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  • 201.
    Holmgren, Kristina
    et al.
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Bartlett, Michael
    Waste incineration in Swedish municipal energy systems: modelling the effects of various waste quantities in the city of Linköping2004In: Sustainable development of energy, water and environment systems, Dubrovnik, Croatia; 2004, 2004Conference paper (Other academic)
  • 202.
    Holmgren, Kristina
    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.
    Modelling a district heating system: introduction of waste incineration, policy instruments and co-operation with an industry2004In: Energy Policy, ISSN 0301-4215, Vol. 32, no 16, p. 1807-1817Article in journal (Refereed)
    Abstract [en]

    The capacity for waste incineration in Swedish municipalities is increasing due to regulations aimed at decreasing landfill with waste. This has a large impact on the municipal energy systems, since waste is an important fuel for district heating production. The object of this study is a municipality, Skövde, which is planning to build a waste incineration plant to produce electricity and heat. The municipality is also planning to extend the district heating grid to include a large industrial heat consumer. The economic effect on the energy system of these measures is analysed as well as environmental effects in terms of carbon dioxide emissions. The consequences of two different policy instruments, green electricity certificates and a tax on waste incineration, are also studied. Economic optimisations show that the advantage of co-operation with industry is twofold: lower heat production costs and a considerable reduction of carbon dioxide emissions. It is economically feasible to invest in a waste incineration plant for heat production. An important measure to lower carbon dioxide emissions is to introduce combined heat and power production on the assumption that locally produced electricity replaces electricity produced by coal condensing power.

  • 203.
    Holmgren, Kristina
    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.
    Comparison between material and energy recovery of municipal waste from an energy perspective: A study of two Swedish municipalities2004In: Resources, Conservation and Recycling, ISSN 0921-3449, Vol. 43, no 1, p. 51-73Article in journal (Refereed)
    Abstract [en]

    The aim of this study is to compare material recovery to waste incineration with energy recovery from the criteria of energy efficiency. Material recovery saves virgin material and also energy since production processes using recovered material are less energy intensive than processes using virgin material, whereas energy recovery saves other fuels that differ among various energy systems. Optimisations are made for the district heating systems in two Swedish municipalities, showing that it is profitable for the energy utilities in the municipalities to invest in plants using waste as a fuel for electricity and heat production. The fuels replaced by the waste differ between the municipalities. For one it is mostly wood chips, and for the other, a lot of biomass is replaced, but the largest saving is in oil. Energy savings by material recycling of the waste are calculated. Non-combustible waste, such as metals and glass save energy in various extensions when material recycled, but give no heat contribution when incinerated. It is more complicated to compare material and energy recovery of combustible waste fractions, such as cardboard, paper, plastics and biodegradable waste since they can be recycled in both fashions. For these fractions it is important to consider the configuration of the energy system. The conclusions from the two municipalities are that even if there is a district heating system able to utilise the heat, from the energy-efficiency view point; paper and hard plastics should preferably be material recovered, whereas cardboard and biodegradable waste is more suited for energy recovery through waste incineration. These calculations are done with the assumption that biomass should be regarded as a limited resource and when saved eventually eliminates fossile fuel combustion in other facilities.

  • 204.
    Hrustic, Adnan
    et al.
    Swerea SWECAST AB.
    Sommarin, Per
    Swerea SWECAST AB.
    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.
    A simplified energy management system towards increased energy efficiency in SMEs2011In: Proceedings of the World Renewable Energy Congress 2011 (WREC 2011), 9-13 May, Linköping / [ed] Bahram Moshfegh, Linköping University Electronic Press, 2011, Vol. 7, p. 1513-1520Conference paper (Refereed)
    Abstract [en]

     

    Swedish companies have since 2003 been able to get certified by an energy management system (EEMS) and companies that have been certified, can now show savings in energy use. The downside of today's EEMs is that too few small and medium-sized enterprises (SMEs) have chosen to certify such a system in the organization. To increase awareness and interest among SMEs, a simplified version of the EEMS would be desirable. This article presents a simplified EEMs for SMEs developed from the original European standard (SSEN 16 001). The article describes how the simple EEMS was developed and how the system was validated, i.e. how different companies responded to test-runs of the developed simplified EEMS. By testing the simplified EEMS in practice among various SMEs, different needs from the industry have been documented. The requests that were of greatest importance was how different incentives can be designed to increase the certification level, e.g. tax exemptions etc. The Swedish LTA for energy-intensive industries includes tax exemptions, as well as the certification of the European EEMS standard, and has shown to lead to large energy savings. An examples of a future energy policy could thus be a Long-Term Agreement (LTA)s program for SMEs including the simplified EEMS.

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  • 205.
    Hu, Yuetong
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, Department of Management and Engineering.
    Development Trends of World Energy2009Independent thesis Advanced level (degree of Master (Two Years)), 30 credits / 45 HE creditsStudent thesis
    Abstract [en]

    Energy has been one of the most important issues and challenge humans face in the 21st century whichhas a bearing on international economic and social development, global climate changes andenvironment protection. With a focus on development trends of world energy, this paper analyses thecurrent world energy status and from the perspectives of energy sources, regions, end-use sectors, thebalance of energy production and consumption, and in the context of its implications on the globalenvironmental and economic and social development by using a series of indicators such as total primaryenergy, total final energy, energy consumption and CO2 emission intensity per capita and per GDP tocompare and study. The main development trends contains depletion of fossil fuels, rapid developmentof renewable energy, aggravated environmental problems by energy-related GHG emissions, moreunbalanced and interdependent regional energy production and consumption, more efficient energyindustry; globalization and so on. This article expounds humans’ efforts to make progress in developingrenewable energy and reducing energy-related environmental impacts. In the end of the paper, worldenergy structure development and middle-term energy consumption are projected, and the generalorientations of world energy development trends in future are presented.

  • 206.
    Hu, Yuetong
    Linköping University, Department of Management and Engineering, Energy Systems.
    Development Trends of World Energy2009Independent thesis Advanced level (degree of Master (Two Years)), 30 credits / 45 HE creditsStudent thesis
    Abstract [en]

    Energy has been one of the most important issues and challenge humans face in the 21st century which has a bearing on international economic and social development, global climate changes and environment protection. With a focus on development trends of world energy, this paper analyses the current world energy status and from the perspectives of energy sources, regions, end-use sectors, the balance of energy production and consumption, and in the context of its implications on the global environmental and economic and social development by using a series of indicators such as total primary energy, total final energy, energy consumption and CO2 emission intensity per capita and per GDP to compare and study. The main development trends contains depletion of fossil fuels, rapid development of renewable energy, aggravated environmental problems by energy-related GHG emissions, more unbalanced and interdependent regional energy production and consumption, more efficient energy industry; globalization and so on. This article expounds humans’ efforts to make progress in developing renewable energy and reducing energy-related environmental impacts. In the end of the paper, world energy structure development and middle-term energy consumption are projected, and the general orientations of world energy development trends in future are presented.

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  • 207.
    Hultgren, Elin
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Making renewable electricity a reality: Policies and challenges when transforming Germany´s electricity system2013Independent thesis Basic level (degree of Bachelor), 10,5 credits / 16 HE creditsStudent thesis
    Abstract [en]

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

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  • 208.
    Hultgren, Elin
    Linköping University, Department of Management and Engineering, Energy Systems.
    Sustainability in the UK domestic sector: A review and analysis of the sustainable energy innovations available to homeowners2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The UK Government has set an ambitious legislative goal of reducing greenhouse gas emissions by 80 % by 2050. Of the total energy used in the UK, 31 % is used in the domestic sector. In the domestic sector energy is used for space and hot water heating, lighting, appliances and cooking. Space and hot water heating make up 82 % of the total energy used in the UK domestic sector. Almost all of the energy used in the UK domestic sector originates from depletable resources. In order for the UK to reach its goal of decreasing greenhouse gas emissions by 80 % by 2050, the way energy is used in the UK domestic sector needs to change dramatically. The aim of this study is to identify opportunities for homeowners to be more sustainable without compromising their standard of living, by changing the way they use and supply energy. Homeowners’ ways of using and supplying energy today will be reviewed followed by an identification of measures that can be taken to create a more sustainable home from an energy perspective. Identified measures not only include usage of small-scale energy technologies but also application of energy efficiency measures and changes in behaviour that result in homeowners using energy in a more efficient way.

     

    The aim has been achieved by conducting a literature review, collecting statistical data regarding energy use from the Department of Energy and Climate Change and the undertaking of a case study. The literature review revealed that air source and solar assisted heat pumps, solar photovoltaic (solar PV) and fuel cell micro combined heat and power (fuel cell mCHP) are the most promising and widely available microgeneration technologies on the market today. LED light bulbs, wall and loft insulation and energy efficient appliances are the energy efficiency measures identified as having the highest potential to decrease the amount of energy used. The literature review also proved that behaviour in relation to energy use is a key area to address in order to make homeowners use energy in a more efficient way.

     

    The case study consisted of six case houses, based on the most common house types in the UK. The reference heating system used in the case study was a gas boiler connected to a central heating system of the house. 80 % of the homes in the UK are heated with a gas boiler and that is why it was chosen as a reference scenario. The case study showed that all of the microgeneration technologies use resources and energy in a more efficient way than the reference scenario. But despite the financial support of governmental subsidies none of the microgeneration technologies were financially viable options compared to a gas boiler. Energy efficiency measures, especially LED lighting, wall and loft insulation, significantly lowered the amount of energy used, they lowered the influence on greenhouse gas emissions and were financially viable options without the support of governmental subsidies.

     

    It was identified that microgeneration technologies are impacted by behaviour and that they can enable demand-side management, especially as the number of supply-driven sources such as wind and solar PV increases.

     

    In summation microgeneration technologies and energy efficiency measures have a large potential to help make homeowners become more sustainable from an energy perspective. Governmental support has a determining role in making them financially viable and therefore accessible to the public. 

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  • 209.
    Håll, Marcus
    et al.
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Johansson, Niklas
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Energiutredning och solkraftsanalys av kyllager: Fallstudie ICA DE Borlänge2013Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    I takt med att energipriserna stiger och resultatet av rådande klimatbelastningen blir allt tydligare så finns det flera starka anledningar att minska energianvändningen. ICA har som mål att minska de direkta utsläppen av växthusgaser med minst 30 % till år 2020 jämfört med år 2006. Examensarbetet behandlar två delar med ett gemensamt syfte; att arbeta fram åtgärder som kan minska energianvändningen och energikostnaderna för kylda lager. Detta gjordes genom en fallstudie på ICA DE Borlänge, vilket är ett av ICAs sex lager på svensk mark. Den ena delen av arbetet är en energiutredning där verksamhetens energianvändning kartlagts och med detta som underlag presenteras sedan ett antal åtgärdsförslag. För några av åtgärderna har kompletta investeringskalkyler tagits fram, medan för andra åtgärder presenteras endast en besparingspotential. Den andra delen av arbetet är en solkraftsanalys av lagerbyggnaden. Där undersöktes först betydelsen av azimut, tilt och radavstånd. Lämpligheten att installera solceller på just kyllager undersöktes vidare genom att analysera bieffekter av att installera en anläggning samt politiska styrmedel. Slutligen jämfördes tre på marknaden tillgängliga solcellssystem med olika tilt och infästningsmetod.

    Energikartläggningen är genomförd med ett top-down perspektiv, där helheten först studeras för att få en god överblick. Därefter analyseras intressanta delar detaljerat. Datainsamling genomfördes med hjälp av intern loggningsutrustning, rundvandringar, egna mätningar samt en kontinuerlig kontakt med ansvarig personal. För att uppskatta investeringskostnader för åtgärder inklusive solkraftanläggningar har dialoger med återförsäljare förts.

    Energikartläggningen visar att den sammanlagda el- och fjärrvärmeanvändningen uppgår till 7,5 GWh respektive 1,9 GWh per år, där kyllast och lagerbelysningen står för dryg 60 % av den totala elanvändningen. Övriga stora poster utgörs av truckladdning, luftrenare samt ventilation och belysning på kontor. Sammanlagt identifierades ca 83 % av den totala ellasten.

    Utredningen visar att ICA har god medvetenhet kring energianvändningen men att det finns potential att på flera sätt minska energianvändningen och energikostnaderna. Åtgärderna innefattar investeringar i ny effektivare teknik, som exempelvis ny belysningsutrustning. Även kostnadsfria åtgärder innefattas, t.ex. omplacering av vissa varor samt ändrade lagertemperaturer. De största energibesparingarna är kopplade till belysningen som i stora delar av lagret inte styrs alls utan lyser oavsett bemanning eller inte. Genom styrning av belysningen och byte till modernare teknik kan energianvändningen för belysningen på lagerdelen minska med 35 % (500 MWh).

    Solkraftsanalysen visar att det för företag som kan avvara kapital på sikt går att spara pengar genom en solcellsinvestering. Hur god ekonomi investeringen får beror till stor del av elprisets utveckling som är mycket osäker. Med en elprishöjning på 5,5 % /år, en inflation på 1,4 % per år och en investeringskostnad 15 kr/W p fås en återbetalningstid mellan 7 och 11 år. Med solcellernas långa livslängd på minst 25 år blir interräntan för investeringen mellan 10 och 15 %.

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  • 210.
    Höglund, Magnus
    et al.
    Linköping University, Department of Management and Engineering, Energy Systems.
    Olsson, Martin
    Linköping University, Department of Science and Technology.
    Återladdning av bergvärmekonfiguration vid samfälligheten Ängsbacken2009Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Under detta projekt har vi tittat på hur man kan återladda en bergvärmekonfiguration med lågtempererade solfångare. Projektet utfördes åt Newsec Energy i Stockholm vars kund samfälligheten Ängsbacken ville minska andelen tillskottsenergi som utgörs av olja till sin bergvärmeanläggning. En utredning av anläggningen gjordes av Newsec Energy som visade att berget kylts ned och att anläggningens borrhål varit underdimensionerade. Vi fick uppdraget att utveckla en systemlösning med lågtempererade solfångare.

