, Nova Publishers , 2008, 1, p. 315-359Chapter in book (Other academic)
    Abstract [en]

    Energy constitutes the motive force of the civilisation and it determines, in a high degree, the level of economy development as a whole. Despite the increase use of different type of energy, particularly, renewable energy sources, fossil fuels will continue dominating the energy combinations in the world near future. However, oil reserves are declining and this situation would have a negative impact in the future economic development of many countries all over the world. In Europe, the import energy dependency is rising. Unless Europe can make domestic energy more competitive in the next 20 to 30 years, around 70% of the European Unions energy requirements, compared to 50% today, will be met by imported products some of them from regions threatened by insecurity. Now, the energy requirements of the different countries are so high that, for the first time in the humanity's history, there is a need to consider different types of available energy sources and their reserves to plan the economic development of the countries. At the same time, there is also a need to use these sources in the most efficient possible manner in order to sustain that development. The EU leads the world in demand management, in promoting new and renewable forms of energy. If the EU backs up a new common policy with a common voice on energy questions, Europe can lead the global search for energy solutions. However, EU must act urgently because it takes many years to bring innovation on stream in the energy sector, as well as to make productive the investments that are need to update the energy infrastructure in the region. This book provides leading-edge research on this field of study from around the globe.

  • 89.
    Danestig, Maria
    et al.
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Henning, Dag
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Increased system benefit from cogeneration due to cooperation between district heating utility and industry2004In: Proceedings of the 9th international symposium on district heating and cooling, Espoo, Finland, 30-31 August., 2004, p. 97-104Conference paper (Refereed)
    Abstract [en]

    District heating and steam supply in the town Örnsköldsvik in northern Sweden is in focus for this study. Low temperature waste heat from pulp manufacturing in the Domsjö mill is now utilised for district heating production in heat pumps, which dominate district heating supply. Based on this traditional cooperation between the local district heating utility and the pulp industry, the parties discuss a partial outsourcing of the industrial steam supply to the utility, which may enable beneficial system solutions for both actors. The local utility must find a new location for a heating plant because a railway line is being built at the heat pump site. Planning for a new combined heat and power production (CHP) plant has started but its location is uncertain. If the plant can be situated close to the mill it can, besides district heating, produce steam, which can be supplied to adjacent industries. The municipality and its local utility are also considering investing in a waste incineration plant. But is waste incineration suitable for Örnsköldsvik and how would it interact with cogeneration?

    Alternative cases have been evaluated with the MODEST energy system optimisation model, which minimises the cost for satisfying district heating and steam demand. The most profitable solution is to invest in a CHP plant and a waste incineration plant. Considering carbon dioxide emissions, the results from applying a local or a global perspective are remarkably different. In the latter case, generated electricity is assumed to replace power from coal condensing plants elsewhere in the North-European power grid. Therefore, minimum global CO2 emissions are achieved through maximal electricity production in a CHP plant. From this viewpoint, waste incineration should not be introduced because it would obstruct cogeneration. The study is carried out within the program Sustainable municipality run by the Swedish Energy Agency.

  • 90.
    Danestig, Maria
    et al.
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Westerberg, Karin
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    A multidisciplinary and interactive method for exploring energy systems in municipalities2009Article in journal (Other academic)
    Abstract [en]

    Due to environmental concerns and changed market conditions in the energy system, the preconditions for energy use and production in Sweden have changed in recent years. To be able to manage these new demands on a local level, municipalities need to adopt new methods to deal with unstructured and complex situations. This article presents a method for multidisciplinary and interactive exploration of energy systems at the local level. The method creates opportunities for local actors to discuss and negotiate the necessary actions within the local energy system.

  • 91. Order onlineBuy this publication >>
    Difs, Kristina
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    District Heating and CHP: Local Possibilities for Global Climate Change Mitigation2010Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Global warming, in combination with increasing energy demand and higher energy prices, makes it necessary to change the energy use. To secure the energy supply and to develop sustainable societies, construction of energy-efficient systems is at the same time most vital. The aim of this thesis is therefore to identify how a local energy company, producing district heating (DH), district cooling (DC) and electricity in combined heat and power (CHP) plants, can contribute to resource-efficient energy systems and cost-effective reductions of global carbon dioxide (CO2) emissions, along with its customers. Analyses have been performed on how a local energy company can optimise their DH and DC production and what supply-side and demand-side measures can lead to energy-efficient systems in combination with economic and climate change benefits. The energy company in focus is located in Linköping, Sweden. Optimisation models, such as MODEST and reMIND, have been used for analysing the energy systems. Scenario and sensitivity analyses have also been performed for evaluation of the robustness of the energy systems studied. For all analyses a European energy system perspective was applied, where a fully deregulated European electricity market with no bottlenecks or other system failures was assumed.

