hh.sePublikationer
Ändra sökning
Avgränsa sökresultatet
1 - 32 av 32
RefereraExporteraLänk till träfflistan
Permanent länk
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Träffar per sida
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sortering
  • Standard (Relevans)
  • Författare A-Ö
  • Författare Ö-A
  • Titel A-Ö
  • Titel Ö-A
  • Publikationstyp A-Ö
  • Publikationstyp Ö-A
  • Äldst först
  • Nyast först
  • Skapad (Äldst först)
  • Skapad (Nyast först)
  • Senast uppdaterad (Äldst först)
  • Senast uppdaterad (Nyast först)
  • Disputationsdatum (tidigaste först)
  • Disputationsdatum (senaste först)
  • Standard (Relevans)
  • Författare A-Ö
  • Författare Ö-A
  • Titel A-Ö
  • Titel Ö-A
  • Publikationstyp A-Ö
  • Publikationstyp Ö-A
  • Äldst först
  • Nyast först
  • Skapad (Äldst först)
  • Skapad (Nyast först)
  • Senast uppdaterad (Äldst först)
  • Senast uppdaterad (Nyast först)
  • Disputationsdatum (tidigaste först)
  • Disputationsdatum (senaste först)
Markera
Maxantalet träffar du kan exportera från sökgränssnittet är 250. Vid större uttag använd dig av utsökningar.
  • 1.
    Averfalk, Helge
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, Rydberglaboratoriet för tillämpad naturvetenskap (RLAS). Lund University, Lund, Sweden.
    Enhanced District Heating Technology: Maintaining Future System Feasibility2017Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    When heat demand and high temperature heat supply gradually decreases in the future, then it will effect district heating systems ability to compete on the heat market. A good way to mitigate less district heating feasibility is to operate systems with lower temperature levels and the most conceivable way to achieve lower temperature levels is to decrease return temperatures.

    Thus, this thesis emphasise temperature errors embedded in district heating systems. Only a selection of temperature errors are analysed in this thesis. First, the temperature error that occurs due to recirculation in distribution networks at low heat demands. Second, the temperature error that occurs due to hot water circulation in multi-family buildings. Third, the temperature error that occurs due to less than possible heat transfer in heat exchangers, i.e. too short thermal lengths.

    In order to address these temperature errors three technology changes have been proposed (i) three-pipe distribution network to separate the recirculation return flow from the delivery return flow, (ii) apartment substations to eliminate hot water circulation utilisation, and (iii) improved heat exchangers for lower return temperatures at a constant scenario. Analysis of proposed changes has resulted in annual average return temperatures between 17-21 °C.

    Furthermore, rapid introduction of intermittent renewable electricity supply in the energy system has prompted an increased necessity of power system balancing capacities. Large-scale conversion of power-to-heat in electric boilers and heat pumps is a feasible alternative to achieve such balancing capacities. Analysis of the unique Swedish experience with utilisation of large heat pumps installations connected to district heating systems show that since the 1980s 1527 MW of heat power has been installed, about 80 % of the capacity was still in use by 2013. Thus, a cumulative value of over three decades of operation and maintenance exists within Swedish district heating systems.

    The two papers presented in this thesis are related to future district heating systems through the five abilities of fourth generation district heating (4GDH), which are documented in the definition paper of 4GDH.

  • 2.
    Averfalk, Helge
    Högskolan i Halmstad, Akademin för företagande, innovation och hållbarhet, Rydberglaboratoriet för tillämpad naturvetenskap (RLAS).
    Faktiska varmvattenflöden i flerfamiljshus2021Rapport (Övrigt vetenskapligt)
    Abstract [sv]

    Detta projekt innehåller insamling av mätdata från tappvarmvattenanvändning från flerbostadshus och bearbetning av densamma. Målet med projektet är att undersöka om det finns förutsättningar att korrigera nuvarande norm för dimensionerande flöde för tappvarmvatten. Resultaten påvisar potential att reducera normen för tappvarmvattenflöde.

    Detta projekt består av genomgång samt sammanställning av litteratur för fastställande av dimensionering av tappvarmvattenflöden till i huvudsak flerbostadshus. Därtill har datainsamling samt dataanalys utförts på tappvarmvattenmätningar tillhandahållna av Ngenic AB.

    Studien syftar till att uppdatera dimensionerande varmvattenbehov vid nybyggnation samt att ge råd till varmvattendimensionering i hus för att förbättra precisionen för den dimensionerade kapaciteten. Bättre dimensionering av bland annat ventiler och värmeväxlare ger mindre slitage och därmed längre livslängd men också förbättrad avkylning.

    Insamlad data har olika tidsupplösning: 6-sekunder (clamp-on, ultraljudsteknik), 1-minut och 15 minuter (enstrålig vinghjulsmätare). Mätningarna har skett vid olika tidsperioder där de längsta (1 år) varit för 15-minutersvärden och de övriga varierat runt cirka tre veckor. Därtill har data samlat för en uppsättning flerbostadshus med varierande storlek.

    Efter bearbetning av data görs följande observationer:

    1. 15-minutersvärden är olämpliga för att skatta momentant flöde (l/s)

    2. I storleksordnad jämförelse mellan 15-minuters värden och 6-sekundersvärden erhölls en mycket mindre avvikelse i momentant flöde (l/s) än förväntat.

    3. I storleksordnad jämförelse mellan 1-minutersvärden och 6-sekundersvärden erhölls så pass liten skillnad i momentant flöde (l/s) att dessa två perspektiv uppfattas som utbytbara och att det därmed inte nödvändigtvis föreligger något behov av att mäta med högre tidsupplösning än 1 minut.

    4. 1-minutersvärden för en uppsättning flerbostadshus av varierande storlek indikerar att det finns möjlighet att reducera dimensioneringsförutsättningarna för tappvarmvattenflöden.

    Denna studie verifierar nuvarande utformning av dimensionerande flöde för tappvarmvatten enligt F101. Vidare rekommenderas som en första ordningens anpassning av nuvarande Ekv. (7), där variabel A kan justeras från 2,10 till 0,84.

  • 3.
    Averfalk, Helge
    Högskolan i Halmstad, Akademin för företagande, innovation och hållbarhet.
    IEA Heat Pumping Technologies TCP Annex 57:Flexibility by implementation of heat pumps in multi-vector energy systems and thermal networks: Task 1, Swedish background report2022Rapport (Övrigt vetenskapligt)
  • 4.
    Averfalk, Helge
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, Rydberglaboratoriet för tillämpad naturvetenskap (RLAS). Department of Energy Sciences, Lund University, Lund, Sweden.
    Low-temperature District Heating: Various Aspects of Fourth-generation Systems2019Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    With decreasing heat demand and less availability of high-temperature heat supply in future energy systems, the current district heating systems may experience increased competition on the heat market. A viable option to mitigate increasing competition is to operate systems with lower temperature levels, and the most conceivable way to achieve lower temperature levels is to decrease return temperatures.In this thesis, aspects of improvements in district heating systems are assessed. Three aspects, in particular, have been analysed. These are integration between energy systems, improvements in heat distribution technology, and economic benefits of low-temperature district heating systems.An increasing interest in integrating different energy systems has been prompted by the rapid introduction of intermittent renewable electricity supply in the energy system. Large-scale conversion of power to heat in electric boilers and heat pumps is a feasible alternative to achieve the balancing capacities required to maintain system functioning. Analysis of the unique Swedish experience using large heat-pump installations connected to district heating systems shows that, since the 1980s, 1527 MW of heat power has been installed, and about 80% of the capacity was still in use in 2013. Thus, a cumulative value of over three decades of operation and maintenance exists within Swedish district heating systems.Increased competition prompted by changes in the operation environment necessitates improved heat distribution. This thesis focuses on three system-embedded temperature errors: first, the temperature error that occurs due to recirculation in distribution networks at low heat demands; second, the temperature error that occurs due to hot-water circulation in multi-family buildings; third, the temperature error that occurs due to lower heat transfer than is possible in heat exchangers (i.e. too-short thermal length). To address these temperature errors, three technology changes have been proposed (i) a three-pipe distribution network to separate the recirculation return flow from the delivery return flow, (ii) apartment substations to eliminate hot-water circulation use, and (iii) improved heat exchangers for lower return temperatures. The analysis of the proposed changes indicates annual average return temperatures between 17°C and 21°C.The final analysed aspect is the economic benefits of low-temperature district heating. It was identified that strong economic motives for lower operating temperatures in future heat supply exist, whereas the economic motives are significantly weaker for the traditional heat supply.The five papers presented in this thesis are related to future district heating systems through the five abilities of fourth-generation district heating (4GDH), which are documented in the definition paper on 4GDH.