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  • 211.
    Ingelhag, Gerda
    et al.
    Linköping University, Department of Management and Engineering, Energy Systems.
    Gullberg, Michael
    Primärenergifaktorer för fjärrvärme: Analys och beräkning av primärenergifaktorer för svensk fjärrvärme2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In January 2017, Boverket issued new proposals for regulations concerning Sweden's realization of primary energy factors for heating in buildings. The new proposal replaces the previous requirements for specific energy use with an energy performance indicator that expresses a building's primary energy use. The use of primary energy factors for the regulation of heating in buildings is derived from the EU's Energy Efficient Buildings Directive (EPBD), which aims guiding new buildings towards Near-Zero Energy Buildings (NZEB). Boverket proposes that electricity should be set to the primary energy factor 1.6 (until 2021) and heating by either district heating, oil, natural gas or biofuel should initially be assigned the factor 1.0. The proposal has received a lot of criticism from, among other players, Swedish energy companies, which argue that the Swedish district heating is given a disadvantage, as it valued the same as energy carriers such as oil. It is also apparent from the EPBD that member countries may develop their own primary energy factors that correspond to local conditions if they want to. All in all, above mentioned issues have led to this thesis’ aim, which is calculating and analyzing primary energy factors specifically for Swedish district heating.

    Within the thesis boundaries, a literature study was conducted in which reports, scientific articles and consultancy reports on the subject of primary energy factors were studied. In addition, it was investigated if other EU countries have calculated national primary energy factors for district heating and how they were implemented. It has been concluded by the authors that there are a large number of methods, values and approaches to be taken into account in the development of primary energy factors.

    Two different calculation perspectives have been identified, the accounting and consequence perspective. In addition to these perspectives, a number of methods were found for the allocation of electricity and heat; In the thesis, the energy method, the alternative production method and the exergy method have been studied in the accounting perspective. For the consequence perspective, system expansion has been utilized through the power bonus method, in which electricity produced in CHP plants is assumed to replace the corresponding electricity generation in the market. In total, 10 different combinations are studied with varying perspectives, allocation methods and input data for the calculation of primary energy factors.

    The authors suggest that the accounting perspective and alternative production method should be used as a first step in the development of Swedish factors for district heating. The method is easy to handle and supported by many actors, such as Värmemarknadskommittén (VMK) and the Swedish Standards Institute (SIS). The calculated primary energy factors have been divided into the following categories: waste in the fuel mix, a national factor, electricity generation and grid size. The authors have chosen not to advocate any calculated factor in front of another, but rather thinks that the upcoming decisions to be taken regarding primary energy factors should be well motivated. An important conclusion, however, is that the calculated factors are considerably smaller than those presented by Boverket. Furthermore, the authors argue that clearer guidelines need to be implemented at an EU level for how national and local primary energy factors can be developed and calculated.

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  • 212.
    Isaksson, Charlotta
    et al.
    Linköping University, The Tema Institute, Technology and Social Change. Linköping University, Faculty of Arts and Sciences.
    Karlsson, Fredrik
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Indoor climate in low-energy houses: An interdisciplinary investigation2006In: Building and Environment, ISSN 0360-1323, Vol. 41, no 12, p. 1678-1690Article in journal (Refereed)
    Abstract [en]

    If energy demand in the building sector should be decreased, low-energy buildings, which are built with the aim of decreasing the use of energy, but still provide a good environment for the occupants, ought to be built on a larger scale. Investigations into how experimental houses function provides the opportunity of improving next-generation houses. This paper presents the results of an interdisciplinary investigation of the thermal environment and the space heating in 20 low-energy terraced houses. Qualitative interviews with the occupants as well as measurements of physical parameters have been conducted for this purpose. When the houses are inhabited and household appliances and candles are being used, the temperature can be managed within acceptable limits, even on cold days. However, those living in middle houses are generally more satisfied with their indoor temperature than the households of the gable houses. Results from both interviews and measurements show that there is a temperature difference between the floor levels, which is more pronounced in the gable houses. One outcome of the investigation is that information about the functionality of the heating system given to the households should be improved. Another outcome is that the accuracy of the temperature regulation system could be better.

  • 213.
    Ivner, Jenny
    et al.
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Broberg Viklund, Sarah
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, Faculty of Science & Engineering.
    Effect of the use of industrial excess heat in district heating on greenhouse gas emissions: A systems perspective2015In: Resources, Conservation and Recycling, ISSN 0921-3449, E-ISSN 1879-0658, Vol. 100, p. 81-87Article in journal (Refereed)
    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.

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  • 214.
    Ivner, Jenny
    et al.
    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.
    Paramonova, Svetlana
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Svensson, Anders
    Tuenter, Gerard
    Swedish Energy Agency.
    Björkman, Thomas
    Swedish Energy Agency.
    Moberg, Johanna
    Swedish Energy Agency.
    Swedish energy manager networks for energy-intensive industry as a driver for improved energy efficiency2014Conference paper (Other academic)
    Abstract [en]

    While the potential for improved energy efficiency in industryis large, deployment of measures is often inhibited by a numberof barriers. In order to overcome these barriers, a number ofenergy end-use policies is functioning in Sweden, the two largestbeing a Voluntary Agreements (VA) for energy-intensiveindustry, an energy audit program, and in addition, various energymanager networks for improved energy efficiency. Whilethe two former have been evaluated and are well-known, theSwedish energy efficiency networks have so far neither beenpresented nor evaluated previously. The aim of this paper is topresent the current Swedish energy efficient network, and theirrole in the energy policy mix from a theoretical viewpoint. TheSwedish energy network, Energiintensiven consisting of about100 companies from the major electricity-intensive sectors isadministrated by the Swedish Energy Agency. Participatingcompanies are all part of the Swedish VA, the PFE. In additionthe aluminum companies have an energy network (GeniAl),one network is functioning among Swedish saw mills (EESI), aswell as there is a network in the iron- and steel industry ENETSteel.Results of the paper show that despite the low emphasison networks as a part of the policy mix, the networks havean important role in overcoming barriers to energy efficiencyamong the participating companies.

  • 215.
    Jahedi, Mohammad
    et al.
    University of Gävle, Sweden.
    Berntsson, Fredrik
    Linköping University, Department of Mathematics, Computational Mathematics. Linköping University, Faculty of Science & Engineering.
    Wren, Joakim
    Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics. Linköping University, Faculty of Science & Engineering.
    Moshfegh, Bahram
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, Faculty of Science & Engineering. University of Gavle, Sweden.
    Transient inverse heat conduction problem of quenching a hollow cylinder by one row of water jets2018In: International Journal of Heat and Mass Transfer, ISSN 0017-9310, E-ISSN 1879-2189, Vol. 117, p. 748-756Article in journal (Refereed)
    Abstract [en]

    In this study, a two-dimensional linear transition inverse heat conduction problem (IHCP) was solved using the Generalized Minimal Residual Method (GMRES) in quenching process by water jets. The inverse solution method was validated by set of artificial data and solution sensitivity analysis was done on data noise level, regularization parameter, cell size, etc. An experimental study has been carried out on quenching a rotary hollow cylinder by one row of subcooled water jets. The inverse solution approach enabled prediction of surface temperature and heat flux distribution of test specimen in the quenching experiments by using measured internal specimen temperature. Three different boiling curves were defined in the quenching process of a rotary cylinder. Result obtained by the inverse solution showed clear footprint of rotation in surface temperature and heat flux on each revolution of cylinder and temperature variation damping from quenching surface toward interior of specimen. (C) 2017 Elsevier Ltd. All rights reserved.

  • 216.
    Jahedi, Mohammad
    et al.
    Univ Gavle, Sweden.
    Moshfegh, Bahram
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, Faculty of Science & Engineering. Univ Gavle, Sweden.
    Quenching a rotary hollow cylinder by multiple configurations of water-impinging jets2019In: International Journal of Heat and Mass Transfer, ISSN 0017-9310, E-ISSN 1879-2189, Vol. 137, p. 124-137Article in journal (Refereed)
    Abstract [en]

    Experiments have been conducted to analyze quenching of a hot rotary hollow cylinder by one and two rows of water-impinging jets. Sub-cooled water jets (Delta T-sub = 45-85 K) with flow rate 8006 to 36,738 impinged on hollow cylinder with rotation speed 10 to 70 rpm at various initial wall superheat temperatures from 250 to 600 degrees C. Jet-to-jet and jet-to-surface spacing varied between 4 to 10d and 1.5 to 7d respectively and angular position of impinging jets were tested from 0 to 135 degrees. Effectiveness of the defined parameters on stagnation points local average heat flux was found lower in the film and nucleate boiling compare to transition boiling regime where rotation speed had the highest impact. Characteristic of maximum heat flux (MHF) at stagnation point and upwash flow point were analyzed based on surface heat flux, time and temperature corresponding to MHF. Same maximum heat flux levels were captured in the both points which reveals importance of the flow behavior at the upwash flow point. The effectiveness of the parameters to improve average heat transfer was studied based on cooling area of each water-impinging jet in the multiple configurations. Higher average heat transfer was obtained by increasing flow rate and subcooling temperature and lower initial wall superheat temperature corresponding to onset of transition boiling regime. (C) 2019 Elsevier Ltd. All rights reserved.

  • 217. Order onlineBuy this publication >>
    Janbakhsh, Setareh
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    A Ventilation Strategy Based on Confluent Jets: An Experimental and Numerical Study2015Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This study presents air distribution systems that are based on confluent jets; this system can be of interest for the establishment of indoor environments, to fulfill the goals of indoor climate and energy-efficient usage. The main objective of this study is to provide deeper understanding of the flow field development of a supply device that is designed based on wall confluent jets and to investigate the ventilation performance by experimental and numerical methods. In this study, the supply device can be described as an array of round jets on a flat surface attached to a side wall. Multiple round jets that issue from supply device apertures are combined at a certain distance downstream from the device and behave as a united jet or so-called confluent jets. Multiple round jets that are generated from the supply device move downward and are attached to the wall at the primary region, due to the Coanda effect, and then they become wall confluent jets until the floor wall is reached. A wall jet in a secondary region is formed along the floor after the stagnation region.

    The characteristics of the flow field and the ventilation performance of conventional wall confluent jets and modified wall confluent jets supply devices are investigated experimentally in an office test room. The study of the modified wall confluent jets is intended to improve the efficiency of the conventional one while maintaining acceptable thermal comfort in an office environment. The results show that the modified wall confluent jets supply device can provide acceptable thermal comfort for the occupant with lower airflow rate compared to the conventional wall confluent jets supply device.

    Numerical predictions using three turbulence models (renormalization group (RNG k– ε), realizable (Re k– ε), and shear stress transport (SST k– ω) are evaluated by measurement results. The computational box and nozzle plate models are used to model the inlet boundary conditions of the nozzle device. In the isothermal study, the wall confluent jets in the primary region and the wall jet in the secondary region, when predicted by the three turbulence models, are in good agreement with the measurements. The non-isothermal validation studies show that the SST k– ω model is slightly better at predicting the wall confluent jets than the other two models. The SST k– ω model is used to investigate the effects of the nozzle diameter, number of nozzles, nozzle array configuration, and inlet discharge height on the ventilation performance of the proposed wall confluent jets supply device. The nozzle diameter and number of nozzles play important roles in determining the airflow pattern, temperature field, and draught distribution. Increased temperature stratification and less draught distribution are achieved by increasing the nozzle diameter and number of nozzles. The supply device with smaller nozzle diameters and fewer nozzles yields rather uniform temperature distribution due to the dominant effect of mixing. The flow behavior is nearly independent of the inlet discharge height for the studied range.

    The proposed wall confluent jets supply device is compared with a mixing supply device, impinging supply device and displacement supply device. The results show that the proposed wall confluent jets supply device has the combined behavior of both mixing and stratification principles. The proposed wall confluent jets supply device provides better overall ventilation performance than the mixing and displacement supply devices used in this study.

    This study covers also another application of confluent jets that is based on impinging technology. The supply device under consideration has an array of round jets on a curve. Multiple jets issue from the supply device aperture, in which the supply device is positioned vertically and the jets are directed against a target wall. The flow behavior and ventilation performance of the impinging confluent jets supply device is studied experimentally in an industrial premise. The results show that the impinging confluent jets supply device maintains acceptable thermal comfort in the occupied zone by creating well-distributed airflow during cold and hot seasons.

    List of papers
    1. Experimental investigation of a new supply diffuser in an office room
    Open this publication in new window or tab >>Experimental investigation of a new supply diffuser in an office room
    2009 (English)In: Proceedings of 11th International Conference on Air Distribution in Rooms. ROOMVENT, 2009,Busan, Korea, 2009Conference paper, Published paper (Other academic)
    Abstract [en]

    Full-scale measurements were carried out for investigation of thermal comfort in an office room for a new supply air diffuser. Results of the measurements were performed with both wholefield measuring and traditional point measuring techniques. Experimental results were carried out for supply Archimedes numbers varying from 0.03 to 0.16 and two cooling loads, i.e. 55 and 70 W/m2. Characteristics of indoor environment and occupants’ comfort were explored and analyzed. It was concluded that the airflow pattern and thermal comfort from the investigated low-velocity diffuser were in good agreement with standard ISO 7730.