    In this thesis it is concluded that of the DH-supply technologies studied, the biomass gasification applications and the natural gas combined cycle (NGCC) CHP are the technologies with the largest global CO2 reduction potential, while the biomass-fuelled plant that only produces heat is the investment with the smallest global CO2 reduction and savings potential. However, the global CO2 reduction potential for the biomass integrated gasification combined cycle (BIGCC) CHP and NGCC CHP, the two technologies with highest electricity efficiencies, is highly dependent on the assumptions made about marginal European electricity production. Regarding the effect on the DH system cost the gasification application integrated with production of renewable biofuels (SNG) for the transport sector is the investment option with the largest savings potential for lower electricity prices, while with increasing electricity prices the BIGCC and NGCC CHP plants are the most cost-effective investment options. The economic outcome for biomass gasification applications is, however, dependent on the level of policy instruments for biofuels and renewable electricity. Moreover, it was shown that the tradable green certificates for renewable electricity can, when applied to DH systems, contribute to investments that will not fully utilise the DH systems’ potential for global CO2 emissions reductions.

    Also illustrated is that conversion of industrial processes, utilising electricity and fossil fuels, to DH and DC can contribute to energy savings. Since DH is mainly used for space heating, the heat demand for DH systems is strongly outdoor temperature-dependent. By converting industrial processes, where the heat demand is often dependent on process hours instead of outdoor temperature, the heat loads in DH systems can become more evenly distributed over the year, with increased base-load heat demand and increased electricity generation in CHP plants as an outcome. This extra electricity production, in combination with the freed electricity when converting electricity-using processes to DH, can replace marginal electricity production in the European electricity market, resulting in reduced global CO2 emissions.

    Demonstrated in this thesis is that the local energy company, along with its customers, can contribute to reaching the European Union’s targets of reducing energy use and decreasing CO2 emissions. This can be achieved in a manner that is cost-effective to both the local energy company and the customers.

    List of papers
    1. Pricing district heating by marginal cost
    Open this publication in new window or tab >>Pricing district heating by marginal cost
    2009 (English)In: ENERGY POLICY, ISSN 0301-4215 , Vol. 37, no 2, p. 606-616Article in journal (Refereed) Published
    Abstract [en]

    A vital measure for industries when redirecting the energy systems towards sustainability is conversion from electricity to district heating (DH). This conversion can be achieved for example, by replacing electrical heating with DH and compression cooling with heat-driven absorption cooling. Conversion to DH must, however, always be an economically attractive choice for an industry. In this paper the effects for industries and the local DH supplier are analysed when pricing DH by marginal cost in combination with industrial energy efficiency measures. Energy audits have shown that the analysed industries can reduce their annual electricity use by 30% and increase the use of DH by 56%. When marginal costs are applied as DH tariffs and the industrial energy efficiency measures are implemented, the industrial energy costs can be reduced by 17%. When implementing the industrial energy efficiency measures and also considering a utility investment in the local energy system, the local DH supplier has a potential to reduce the total energy system cost by 1.6 million EUR. Global carbon dioxide emissions can be reduced by 25,000 tonnes if the industrial energy efficiency measures are implemented and when coal-condensing power is assumed to be the marginal electricity source.

    Keywords
    District heating, Marginal cost, Carbon dioxide emissions
    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:liu:diva-16972 (URN)10.1016/j.enpol.2008.10.003 (DOI)
    Available from: 2009-03-01 Created: 2009-02-27 Last updated: 2010-09-01
    2. Biomass gasification opportunities in a district heating system
    Open this publication in new window or tab >>Biomass gasification opportunities in a district heating system
    2010 (English)In: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 34, no 5, p. 637-651Article in journal (Refereed) Published
    Abstract [en]