  • 5.
    Averfalk, Helge
    Högskolan i Halmstad, Sektionen för ekonomi och teknik (SET), Bio- och miljösystemforskning (BLESS), Energiteknik.
    Morgondagens effektiva fjärrvärme: En beskrivande litteraturstudie2014Självständigt arbete på avancerad nivå (magisterexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [en]

    This report is made as a literature review, focusing on the work done to increase understanding of efficiency in the categories of substations and secondary heating systems, with respect to the deviation from the theoretically possible cooling off in the distribution network as well as the economic benefit that appear. The main purpose of a considerable part of the literature used in this report addresses the issue of identifying individual causes of reduced cooling in district heating systems. These literature resources have been compiled and summarized as part of the report.

    The technology of district heating is associated with benefits such as better use of the energy in a fuel. This is the case of cogeneration plants where serial generation of electricity and thermal energy increases efficiency compared with the parallel generation where heat is generated locally and electricity is generated centrally. Serial generation thus allows for lower primary energy demand. Another benefit from combustion in units with higher capacity installed is that a higher control of emission with environmental impact is permitted. Additionally local environment change drastically when a few large supply units replace a large number of local supply units. It has also been shown that district heating can reduce greenhouse gas emissions in a cost efficient way. Thus being a part of the energy system to achieve the EU climate goals

    In Sweden, district heating is developed to a high degree. In connection with decreasing focus on expansion, the focus on maintenance and optimization and how district heating should look like in the future increases. In conjunction with lower heat demand from new and renovated buildings distribution cost will increase. For district heating to maintain competitiveness a development in distribution technology that move toward the next generation of distribution technology is necessary. Average temperatures today in Swedish district heating systems are for supply water 86 ° C and for return water 47 ° C. In the future temperature levels could decrease to current with temperatures down against 55 ° C supply temperature and 25-20 ° C return temperature. The latter system temperature levels moves towards the ideal possible.

    It is possible to distinguish four generations of district heating distribution technology. The differences between generations are essentially depending on temperature levels but also depend on state of matter. The first generation district heating used high-temperature steam for heat transfer and then the newer distribution technologies resulted in lower temperatures and change of phase, from gas to liquid. The third generation of district heating distribution technology meant lower temperature than the second generation, and likewise the fourth generation will have a lower temperature level than the third-generation distribution technology for district heating. The development is driven by the benefits of lower temperature levels. One of the more appealing benefits of lower supply temperature is the possibility to use low exergy heat, resulting in reduced need of primary energy. The potential heat sources where increased heat supply with lower system temperatures becomes available can be seen in the four next bullets.

    • Waste heat
    • Geothermal heat
    • Solar heat
    • Heat pump

    Other advantages obtained with lower temperature levels in heat distribution are.

    • Lower distribution losses
    • Higher electrical power efficiency in CHP
    • Increased efficiency in flue gas condensation
    • Increased capacity in the distribution network
    • Reduced need for pump power in the distribution network
    • Lower risk of serious scalding
    • Increased capacity in heat storage
    • Ability to use other materials for distribution at lower cost

    There seem to be a consensus in the literature that lower temperature levels in district heating systems are a desirable change. The reason for this is likely that there are mostly advantages of lower temperature levels. The drawbacks of lower temperature levels are negligible which make the risk of investment low.

    Ladda ner fulltext (pdf)
    fulltext
  • 6.
    Averfalk, Helge
    et al.
    Högskolan i Halmstad, Akademin för företagande, innovation och hållbarhet, Rydberglaboratoriet för tillämpad naturvetenskap (RLAS).
    Benakopoulos, Theofanis
    Technical University of Denmark (DTU), Kongens Lyngby, Denmark.
    Best, Isabelle
    University of Kassel, Kassel, Germany.
    Dammel, Frank
    Technical University of Darmstadt, Darmstadt, Germany.
    Engel, Christian
    Austroflex Rohr-Isoliersysteme GmbH, Perchtoldsdorf, Austria.
    Geyer, Roman
    AIT Austrian Institute of Technology GmbH, Vienna, Austria.
    Gudmundsson, Oddgeir
    Danfoss, Sønderborg, Denmark.
    Lygnerud, Kristina
    Högskolan i Halmstad, Akademin för företagande, innovation och hållbarhet, Rydberglaboratoriet för tillämpad naturvetenskap (RLAS).
    Oltmanns, Johannes
    Technical University of Darmstadt, Darmstadt, Germany.
    Nord, Natasa
    Norwegian University of Science and Technology (NTNU), Trondheim, Norway.
    Ponweiser, Karl
    Vienna University of Technology, Vienna, Austria.
    Schmidt, Dietrich
    Fraunhofer IEE, Kassel, Germany.
    Schrammel, Harald
    AEE Intec, Gleisdorf, Austria.
    Skaarup Østergaard, Dorte
    Technical University of Denmark (DTU), Kongens Lyngby, Denmark.
    Svendsen, Svend
    Technical University of Denmark (DTU), Kongens Lyngby, Denmark.
    Tunzi, Michele
    Technical University of Denmark (DTU), Kongens Lyngby, Denmark.
    Werner, Sven
    Högskolan i Halmstad, Akademin för företagande, innovation och hållbarhet, Rydberglaboratoriet för tillämpad naturvetenskap (RLAS).
    Low-Temperature District Heating Implementation Guidebook: Final Report of IEA DHC Annex TS2. Implementation of Low-Temperature District Heating Systems2021Rapport (Övrigt vetenskapligt)
    Abstract [en]

    This guidebook was written between 2018 and 2021 by seventeen authors that used approximately 15 000 hours of work within the IEA DHC TS2 annex. The content is based on more than 250 literature references and 165 inspiration initiatives to obtain lower temperatures in buildings and heat distribution networks. The author group wrote 40 internal documents about early implementations of low-temperature district heating. Fifteen of these early implementations are presented in this guidebook.The guidebook contains aggregated information about the main economic drivers for low-temperature district heating. It shows how to obtain lower temperatures in heating systems inside existing and new buildings, as well as in existing and new heat distribution networks. An applied study of a campus system in Darmstadt shows the possibility of reducing temperatures in an existing heat distribution network with rather high temperatures. The competitiveness of low-temperature district heating is explored by analysing business models and heat distribution costs. Early adopters of low-temperature district heating are presented by examples and by identified transition strategies. Five groups of network configurations with fourteen variants are presented to be used for low-temperature district heating. Finally, all 165 identified inspiration initiatives and all 137 locations mentioned are listed.