    National Category
    Mechanical Engineering
    Identifiers
    urn:nbn:se:liu:diva-117438 (URN)
    Conference
    The 11th International Conference on Air Distribution in Rooms. ROOMVENT, May 24-27, Busan, Korea
    Available from: 2015-04-27 Created: 2015-04-27 Last updated: 2015-05-04Bibliographically approved
    2. Experimental investigation of a ventilation system based on wall confluent jets
    Open this publication in new window or tab >>Experimental investigation of a ventilation system based on wall confluent jets
    2014 (English)In: Building and Environment, ISSN 0360-1323, E-ISSN 1873-684X, Vol. 80, p. 18-31Article in journal (Refereed) Published
    Abstract [en]

    The flow behavior of isothermal and non-isothermal wall confluent jets (WCJ) ventilation system was investigated experimentally in a mock-up office environment. Two flow regions were identified: first, a primary region is developed below the supply device, with axis along the inlet wall, and a secondary wall-jet forms along the floor. The velocity and temperature fields were recorded by traversing a hot wire and thermistor anemometers for both primary and secondary regions. The results show self-similarity characteristic of the velocity and temperature profiles for both isothermal and non-isothermal WCJ. Maximum velocity decay and its spreading rate are linear and independent of the inlet airflow rate. Minimum temperature difference and its spread also show linear decay. The spreading rates for maximum velocity are similar in both the primary and secondary regions normal to the inlet wall and floor, respectively, which is consistent with previous studies on wall jets. The variation of draught rating is evaluated via mean velocity, turbulence intensity and temperature. Although the WCJ has slow velocity decay, which enables it to cover almost the entire floor of the test room, the draught is acceptable in the occupied zone according to ISO 7730. PMV (predicted mean vote) and PPD (predicted percentage dissatisfied) are presented for the occupied zone of the room.

    Place, publisher, year, edition, pages
    Elsevier, 2014
    Keywords
    Ventilation system; Supply device; Wall confluent jets; Measurement; Draught rate; Thermal comfort indices
    National Category
    Mechanical Engineering
    Identifiers
    urn:nbn:se:liu:diva-110263 (URN)10.1016/j.buildenv.2014.05.011 (DOI)000340323300003 ()
    Note

    Funding Agencies|University of Gavle, Sweden; Stravent AB, Finland

    Available from: 2014-09-05 Created: 2014-09-05 Last updated: 2017-12-05
    3. Numerical study of a ventilation system based on wall confluent jets
    Open this publication in new window or tab >>Numerical study of a ventilation system based on wall confluent jets
    2014 (English)In: HVAC & R RESEARCH, ISSN 1078-9669, E-ISSN 1938-5587, Vol. 20, no 8, p. 846-861Article in journal (Refereed) Published
    Abstract [en]

    This study presents numerical investigation of an air supply device based on wall confluent jets in a ventilated room. Confluent jets can be described as multiple round jets issuing from supply device apertures. The jets converge, merge, and combine at a certain distance downstream from the supply device and behave as a united jet, or so-called confluent jet. The numerical predictions of the velocity flow field of isothermal confluent jets with three Reynolds-averaged Navier-Stokes turbulence models (renormalization group k-epsilon, realizable k-epsilon, and shear stress transport k-omega) are reported in the present study. The results of the numerical predictions are verified with detailed experimental measurements by a hot wire anemometer and constant temperature anemometers for two airflow rates. The box method is used to provide the inlet boundary conditions. The study of the airflow distribution shows that a primary wall jet (wall confluent jet) exists close to the supply device along the wetted wall, and a secondary wall jet is created after the stagnation region along the floor. It is presented that the flow field of the primary and secondary wall jet predicted by turbulence models is in good agreement with the experimental data. The current study is also compared with the literature in terms of velocity decay and the spreading rate of the primary and secondary wall jet, the results of which are consistent with each other. Velocity decay and the spreading rate of the secondary wall jet in vertical and lateral directions were studied for different inlet airflow rates and inlet discharge heights. The comparative results demonstrate that the flow behavior is nearly independent of the inlet flow rate. Inlet discharge height is found to have impact close to the inlet, where the velocity decays faster when the jet discharges at higher level. The decay tendency is similar as the jet enters into the room for all discharge heights.

    Place, publisher, year, edition, pages
    Taylor and Francis: STM, Behavioural Science and Public Health Titles - No Open Select, 2014
    National Category
    Mechanical Engineering
    Identifiers
    urn:nbn:se:liu:diva-112461 (URN)10.1080/10789669.2014.957111 (DOI)000344407100002 ()
    Note

    Funding Agencies|University of Gavle; Stravent AB, Finland

    Available from: 2014-11-28 Created: 2014-11-28 Last updated: 2017-12-05
    4. Investigation of design parameters for an air supply device based on wall confluent jets
    Open this publication in new window or tab >>Investigation of design parameters for an air supply device based on wall confluent jets
    2015 (English)Manuscript (preprint) (Other academic)
    Abstract [en]

    Numerical predictions of the flow field generated by an air supply device based on wall confluent jets are investigated. The numerical predictions of three turbulence models (RNG 𝑘 − 𝜀, Re 𝑘 − 𝜀, and SST 𝑘 − 𝜔) are compared by velocity and temperature measurements. Ventilation performance in terms of thermal comfort and ventilation efficiency is numerically investigated by systematically varying the design of the air supply (nozzle array configuration, nozzle diameter, number of nozzles, and inlet discharge height). The numerical predictions accomplished by the SST 𝑘 − 𝜔 model provide the best agreement with the experimental results. The numerical predictions for supply devices of varying design configuration show that different device designs provide acceptable thermal environments and efficient heat removal. The nozzle diameter and number of nozzles play important roles in determining the airflow pattern, temperature field, and draught distribution. Increased temperature stratification and less draught distribution are achieved by increasing the nozzle diameter and number of nozzles. The spreading rates of the wall jet along the vertical direction for the cases studied are in close agreement with each other and independent of the studied parameters. The flow behavior is rarely independent of the inlet discharge height and configuration of the nozzle array for the studied range.

    Keywords
    Wall confluent jets supply device, Numerical predictions, Parametric studies, Ventilation performance, Ventilation efficiency, Thermal comfort
    National Category
    Mechanical Engineering
    Identifiers
    urn:nbn:se:liu:diva-117437 (URN)
    Available from: 2015-04-27 Created: 2015-04-27 Last updated: 2015-04-27Bibliographically approved
    5. Numerical investigation of ventilation performance of different air supply devices in an office environment
    Open this publication in new window or tab >>Numerical investigation of ventilation performance of different air supply devices in an office environment
    2015 (English)In: Building and Environment, ISSN 0360-1323, E-ISSN 1873-684X, Vol. 90, p. 37-50Article in journal (Refereed) Published
    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.

    Place, publisher, year, edition, pages
    Elsevier, 2015
    Keywords
    Ventilation performance, Air supply devices, Thermal comfort, Energy-saving potential
    National Category
    Energy Engineering
    Identifiers
    urn:nbn:se:liu:diva-117439 (URN)10.1016/j.buildenv.2015.03.021 (DOI)000356189000004 ()
    Note

    Formas [242-2008-835]; KK Foundation [2007/0289]; University of Gavle (Gavle, Sweden); Linkoping University (Linkoping, Sweden)

    Available from: 2015-04-27 Created: 2015-04-27 Last updated: 2018-07-26Bibliographically approved
    6. A Newly Designed Supply Diffuser for Industrial Premises
    Open this publication in new window or tab >>A Newly Designed Supply Diffuser for Industrial Premises
    2010 (English)In: The International Journal of Ventilation, ISSN 1473-3315, E-ISSN 2044-4044, Vol. 9, no 1, p. 59-67Article in journal (Refereed) Published
    Abstract [en]

    The results of this investigation revealed the airflow distribution from a new design of supply diffuser under non-isothermal conditions. To illustrate the indoor climate parameters in the occupied zone, for both the heating and cooling seasons, an experimental investigation was carried out in industrial premises. The indoor climate was explored at ankle, waist and neck levels for a standing person at different positions, to determine the variation of the thermal comfort indexes and draught rating (DR) with position in the facility. The observed PPD and DR values indicate acceptable levels of thermal comfort in the facility for both summer and winter cases. The conclusion can be drawn that well-distributed airflow saves energy by removing the need for an additional heating and cooling systems during cold and hot weather seasons.

    Place, publisher, year, edition, pages
    Veetech Ltd., 2010
    Keywords
    industrial ventilation; experimental investigation; indoor climate; supply diffuser
    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:liu:diva-58296 (URN)000279036000006 ()
    Conference
    9th International Conference on Industrial Ventilation, Zurich, Switzerland, 18-21 October 2009
    Available from: 2010-08-10 Created: 2010-08-09 Last updated: 2017-12-12Bibliographically approved
    Download full text (pdf)
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  • 218.
    Janbakhsh, Setareh
    et al.
    Linköping University, Department of Management and Engineering. Linköping University, The Institute of Technology. University of Gävle, Department of Technology and Built Environment, Division of Energy and Mechanical Engineering.
    Moshfegh, Bahram
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Experimental investigation of a new supply diffuser in an office room2009In: Proceedings of 11th International Conference on Air Distribution in Rooms. ROOMVENT, 2009,Busan, Korea, 2009Conference paper (Other academic)
    Abstract [en]

    Full-scale measurements were carried out for investigation of thermal comfort in an office room for a new supply air diffuser. Results of the measurements were performed with both wholefield measuring and traditional point measuring techniques. Experimental results were carried out for supply Archimedes numbers varying from 0.03 to 0.16 and two cooling loads, i.e. 55 and 70 W/m2. Characteristics of indoor environment and occupants’ comfort were explored and analyzed. It was concluded that the airflow pattern and thermal comfort from the investigated low-velocity diffuser were in good agreement with standard ISO 7730.

  • 219.
    Janbakhsh, Setareh
    et al.
    Linköping University, Department of Management and Engineering. Linköping University, The Institute of Technology.
    Moshfegh, Bahram
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Experimental investigation of a ventilation system based on wall confluent jets2014In: Building and Environment, ISSN 0360-1323, E-ISSN 1873-684X, Vol. 80, p. 18-31Article in journal (Refereed)
    Abstract [en]

    The flow behavior of isothermal and non-isothermal wall confluent jets (WCJ) ventilation system was investigated experimentally in a mock-up office environment. Two flow regions were identified: first, a primary region is developed below the supply device, with axis along the inlet wall, and a secondary wall-jet forms along the floor. The velocity and temperature fields were recorded by traversing a hot wire and thermistor anemometers for both primary and secondary regions. The results show self-similarity characteristic of the velocity and temperature profiles for both isothermal and non-isothermal WCJ. Maximum velocity decay and its spreading rate are linear and independent of the inlet airflow rate. Minimum temperature difference and its spread also show linear decay. The spreading rates for maximum velocity are similar in both the primary and secondary regions normal to the inlet wall and floor, respectively, which is consistent with previous studies on wall jets. The variation of draught rating is evaluated via mean velocity, turbulence intensity and temperature. Although the WCJ has slow velocity decay, which enables it to cover almost the entire floor of the test room, the draught is acceptable in the occupied zone according to ISO 7730. PMV (predicted mean vote) and PPD (predicted percentage dissatisfied) are presented for the occupied zone of the room.

  • 220.
    Janbakhsh, Setareh
    et al.
    Linköping University, Department of Management and Engineering. Linköping University, The Institute of Technology. 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.
    Investigation of design parameters for an air supply device based on wall confluent jets2015Manuscript (preprint) (Other academic)
    Abstract [en]

    Numerical predictions of the flow field generated by an air supply device based on wall confluent jets are investigated. The numerical predictions of three turbulence models (RNG 𝑘 − 𝜀, Re 𝑘 − 𝜀, and SST 𝑘 − 𝜔) are compared by velocity and temperature measurements. Ventilation performance in terms of thermal comfort and ventilation efficiency is numerically investigated by systematically varying the design of the air supply (nozzle array configuration, nozzle diameter, number of nozzles, and inlet discharge height). The numerical predictions accomplished by the SST 𝑘 − 𝜔 model provide the best agreement with the experimental results. The numerical predictions for supply devices of varying design configuration show that different device designs provide acceptable thermal environments and efficient heat removal. The nozzle diameter and number of nozzles play important roles in determining the airflow pattern, temperature field, and draught distribution. Increased temperature stratification and less draught distribution are achieved by increasing the nozzle diameter and number of nozzles. The spreading rates of the wall jet along the vertical direction for the cases studied are in close agreement with each other and independent of the studied parameters. The flow behavior is rarely independent of the inlet discharge height and configuration of the nozzle array for the studied range.

  • 221.
    Janbakhsh, Setareh
    et al.
    Linköping University, Department of Management and Engineering. Linköping University, The Institute of Technology.
    Moshfegh, Bahram
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Numerical study of a ventilation system based on wall confluent jets2014In: HVAC & R RESEARCH, ISSN 1078-9669, E-ISSN 1938-5587, Vol. 20, no 8, p. 846-861Article in journal (Refereed)
    Abstract [en]

    This study presents numerical investigation of an air supply device based on wall confluent jets in a ventilated room. Confluent jets can be described as multiple round jets issuing from supply device apertures. The jets converge, merge, and combine at a certain distance downstream from the supply device and behave as a united jet, or so-called confluent jet. The numerical predictions of the velocity flow field of isothermal confluent jets with three Reynolds-averaged Navier-Stokes turbulence models (renormalization group k-epsilon, realizable k-epsilon, and shear stress transport k-omega) are reported in the present study. The results of the numerical predictions are verified with detailed experimental measurements by a hot wire anemometer and constant temperature anemometers for two airflow rates. The box method is used to provide the inlet boundary conditions. The study of the airflow distribution shows that a primary wall jet (wall confluent jet) exists close to the supply device along the wetted wall, and a secondary wall jet is created after the stagnation region along the floor. It is presented that the flow field of the primary and secondary wall jet predicted by turbulence models is in good agreement with the experimental data. The current study is also compared with the literature in terms of velocity decay and the spreading rate of the primary and secondary wall jet, the results of which are consistent with each other. Velocity decay and the spreading rate of the secondary wall jet in vertical and lateral directions were studied for different inlet airflow rates and inlet discharge heights. The comparative results demonstrate that the flow behavior is nearly independent of the inlet flow rate. Inlet discharge height is found to have impact close to the inlet, where the velocity decays faster when the jet discharges at higher level. The decay tendency is similar as the jet enters into the room for all discharge heights.

