| 1. |
- Engstrand, Per O., 1955-, et al.
(author)
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Mekmassainitiativet för energieffektivitet, e2mp-i
- 2015
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Reports (other academic/artistic)abstract
- Projektet har drivits som ett program för finansiering av forskning som ska utveckla ochdemonstrera tekniker som reducerar elenergiförbrukningen med 50% vid tillverkning avTMP och CTMP med bibehållna slutproduktegenskaper hos tryckpapper och kartong.Programmet är en del av skogsindustrins initiativ att under en tioårsperiod tillsammansmed svenska och norska finansiärer investera minst 200 Mkr för att nå detta radikalaeffektiviseringsmål. Ett uttalat mål för industriinitiativet är också att befästaforskningsnoderna vid FSCN i Sundsvall och PFI i Trondheim.Parallellt med Energimyndighetens finansiering, 30 Mkr, har Norges Forskningsråd satsat25 MNOK (2010‐14) i industriinitiativet, KK‐stiftelsen 36 MSEK (2011‐17) ochMittuniversitetet har finansierat12 MSEK. Industrins totala satsning kommer att överstiga100 MSEK redan vid utgången av 2017.Resultat från benchmarkingstudien BAT2012 av industrins modernaste TMP‐ och CTMPlinjersamt från demonstrationsskaleprojekt visas i rapporten. Projekten baseras delvis pågrundläggande forskningsprojekt genomförda inom FSCN´s KK‐stiftelse‐finansieradeforskningsprofil och projektet ”Filling the Gap” 31676‐, ISSN 1650‐5387 2014:57. Resultaten visar följande reduktionsnivåer; 28% TMP för news (Braviken), 14% TMP för SC(Kvarnsveden) och 21% CTMP för kartong (Skoghall).Utöver demoprojekten finns ytterligare tydliga potentialer beskrivna i övriga delprojekt:Processintensifiering och processmodifiering > 15%Processtabilitet via avancerad processanalys och reglering > 15%Kombinera effektivaste processavsnitt från benchmarking ca 25%Detta gör det troligt att det kommer att gå att i fullskaliga demonstrationsförsök validera50% elenergireduktion inom de tre produktområdena, förutsatt att fortsattforskningsfinansiering finns tillgänglig. Tre av de idéer till avknoppningsprojekt somframkommit under projektets gång har redan erhållit beslut om finansiering frånEnergimyndigheten 2015. Ytterligare projektförslag baserade på den här redovisadeforskningen kommer att ingå i ansökningar under 2016. Utöver energireduktion i själva TMP‐ och CTMP‐processerna har forskare vid FSCN lagt forskningsgrunden för hur manska kunna tillverka mycket starka förpackningsmaterial från dessa massatyper på ettenergieffektivt sätt. Även inom detta område kommer en ansökning omuppskalningsprojekt att skickas in.
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| 2. |
- Björkqvist, Olof, 1962-, et al.
(author)
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Concepts of Steam Recovery from LC-Refining by Increase Temperature
- 2009
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In: Proceedings - 2009 International Mechanical Pulping Conference, IMPC 2009. ; , s. 190-194
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Conference paper (peer-reviewed)abstract
- In a mechanical pulping process, (TMP) wood is refined to pulp in a process with very high wood utilization. However, the power demand in the process is high. Thus efficient energy recovery, especially steam recov-ery, is very important. In high consistency (HC) refining the pulp wood is refined at high temperature (140°C) and pressure. The high temperature makes it possible to recover process heat with usable steam properties. One strategy to decrease the power consumption is to split the refining into two stages, one HC-stage and one low consistency (LC) refining stage. This kind of sys-tem is quite common today. One drawback with LC-refining is that it operates at a low temperature normally below 100°C. Hence, the steam recovery potential from conventional LC-refining is limited. In this project, we analyse three concepts of steam re-covery in LC-refining by increasing the temperature in the LC-stage. Two base cases: Conventional HC refin-ing only and conventional HC/LC refining is compared with three steam recovery cases: Pulp/Pulp heat ex-changing, Screw Press Dewatering combined with proc-ess water re-circulation and finally Pulp/Water Heat Exchanging. The study shows that it is possible to recover steam from the LC-stage and, hence, increase the energy effi-ciency of a combined HC/LC refining system. The screw press case has the highest steam recovery poten-tial of the HC/LC configurations. An initial economic estimate indicates that steam recovery in LC-refining is profitable compared to a conventional HC/LC-configuration.
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| 3. |
- Björkqvist, Olof, 1962-, et al.