  • 7.
    Averfalk, Helge
    et al.
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, Rydberglaboratoriet för tillämpad naturvetenskap (RLAS).
    Dalman, Bengt-Göran
    BG Dalman AB, Göteborg, Sverige.
    Kilersjö, Christer
    EKSTA, Kungsbacka, Sverige.
    Lygnerud, Kristina
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, Rydberglaboratoriet för tillämpad naturvetenskap (RLAS). IVL Svenska Miljöinstitutet, Stockholm, Sverige.
    Welling, Sebastian
    IVL Svenska Miljöinstitutet, Stockholm, Sverige.
    Analys av 4e generationens fjärrvärmeteknik jämfört med 3e generationens: Simulering av sekundärnät i nybyggnationsområde2017Rapport (Övrigt vetenskapligt)
    Abstract [sv]

    Bakgrunden till studien är att nya förutsättningar genom energieffektivisering, konkurrens från värmepumpar och nya krav på kundsidan gör en modernisering av fjärrvärmeverksamhet nödvändig. En del av denna modernisering är att kunna dra nytta av de fördelar som lägre temperaturer i näten medför. Därtill skapas genom den nya tekniken förutsättningar för att ta hand om värmekällor som idag inte utnyttjas (t.ex. värme från kylprocesser och annan infrastruktur såsom värme från avloppsvatten och värme från kollektivtrafik).

    Befintlig teknik är beprövad och bygger på att det finns ekonomiska incitament att förbränna biobränsle och avfall. Steget till att pröva en ny teknik där andra värmekällor och en ny gränsdragning gentemot kund blir nödvändig är därför stort och förenat med ett antal frågor. Det är just de frågor som uppkommer i ett fjärrvärmeföretag inför implementering av 4e generationens fjärrvärmeteknik som projektet försöker identifiera. Det blir dock så att enbart en del av frågorna besvaras genom att studien har ett avgränsat fokus. Fokus är på jämförelse mellan ett 3GDHtvårörsystem och ett 4GDH-trerörsystem i ett sekundärnät i ett nybyggnationsområde.

    I projektet simuleras hur utfallet blir för olika parametrar om man hade valt att implementera 4e generationens teknik istället för 3e generationens teknik.

    Resultaten påvisar att:

    • 4e generationens lösning ökar energieffektiviteten i byggnader, detta främst genom att behovet av varmvattencirkulation försvinner.• Beaktas enbart distributionsförluster i näten så är 4e generationen mer effektiv än 3e generationen.• Genom lägenhetsväxlaren i 4e generationens lösning så elimineras risken för Legionella helt. En möjlig barriär för 4e generationens teknik består dock i att boverkets byggregler inte är konstruerade för att varmvattencirkulation inte finns.• Lägenhetsväxlarna innebär en kostnad per lägenhet vilket begränsar lösningens kostnadseffektivitet jämfört med en större värmeväxlare i fastighetens bottenplan. Idag är 4e generationens teknik lämpad för fastigheter med 10-15 lägenheter, är det fler lägenheter blir 4e generationens lösning dyrare än den konventionella 3e generationens lösning.• En viktig aspekt med 4e generationens lösning att värmeförlusten från huset förflyttas från fastighetsägaren till fjärrvärmeföretaget, genom att värmeleverans sker till varje lägenhet och inte vid husvägg. Initialt kan sådan börda på fjärrvärmeföretaget verka negativ med avseende på kostnad. Diskussionerna i projektet mynnade ut i att parterna enas om att affären blir mer rättvisande och att fastighetsägaren får ökad insyn i värmeförbrukningen vilket, med rätt affärsmodell, kan skapa ökat förtroende och en möjlighet att dela på förlusten mellan de två parterna.

    Projektet har omfattat löpande dialog med EKSTAs VD vilket varit värdefullt för att skapa förståelse kring fastighetsägarens perspektiv och frågor rörande 4e generationens teknik. Därtill har en workshop med EKSTAs driftspersonal hållits för att diskutera relevansen i de resultat som tagits fram. I projektet ingår BengtGöran Dalman med över 35 års erfarenhet av fjärrvärmeverksamhet vid Göteborg Energi. Projektets verklighetskoppling leder till slutsatsen att det inte föreligger någon särskild driftsproblematik för implementering av 4e generationens system.

    Som en egen del i projektet uppmärksammas den diskussion som förs i branschen kring möjligheten att dra nytta av billig el, främst under perioder då det blåser mycket och det blir ett överskott av el i elnätet. I studien analyseras möjligheten att inte använda en konventionell pelletspanna som tilläggsvärmekälla utan en eldriven panna. Resultaten visar att med dagens styrning genom skatter och avgifter så är det inte möjligt att dra nytta av att det förekommer perioder med mycket lågt elpris. Rådande regelverk stödjer istället installationer såsom pelletspannor.

    © ENERGIFORSK

  • 8.
    Averfalk, Helge
    et al.
    Högskolan i Halmstad, Sektionen för ekonomi och teknik (SET), Bio- och miljösystemforskning (BLESS), Energiteknik.
    Hansson, Anna
    Högskolan i Halmstad, Sektionen för ekonomi och teknik (SET), Bio- och miljösystemforskning (BLESS), Ekologi och miljövetenskap.
    Karlsson, Niklas
    Högskolan i Halmstad, Sektionen för ekonomi och teknik (SET), Bio- och miljösystemforskning (BLESS), Ekologi och miljövetenskap.
    Werner, Sven
    Högskolan i Halmstad, Sektionen för ekonomi och teknik (SET), Bio- och miljösystemforskning (BLESS), Energiteknik.
    Mattsson, Marie
    Högskolan i Halmstad, Sektionen för ekonomi och teknik (SET), Bio- och miljösystemforskning (BLESS), Ekologi och miljövetenskap.
    Klimatgaser i Halland – en målinriktad analys med framtidsperspektiv2014Rapport (Övrigt vetenskapligt)
    Abstract [sv]

    Rapporten innehåller en analys av utsläppen av de sex klimatgaserna i Halland mellan 1990 och 2011, en skattning vad som kommer att genomföras till 2020 och förslag till åtgärder för att kunna leverera utsläppsreduktioner efter 2020. Resultaten visar att de halländska utsläppen har minskat med 20 procent sedan 1990, målet om 27 procent lägre utsläpp till 2020 kommer troligen att uppnås, transporter och jordbruk måste kunna leverera utsläppsreduktioner efter 2020, regionala plan- och styrdokument måste i större utsträckning kunna kvantifiera framtida utsläppsreduktioner samt att det behövs ett regionalt kompetenscenter i Halland för att länet ska kunna leverera utsläppsreduktioner i framtiden.

    Ladda ner fulltext (pdf)
    Klimatgaser i Halland 2014
  • 9.
    Averfalk, Helge
    et al.
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, Rydberglaboratoriet för tillämpad naturvetenskap (RLAS).
    Ingvarsson, Paul
    ÅF, Division Industry, Stockholm, Sweden.
    Persson, Urban
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, Rydberglaboratoriet för tillämpad naturvetenskap (RLAS).
    Gong, Mei
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, Rydberglaboratoriet för tillämpad naturvetenskap (RLAS).
    Werner, Sven
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, Rydberglaboratoriet för tillämpad naturvetenskap (RLAS).
    Large heat pumps in Swedish district heating systems2017Ingår i: Renewable & sustainable energy reviews, ISSN 1364-0321, E-ISSN 1879-0690, Vol. 79, s. 1275-1284Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Power-to-heat solutions like heat pumps and electric boilers are foreseen to be possible future tools to stabilise international power markets with high proportions of variable power supply. Temporary low cost electricity can be used for heat generation at times with high availability of wind and solar power through substitution of ordinary heat supply, hence contributing to increased energy system sustainability. Power-to-heat installations in district heating systems are competitive due to low specific investment and installation costs for large electric boilers, heat pumps, and heat storages. Several large-scale heat pumps were installed in Swedish district heating systems during the 1980s, since a national electricity surplus from new nuclear power existed for some years. The aim of this paper is to summarise the accumulated operation experiences from these large Swedish heat pumps to support and facilitate planning of future power-to-heat solutions with heat pumps in district heating systems. Gained experiences consider; installed capacities, capacity utilisation, heat sources used, refrigerant replacements, refrigerant leakages, and wear of mechanical components. The major conclusion is that many of the large thirty-year-old heat pumps are still in operation, but with reduced capacity utilisation due to internal competition from waste and biomass cogeneration plants in the district heating systems.