  • 222.
    Janbakhsh, Setareh
    et al.
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology. University of Gävle, Department of Technology and Built Environment, Division of Energy and Mechanical Engineerin.
    Moshfegh, Bahram
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology. University of Gävle, Department of Technology and Built Environment, Division of Energy and Mechanical Engineerin.
    Ghahremanian, Shahriar
    Linköping University, Department of Management and Engineering. Linköping University, The Institute of Technology. University of Gävle, Department of Technology and Built Environment, Division of Energy and Mechanical Engineerin.
    A Newly Designed Supply Diffuser for Industrial Premises2010In: The International Journal of Ventilation, ISSN 1473-3315, E-ISSN 2044-4044, Vol. 9, no 1, p. 59-67Article in journal (Refereed)
    Abstract [en]

    The results of this investigation revealed the airflow distribution from a new design of supply diffuser under non-isothermal conditions. To illustrate the indoor climate parameters in the occupied zone, for both the heating and cooling seasons, an experimental investigation was carried out in industrial premises. The indoor climate was explored at ankle, waist and neck levels for a standing person at different positions, to determine the variation of the thermal comfort indexes and draught rating (DR) with position in the facility. The observed PPD and DR values indicate acceptable levels of thermal comfort in the facility for both summer and winter cases. The conclusion can be drawn that well-distributed airflow saves energy by removing the need for an additional heating and cooling systems during cold and hot weather seasons.

  • 223.
    Jansson, Tomas
    et al.
    Linköping University, Department of Management and Engineering, Solid Mechanics. Linköping University, The Institute of Technology.
    Nilsson, Lars
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Moshfegh, Ramin
    Linköping University, Department of Mechanical Engineering, Solid Mechanics. Linköping University, The Institute of Technology.
    Reliability analysis of a sheet metal forming process using Monte Carlo analysis and metamodels2008In: Journal of Materials Processing Technology, ISSN 0924-0136, E-ISSN 1873-4774, Vol. 202, no 1-3, p. 255-268Article in journal (Refereed)
    Abstract [en]

    The aim of the present paper is to evaluate the use of linear and quadratic approximating response surfaces as metamodels in a reliability assessment of a sheet metal forming process using the Monte Carlo simulation technique. Monte Carlo simulation was used to determine the probability for springback and thickness variation in a sheet metal part. The conclusions of this study is that Monte Carlo analysis can be used to identify the most important variables and to estimate the range of the studied responses. Linear metamodels can be used to identify the important variables and to give an estimate of the probabilistic response. But quadratic surfaces are required for a more accurate analysis.

  • 224.
    Johansson, Daniella
    et al.
    Värmeteknik och maskinlära, Chalmers tekniska högskola, Göteborg.
    Johansson, Maria
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Karltorp, Kersti
    Miljösystemanalys ,Chalmers tekniska högskola, Göteborg.
    Ljungstedt, Hanna
    Värmeteknik och maskinlära, Chalmers tekniska högskola, Göteborg.
    Schwabecker, Julia
    Linköping University, The Tema Institute, Technology and Social Change. Linköping University, Faculty of Arts and Sciences.
    Pathways for Increased Use and Refining of Biomass in Swedish Energy-intensive Industry: Changes in a socio-technical system2009Report (Other academic)
    Abstract [en]

    Events in recent decades have placed climate change at the top of the political agenda. The European Union has assumed a vanguard role in global climate negotiations, pushing for ambitious international commitments. Furthermore, Sweden is positioning itself as a leader within the EU when it comes to setting the agenda for climate change. In Sweden, energy-intensive industries are responsible for a large proportion of greenhouse gas emissions and their ability to switch to a renewable energy source could contribute significantly to the transition to a decarbonised economy.

     

    This study analyses the role of three energy-intensive industries with regard to increased refining and use of biomass and will also take a glimpse into the future in an attempt to gain further insight into what will affect future developments in this area. The study is limited to the pulp and paper industry, the iron and steel industry and the oil refining industry as well as the EU legislation that affects these industries. For each industry the operations of the following case companies, Södra, SSAB and Preem AB, are analysed specifically and for each company one or two selected plants exemplify the outcome of the implementation of different technologies. This interdisciplinary study combines a range of methods taken from engineering and social sciences.

     

    The industries studied all have different preconditions for transformations and the technological options available diverge to a large extent. There are many options for the pulp and paper industry compared to the iron and steel industry and the oil refining industry. The most likely technological option for this sector is to utilise internal resources for conversion to energy or material products and export of excess energy. Options for the steel producer SSAB include the substitution of part of the coke in the blast furnace with biomass or refined biomass products such as syngas and biomethane and forming an industrial symbiotic partnership. There are several options for the oil refining industry to substitute fossil feedstocks without the need to modify the existing infrastructure. One option is hydrotreatment of bio-oil into green diesel, which will be implemented at the Preem refinery in Gothenburg. However, green production of transportation fuels and substitution of coke in the blast furnace require large amounts of biomass and since biomass is a limited resource this is likely to act as a barrier to the development of these technologies.

     

    Furthermore, it can be concluded that the companies studied could contribute significantly to the development of technologies that are in line with their core capabilities, while the development of technological options that require a change in their core capabilities is more limited. This discovery is further supported by the finding that the EU directives relevant to this report do not push industrial operators beyond efficiency measures along established technological lines. On the one hand, these legislative instruments, which are designed in the spirit of ecological modernisation, encourage the most cost-effective technologies and processes for the abatement of greenhouse gases relevant to each industry. On the other, they do not appear to be sufficient to raise the cost of carbon emissions and this contributes to a situation where incentives to make different biomass-based technologies economic are not present on the market. Over a longer time perspective none of the case companies believes that biomass will have increased significantly in the Swedish energy system by 2050. These case companies claim that biomass is too limited a resource and can only contribute in part to the necessary substitution of fossil fuels.

    Download full text (pdf)
    Pathways for Increased Use and Refining of Biomass in Swedish Energy-intensive Industry : Changes in a socio-technical system
  • 225.
    Johansson, Maria
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology. Högskolan i Gävle.
    Bio-synthetic natural gas as fuel in steel industry reheating furnaces: A case study of economic performance and effects on global COemissions2013In: Energy, ISSN 0360-5442, E-ISSN 1873-6785, Vol. 57, p. 699-708Article in journal (Refereed)
    Abstract [en]

    Climate change is of great concern for society today. Manufacturing industries and construction account for approximately 20% of global CO2 emissions and, consequently, it is important that this sector investigate options to reduce its CO2 emissions. One option could be to substitute fossil fuels with renewable alternatives. This paper describes a case study in which four future energy market scenarios predicting 2030 were used to analyse whether it would be profitable for a steel plant to produce bio-SNG (bio-synthetic natural gas) in a biomass gasifier and to substitute LPG (liquefied petroleum gas) with bio-SNG as fuel in reheating furnaces. The effects on global CO2 emissions were analysed from a perspective in which biomass is considered a limited resource. The results from the analysis show that investment in a biomass gasifier and fuel conversion would not be profitable in any of the scenarios. Depending on the scenario, the production cost for bio-SNG ranged between 22 and 36 EUR/GJ. Fuel substitution would reduce global CO2 emission if the marginal biomass user is a producer of transportation fuel. However, if the marginal user of biomass is a coal power plant with wood co-firing, the result would be increased global CO2 emissions

    Download full text (pdf)
    Bio-synthetic natural gas as fuel in steel industry reheating furnaces – a case study of economic performance and effects on global CO2 emissions
  • 226. Order onlineBuy this publication >>
    Johansson, Maria
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Improved Energy Efficiency and Fuel Substitution in the Iron and Steel Industry2014Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    IPCC reported in its climate change report 2013 that the atmospheric concentrations of the greenhouse gases (GHG) carbon dioxide (CO2), methane, and nitrous oxide now have reached the highest levels in the past 800,000 years. CO2 concentration has increased by 40% since pre-industrial times and the primary source is fossil fuel combustion. It is vital to reduce anthropogenic emissions of GHGs in order to combat climate change. Industry accounts for 20% of global anthropogenic CO2 emissions and the iron and steel industry accounts for 30% of industrial emissions. The iron and steel industry is at date highly dependent on fossil fuels and electricity. Energy efficiency measures and substitution of fossil fuels with renewable energy would make an important contribution to the efforts to reduce emissions of GHGs.

    This thesis studies energy efficiency measures and fuel substitution in the iron and steel industry and focuses on recovery and utilisation of excess energy and substitution of fossil fuels with biomass. Energy systems analysis has been used to investigate how changes in the iron and steel industry’s energy system would affect the steel plant’s economy and global CO2 emissions. The thesis also studies energy management practices in the Swedish iron and steel industry with the focus on how energy managers think about why energy efficiency measures are implemented or why they are not implemented. In-depth interviews with energy managers at eleven Swedish steel plants were conducted to analyse energy management practices.

    In order to show some of the large untapped heat flows in industry, excess heat recovery potential in the industrial sector in Gävleborg County in Sweden was analysed. Under the assumptions made in this thesis, the recovery output would be more than three times higher if the excess heat is used in a district heating system than if electricity is generated. An economic evaluation was performed for three electricity generation technologies for the conversion of low-temperature industrial excess heat. The results show that electricity generation with organic Rankine cycles and phase change material engines could be profitable, but that thermoelectric generation of electricity from low-temperature industrial excess heat would not be profitable at the present stage of technology development. With regard to fossil fuels substituted with biomass, there are opportunities to substitute fossil coal with charcoal in the blast furnace and to substitute liquefied petroleum gas (LPG) with bio-syngas or bio synthetic natural gas (bio-SNG) as fuel in the steel industry’s reheating furnaces. However, in the energy market scenarios studied, substituting LPG with bio-SNG as fuel in reheating furnaces at the studied scrap-based steel plant would not be profitable without economic policy support. The development of the energy market is shown to play a vital role for the outcome of how different measures would affect global CO2 emissions.

    Results from the interviews show that Swedish steel companies regard improved energy efficiency as important. However, the majority of the interviewed energy managers only worked part-time with energy issues and they experienced that lack of time often was a barrier for successful energy management. More efforts could also be put into engaging and educating employees in order to introduce a common practice of improving energy efficiency at the company.

    List of papers
    1. Options for the Swedish steel industry - Energy efficiency measures and fuel conversion
    Open this publication in new window or tab >>Options for the Swedish steel industry - Energy efficiency measures and fuel conversion
    2011 (English)In: Energy, ISSN 0360-5442, E-ISSN 1873-6785, Vol. 36, no 1, p. 191-198Article in journal (Refereed) Published
    Abstract [en]

    The processes of iron and steel making are energy intensive and consume large quantities of electricity and fossil fuels. In order to meet future climate targets and energy prices, the iron and steel industry has to improve its energy and resource efficiency. For the iron and steel industry to utilize its energy resources more efficiently and at the same time reduce its CO2 emissions a number of options are available. In this paper, opportunities for both integrated and scrap-based steel plants are presented and some of the options are electricity production, fuel conversion, methane reforming of coke oven gas and partnership in industrial symbiosis. The options are evaluated from a system perspective and more specific measures are reported for two Swedish case companies: SSAB Strip Products and Sandvik AB. The survey shows that both case companies have great potentials to reduce their CO2 emissions.

    Place, publisher, year, edition, pages
    Elsevier, 2011
    Keywords
    Iron and steel industry, Energy efficiency, Fuel conversion, Industrial symbiosis, Excess energy, CO2 emissions
    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:liu:diva-66142 (URN)10.1016/j.energy.2010.10.053 (DOI)000286781800021 ()
    Note

    Original Publication: Maria Johansson and Mats Söderström, Options for the Swedish steel industry - Energy efficiency measures and fuel conversion, 2011, ENERGY, (36), 1, 191-198. http://dx.doi.org/10.1016/j.energy.2010.10.053 Copyright: Elsevier Science B.V., Amsterdam. http://www.elsevier.com/

    Available from: 2011-03-04 Created: 2011-03-04 Last updated: 2017-12-11Bibliographically approved
    2. 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
    3. Electricity generation from low-temperature industrial excess heat—an opportunity for the steel industry
    Open this publication in new window or tab >>Electricity generation from low-temperature industrial excess heat—an opportunity for the steel industry
    2014 (English)In: Energy Efficiency, ISSN 1570-646X, E-ISSN 1570-6478, Vol. 7, no 2, p. 203-215Article in journal (Refereed) Published
    Abstract [en]

    Awareness of climate change and the threat of rising energy prices have resulted in increased attention being paid to energy issues and industry seeing a cost benefit in using more energy-efficient production processes. One energy-efficient measure is the recovery of industrial excess heat. However, this option has not been fully investigated and some of the technologies for recovery of excess heat are not yet commercially available. This paper proposes three technologies for the generation of electricity from low-temperature industrial excess heat. The technologies are thermoelectric generation, organic Rankine cycle and phase change material engine system. The technologies are evaluated in relation to each other, with regard to temperature range of the heat source, conversion efficiency, capacity and economy. Because the technologies use heat of different temperature ranges, there is potential for concurrent implementation of two or more of these technologies. Even if the conversion efficiency of a technology is low, it could be worthwhile to utilise if there is no other use for the excess heat. The iron and steel industry is energy intensive and its production processes are often conducted at high temperatures. As a consequence, large amounts of excess heat are generated. The potential electricity production from low-temperature excess heat at a steel plant was calculated together with the corresponding reduction in global CO2 emissions.