(author)
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Energiåtervinning vid LC-raffinering – Förstudie
- 2008
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Reports (other academic/artistic)abstract
- Ökade energikostnader och råvarupriser innebär att effektiv energianvändning blir enviktig faktor för att skapa långsiktig konkurrenskraft och utvecklingsförmåga för massaochpappersindustrin. I detta projekt analyseras möjligheten att öka ångåtervinningenfrån en mekanisk massaprocess där raffinering vid hög massakoncentration (HCraffinering)kombineras med raffinering vid låg massakoncentration (LC-raffinering).Vid HC-raffinering finns sedan många år väl utvecklad teknik för att återvinna ånga.Vid konventionell LC-raffinering är det inte möjligt att återvinna ånga eftersom temperaturnivåernaär för låga, lägre än 100°C. Genom att värmeväxla producerad massa ellerpressat från processen kan man öka temperaturen i LC-steget så att det blir möjligt attåtervinna processånga med användbara ångdata, i detta fall 2,7 bar och 130°C.I projektet har tre alternativa konfigurationer för ångåtervinning analyserats(A) Ångåtervinning i kombination med massa/massa värmeväxling (B) Ångåtervinningi kombination med en trycksatt skruvpress och (C) Ångåtervinning i kombination medmassa/vatten värmeväxling.En inledande lönsamhetsberäkning visar att ångåtervinning från LC-steget kan ha enmycket god lönsamhet. Fall B, ångåtervinning i kombination med trycksatt skruvpressvisar bäst potential för fortsatta studier. Det beror på att värmeåtervinningen sker genominblandning av pressat i spädvattnet och värmeväxling av vatten med en konventionellvärmeväxlare. Det innebär att de tekniska riskerna i detta alternativ är låga.Utvecklingen av de värmeväxlare som ingår i fallen A och B och som kan hantera massamed 5% massakoncentration innebär en stor teknisk utmaning och associerad risk.Det finns idag inga sådana växlare på marknaden och det är osäkert om man kan konstrueraen växlare som kan hantera massa med hög viskositet och som har tillräckligthög temperaturverkningsgrad.Projektet har uppfyllt målet att visa att det teoretiskt är energitekniskt möjligt att modifieraen LC-process så att ånga kan återvinnas även från detta steg. Detta innebär enförbättring av den konventionella LC-processens energieffektivitet. Projektets resultatkan vara ett underlag för beslut om fortsatt forskning inom området energieffektiv LCraffinering.
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| 5. |
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| 6. |
- Björkqvist, Olof, 1962
(author)
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Perspectives on Demand Side Energy Efficiency
- 1996
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Doctoral thesis (other academic/artistic)abstract
- This work treats recommendations based on energy systems engineering. The focus is on what can be learned by different methods about the roles that demand-side energy efficiency should play in the energy system. In the first part of the thesis, two case studies of local energy planning demonstrate the role of demand-side energy efficiency: energy systems engineering suggests a design in which energy efficiency improvements are aligned with the whole technical energy system. One result of the case studies is that the energy consumers invest in fewer energy efficiency measures than recommended by the methodologies applied. This indicates that there are important aspects of demand-side energy efficiency that are ignored by the methodologies used. In this work, the cause of the difference between the recommended and observed investments is addressed by an investigation of the customer's transaction cost for the energy efficiency investment. The second part is an application of the viable system model and focuses on the role of energy efficiency activities at a public energy utility. A case study demonstrates that most energy efficiency activities were run to support energy sales and, hence, were totally entwined with the traditional business. This role observed is compared with that suggested by the demand-side management methodology. The comparison shows that demand-side management is not capable of handling important aspects of interrelations between energy efficiency activities and energy sales. The work provides a language for further discussion of the role of energy efficiency activities at energy utilities.
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| 7. |
- Björkqvist, Olof
(author)
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Perspectives on Demand Side Management
- 1996
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Book (other academic/artistic)abstract
- This work treats recommendations based on energy systems engineering. The focus is on what can be learned by different methods about the roles that demand-side energy efficiency should play in the energy system. In the first part of the thesis, two case studies of local energy planning demonstrate the role of demand-side energy efficiency: energy systems engineering suggests a design in which energy efficiency improvements are aligned with the whole technical energy system. One result of the case studies is that the energy consumers invest in fewer energy efficiency measures than recommended by the methodologies applied. This indicates that there are important aspects of demand-side energy efficiency that are ignored by the methodologies used. In this work, the cause of the difference between the recommended and observed investments is addressed by an investigation of the customer's transaction cost for the energy efficiency investment. The second part is an application of the viable system model and focuses on the role of energy efficiency activities at a public energy utility. A case study demonstrates that most energy efficiency activities were run to support energy sales and, hence, were totally entwined with the traditional business. This role observed is compared with that suggested by the demand-side management methodology. The comparison shows that demand-side management is not capable of handling important aspects of interrelations between energy efficiency activities and energy sales. The work provides a language for further discussion of the role of energy efficiency activities at energy utilities.