  • 10.
    Averfalk, Helge
    et al.
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, Bio- och miljösystemforskning (BLESS), Energiteknik.
    Ingvarsson, Paul
    ÅF, Division Industry, Stockholm, Sweden.
    Persson, Urban
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, Bio- och miljösystemforskning (BLESS), Energiteknik.
    Werner, Sven
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, Bio- och miljösystemforskning (BLESS), Energiteknik.
    On the use of surplus electricity in district heating systems2014Ingår i: Proceedings from the 14th International Symposium on District Heating and Cooling: September, 6-10, 2014: Stockholm, Sweden / [ed] Anna Land, Stockholm: Swedish District Heating Association , 2014, s. 469-474Konferensbidrag (Refereegranskat)
    Abstract [en]

    Maintained balance between supply and demand is a fundamental prerequisite for proper operation of electric power grids. For this end, power systems rely on accessibility to various balancing technologies and solutions by which fluctuations in supply and demand can be promptly met. In this paper, balancing approaches in the case of surplus electricity supply, due to long-term, seasonal, or short-term causes, are discussed on the basis mainly of compiled experiences from the Swedish national power grid. In Sweden, a structural long-term electricity surplus was created in the 1980s when several new nuclear plants were commissioned and built. One of four explicit domestic power-to-heat solutions initiated to maximize the utilization of this surplus electricity, as export capacities were limited, was the introduction of large scale electric boilers and compressor heat pumps in district heating systems. In retrospective, this solution not only satisfied the primary objective by providing additional electricity demand to balance the power grid, but represents today – from an energy systems perspective – a contemporary example of increased system flexibility by the attainment of higher integration levels between power and heat sectors. As European power supply will be reshaped to include higher proportions of fluctuating supply technologies (e.g. wind and solar), causing occasional but recurring short-term electricity surpluses, the unique Swedish experiences may provide valuable input in the development of rational responses to future balancing challenges. The main conclusions from this study are that district heating systems can add additional balancing capabilities to power systems, if equipped with electrical heat supply technologies, hereby contributing to higher energy system flexibility. Consequently, district heating systems also have a discrete but key role in the continued integration of renewable intermittent power supply technologies in the future European energy system.

    Ladda ner fulltext (pdf)
    On the use of surplus electricity in district heating systems
  • 11.
    Averfalk, Helge
    et al.
    Högskolan i Halmstad, Akademin för företagande, innovation och hållbarhet, Rydberglaboratoriet för tillämpad naturvetenskap (RLAS).
    Möllerström, Erik
    Högskolan i Halmstad, Akademin för företagande, innovation och hållbarhet, Rydberglaboratoriet för tillämpad naturvetenskap (RLAS).
    Ottermo, Fredric
    Högskolan i Halmstad, Akademin för företagande, innovation och hållbarhet, Rydberglaboratoriet för tillämpad naturvetenskap (RLAS).
    Domestic hot water design and flow measurements2021Ingår i: Energy Reports, E-ISSN 2352-4847, Vol. 7, nr Suppl. 4, s. 304-310Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this study, the sizing of primary side components for preparation of domestic hot water are analysed, both qualitatively and based on measurements of domestic hot water demand in one multi-family building with 268 apartments. The collected data spans a period of 18 days during the end of 2020 and is collected in 15-min, 1-min, and 6-s intervals. An overview of the historic development for the design of domestic hot water flow in Sweden is also presented. There is a long-standing argument in Sweden, that the current district heating guidelines result in an overdesign of the flow for domestic hot water. The consequence of this is oversizing heat exchangers and valves in the substations. This study assesses, qualitatively, the issues related to overdesigned primary side valves for preparation of domestic hot water. A revised design for domestic hot water flow for the Swedish context is also conceptualised. The study suggests that an improved design flow for domestic hot water in multi-family buildings can be derived based on empirical measurements. The 15-min intervals are observed to tone down information of peaks to a degree where it is unsuitable to use as basis for a new design flow. The 1-min data does appear to preserve information to a degree where it can be used to assess a design flow when related to data with a 6-s interval. The 6-s data is expected to constitute a resolution that may be less available, and in this study, it constitutes a representation of the real domestic hot water demands. However, to find a fitted curve to empirical data, for the design flow based on number of apartments per multi-family building, the population of datasets needs to be increased. © 2021 The Authors. Published by Elsevier Ltd.

  • 12.
    Averfalk, Helge
    et al.
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, Rydberglaboratoriet för tillämpad naturvetenskap (RLAS).
    Ottermo, Fredric
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, Rydberglaboratoriet för tillämpad naturvetenskap (RLAS).
    Werner, Sven
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, Rydberglaboratoriet för tillämpad naturvetenskap (RLAS).
    Pipe Sizing for Novel Heat Distribution Technology2019Ingår i: Energies, E-ISSN 1996-1073, Vol. 12, nr 7, artikel-id 1276Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This paper assesses pipe sizing aspects for previously proposed, novel, low heat distribution technology with three pipes. Assessment issues include heat loss, pressure loss, and pipe sizing for different typical pipe configurations. This assessment has been provided by the analysis of a case area with single-family houses. Concerning heat loss, the proposed three-pipe solutions have the same magnitude of heat loss as conventional twin pipes, since lower return temperatures compensate for the larger heat loss area from the third pipe. Regarding pressure loss, the main restriction on the size of the third pipe is limited to the pressure loss in the third pipe. Thermostatic valves to manage the flow rate of the third pipe are advocated, since alternative small pumps have not been found to be commercially available. The pipe sizing recommendation is that the third pipe for recirculation purposes can be two to three standard pipe sizes smaller than the corresponding supply and return pipe, if no prosumer is connected in the heat distribution network.

    Ladda ner fulltext (pdf)
    Pipe Sizing for Novel Heat Distribution Technology
  • 13.
    Averfalk, Helge
    et al.
    Högskolan i Halmstad, Akademin för företagande, innovation och hållbarhet, Rydberglaboratoriet för tillämpad naturvetenskap (RLAS).
    Persson, Urban
    Högskolan i Halmstad, Akademin för företagande, innovation och hållbarhet, Rydberglaboratoriet för tillämpad naturvetenskap (RLAS).
    Low‐temperature excess heat recovery in district heating systems: The potential of European Union metro stations2020Ingår i: Book of Abstracts: 6th International Conference on Smart Energy Systems / [ed] Henrik Lund, Brian Vad Mathiesen, Poul Alberg Østergaard & Hans Jørgen Brodersen, 2020, s. 34-34Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    This paper presents an assessment of the excess heat recovery potential from EU metro stations. The assessment is a sub-study on low temperature recovery opportunities, explored in the H2020 ReUseHeat project, and consists of spatial mapping of 1994 underground stations with quantitative estimates of sensible and latent heat, monthly and annually, attainable in rejected platform ventilation exhaust air. Being a low-temperature source, the assessment conceptually anticipates recovery of attainable heat with compressor heat pumps to facilitate the temperature increase necessary for utilisation in district heating systems. Further, the paper explores the influence on useful excess heat volumes from low-temperature heat recoveries when distributed at different temperature levels. The findings, which distinguishes available (resource) and accessible (useful) excess heat potentials, indicate an annual total EU28 available potential of ~21 PJ, characterised by a certain degree of seasonal temporality, and corresponding accessible potentials of ~40 PJ per year at 3rd generation distribution, and of ~31 PJ at anticipated 4th generation conditions. Despite lower accessible volumes, utilisation in 4th generation systems are naturally more energy efficient, since relatively less electricity is used in the recovery process, but also more cost-effective, since heat pumps, at lower temperatures, can be operated at capacities closer to design conditions and with less annual deviations.