    Place, publisher, year, edition, pages
    Springer Netherlands, 2014
    Keywords
    Low-temperature excess heat, Heat recovery, Electricity generation, Thermoelectric generator (TEG), Organic Rankine cycle (ORC), Phase change material (PCM) engine
    National Category
    Energy Systems
    Identifiers
    urn:nbn:se:liu:diva-94561 (URN)10.1007/s12053-013-9218-6 (DOI)000332789200003 ()
    Funder
    Swedish Energy Agency
    Available from: 2013-06-26 Created: 2013-06-26 Last updated: 2017-12-06
    4. Bio-syngas as fuel in the steel industry's heating furnaces: a case study on feasibility and CO2 mitigation effects
    Open this publication in new window or tab >>Bio-syngas as fuel in the steel industry's heating furnaces: a case study on feasibility and CO2 mitigation effects
    2011 (English)Conference paper, Published paper (Other academic)
    Abstract [en]

    Today, climate change is at the top of the political agenda. The European Commission has set atarget to reduce greenhouse gas emissions by 20 % by 2020, compared to 1990 levels. The steelindustry contributes significantly to industrial CO2 emissions, and thus it is important for thissector to find options to reduce its CO2 emissions. One alternative is to substitute fossil fuelswith biomass derived fuels; a promising option is to replace LPG (Liquefied Petroleum Gas) used asfuel in heating furnaces with bio-syngas produced through the gasification of biomass. This paperis a feasibility study of the implementation of this concept at a Swedish scrap-based steel plant.The results have been obtained through a case study approach with interviews and literaturesurveys. The study shows that if a fuel gas mixture of 50 vol% bio-syngas and 50 vol% LPG would beused, the global CO2 emissions would be reduced by 5,400 tonnes/year. Moreover, a full-scale fuelsubstitution would result in reduced emissions by 68,600 tonnes/year. In the case of a partial fuelsubstitution, a 4 MWth High Temperature Agent Gasifier (HTAG) is a suitable choice while a 45 MWthindirectly heated Circulating Fluidised Bed Gasifier (CFBG) would be suitable for a full-scale fuelsubstitution. In the case of a fuel switch, the lower heating value of syngas, compared to LPG, notonly implies that a different combustion technology must be used, but also that the exhaust gasflows will be substantially larger, and consequently the exhaust gas cleaning system must bedesigned with dimensions suitable for larger flows. Excess heat from the gasifier can be used forspace heating, but if the excess heat replaces district heating from a Combined Heat and Power(CHP) plant, the global CO2 emissionsreductions would be less than if the excess heat is not recovered.

    Keywords
    Fuel conversion, steel industry, biomass, case study, gasification
    National Category
    Energy Systems
    Identifiers
    urn:nbn:se:liu:diva-71824 (URN)
    Conference
    ECOS 2011 - 24th International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems, July 4-7, Novi Sad, Serbia
    Available from: 2011-11-07 Created: 2011-11-07 Last updated: 2016-05-04Bibliographically approved
    5. Bio-synthetic natural gas as fuel in steel industry reheating furnaces: A case study of economic performance and effects on global COemissions
    Open this publication in new window or tab >>Bio-synthetic natural gas as fuel in steel industry reheating furnaces: A case study of economic performance and effects on global COemissions
    2013 (English)In: Energy, ISSN 0360-5442, E-ISSN 1873-6785, Vol. 57, p. 699-708Article in journal (Refereed) Published
    Abstract [en]

    Climate change is of great concern for society today. Manufacturing industries and construction account for approximately 20% of global CO2 emissions and, consequently, it is important that this sector investigate options to reduce its CO2 emissions. One option could be to substitute fossil fuels with renewable alternatives. This paper describes a case study in which four future energy market scenarios predicting 2030 were used to analyse whether it would be profitable for a steel plant to produce bio-SNG (bio-synthetic natural gas) in a biomass gasifier and to substitute LPG (liquefied petroleum gas) with bio-SNG as fuel in reheating furnaces. The effects on global CO2 emissions were analysed from a perspective in which biomass is considered a limited resource. The results from the analysis show that investment in a biomass gasifier and fuel conversion would not be profitable in any of the scenarios. Depending on the scenario, the production cost for bio-SNG ranged between 22 and 36 EUR/GJ. Fuel substitution would reduce global CO2 emission if the marginal biomass user is a producer of transportation fuel. However, if the marginal user of biomass is a coal power plant with wood co-firing, the result would be increased global CO2 emissions

    Place, publisher, year, edition, pages
    Elsevier, 2013
    Keywords
    Biomass gasification, Steel industry, Case study, Fuel substitution, Bio-synthetic natural gas (bio-SNG), CO2 emissions
    National Category
    Energy Systems
    Identifiers
    urn:nbn:se:liu:diva-96677 (URN)10.1016/j.energy.2013.06.010 (DOI)000323355600073 ()
    Funder
    Swedish Energy Agency
    Available from: 2013-08-22 Created: 2013-08-22 Last updated: 2017-12-06Bibliographically approved
    6. Improved energy efficiency within the Swedish steel industry: the importance of energy management and networking
    Open this publication in new window or tab >>Improved energy efficiency within the Swedish steel industry: the importance of energy management and networking
    2015 (English)In: Energy Efficiency, ISSN 1570-646X, E-ISSN 1570-6478, Vol. 8, no 4, p. 713-744Article in journal (Refereed) Published
    Abstract [en]

    The iron and steel industry is an energy-intensive industry that consumes a significant portion of fossil fuel and electricity production. Climate change, the threat of an unsecure energy supply, and rising energy prices have emphasized the issue of improved energy efficiency in the iron and steel industry. However, an energy efficiency gap is well recognised, i.e. cost efficient measures are not implemented in practice. This study will go deeper into why this gap occurs by investigating energy management practices at 11 iron and steel companies in Sweden. Energy managers at the steel plants were interviewed about how they perceived their own and their companies’ efforts to improve energy efficiency and how networking among energy managers influenced the efforts to improve energy efficiency. Reported barriers to improved energy efficiency were, for example, too long of a payback period, lack of profitability, lack of personnel, risk of production disruption, lack of time, and lack of commitment. Only three out of the eleven companies had assigned a person to work full time with energy management, and some of the energy managers were frustrated with not having enough time to work with energy issues. Generally, the respondents felt that they had support from senior management and that energy issues were prioritised, but only a few of the companies had made great efforts to involve employees in improving energy efficiency. Networking among Swedish steel companies was administered by the Swedish Steel Producers’ Association, and their networking meetings contributed to the exchange of knowledge and ideas. In conclusion, Swedish steel companies regard improved energy efficiency as important but have much work left to do in this area. For example, vast amounts of excess heat are not being recovered and more efforts could be put into engaging employees and introducing a culture of energy  efficiency.

    Place, publisher, year, edition, pages
    Springer Netherlands, 2015
    Keywords
    Energy efficiency, Energy management, Networking, Iron and steel industry, Interviews
    National Category
    Energy Engineering
    Identifiers
    urn:nbn:se:liu:diva-105873 (URN)10.1007/s12053-014-9317-z (DOI)000358046700006 ()
    Available from: 2014-04-11 Created: 2014-04-11 Last updated: 2017-12-05Bibliographically approved
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    Improved Energy Efficiency and Fuel Substitution in the Iron and Steel Industry
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  • 227.
    Johansson, Maria
    et al.
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, Faculty of Science & Engineering.
    Djuric Ilic, Danica
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, Faculty of Science & Engineering.
    Review of sustainable development of the road transport sector: Are there geographical differences?2018In: WEENTECH Proceedings in Energy 4 (2018) 67-87, WEENTECH Ltd. , 2018, Vol. 4, p. 67-87Conference paper (Refereed)
    Abstract [en]

    Even though the share of renewable energy in the transport sector has increased during the last decade, the sector is still highly dependent on fossil fuels. Consequences are for example emissions of greenhouse gases, particulates, carbon monoxide and nitrogen oxides. This is of great concern for the environment, climate change, and human health. This study reviews scientific publications about sustainable development of the road transport sector, published 2005-2018. The aim of the study is to investigate if there are differences in the measures and strategies presented in the publications depending on the geographical areas studied, and to analyse if there are differences depending on year of publication. The authors analysed to what extent local conditions influence the choice of proposed measures and strategies. A system perspective was applied in order to include measures related to the whole life cycle of the road transport, as well as other sectors, which influence or are influenced by the transport sector. A literature review was performed using the search-engine Web of Science. Results show that important local conditions that may influence the research focus within the area of sustainable development of the road transport sector are for example: energy supply security (e.g. availability of biomass and renewable electricity, as well as access to domestic fossil fuel resources), possibilities for developing infrastructure for biofuel supply and charging of electric vehicles, political priorities and approaches, and traditions.

  • 228.
    Johansson, Maria
    et al.
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, Faculty of Science & Engineering.
    Haraldsson, Joakim
    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.
    Energy efficient supply chain of an aluminium product in Sweden – What can be done in-house and between the companies?2018In: eceee 2018 Industrial Summer Study proceedings / [ed] Therese Laitinen Lindström, Ylva Blume & Nina Hampus, Stockholm, Sweden: European Council for an Energy Efficient Economy (ECEEE), 2018, p. 369-377Conference paper (Refereed)
    Abstract [en]

    According to the Energy Efficiency Directive executed by the European Union, each member state is obliged to set a national target on energy efficiency. This requirement constitutes the basis for governments to formulate policy measures directed towards industrial companies. Such policy measures, along with the demand for cost-effective production to remain competitive on the market, motivates industrial companies to improve their energy efficiency. The aluminium industry is energy intensive and consumes substantial amounts of electricity and fossil fuels, resulting in both direct and indirect greenhouse gas emissions. This paper presents a study of the production of an aluminium product in Sweden in terms of implemented energy efficiency measures in the supply chain and potential areas for further improvement. Most previous studies have focused on energy efficiency measures in individual companies (value chains). However, this paper presents and analyses energy efficiency measures not only in each individual company but also in the entire supply chain of the product. The supply chain studied starts with secondary aluminium production followed by the production of a part of an automobile motor and ends with installing the motor detail in a car. Empirical data were gathered through a questionnaire and a focus group. The study shows the great potential for further energy efficiency improvements in the value chains of each individual company and in the whole supply chain. The work shown here is a part of a larger research project performed in close cooperation with the Swedish aluminium industry.

    Download full text (pdf)
    fulltext
  • 229.
    Johansson, Maria
    et al.
    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.
    Bio-SNG as fuel in steel industry heating furnaces: integration of a biomass gasifier with a steel plant2012In: Asia Steel International Conference 2012, 2012Conference paper (Other academic)
    Abstract [en]

    Climate change, as a result of anthropogenic greenhouse gas (GHG) emissions, is of great concern for society today. Industry accounts for almost 40% of global CO2 emissions and consequently it is important that this sector investigate options to reduce its CO2 emissions. In this paper, an economic evaluation of integration of a biomass gasifier with a steel plant is performed. Synthetic natural gas (bio-SNG) from the gasifier substitutes liquefied petroleum gas as fuel in the steel plant’s heating furnaces. Eight future market scenarios are used to analyse investment opportunities to integrate production of bio-SNG with a case study steel plant. Results from the analysis show that high fossil fuel prices could make integration of a biomass gasifier and fuel conversion profitable. Moreover, profitability is highly dependent on biomass price. At current price levels, production cost for bio-SNG is 82 EUR/MWh.

  • 230.
    Johansson, Maria
    et al.
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, Faculty of Science & Engineering. Linköping University, Biogas Research Center.
    Lindkvist, Emma
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, Faculty of Science & Engineering. Linköping University, Biogas Research Center.
    Rosenqvist, Jakob
    Tranås Energi, Sweden.
    Methodology for Analysing Energy Demand in Biogas Production Plants: A Comparative Study of Two Biogas Plants2017In: Energies, ISSN 1996-1073, E-ISSN 1996-1073, Vol. 10, no 11, article id 1822Article in journal (Refereed)
    Abstract [en]

    Biogas production through anaerobic digestion may play an important role in a circular economy because of the opportunity to produce a renewable fuel from organic waste. However, the production of biogas may require energy in the form of heat and electricity. Therefore, resource-effective biogas production must consider both biological and energy performance. For the individual biogas plant to improve its energy performance, a robust methodology to analyse and evaluate the energy demand on a detailed level is needed. Moreover, to compare the energy performance of different biogas plants, a methodology with a consistent terminology, system boundary and procedure is vital. The aim of this study was to develop a methodology for analysing the energy demand in biogas plants on a detailed level. In the methodology, the energy carriers are allocated to: (1) sub-processes (e.g., pretreatment, anaerobic digestion, gas cleaning), (2) unit processes (e.g., heating, mixing, pumping, lighting) and (3) a combination of these. For a thorough energy analysis, a combination of allocations is recommended. The methodology was validated by applying it to two different biogas plants. The results show that the methodology is applicable to biogas plants with different configurations of their production system.