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| 8. |
- Björkqvist, Olof, et al.
(author)
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Risk Assessment of New Pricing Strategies in the District Heating Market : A Case Study at Sundsvall Energi AB
- 2010
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In: Energy Policy. - : Elsevier. - 0301-4215 .- 1873-6777. ; 38:5, s. 2171-2178
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Journal article (peer-reviewed)abstract
- The price structure of district heating has been no major scientific issue for the last decades in energy-related research. However, today trends in district heating pricing tend to move towards a more customer-oriented approach with predetermined prices under a longer periods, leading to a more complex price structure. If a district heating supplier offers district heating with predetermined prices in order to compete with similar electricity offers, the financial risk of the new price structure is significantly higher than the risk of an ordinary variable cost offer based on short-run marginal cost. In contrary to an electricity seller, the district heating company cannot transfer all of the risk of predetermined prices to the financial market, instead the company is thrown upon its own ability to handle the risk by, e.g., hedging its own energy purchase. However, all uncertainties cannot be coped with in this manner. Thus, there is a need for a methodology that can be used to estimate the financial risk of different price structures and to value different opportunities to reduce the risk. In this article, we propose a methodology, implemented in prototype software, to evaluate the risk associated with new price structures in district heating.
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| 9. |
- Engström, Lil, 1943-
(author)
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Möjligheter till lärande i matematik : Lärares problemformuleringar och dynamisk programvara
- 2006
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Doctoral thesis (other academic/artistic)abstract
- This thesis presents the first Swedish empirical evidence on how teachers employ a dynamic mathematical software when teaching mathematics in upper secondary school. The study examines: a) How teachers formulate mathematical problems? b) How they use the experience the students have gained? and c) What use they make of the software’s potential? These questions are examined through classroom observations followed up by discussions with the teachers.The study comprises three teachers and shows that they have very different mathematical experiences and teaching skills. A questionnaire was sent to the teachers prior to the classroom visits to collect relevant background information; e.g., the teachers were asked to describe their teacher training, their view of mathematics and of how a dynamic software could contribute to their teaching.The results show that the teachers’ ability to pose thought-provoking openended problems is the most important factor as it significantly influences what the students learn. The way a mathematical problem is formulated could, in conjunction with a dynamic software, actually limit the students’ achievement.However, this study confirms that it could also provide an opportunity for students to discover new mathematical relations, draw conclusions, generalise and formulate hypotheses. This could in turn lead to an in formally proving a mathematical relation. A conclusion of the study is that to be successful, teachers need a good mathematical background with a firm knowledge base and an understanding of the software’s potential, but they also need the skill to formulate open-ended problems that will enable their students to work successfully with a dynamic mathematical software.
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| 10. |
- Gebremedhin, Alemayehu, 1962-
(author)
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The impact of a widened energy system boundary on cost effectiveness
- 2000
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Licentiate thesis (other academic/artistic)abstract
- This study describes the impact of widened system boundaries in the choice of heat generating plants, the total cost of the defined energy system and the use of combined heat and power (CHP) production plants. The economic and environmental benefits of co operation between public utilities and industries and the importance of enlarged system boundaries are shown in the different case-studies.The analysis was based on computer modelling of municipal and industrial energy systems. A user-friendly graphical interface program based on the linear programming model, MODEST, was developed as part of this study. The majority of the case-studies presented in this thesis were then performed with this application program.The various case-studies clearly indicate the cost reduction potential of co-operation. Both utilities and heat supplying industries benefit from this co-operation concerning heat supply. The cost saving potentials change from one case to another and depend on several factors.New plants within a sub-system appear to be attractive when this system is connected with other sub-systems within the extended system boundaries. In general, we can say that an extended system boundary leads normally to reduced total costs, more rational utilisation of plants, increased heat and electricity generation through the CHP plant and declining use of fossil fuels.The net present value of the maximum allowable investment cost for district-heating pipeline connections is roughly estimated when the cost for connection is not given or known. This cost can be used as a guideline to indicate whether connections should be considered or not.
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