    Ladda ner fulltext (pdf)
    Conference_presentation
  • 14.
    Averfalk, Helge
    et al.
    Högskolan i Halmstad, Akademin för företagande, innovation och hållbarhet, Rydberglaboratoriet för tillämpad naturvetenskap (RLAS).
    Werner, Sven
    Högskolan i Halmstad, Akademin för företagande, innovation och hållbarhet, Rydberglaboratoriet för tillämpad naturvetenskap (RLAS).
    Economic benefits of fourth generation district heating2020Ingår i: Energy, ISSN 0360-5442, E-ISSN 1873-6785, Vol. 193, artikel-id 116727Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The main impetus for lower distribution temperatures in district heating systems is the lower heat supply costs obtained by these lower temperatures. In this paper, the differences in heat supply costs for two different temperature levels have been estimated for various future heat supply options. The estimations were obtained by modelling a district heating system characterised by typical climate conditions for Central Europe. High sensitivity to lower supply costs from lower temperatures was found for geothermal heat, industrial excess heat, and heat pumps, whereas low cost sensitivity was estimated for combined heat and power plants using waste or biomass. Lower heat distribution loss constitutes a minor component of the total cost reductions. The current use of high heat distribution temperatures was identified as an important barrier for the transition to renewable and recycled heat supply in district heating systems. Hence, lower distribution temperatures would facilitate this required transition because lower distribution temperatures provide higher profitability for these renewable and recycled heat sources. © 2019 The Authors. Published by Elsevier Ltd.

  • 15.
    Averfalk, Helge
    et al.
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, Rydberglaboratoriet för tillämpad naturvetenskap (RLAS).
    Werner, Sven
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, Rydberglaboratoriet för tillämpad naturvetenskap (RLAS).
    Efficient heat distribution in solar district heating systems2018Ingår i: SDH Solar District Heating: Proceeding, 2018, s. 63-66Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper contains a short analysis showing the main benefit for solar district heating when a novel heat distribution concept with low temperatures is applied. The analysis is performed by comparing the annual solar heat output from a solar collector field for current heat distribution temperatures in Sweden with the corresponding output for the novel heat distribution concept. The results show that the new low temperature concept provides 66% more solar heat for a typical solar collector. Hereby, the solar collector field can be reduced with 40%, giving a corresponding cost reduction for solar heat generated. Another result is that the cost gradient for lower costs from lower return temperatures is five times higher for solar district heating compared to current heat supply in Swedish district heating systems. One major conclusion is that high heat distribution temperatures in current European district heating systems are a major barrier for the competitiveness of solar district heating.

    Ladda ner fulltext (pdf)
    fulltext
  • 16.
    Averfalk, Helge
    et al.
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, Bio- och miljösystemforskning (BLESS).
    Werner, Sven
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, Bio- och miljösystemforskning (BLESS), Energivetenskap.
    Essential Improvements in Future District Heating Systems2016Ingår i: Proceedings of the 15th International Symposium on District Heating and Cooling: September 4th - 7th, 2016, Seoul, South Korea / [ed] Rolf Ulseth & Kyung Min Kim, 2016, s. 194-200Konferensbidrag (Refereegranskat)
    Abstract [en]

    The major common denominator for future efficient fourth generation district heating systems is lower temperature levels in the distribution networks. Higher efficiencies are then obtained in both heat supply and heat distribution. Heat supply becomes more efficient with respect to combined heat and power, flue gas condensation, heat pumps, geothermal extraction, low temperature excess heat, and heat storage. Heat distribution becomes more efficient from lower distribution losses, less pipe expansion, lower scalding risks, and plastic pipes. The lower temperature levels will be possible since future buildings will have lower temperature demands when requiring lower heat demands. This paper aims at providing seven essential recommendations concerning design and construction strategies for future fourth generation systems. The method used is based on a critical examination of the barriers for lower temperature levels and the origins of high return temperatures in contemporary third generation systems. The two main research questions applied are: Which parts of contemporary system design are undesirable? Which possible improvements are desirable? Key results and the corresponding recommendations include temperature levels for heat distribution, recirculation, metering, supervision, thermal lengths for heat exchangers and heat sinks, hydronic balancing, and legionella. The main conclusion is that it should be possible to construct new fourth generation district heating networks according to these seven essential recommendations presented in this paper.

    Ladda ner fulltext (pdf)
    fulltext
  • 17.
    Averfalk, Helge
    et al.
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, Rydberglaboratoriet för tillämpad naturvetenskap (RLAS).
    Werner, Sven
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, Rydberglaboratoriet för tillämpad naturvetenskap (RLAS).
    Essential improvements in future district heating systems2017Ingår i: Energy Procedia, ISSN 1876-6102, Vol. 116, s. 217-225Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The major common denominator for future efficient fourth generation district heating systems is lower temperature levels in the distribution networks. Higher efficiencies are then obtained in both heat supply and heat distribution. Heat supply becomes more efficient with respect to combined heat and power, flue gas condensation, heat pumps, geothermal extraction, low temperature excess heat, and heat storage. Heat distribution becomes more efficient from lower distribution losses, less pipe expansion, lower scalding risks, and plastic pipes. The lower temperature levels will be possible since future buildings will have lower temperature demands when requiring lower heat demands. This paper aims at providing seven essential recommendations concerning design and construction strategies for future fourth generation systems. The method used is based on a critical examination of the barriers for lower temperature levels and the origins of high return temperatures in contemporary third generation systems. The two main research questions applied are: Which parts of contemporary system design are undesirable? Which possible improvements are desirable? Key results and the corresponding recommendations include temperature levels for heat distribution, recirculation, metering, supervision, thermal lengths for heat exchangers and heat sinks, hydronic balancing, and legionella. The main conclusion is that it should be possible to construct new fourth generation district heating networks according to these seven essential recommendations presented in this paper. © 2017 The Authors. Published by Elsevier

    Ladda ner fulltext (pdf)
    fulltext
  • 18.
    Averfalk, Helge
    et al.
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, Rydberglaboratoriet för tillämpad naturvetenskap (RLAS).
    Werner, Sven
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, Rydberglaboratoriet för tillämpad naturvetenskap (RLAS).
    Framtida fjärrvärmeteknik: Möjligheter med en fjärde teknikgeneration2017Rapport (Refereegranskat)
  • 19.
    Averfalk, Helge
    et al.
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, Rydberglaboratoriet för tillämpad naturvetenskap (RLAS).
    Werner, Sven
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, Rydberglaboratoriet för tillämpad naturvetenskap (RLAS).
    Novel low temperature heat distribution technology2018Ingår i: Energy, ISSN 0360-5442, E-ISSN 1873-6785, Vol. 145, s. 526-539Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Lower future heat demands and lower availability of non-fossil high temperature heat supply are expected future market conditions that restrain the long-term viability of contemporary district heating systems. Hence, current district heating technology should be enhanced to increase system performance in new heat distribution areas. This paper aims to outline a proposal for technical improvements required to achieve lower annual average return temperatures in new residential buildings to improve viability in future market conditions. The proposed technical solution consists of three principle changes: three-pipe distribution networks, apartment substations, and longer thermal lengths for heat exchangers. The three technical modifications aims at addressing system embedded temperature errors. Furthermore, a simulation model was developed to assess the proposed technical solution concerning different energy performances of buildings and different thermal lengths in heat exchangers. The results show that implementation of the three technical modifications reaches time-weighted annual average return temperatures of 17–21 °C with supply temperatures of about 50 °C. The results also verify the increased necessity to separate the network return flows into delivery and recirculation flows in residential substations as energy performance in buildings increase.