    Download full text (pdf)
    fulltext
  • 231.
    Johansson, Maria
    et al.
    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.
    Bio-syngas as fuel in the steel industry's heating furnaces: a case study on feasibility and CO2 mitigation effects2011Conference paper (Other academic)
    Abstract [en]

    Today, climate change is at the top of the political agenda. The European Commission has set atarget to reduce greenhouse gas emissions by 20 % by 2020, compared to 1990 levels. The steelindustry contributes significantly to industrial CO2 emissions, and thus it is important for thissector to find options to reduce its CO2 emissions. One alternative is to substitute fossil fuelswith biomass derived fuels; a promising option is to replace LPG (Liquefied Petroleum Gas) used asfuel in heating furnaces with bio-syngas produced through the gasification of biomass. This paperis a feasibility study of the implementation of this concept at a Swedish scrap-based steel plant.The results have been obtained through a case study approach with interviews and literaturesurveys. The study shows that if a fuel gas mixture of 50 vol% bio-syngas and 50 vol% LPG would beused, the global CO2 emissions would be reduced by 5,400 tonnes/year. Moreover, a full-scale fuelsubstitution would result in reduced emissions by 68,600 tonnes/year. In the case of a partial fuelsubstitution, a 4 MWth High Temperature Agent Gasifier (HTAG) is a suitable choice while a 45 MWthindirectly heated Circulating Fluidised Bed Gasifier (CFBG) would be suitable for a full-scale fuelsubstitution. In the case of a fuel switch, the lower heating value of syngas, compared to LPG, notonly implies that a different combustion technology must be used, but also that the exhaust gasflows will be substantially larger, and consequently the exhaust gas cleaning system must bedesigned with dimensions suitable for larger flows. Excess heat from the gasifier can be used forspace heating, but if the excess heat replaces district heating from a Combined Heat and Power(CHP) plant, the global CO2 emissionsreductions would be less than if the excess heat is not recovered.

  • 232.
    Johansson, Maria
    et al.
    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.
    Electricity generation from low-temperature industrial excess heat—an opportunity for the steel industry2014In: Energy Efficiency, ISSN 1570-646X, E-ISSN 1570-6478, Vol. 7, no 2, p. 203-215Article in journal (Refereed)
    Abstract [en]

    Awareness of climate change and the threat of rising energy prices have resulted in increased attention being paid to energy issues and industry seeing a cost benefit in using more energy-efficient production processes. One energy-efficient measure is the recovery of industrial excess heat. However, this option has not been fully investigated and some of the technologies for recovery of excess heat are not yet commercially available. This paper proposes three technologies for the generation of electricity from low-temperature industrial excess heat. The technologies are thermoelectric generation, organic Rankine cycle and phase change material engine system. The technologies are evaluated in relation to each other, with regard to temperature range of the heat source, conversion efficiency, capacity and economy. Because the technologies use heat of different temperature ranges, there is potential for concurrent implementation of two or more of these technologies. Even if the conversion efficiency of a technology is low, it could be worthwhile to utilise if there is no other use for the excess heat. The iron and steel industry is energy intensive and its production processes are often conducted at high temperatures. As a consequence, large amounts of excess heat are generated. The potential electricity production from low-temperature excess heat at a steel plant was calculated together with the corresponding reduction in global CO2 emissions.

    Download full text (pdf)
    Electricity generation from low temperature industrial excess heat – an opportunity for the steel industry
  • 233.
    Johansson, Maria
    et al.
    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.
    Options for the Swedish steel industry - Energy efficiency measures and fuel conversion2011In: Energy, ISSN 0360-5442, E-ISSN 1873-6785, Vol. 36, no 1, p. 191-198Article in journal (Refereed)
    Abstract [en]

    The processes of iron and steel making are energy intensive and consume large quantities of electricity and fossil fuels. In order to meet future climate targets and energy prices, the iron and steel industry has to improve its energy and resource efficiency. For the iron and steel industry to utilize its energy resources more efficiently and at the same time reduce its CO2 emissions a number of options are available. In this paper, opportunities for both integrated and scrap-based steel plants are presented and some of the options are electricity production, fuel conversion, methane reforming of coke oven gas and partnership in industrial symbiosis. The options are evaluated from a system perspective and more specific measures are reported for two Swedish case companies: SSAB Strip Products and Sandvik AB. The survey shows that both case companies have great potentials to reduce their CO2 emissions.

    Download full text (pdf)
    FULLTEXT01
  • 234.
    Johansson, Maria
    et al.
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, Faculty of Science & Engineering.
    Söderström, Mats
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, Faculty of Science & Engineering.
    Ökad energieffektivitet i aluminiumindustrins värdekedjor2015In: Aluminium Scandinavia, ISSN 0282-2628, Vol. 32, no 5, p. 1Article in journal (Other academic)
    Abstract [sv]

    Det övergripande syftet är att undersöka energieffektiviseringspotentialerna och möjligheterna att realisera dessa i hela värdekedjan (från metallframställning till återvinning) i aluminiumindustrin. Branschen använder årligen ca 3 TWh och delar av den är mycket energiintensiv, 30-40% av kostnaderna för produktion av primäralúminium är energi.

  • 235.
    Johansson, Maria T.
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, Faculty of Science & Engineering.
    Effects on global CO2 emissions when substituting LPG with bio-SNG as fuel in steel industry reheating furnaces: The impact of different perspectives on CO2 assessment2016In: Energy Efficiency, ISSN 1570-646X, E-ISSN 1570-6478, Vol. 9, no 6, p. 1437-1445Article in journal (Refereed)
    Abstract [en]

    The iron and steel industry is the second largest user of energy in the world industrial sector and is currently highly dependent on fossil fuels and electricity. Substituting fossil fuels with renewable energy in the iron and steel industry would make an important contribution to the efforts to reduce emissions of CO2. However, different approaches to assessing CO2 emissions from biomass and electricity use generate different results when evaluating how fuel substitution would affect global CO2 emissions. This study analyses the effects on global CO2 emissions when substituting liquefied petroleum gas with synthetic natural gas, produced through gasification of wood fuel, as a fuel in reheating furnaces at a scrap-based steel plant. The study shows that the choice of system perspective has a large impact on the results. When wood fuel is considered available for all potential users, a fuel switch would result in reduced global CO2 emissions. However, applying a perspective where wood fuel is seen as a limited resource and alternative use of wood fuel is considered, a fuel switch could in some cases result in increased global CO2 emissions. As an example, in one of the scenarios studied, a fuel switch would reduce global CO2 emissions by 52 ktonnes/year if wood fuel is considered available for all potential users, while seeing wood fuel as a limited resource implies, in the same scenario, increased CO2 emissions by 70 ktonnes/year. The choice of method for assessing electricity use also affects the results.

    Download full text (pdf)
    fulltext
  • 236.
    Johansson, Maria T.
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Improved energy efficiency within the Swedish steel industry: the importance of energy management and networking2015In: Energy Efficiency, ISSN 1570-646X, E-ISSN 1570-6478, Vol. 8, no 4, p. 713-744Article in journal (Refereed)
    Abstract [en]

    The iron and steel industry is an energy-intensive industry that consumes a significant portion of fossil fuel and electricity production. Climate change, the threat of an unsecure energy supply, and rising energy prices have emphasized the issue of improved energy efficiency in the iron and steel industry. However, an energy efficiency gap is well recognised, i.e. cost efficient measures are not implemented in practice. This study will go deeper into why this gap occurs by investigating energy management practices at 11 iron and steel companies in Sweden. Energy managers at the steel plants were interviewed about how they perceived their own and their companies’ efforts to improve energy efficiency and how networking among energy managers influenced the efforts to improve energy efficiency. Reported barriers to improved energy efficiency were, for example, too long of a payback period, lack of profitability, lack of personnel, risk of production disruption, lack of time, and lack of commitment. Only three out of the eleven companies had assigned a person to work full time with energy management, and some of the energy managers were frustrated with not having enough time to work with energy issues. Generally, the respondents felt that they had support from senior management and that energy issues were prioritised, but only a few of the companies had made great efforts to involve employees in improving energy efficiency. Networking among Swedish steel companies was administered by the Swedish Steel Producers’ Association, and their networking meetings contributed to the exchange of knowledge and ideas. In conclusion, Swedish steel companies regard improved energy efficiency as important but have much work left to do in this area. For example, vast amounts of excess heat are not being recovered and more efforts could be put into engaging employees and introducing a culture of energy  efficiency.

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  • 237.
    Johansson, Maria
    et al.
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, Faculty of Science & Engineering.
    Thollander, Patrik
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, Faculty of Science & Engineering.
    A review of barriers to and driving forces for improved energy efficiency in Swedish industry: Recommendations for successful in-house energy management2018In: Renewable & sustainable energy reviews, ISSN 1364-0321, E-ISSN 1879-0690, Vol. 82, no Part 1, p. 618-628Article, review/survey (Refereed)
    Abstract [en]

    From an environmental point of view, reduced use of energy remains a cornerstone in global greenhouse gas mitigation. However, without full internalization of external costs, greenhouse gas mitigation as such may not be highly prioritized among business leaders. Rather, it is the magnitude of production costs and ultimately the size of market revenue that articulates success or failure for business leaders. Nevertheless, reduced energy use or improved energy efficiency can have a vast impact on profitability even for companies with low energy costs, as the reduced energy costs directly lead to increased profits. In this paper, a review of ten years of empirical research in the field of industrial energy management in Swedish industry is presented. Based on the review, the paper proposes success factors for efficient energy management, factors which could help guide individual energy managers as well as policy makers in order to close the energy efficiency and management gaps. The paper also presents an overview of important industrial energy management tools, which would facilitate in-house energy management in industry.

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  • 238.
    Johansson, Per-Erik
    et al.
    DynaMate Industrial Services AB, Stockholm, Sweden.
    Thollander, Patrik
    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.
    Towards increased energy efficiency in industry – a manager’s perspective2011In: Proceedings of the World Renewable Energy Congress 2011 (WREC 2011), 9-13 May, Linköping., Linköping University Electronic Press, 2011, Vol. 7, p. 1644-1651Conference paper (Refereed)
    Abstract [en]

    Industry is one of the major users of fossils fuels resulting in emissions of GHG (Green House Gases), leading to global climate change. One means of promoting energy efficiency in industry is energy management. The aim of this paper is to outline a number of energy management related factors which affects energy management in industry positively. The paper is a result of collaboration between industry professionals and researchers within an ongoing research project and addresses the issue using a bottom-up energy management perspective. Results indicate that that the “soft” issues of energy management play a crucial role in the success (or not) of energy management in industry, e.g. the manager’s role and attitude towards the employees cannot be understated. Instead it addresses that implementation is not only about technology but equally or even more important, concerns the diffusion and adoption of energy management practices and principals.

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  • 239.
    Johnsson, Simon
    Linköping University, Department of Management and Engineering, Energy Systems.
    Energisystemanalys vid Tekniska verkens kraftvärmeverk2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The CHP-plant in Linköping (KV1) run by Tekniska verken has experienced an imbalance partly between the amount of fuel added to the boiler and the amount of produced steam, partly between the amount of produced steam and the amount of useful steam in the district heating grid. This thesis aimed to help Tekniska verken investigate the imbalance between the amount of added fuel and the amount of produced steam. The investigation was done by developing a method for calculating the direct and indirect efficiency through studying standards and old theses within the field. Initially there were no clear theory behind what caused the imbalance from Tekniska verken’s side.

    Before the calculation of the direct and indirect efficiency was initiated, the credibility of the stationary flowmeters was verified. This was done by measuring several waterflows at KV1 with a handheld ultrasonic flowmeter and comparing the measured flows with the flows registered in the stationary flow meters. When the verification of the stationary flow meters was done, the calculations of the indirect efficiency was initiated by collecting ash- and fuel samples for boiler 1 and 3. In connection with the collection of those samples, the air flow rate and temperature at the boiler surface was also measured. The ash- and fuel samples was sent for lab analysis. The collected data was applied in the calculation of unburnt fuel in the ashes, unburnt residual in gas phase, flue gas losses and convection- and radiation losses, which were variables that were necessary for calculating the indirect efficiency.

    The indirect efficiency was calculated at 92,24 % for boiler 1 and 95,85 % for boiler 3. Those efficiencies were both in line with the boilers expected efficiencies (85-90 % for boiler 1 and over 90 % for boiler 3.) and the efficiencies received in previous theses that had calculated the indirect efficiency in CHP-plants. Except the boiler efficiency, the steam efficiency was also received through the indirect efficiency. The steam efficiency received through indirect efficiency was 90,66 for boiler 1 and 88,79 % for boiler 3. To get perspective from a less complex method, the steam efficiency was also calculated with the direct method (90,22 % for boiler 1 and 97,78 % for boiler 3). Those results indicated that KV1 had higher boiler- and steam efficiencies than what Tekniska verken’s own calculation showed.

    Three reasons were raised as potential causes to the unsatisfying boiler- and steam efficiencies that Tekniska verken received with their own calculations. Those reasons were the following:

    • Produced steam that is not going to the turbine is excluded from the steam flow that the calculated steam effect is based on.

    • The energy content of the biofuel in boiler 3 is changing between point when the fuel is delivered to the storage and the point when it’s fed in to the boiler, due to decay.

    • Problem with the weigh-in of the fuel. The problem could be related both to the vechicle scale (affecting both boiler 1 and 3) or that the fuel weight from the weigh in at the Gärstad area is used in the calculation of the added fuel energy to the boiler (affecting mostly boiler 3).

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    Energisystemanalys vid Tekniska verkens kraftvärmeverk
  • 240.
    Johnsson, Simon
    et al.
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, Faculty of Science & Engineering.
    Andersson, Elias
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, Faculty of Science & Engineering.
    Thollander, Patrik
    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.
    Energy savings and greenhouse gas mitigation potential in the Swedish wood industry2019In: Energy, ISSN 0360-5442, E-ISSN 1873-6785, Vol. 187, article id 115919Article in journal (Refereed)
    Abstract [en]

    Improving energy efficiency in industry is recognized as one of the most crucial actions for mitigating climate change. The lack of knowledge regarding energy end-use makes it difficult for companies to know in which processes the highest energy efficiency potential is located. Using a case study design, the paper provides a taxonomy for energy end-use and greenhouse gas (GHG) emissions on a process and energy carrier level. It can be seen that drying of wood is the largest energy using and GHG emitting process in the studied companies. The paper also investigates applied and potentially viable energy key performance indicators (KPIs). Suggestions for improving energy KPIs within the wood industry include separating figures for different wood varieties and different end-products and distinguishing between different drying kiln technologies. Finally, the paper presents the major energy saving and carbon mitigating measures by constructing conservation supply curves and marginal abatement cost curves. The energy saving potential found in the studied companies indicates that significant improvements might be achieved throughout the Swedish wood industry. Even though the scope of this paper is the Swedish wood industry, several of the findings are likely to be relevant in other countries with a prominent wood industry.

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  • 241.
    Jonell, Magnus
    et al.
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Kairis, Robin
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Torkventilation vid kartongtillverkning: En fallstudie på Fiskeby Board AB2013Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Pappers- och massaindustrin stod år 2010 för 52 procent av den svenska industrins energianvändning, vilket motsvarade 76 TWh. Detta gör branschen intressant ur ett energieffektiviseringsperspektiv då små åtgärder kan leda till stora besparingar.

    Fiskeby Board AB är ett företag som tillverkar kartong baserad på returfiber. Då torkning- samt bestrykningsprocessen står för 2/3 av företagets energibehov föreligger intresse att använda energin på ett bättre sätt för att minska energibehovet och därav minska sina kostnader. Syftet med denna rapport var således att genomföra en energikartläggning av tork- samt bestrykningspartiet och utifrån resultaten presentera åtgärder för att minska energibehovet. Arbetet utfördes genom mätningar av lufttemperaturer och flöden, beräkningar, litteraturstudier samt intervjuer. De ytvikter som undersöktes var för vinterdrift 300 g/m2, 350 g/m2 samt 450 g/m2 och för sommardrift 450 g/m2.

    Resultaten visade att inläckaget till torkkåpan, som rekommenderas till 25 procent av totalt inflöde, var mellan 48 och 59 procent. Vidare påvisades även hypotesen om att det i regel används större mängd luft för att transportera bort vattnet från kartongen än vad som krävs. Detta på grund av att det inte finns någon reglering av värmeåtervinningsaggregatens fläktar, vilket medför att frånluften får ett lågt vatteninnehåll vid viss produktion. Ett annat viktigt resultat behandlar hetluftsystemet. Här bör ett visst undertryck föreligga i hetluftskåporna, men genomförda mätningar visade på att enbart en av tre hetluftskåpor erhöll detta undertryck.

    Åtgärdsförslagen som presenteras i rapporten behandlar bland annat de påträffade bristerna ovan. Ett förslag är att minska det våta frånluftsflödet samtidigt som den inläckande luften bör ersättas med redan uppvärmd luft från andra delar av anläggningen. Enligt förslaget kan detta göras genom att nyttja frekvensstyrda till- och frånluftsfläktar vilka styrs av frånluftens daggpunktstemperatur och nollnivån i torkkåpan. Denna lösning har potential att minska den årliga energianvändningen med 17,9 GWh vilket kan ge en kostnadsbesparing av 2,25 miljoner SEK per år.

    Ett annat åtgärdsförslag är att ta bort förbigångsventilerna till värmeåtervinningsaggregaten och låta ångtillförseln styras med enbart reglerventiler. Detta ger en potential att minska energibehovet med 0,47-0,64 GWh per år vilket skulle ge en kostnadsbesparing av 55 000-77 000 SEK per år.

    För hetluftsystemet finns potential att spara 0,64 GWh vilket skulle ge en kostnadsbesparing på 77 000 SEK per år. Det som behövs är ett manuellt reglerspjäll i kanalen från hetluftskåpa 1 alternativt hetluftskåpa 2, för att styra luftflödet och därav erhålla ett undertryck i systemet.

    Genom att sammanställa de tre mest rekommenderade åtgärdsförslagen skapas en möjlighet att spara 5,7 procent av Fiskeby Board ABs energibehov vilket skulle resultera i en årlig kostnadsreduktion av 2,41 miljoner SEK. Om en generalisering att även den övriga pappers- och massaindustrin besitter liknande potential finns möjlighet för denna bransch att årligen minska energianvändningen med 4,4 TWh.

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  • 242.
    Jonsson, Erik
    et al.
    Linköping University, Department of Management and Engineering, Energy Systems.
    Ingvarsson, Erik
    Linköping University, Department of Management and Engineering, Energy Systems.
    Isproduktion genom absorptionskyla vid Linköpings ishall: Samt kylning av ishallens kompressorkylmaskiner genom fjärrkyla2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Under sommarmånaderna är behovet i fjärrvärmenät lågt, vilket innebär att fjärrvärmeproducenter i större utsträckning kan elda de mest lönsamma bränslena för att täcka behovet. Vid Linköpings kraftvärmeverk eldas under sommarperioden stora mängder billigt avfall vilket leder till låga och ibland negativa marginalkostnader i produktionen. Därmed är det intressant att utnyttja denna värme i så stor mån som möjligt, vilket kan göras via fjärrvärmedrivna absorptionskylmaskiner. Absorptionskylmaskiner används i dagsläget för produktion av fjärrkyla i Linköping, men är dessutom möjliga att använda för isproduktion.Denna rapport är tänkt att agera underlag för de beslut som fastighetsbolaget Lejonfastigheter AB i Linköping tar angående framtiden för kylsystemet vid Linköpings ishall. Rapporten syftar till att utreda möjligheterna för att installera en absorptionskylmaskin för isproduktion till ispistarna vid området Stångebro i Linköping. Som komplettering till den befintliga maskinparken bestående av eldrivna kompressorkylmaskiner skulle en absorptionskylmaskin kunna leda till en minskad elförbrukning i isproduktionen.Utöver detta syftar rapporten även till att undersöka effektiviseringsåtgärder för de befintliga kompressorkylmaskinerna, i form av en sänkning av kondenseringstemperaturen. Temperatursänkningen, som innebär att hela kompressorcykeln blir effektivare och att kompressorernas elförbrukning sänks, uppnås genom att använda fjärrkyla i kylningen av kondensorerna.

    Resultaten visar att den undersökta absorptionskylmaskinen inte leder till några kostnadsminskningar, utan är lika dyr eller dyrare än de befintliga kompressorkylmaskinerna under större delen av året. Däremot visar sig ett byte av kondensorkylning för de befintliga kompressorkylmaskinerna från dagens kylning mot utomhusluft till kylning med fjärrkyla, kunna ge en årlig besparing på runt 350 000 kr. Denna siffra inkluderar även ett byte av komfortkyla från dagens system med kompressorkylmaskin, till att istället använda sig av fjärrkyla direkt. Dessutom kan en sänkning av den årliga abonnerade toppeffekten för den inköpta elektriciteten erhållas i och med kylmaskinernas ökade effektivitet. Inkluderat investeringskostnader, så som rörläggning, fås en ungefärlig återbetalningstid på 13 år.

    Arbetet i denna rapport innehåller ett antal uppskattningar och osäkerheter vilket gör att det verkliga fallet kan komma att skilja sig från de resultat som här presenteras. Det är därmed intressant för framtiden att i mera detalj studera hur en eventuell absorptionskylmaskin skulle passa in i systemet med kompressorkylmaskiner, samt hur fjärrkylenätet på bästa sätt integreras i arenaområdets energisystem.

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  • 243.
    Jonsson, Nicklas
    et al.
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Kronqvist, Jonas
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Utvärdering av kvalitén på vatten till anaerobt reningssteg vid kartongproducerande industri: Temperatur, mängd suspenderade ämnen samt flöden på Fiskeby Board AB2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Fiskeby Board AB has invested in a new anaerobic treatment plant that will lower their emissions and as a positive side effect produce biogas. The aim of this project is to present several measures that will improve the quality of Fiskeby’s process wastewater as it will serve as the inflow to the new anaerobic treatment plant and is at the moment not fulfilling the specified requirements set by the anaerobic treatment plant. The measures will lead to a temperature increase of Fiskeby's process wastewater and a lower amount of suspended solids in the process. To achieve these measures discussions and interviews with staff, a literature study, calculations, measurements and a survey of Fiskeby’s water system have been carried out.

    • Proposal 1: Increase the temperature of the process wastewater by using existing energy on Fiskeby.
    • Proposal 2: Lower the amount of suspended solids in the process wastewater with new treatment equipment.
    • Proposal 3: Secure the temperature of the process wastewater by using the process water.

    In proposal 1, six cooling water flows can be switched to a new rinsing water tank that will replace the existing rinsing water. This would lead to an increased amount of energy in the rinsing water corresponding to an average power of 1000 kW that will affect the whole water system. In addition to this the fresh water consumption will decrease by 60-70 m3/h or around 25 % of the total fresh water use at ”kartongmaskin1”. A lower amount of bromocid used leads to a saving of 50 000 SEK/year due to the lower fresh water consumption. The lower fresh water consumption also leads to lower COD-emissions (chemical oxygen demand). In proposal 1, 960 kW heat can also be exchanged from the return water to the sealing water with a plate heat exchanger. This would increase the energy in the sealing water but also increase the energy in the whole water system. Both the cooling water proposal and the heat exchanger proposal are of interest from 1st of November – 1st of May when a heat demand is occurring on the process waste water to reach 35 °C. The costs to implement these proposals have not been further investigated.

    In proposal 2 a static screen and a drum filter that increases the rate of filtration from the existing 4 mm to 0,5 mm and improves Fiskeby’s treatment process of water are presented. The cost of a static screen is around 330 000 SEK and for a drum filter around 560 000 SEK. To lower the amount of heavy particles that ends up in the disc filter a metal trap or a grit trap can be installed. The cost for a grit trap and metal trap that suits Fiskeby is around 270 000 SEK each. To present more detailed results on how much the equipment cleans the water, a pilot test is needed.

    In proposal 3 a plate heat exchanger can be installed and exchange approximately 1800 kW to the process wastewater and thereby secure a temperature of 35 °C for the whole year. The negative part with this proposal is that the heat is taken from the process water which directly affects the system temperature and the profit.

    Fiskeby should therefore begin a design work with proposal 1 and in parallel conduct a pilot test on a static screen or a drum filter from proposal 2.

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  • 244.
    Joudi, Ali
    et al.
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, Faculty of Science & Engineering. Energy and Environmental Technology, Dalarna University, Falun, Sweden.
    Cehlin, Mathias
    Building, Energy & Environmental Engineering, University of Gävle, Gävle, Sweden.
    Svedung, Harald
    SSAB Europe, Borlänge, Sweden.
    Rohdin, Patrik
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, Faculty of Science & Engineering.
    Moshfegh, Bahram
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, Faculty of Science & Engineering.
    Influence of reflective interior surfaces on indoor thermal environment and energy use using a coupling model for energy simulation and CFD2015Manuscript (preprint) (Other academic)
    Abstract [en]

    The importance of reducing the building energy use and maintaining the desired indoor climate has long inspired creative solution such as optimized optical properties for building surfaces. This paper aims to address the influence of interior thermal reflective surfaces on both indoor thermal environments with high spatial resolution and energy use. To do so, this work employs a coupling method using building energy simulation (BES) and computational fluid dynamics (CFD). The results indicate increase in the mean radiation temperature (MRT) and reduction in the floor heating energy use by the use of interior reflective surfaces. The study yields analysis of operative temperatures and interior surface heat fluxes. Overall, the interior reflective surfaces can contribute to improved building thermal performance and energy saving.

  • 245.
    Joudi, Ali
    et al.
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, Faculty of Science & Engineering. Energy Technology, Dalarna University, Falun, Sweden; SSAB Europe, Borlänge, Sweden.
    Cehlin, Mathias
    Building, Energy & Environmental Engineering, University of Gävle, Gävle, Sweden .
    Svedung, Harald
    Energy Technology, Dalarna University, Falun, Sweden; SSAB Europe, Borlänge, Sweden.
    Rönnelid, Mats
    Energy Technology, Dalarna University, Falun, Sweden .
    Moshfegh, Bahram
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, Faculty of Science & Engineering. Building, Energy & Environmental Engineering, University of Gävle, Gävle, Sweden .
    Numerical and experimental investigation of the influence of infrared reflective interior surfaces on building temperature distributions2017In: Indoor + Built Environment, ISSN 1420-326X, E-ISSN 1423-0070, Vol. 26, no 3, p. 355-367Article in journal (Refereed)
    Abstract [en]

    Radiative properties of interior surfaces can affect not only the building heat flux but also the indoor environment, the latter of which has not been thoroughly investigated. The aim of this study is to analyse the effect of surface emissivity on indoor air and surface temperature distributions in a test cabin with reflective interior surfaces. This was done by comparing experimental and simulation data of the test cabin with that of a normal cabin. This study employs transient computational fluid dynamics (CFD) using re-normalisation group (RNG) kε model, surface-to-surface radiation model and an enhanced wall function. Boundary conditions were assigned to exterior surfaces under variable outdoor conditions. The numerical and the measurement results indicate that using interior reflective surfaces will affect the indoor air temperature distribution by increasing the vertical temperature gradient depending on the time of the day. CFD simulations with high spatial resolution results show increased interior surface temperature gradients consistent with the increased vertical air temperature gradient. The influence of reflective surfaces is potentially greater with higher indoor surface temperature asymmetry. The vertical indoor air temperature gradient and surface temperatures are important parameters for indoor thermal comfort.