    This paper evaluates the economic effects and the potential for reduced CO2 emissions when biomass gasification applications are introduced in a Swedish district heating (DH) system. The gasification applications included in the study deliver heat to the DH network while producing renewable electricity or biofuels. Gasification applications included are: external superheater for steam from waste incineration (waste boost, WE), gas engine CHP (BIGGE), combined cycle CHP (BIGCC) and production of synthetic natural gas (SNG) for use as transportation fuel. Six scenarios are used, employing two time perspectives - short-term and medium-term - and differing in economic input data, investment options and technical system. To evaluate the economic performance an optimisation model is used to identify the most profitable alternatives regarding investments and plant operation while meeting the DH demand. This study shows that introducing biomass gasification in the DH system will lead to economic benefits for the DH supplier as well as reduce global CO2 emissions. Biomass gasification significantly increases the potential for production of high value products (electricity or SNG) in the DH system. However, which form of investment that is most profitable is shown to be highly dependent on the level of policy instruments for biofuels and renewable electricity. Biomass gasification applications can thus be interesting for DH suppliers in the future, and may be a vital measure to reach the 2020 targets for greenhouse gases and renewable energy, given continued technology development and long-term policy instruments.

    Place, publisher, year, edition, pages
    Elsevier Science B.V., Amsterdam., 2010
    Keywords
    Biomass gasification, District heating, Optimisation, Global CO2 emissions, Energy system, Biorefinery
    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:liu:diva-56808 (URN)10.1016/j.biombioe.2010.01.007 (DOI)000277918300007 ()
    Note
    Original Publication: Kristina Difs, Elisabeth Wetterlund, Louise Trygg and Mats Söderström, Biomass gasification opportunities in a district heating system, 2010, BIOMASS and BIOENERGY, (34), 5, 637-651. http://dx.doi.org/10.1016/j.biombioe.2010.01.007 Copyright: Elsevier Science B.V., Amsterdam. http://www.elsevier.com/ Available from: 2010-06-04 Created: 2010-06-04 Last updated: 2017-12-12Bibliographically approved
    3. Absorption Cooling in CHP systems - old technique with new opportunities
    Open this publication in new window or tab >>Absorption Cooling in CHP systems - old technique with new opportunities
    2008 (English)In: World Renewable Energy Congress and Exhibition,2008, 2008Conference paper, Published paper (Refereed)
    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:liu:diva-44120 (URN)75681 (Local ID)75681 (Archive number)75681 (OAI)
    Available from: 2009-10-10 Created: 2009-10-10 Last updated: 2010-09-01
    4. Increased use of district heating in industrial processes - Impacts on heat load duration
    Open this publication in new window or tab >>Increased use of district heating in industrial processes - Impacts on heat load duration
    2009 (English)In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 86, no 11, p. 2327-2334Article in journal (Refereed) Published
    Abstract [en]

    Current knowledge of the potential for an increased use of industrial district heating (DH) due to conversions of industrial processes to DH is limited. In this paper, a Method for Heat Load Analysis (MeHLA) for exploring industrial DH conversions has been developed. This method can be a helpful tool for analyzing the impact different industrial processes have on the local DH system, when processes that utilize electricity and other fuels, convert to utilizing DH instead. Heat loads for different types of industries and processes are analyzed according to characteristics such as temperature levels and time dependency. MeHLA has been used to analyze 34 Swedish industries and the method demonstrates how conversion of industrial processes to DH can result in heat load duration curves that are less outdoor temperature-dependent and more evenly distributed over the year. An evenly distributed heat load curve can result in increased annual operating time for base load DH plants such as cogeneration plants, leading to increased electricity generation. In addition to the positive effects for the DH load duration curve, the conversions to DH can also lead to an 11% reduction in the use of electricity, a 40% reduction in the use of fossil fuels and a total energy end-use saving of 6% in the industries. Converting the industrial processes to DH will also lead to a potential reduction of the global carbon dioxide emissions by 112,000 tonnes per year.

    Keywords
    District heating, heat load duration curve, industrial heat load, global CO2
    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:liu:diva-17212 (URN)10.1016/j.apenergy.2009.03.011 (DOI)
    Available from: 2009-03-11 Created: 2009-03-11 Last updated: 2017-12-13Bibliographically approved
    5. Increased industrial district heating use in a CHP system: economic consequences and impact on global CO2 emissions
    Open this publication in new window or tab >>Increased industrial district heating use in a CHP system: economic consequences and impact on global CO2 emissions