  • 20.
    Averfalk, Helge
    et al.
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, Rydberglaboratoriet för tillämpad naturvetenskap (RLAS).
    Werner, Sven
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, Rydberglaboratoriet för tillämpad naturvetenskap (RLAS).
    Felsmann, Clemens
    Technische Universität Dresden, Dresden, Germany.
    Rühling, Karin
    Technische Universität Dresden, Dresden, Germany.
    Wiltshire, Robin
    Building Research Establishment (BRE), Garston, Watford, United Kingdom.
    Svendsen, Svend
    Technical University of Denmark, Kongens Lyngby, Denmark.
    Li, Hongwei
    Technical University of Denmark, Kongens Lyngby, Denmark.
    Faessler, Jérôme
    University of Geneva, Geneva, Switzerland.
    Floriane, Mermoud
    University of Geneva, Geneva, Switzerland.
    Quiquerez, Loïc
    University of Geneva, Geneva, Switzerland.
    Transformation Roadmap from High to Low Temperature District Heating Systems: Annex XI final report2017Rapport (Övrigt vetenskapligt)
    Ladda ner (pdf)
    summary
  • 21.
    David, Andrei
    et al.
    Aalborg Univ, Dept Planning, Copenhagen, Denmark.
    Vad Mathiesen, Brian
    Aalborg Univ, Dept Planning, Copenhagen, Denmark.
    Averfalk, Helge
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, Rydberglaboratoriet för tillämpad naturvetenskap (RLAS).
    Werner, Sven
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, Rydberglaboratoriet för tillämpad naturvetenskap (RLAS).
    Lund, Henrik
    Aalborg Univ, Dept Planning, Aalborg, Denmark.
    Heat Roadmap Europe: Large-Scale Electric Heat Pumps in District Heating Systems2017Ingår i: Energies, E-ISSN 1996-1073, Vol. 10, nr 4, artikel-id 578Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The Heat Roadmap Europe (HRE) studies estimated a potential increase of the district heating (DH) share to 50% of the entire heat demand by 2050, with approximately 25–30% of it being supplied using large-scale electric heat pumps. This study builds on this potential and aims to document that such developments can begin now with technologies currently available. We present a database and the status of the technology and its ability of expansion to other European locations by reviewing experiences aimed at further research or application in the heating industry. This is based on a survey of the existing capacity of electric large-scale heat pumps with more than 1 MW thermal output, operating in European DH systems. The survey is the first database of its kind containing the technical characteristics of these heat pumps, and provides the basis for the analysis of this paper. By quantifying the heat sources, refrigerants, efficiency and types of operation of 149 units with 1580 MW of thermal output, the study further uses this data to analyze if the deployment of this technology on a large-scale is possible in other locations in Europe. It finally demonstrates that the technical level of the existing heat pumps is mature enough to make them suitable for replication in other locations in Europe.

  • 22.
    Lind, Johan
    et al.
    Högskolan i Halmstad, Akademin för företagande, innovation och hållbarhet.
    Möllerström, Erik
    Högskolan i Halmstad, Akademin för företagande, innovation och hållbarhet.
    Averfalk, Helge
    Högskolan i Halmstad, Akademin för företagande, innovation och hållbarhet.
    Ottermo, Fredric
    Högskolan i Halmstad, Akademin för företagande, innovation och hållbarhet.
    Energy flexibility using the thermal mass of residential buildings2023Ingår i: Energy and Buildings, ISSN 0378-7788, E-ISSN 1872-6178, Vol. 301, s. 1-12, artikel-id 113698Artikel, forskningsöversikt (Refereegranskat)
    Abstract [en]

    The transition to a more sustainable energy system with a growing amount of intermittent renewable energy sources brings an increasing need for flexibility measures to maintain balance between supply and demand. Buildings represent a promising source of demand-side flexibility due to their large energy demand and thermal mass. This review provides insights into the storage potential of building thermal mass, and the benefits and challenges it brings. It is found that building thermal mass storage have good ability to shift loads on short term, from peak to off-peak hours. This ability can be utilized for different purposes, for instance reduced costs for end-users or energy providers, reduced primary energy demand, or reduced CO2 emissions. Furthermore, this review explores different factors that influence the storage potential of building thermal mass, with special attention paid to the heat emission system. It is shown that hydronic floor heating is beneficial compared to radiators since it directly can activate the thermal mass with smaller impact on the indoor temperature. It is also found that the factor with largest impact is the envelope insulation level; increased insulation level brings improved storage efficiency and prolonged thermal autonomy but also decreased storage capacity and increased risk of overheating. Finally, research gaps are identified. © 2023 The Authors

  • 23.
    Norrström, Heidi
    et al.
    Högskolan i Halmstad, Akademin för företagande, innovation och hållbarhet.
    Stålne, Kristian
    Malmö universitet, Malmö, Sverige.
    Averfalk, Helge
    Högskolan i Halmstad, Akademin för företagande, innovation och hållbarhet.
    Werner, Sven
    Högskolan i Halmstad, Akademin för företagande, innovation och hållbarhet.
    Ranagård med 4GDH-teknik: Slutrapport mars 20222022Rapport (Övrigt vetenskapligt)
  • 24.
    Persson, Urban
    et al.
    Högskolan i Halmstad, Akademin för företagande, innovation och hållbarhet, Rydberglaboratoriet för tillämpad naturvetenskap (RLAS).
    Averfalk, Helge
    Högskolan i Halmstad, Akademin för företagande, innovation och hållbarhet, Rydberglaboratoriet för tillämpad naturvetenskap (RLAS).
    Accessible urban waste heat: Deliverable 1.42018Rapport (Övrigt vetenskapligt)
    Abstract [en]

    This report presents the work performed in Task T1.2 of the ReUseHeat project to assess the accessible EU28 urban excess heat recovery potential from four unconventional excess heat sources: data centres, metro stations, service sector buildings, and waste water treatment plants. The report presents in overview and detail the concepts, data, basic premises, and methods, used to produce the results from this work. In all, excess heat potentials are modelled and spatially mapped for a total of some 26,400 unique activities, but by application of two new concepts: available excess heat and accessible excess heat, by which total potentials are distinguished from practical utilisation potentials, a significantly reduced count of some 6800 unique facilities represent the final cut. Common for these facilities are that they all are located inside or within 2 kilometres of urban district heating areas. For the total count of activities, the full available excess heat potential is assessed at some 1.56 EJ per year. At the restrained conditions, thus representing a conservative estimate, the final available excess heat potential from the four unconventional sources is estimated at 0.82 EJ per year, which here corresponds to a final accessible excess heat potential anticipated at 1.24 EJ annually.