  • 246. Order onlineBuy this publication >>
    Joudi, Mohammad Ali
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, Faculty of Science & Engineering.
    Radiation properties of coil-coated steel in building envelope surfaces and the influence on building thermal performance2015Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Recent studies have shown that the optical properties of building exterior surfaces are important in terms of energy use and thermal comfort. While the majority of the studies are related to exterior surfaces, the radiation properties of interior surfaces are less thoroughly investigated. Development in the coil-coating industries has now made it possible to allocate different optical properties for both exterior and interior surfaces of steel-clad buildings. The aim of this thesis is to investigate the influence of surface radiation properties with the focus on the thermal emittance of the interior surfaces, the modeling approaches and their consequences in the context of the building energy performance and indoor thermal environment.

    The study consists of both numerical and experimental investigations. The experimental investigations include parallel field measurements on three similar test cabins with different interior and exterior surface radiation properties in Borlänge, Sweden, and two ice rink arenas with normal and low emissive ceiling in Luleå, Sweden. The numerical methods include comparative simulations by the use of dynamic heat flux models, Building Energy Simulation (BES), Computational Fluid Dynamics (CFD) and a coupled model for BES and CFD. Several parametric studies and thermal performance analyses were carried out in combination with the different numerical methods.

    The parallel field measurements on the test cabins include the air, surface and radiation temperatures and energy use during passive and active (heating and cooling) measurements. Both measurement and comparative simulation results indicate an improvement in the indoor thermal environment when the interior surfaces have low emittance. In the ice rink arenas, surface and radiation temperature measurements indicate a considerable reduction in the ceiling-to-ice radiation by the use of low emittance surfaces, in agreement with a ceiling-toice radiation model using schematic dynamic heat flux calculations.

    The measurements in the test cabins indicate that the use of low emittance surfaces can increase the vertical indoor air temperature gradients depending on the time of day and outdoor conditions. This is in agreement with the transient CFD simulations having the boundary condition assigned on the exterior surfaces. The sensitivity analyses have been performed under different outdoor conditions and surface thermal radiation properties. The spatially resolved simulations indicate an increase in the air and surface temperature gradients by the use of low emittance coatings. This can allow for lower air temperature at the occupied zone during the summer.

    The combined effect of interior and exterior reflective coatings in terms of energy use has been investigated by the use of building energy simulation for different climates and internal heat loads. The results indicate possible energy savings by the smart choice of optical properties on interior and exterior surfaces of the building.

    Overall, it is concluded that the interior reflective coatings can contribute to building energy savings and improvement of the indoor thermal environment. This can be numerically investigated by the choice of appropriate models with respect to the level of detail and computational load. This thesis includes comparative simulations at different levels of detail.

    List of papers
    1. Highly reflective coatings for interior and exterior steel cladding and the energy efficiency of buildings
    Open this publication in new window or tab >>Highly reflective coatings for interior and exterior steel cladding and the energy efficiency of buildings
    2011 (English)In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 88, no 12, p. 4655-4666Article in journal (Refereed) Published
    Abstract [en]

    The effect of surface heat-radiation properties of coil-coated steel cladding material on the energy efficiency of buildings in Nordic climate is addressed by parallel temperature and energy usage measurements in a series of test cabins with different exterior solar reflectivity and interior thermal reflectivity. During one year, a number of one- or two-week experiments with air conditioner cooling and electrical floor heating were made while logging air-, radiation- and surface temperatures, energy consumption and weather conditions. Measurements show significant energy savings in the test cabins by the use of high thermal reflectivity interior surfaces both during heating and cooling and a strongly reduced cooling demand by the use of high solar reflectivity exterior surfaces. Results are interpreted within the context of a steady-state energy flux model, to illuminate the importance of surface resistance properties (radiation and convective heat dissipation).

    Place, publisher, year, edition, pages
    Elsevier, 2011
    Keywords
    Total solar reflectivity, Reflective coating, Thermal emissivity, Building interior heat flux, Energy efficient buildings Energy saving
    National Category
    Energy Systems
    Identifiers
    urn:nbn:se:liu:diva-118285 (URN)10.1016/j.apenergy.2011.06.002 (DOI)000295387200041 ()
    Available from: 2011-09-01 Created: 2015-05-25 Last updated: 2017-12-04Bibliographically approved
    2. Energy efficient surfaces on building sandwich panels - A dynamic simulation model
    Open this publication in new window or tab >>Energy efficient surfaces on building sandwich panels - A dynamic simulation model
    2011 (English)In: Energy and Buildings, ISSN 0378-7788, E-ISSN 1872-6178, Vol. 43, no 9, p. 2462-2467Article in journal (Refereed) Published
    Abstract [en]

    The choice of building envelope is critical for the energy performance of buildings. The major part of the energy used by a building during its lifetime is used for maintaining a suitable interior thermal climate under varying exterior conditions. Although exterior heat radiation properties (i.e. total solar reflectivity and long wave thermal emissivity) have been well accepted to have a large impact on the need for active cooling in warmer climate, the effect of a reduced thermal emissivity on interior surfaces on the building thermal energy flux is rarely studied. This paper addresses the sensitivity of the thermal energy flux through a sandwich panel, by systematically varying the surface thermal emissivity (both interior and exterior) and total solar reflectance of exterior surface, for three geographical locations: southern, middle and northern Europe. A model is introduced for calculating the effect of both interior and exterior optical properties of a horizontal roof panel in terms of net energy flux per unit area. The results indicate potential energy saving by the smart choice of optical properties of interior and exterior surfaces.

    Keywords
    Total solar reflectivity, Reflective coating, Thermal emissivity, Building heat flux, Energy efficiency
    National Category
    Energy Systems
    Identifiers
    urn:nbn:se:liu:diva-118286 (URN)10.1016/j.enbuild.2011.05.026 (DOI)000294834900048 ()
    Available from: 2011-09-01 Created: 2015-05-25 Last updated: 2017-12-04Bibliographically approved
    3. Energy Efficient Buildings with Functional Steel Cladding
    Open this publication in new window or tab >>Energy Efficient Buildings with Functional Steel Cladding
    2011 (English)In: World Renewable Energy Congress, Linköping: Linköping University Electronic Press, 2011, Vol. 8, p. 2004-2009Conference paper, Published paper (Refereed)
    Abstract [en]

    The aim of the study is to develop a model for the energy balance of buildings that includes the effect from the radiation properties of interior and exterior surfaces of the building envelope. As a first step we have used ice arenas as case study objects to investigate the importance of interior low emissivity surfaces. Measurements have been done in two ice arenas in the north part of Sweden, one with lower and one with higher ceiling emissivity. The results show that the low emissivity ceiling gives a much lower radiation temperature interacting with the ice under similar conditions. The dynamic modelling of the roof in ice arenas shows a similar dependence of the roof-to-ice heat flux and the ceiling emissivity. A second part of the study focus on how to realise paints with very low thermal emissivity to be used on interior building surfaces.

    Place, publisher, year, edition, pages
    Linköping: Linköping University Electronic Press, 2011
    Series
    Linköping Electronic Conference Proceedings, ISSN 1650-3686, E-ISSN 1650-3740 ; 57
    Keywords
    energy balance, low emissivity, radiation properties
    National Category
    Energy Systems
    Identifiers
    urn:nbn:se:liu:diva-118287 (URN)10.3384/ecp110572004 (DOI)978-91-7393-070-3 (ISBN)
    Conference
    World Renewable Energy Congress – Sweden; 8–13 May, 2011, Linköping, Sweden
    Available from: 2015-05-25 Created: 2015-05-25 Last updated: 2019-12-30Bibliographically approved
    4. Reflective coatings for interior and exterior of buildings and improving thermal performance
    Open this publication in new window or tab >>Reflective coatings for interior and exterior of buildings and improving thermal performance
    2013 (English)In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 103, p. 562-570Article in journal (Refereed) Published
    Abstract [en]

    The importance of reducing building energy usage and thriving for more energy efficient architectures, has nurtured creative solutions and smart choices of materials in the last few decades. Among those are optimizing surface optical properties for both interior and exterior claddings of the building. Development in the coil-coating steel industries has now made it possible to allocate correct optical properties for steel clad buildings with improved thermal performance. Although the importance of the exterior coating and solar gain are thoroughly studied in many literatures, the effect of interior cladding are less tackled, especially when considering a combination of both interior and exterior reflective coatings. This paper contemplates the thermal behavior of small cabins with reflective coatings on both interior and exterior cladding, under different conditions and climates with the aim to clarify and point out to the potential energy saving by smart choices of clad coatings.

    Place, publisher, year, edition, pages
    Oxford: Elsevier, 2013
    Keywords
    Reflective coatings, Low energy building, Energy simulation, Total solar reflectance, Interior thermal emittance
    National Category
    Energy Systems Building Technologies
    Identifiers
    urn:nbn:se:liu:diva-118288 (URN)10.1016/j.apenergy.2012.10.019 (DOI)000314669500053 ()2-s2.0-84871715773 (Scopus ID)
    Available from: 2014-11-09 Created: 2015-05-25 Last updated: 2019-12-28Bibliographically approved
    5. Numerical and experimental investigation of the influence of infrared reflective interior surfaces on building temperature distributions
    Open this publication in new window or tab >>Numerical and experimental investigation of the influence of infrared reflective interior surfaces on building temperature distributions
    Show others...
    2017 (English)In: Indoor + Built Environment, ISSN 1420-326X, E-ISSN 1423-0070, Vol. 26, no 3, p. 355-367Article in journal (Refereed) Published
    Abstract [en]

    Radiative properties of interior surfaces can affect not only the building heat flux but also the indoor environment, the latter of which has not been thoroughly investigated. The aim of this study is to analyse the effect of surface emissivity on indoor air and surface temperature distributions in a test cabin with reflective interior surfaces. This was done by comparing experimental and simulation data of the test cabin with that of a normal cabin. This study employs transient computational fluid dynamics (CFD) using re-normalisation group (RNG) kε model, surface-to-surface radiation model and an enhanced wall function. Boundary conditions were assigned to exterior surfaces under variable outdoor conditions. The numerical and the measurement results indicate that using interior reflective surfaces will affect the indoor air temperature distribution by increasing the vertical temperature gradient depending on the time of the day. CFD simulations with high spatial resolution results show increased interior surface temperature gradients consistent with the increased vertical air temperature gradient. The influence of reflective surfaces is potentially greater with higher indoor surface temperature asymmetry. The vertical indoor air temperature gradient and surface temperatures are important parameters for indoor thermal comfort.

    Place, publisher, year, edition, pages
    Sage Publications, 2017
    Keywords
    Reflective interior surfaces, indoor air temperature gradient, Transient computational fluid dynamics, surface-to-surface radiation, building thermal performance
    National Category
    Energy Systems Building Technologies
    Identifiers
    urn:nbn:se:liu:diva-118289 (URN)10.1177/1420326X15609966 (DOI)000399487300007 ()
    Note

    Funding agencies|SSAB Europe; Dalarna University; University of Gävle; Linköping University.

    At the time for thesis presentation publication was in status: Manuscript

    Available from: 2015-05-25 Created: 2015-05-25 Last updated: 2017-05-05Bibliographically approved
    6. Influence of reflective interior surfaces on indoor thermal environment and energy use using a coupling model for energy simulation and CFD
    Open this publication in new window or tab >>Influence of reflective interior surfaces on indoor thermal environment and energy use using a coupling model for energy simulation and CFD
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    2015 (English)Manuscript (preprint) (Other academic)
    Abstract [en]

    The importance of reducing the building energy use and maintaining the desired indoor climate has long inspired creative solution such as optimized optical properties for building surfaces. This paper aims to address the influence of interior thermal reflective surfaces on both indoor thermal environments with high spatial resolution and energy use. To do so, this work employs a coupling method using building energy simulation (BES) and computational fluid dynamics (CFD). The results indicate increase in the mean radiation temperature (MRT) and reduction in the floor heating energy use by the use of interior reflective surfaces. The study yields analysis of operative temperatures and interior surface heat fluxes. Overall, the interior reflective surfaces can contribute to improved building thermal performance and energy saving.

    Keywords
    Thermal reflective surfaces, mean radiation temperature, building thermal performance, coupling building energy simulation and CFD
    National Category
    Energy Systems Building Technologies
    Identifiers
    urn:nbn:se:liu:diva-118290 (URN)
    Available from: 2015-05-25 Created: 2015-05-25 Last updated: 2015-05-26Bibliographically approved
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  • 247.
    Jönsson, Johanna
    et al.
    Chalmers University.
    Svensson, Inger-Lise
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Berntsson, Thore
    Chalmers University.
    Moshfegh, Bahram
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Excess heat from kraft pulp mills: Trade-offs between internal and external use in the case of Sweden - Part 22008In: Energy Policy, ISSN 0301-4215, E-ISSN 1873-6777, Vol. 36, no 11, p. 4186-4197Article in journal (Refereed)
    Abstract [en]

    In this paper the trade-off between internal and external use of excess heat from a kraft pulp mill is investigated for four different future energy market scenarios. The work follows the methodology described in Svensson et al. [2008. Excess heat from kraft pulp mills: trade-offs between internal and external use in the case of Sweden-Part 1: methodology. Energy Policy, submitted for publication], where a systematic approach is proposed for investigating the potential for profitable excess heat cooperation. The trade-off is analyzed by economic optimization of an energy system model consisting of a pulp mill and an energy company (ECO). In the model, investments can be made, which increase the systems energy efficiency by utilization of the mills excess heat, as well as investments that increase the electricity production. The results show that the trade-off depends on energy market prices, the district heating demand and the type of existing heat production. From an economic point of view, external use of the excess heat is preferred for all investigated energy market scenarios if the mill is studied together with an ECO with a small heat load. For the cases with medium or large district heating loads, the optimal use of excess heat varies with the energy market price scenarios. However, from a CO2 emissions perspective, external use is preferred, giving the largest reduction of global emissions in most cases.