  • 25.
    Persson, Urban
    et al.
    Högskolan i Halmstad, Akademin för företagande, innovation och hållbarhet, Rydberglaboratoriet för tillämpad naturvetenskap (RLAS).
    Averfalk, Helge
    Högskolan i Halmstad, Akademin för företagande, innovation och hållbarhet, Rydberglaboratoriet för tillämpad naturvetenskap (RLAS).
    Nielsen, Steffen
    Aalborg University, Aalborg, Denmark.
    Moreno, Diana
    Aalborg University, Aalborg, Denmark.
    Accessible urban waste heat (Revised version): Deliverable D1.42020Rapport (Övrigt vetenskapligt)
    Abstract [en]

    This report presents the revised work performed in Task T1.2 of the ReUseHeat project to assess the accessible EU28 urban excess heat recovery potential from seven unconventional excess heat sources: data centres, metro stations, food production facilities, food retail stores, residential sector buildings, service sector buildings, and waste water treatment plants. The report presents in overview and detail the concepts, data, basic premises, and methods, used to produce the results from this work. In all, excess heat potentials are modelled and spatially mapped for a total of some 70,800 unique activities, but by application of two new concepts: available excess heat and accessible excess heat, by which total potentials are distinguished from practical utilisation potentials, a significantly reduced count of some 27,700 unique facilities represent the final cut. Common for these facilities are that they all are located inside or within 2 kilometres of urban district heating areas. For the total count of activities, the full available excess heat potential is assessed at some 1.84 EJ per year. At the restrained conditions, thus representing a conservative estimate, the final available excess heat potential from the seven unconventional sources is estimated at 0.96 EJ per year, which here corresponds to a final accessible excess heat potential anticipated at 1.41 EJ annually.

    Ladda ner fulltext (pdf)
    fulltext
  • 26.
    Sánchez-García, Luis
    et al.
    Högskolan i Halmstad, Akademin för företagande, innovation och hållbarhet.
    Averfalk, Helge
    Högskolan i Halmstad, Akademin för företagande, innovation och hållbarhet.
    Möllerström, Erik
    Högskolan i Halmstad, Akademin för företagande, innovation och hållbarhet.
    Persson, Urban
    Högskolan i Halmstad, Akademin för företagande, innovation och hållbarhet.
    Understanding effective width for district heating2023Ingår i: Energy, ISSN 0360-5442, E-ISSN 1873-6785, Vol. 277, artikel-id 127427Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    District heating is one of the technologies that can contribute to the decarbonisation of the European heat sector. Nonetheless, these infrastructures only deliver about a tenth of the heat demands in the continent. Therefore, it is essential to assess the expansion potential of these systems and to identify which areas should be target for further investigations, which calls for easy-to-use and straightforward methods such as Persson & Werner's network capital cost model. Pivotal parameters of the model are the effective width, a metric of trench length by land area, alongside the average pipe diameter and the linear heat density. This study has carried out an in-depth analysis of these crucial parameters with respect to both distribution and service pipes in a large Danish district heating network, which has allowed to explore the behaviour of effective width in a broad range of building densities and derive new equations for both effective width and average pipe diameter. The model has subsequently been validated in another large network in Denmark and several minor districts in the same country, showing the accuracy of the model on an aggregated level. © 2023 Elsevier Ltd.

  • 27.
    Sánchez-García, Luis
    et al.
    Högskolan i Halmstad, Akademin för företagande, innovation och hållbarhet, Rydberglaboratoriet för tillämpad naturvetenskap (RLAS).
    Averfalk, Helge
    Högskolan i Halmstad, Akademin för företagande, innovation och hållbarhet, Rydberglaboratoriet för tillämpad naturvetenskap (RLAS).
    Persson, Urban
    Högskolan i Halmstad, Akademin för företagande, innovation och hållbarhet, Rydberglaboratoriet för tillämpad naturvetenskap (RLAS).
    Further investigations on the Effective Width for district heating systems2021Ingår i: Energy Reports, E-ISSN 2352-4847, Vol. 7, nr Suppl. 4, s. 351-358Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    District Heating is a cornerstone for the decarbonisation of the heating and cooling sector in Europe. Nonetheless, this technology is currently absent in a majority of the continent’s urban areas, and hence the need for appropriate methods by which to estimate the cost, as well as underlying cost parameters, to assess the feasibility of developing district heating networks is of general interest. One key underlying cost parameter, the concept of Effective Width, which is the ratio between a land area and the trench length within that land area, is the focus quantity of this work. Effective Width enables a first order assessment of the total route length of pipes in a given urban area and, together with the average diameter of the pipes, allows an estimation of the investment cost of installing district heating pipes. However, initial implementations of the Effective Width have been based on rather limited empirical evidence, such as a small set of cases and often disregarding service pipes due to lack of data. Another shortcoming of previous studies is the extrapolation of established relations into more sparsely populated areas. By assembly of a richer database, which contains building data, heat consumption data in the supplied areas, as well as actual network information (numerical and geographical), provided by several district heating companies in Denmark and Sweden, the objectives of this study are twofold: first, to improve the general understanding of Effective Width and its relation to building density, and secondly, to study the particular case of sparse areas. The results of this study provide new insight to enhance our understanding of the Effective Width concept which may facilitate better assessments of future district heating systems. © 2021 The Author(s). Published by Elsevier Ltd.

  • 28.
    Sánchez-García, Luis
    et al.
    Högskolan i Halmstad, Akademin för företagande, innovation och hållbarhet.
    Averfalk, Helge
    Högskolan i Halmstad, Akademin för företagande, innovation och hållbarhet.
    Persson, Urban
    Högskolan i Halmstad, Akademin för företagande, innovation och hållbarhet.
    sEEnergies special report: Construction costs of new district heating networks in Germany2022Rapport (Övrigt vetenskapligt)
    Abstract [en]

    This report aims to present the results of the work carried out within the sEEnergies project pertaining to estimating construction costs of new district heating networks in Germany.

    This project has followed a similar methodology to Heat Roadmap Europe when estimating the costs of district heating systems. Nonetheless, several improvements have been introduced to attain more realistic results. On the one hand, it has been carried out a detailed geographic analysis of two large Danish networks so the necessary pipe length can be better appraised. Moreover, both the distribution network and service pipes have been taken into consideration. On the other hand, pipe construction cost data from each country has been used to the maximum extent possible.  

    This part of the project has only focused on the pipe network and has not taken into account other elements for the development of a district heating system, such as heat supply plants or the connections to the heat demands via a substation. 

    The results for Germany show that the country has a significant potential for District Heating expansion. Approximately a quarter of the total heat demand could be supplied with a cost lower than 20 €/MWh and nearly half of the heat demand would be economically viable with a higher marginal cost of 30 €/MWh. Nonetheless, there is significant regional variation, and whilst the most urban districts (kreise) could reach penetration rates above 70% for a marginal cost of 20 €/MWh, the least dense would fall below 10% of the heat demand. 

    Ladda ner fulltext (pdf)
    fulltext
  • 29.
    Sánchez-García, Luis
    et al.
    Högskolan i Halmstad, Akademin för företagande, innovation och hållbarhet.
    Averfalk, Helge
    Högskolan i Halmstad, Akademin för företagande, innovation och hållbarhet.
    Persson, Urban
    Högskolan i Halmstad, Akademin för företagande, innovation och hållbarhet.
    Hermoso-Martínez, Nekane
    TECNALIA, Basque Research and Technology Alliance (BRTA), Derio, Spain.
    Hernández-Iñarra, Patxi
    TECNALIA, Basque Research and Technology Alliance (BRTA), Derio, Spain.
    Viability of district heating networks in temperate climates: Benefits and barriers of cold and warm temperature networks2023Ingår i: Book of Abstracts: 9th International Conference on Smart Energy Systems / [ed] Lund, Henrik; Mathiesen, Brian Vad; Østergaard, Poul Alberg; Brodersen, Hans Jørgen, Aalborg, 2023, s. 280-281Konferensbidrag (Refereegranskat)
    Abstract [en]

    The decarbonization of the heat supply and the attainment of a higher security of supply demand the transition towards zero-carbon heating solutions. In dense urban environments, where the construction cost of a pipe network is relatively low, heating and cooling networks can deliver heating and cooling at a lower cost compared to individual solutions. 

    This paper builds on prior research by these authors mapping heating and cooling energy use in Bilbao, Spain, a city characterised by mild oceanic climate and a dense urban pattern. Areas within the city where heating and cooling networks could be more feasible have been identified taking into account the building stock characteristics and energy use, together with other urban and resource parameters, and a city district has been selected for further study.      

    Warm networks deliver heat at a sufficiently high temperature to be directly used by the consumers whereas cold networks employ lower temperatures, thus requiring heat pumps at the consumers premises. Research has highlighted as advantages of this newer configuration the possibility of delivering both heating and cooling with the same network, the lower capital costs of these networks and negligible heat losses. Nonetheless, comparisons between the two technologies have been seldom performed in the literature. In this paper, an economic comparison between these two solutions is presented for the selected district of Bilbao.  Results show that cold networks require a lower investment in the actual network infrastructure but the distributed heat pumps increase the costs to a higher total CAPEX than in warm networks.  Overall life cycle costs of heat are also slightly higher for cold networks than for warm networks. Other benefits and barriers for each of the solutions, for example regarding necessary space or speed and modularity of the implementation of the network are also discussed.

    Ladda ner fulltext (pdf)
    Abstract
    Ladda ner fulltext (pdf)
    Power Point Presentation
  • 30.
    Sánchez-García, Luis
    et al.
    Högskolan i Halmstad, Akademin för företagande, innovation och hållbarhet.
    Averfalk, Helge
    Högskolan i Halmstad, Akademin för företagande, innovation och hållbarhet.
    Persson, Urban
    Högskolan i Halmstad, Akademin för företagande, innovation och hållbarhet.
    Werner, Sven
    Högskolan i Halmstad, Akademin för företagande, innovation och hållbarhet.
    A Closer Look at the Effective Width for District Heating Systems2021Ingår i: Book of Abstracts: 7th International Conference on Smart Energy Systems / [ed] Henrik Lund; Brian Vad Mathiesen; Poul Alberg Østergaard; Hans Jørgen Brodersen, Aalborg: Aalborg Universitetsforlag, 2021, s. 153-153Konferensbidrag (Refereegranskat)
    Abstract [en]

    District heating is an important technology for decarbonizing the heating supply in urban areas since it enables the recovery of waste heat that would otherwise be wasted and the cost-effective utilization of renewable heat. Nonetheless, the current general extent of these systems in Europe is very low, hence the need for simple methods and parameters to estimate their cost and feasibility on a large scale. One of these cost parameters is the Effective Width, which enables a first order approximation of the total pipe length in a given area. This concept, in conjunction with the average pipe diameter in the area, permits the determination of the network’s capital cost. However, previous research of Effective Width has relied on a small set of cases and has not contemplated service pipes. Therefore, there is need for a closer look and a deeper understanding of the underlying phenomena that influences this parameter. This study has analysed several Scandinavian District Heating Systems in detail and provides new evidence on the relation between Effective Width and the urban environment for both distribution and service pipes.

  • 31.
    Sánchez-García, Luis
    et al.
    Högskolan i Halmstad, Akademin för företagande, innovation och hållbarhet.
    Persson, Urban
    Högskolan i Halmstad, Akademin för företagande, innovation och hållbarhet.
    Averfalk, Helge
    Högskolan i Halmstad, Akademin för företagande, innovation och hållbarhet.
    sEEnergies special report: Construction costs of new district heating networks in France2022Rapport (Övrigt vetenskapligt)
    Abstract [en]

    This report aims to present the results of the work carried out within the sEEnergies project pertaining to estimating construction costs of new district heating networks in France.

    This project has followed a similar methodology to Heat Roadmap Europe when estimating the costs of district heating systems. Nonetheless, several improvements have been introduced to attain more realistic results. On the one hand, it has been carried out a detailed geographic analysis of two large Danish networks so the necessary pipe length can be better appraised. Moreover, both the distribution network and service pipes have been taken into consideration. On the other hand, pipe construction cost data from each country has been used to the maximum extent possible.  

    This part of the project has only focused on the pipe network and has not taken into account other elements for the development of a district heating system, such as heat supply plants or the connections to the heat demands via a substation. 

    The results for France show that the country has a significant potential for District Heating expansion. Approximately a quarter of the total heat demand (28%) could be supplied with a cost lower than 20 €/MWh and nearly half of the heat demand (47%) would be economically viable with a higher marginal cost of 30 €/MWh. Nonetheless, there is significant regional variation. For instance, for a marginal cost threshold of 20 €/MWh, Paris could cover nearly the entire heat demand and the other départements of the petite couronne de París, could reach penetration rates above 70%. On the contrary, the 12 least dense départements would not be able to deliver more than 10% of the heat demand, having the département of Vendée the lowest potential with merely 3%. 

    Ladda ner fulltext (pdf)
    Construction costs of new district heating networks in France - Luis Sánchez-García, Helge Averfalk & Urban Persson, 2022
  • 32.
    Sánchez-García, Luis
    et al.
    Högskolan i Halmstad, Akademin för företagande, innovation och hållbarhet.
    Persson, Urban
    Högskolan i Halmstad, Akademin för företagande, innovation och hållbarhet.
    Averfalk, Helge
    Högskolan i Halmstad, Akademin för företagande, innovation och hållbarhet.
    Hermoso-Martínez, Nekane
    TECNALIA, Basque Research and Technology Alliance (BRTA), Derio, Spain.
    Hernández-Iñarra, Patxi
    TECNALIA, Basque Research and Technology Alliance (BRTA), Derio, Spain.
    Viability of district heating networks in temperate climates: Benefits and barriers of ultra-low cold and warm temperature networks2022Ingår i: 8th International Conference on Smart Energy Systems: 13-14 September 2022: Book of abstracts / [ed] Lund, Henrik, Aalborg, 2022, s. 186-186Konferensbidrag (Refereegranskat)
    Abstract [en]

    The decarbonization of the heat supply and the achievement of a higher energy security calls for the substitution of conventional fossil fuel boilers by other means of heat supply. In dense urban areas, where the pipe network cost is proportionally lower, district heating can be an attractive solution for this goal. If there is a possibility to recover heat that would otherwise be wasted or produce renewable heat centrally in a more economic manner, this can be a very cost-effective solution for decarbonising the heat supply. Networks for district heating have traditionally distributed heat at a temperature sufficiently high to virtually all consumers. In cold district networks , the network is maintained at close to ambient temperature (10-30°C), and require the heat to be boosted at the consumer level. Cold networks have drawn plenty of research attention thanks to several advantages such as their capacity to provide with the same network both heating and cooling or using more economic piping.  Nonetheless, comparisons between the two technologies have been seldom performed in the literature. This study has aimed to fill this gap and has drawn an economic comparison between these two solutions in a case study for the city of Bilbao, which presents a mild oceanic climate but features a very dense urban fabric. 

    Ladda ner fulltext (pdf)
    Abstract
    Ladda ner (pdf)
    Power Point Presentation
1 - 32 av 32
RefereraExporteraLänk till träfflistan
Permanent länk
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf