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  • 1.
    Arias, Jaime
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Claesson, Joachim
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration. KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Sustainable Building Systems.
    Effektivare butikskyla: Värme ur kylanläggningar samt system med flytande kondensering, Aktiviteter 20062007Report (Other academic)
  • 2.
    Claesson, Joachim
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration. KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Sustainable Building Systems.
    Adiabatic two-phase flow hydraulic performance in a compact brazed plate heat exchanger2007In: Heat SET: Heat Transfer in Components and Systems for Sustainable Energy Technologies / [ed] Thonon, 2007Conference paper (Refereed)
  • 3.
    Claesson, Joachim
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration. KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Sustainable Building Systems.
    Beräkningsmetoder för årsvärmefaktor för värmepumpsystem för jämförelse, systemval och dimensionering2010Report (Other academic)
  • 4.
    Claesson, Joachim
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration. KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Sustainable Building Systems.
    Butiken i kyllabbet på IUC har öppnat2006In: ScanRef, ISSN 0284-0758, no 4, p. 44-47Article in journal (Other (popular science, discussion, etc.))
  • 5.
    Claesson, Joachim
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration. KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Sustainable Building Systems.
    CERBOF Projekt no. 72: Utfall och metodutvärdering av energideklaration av byggnader2011Report (Other academic)
  • 6.
    Claesson, Joachim
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Chapter 2 - Köldmedier2016In: VVS 2000 TABELLER & DIAGRAM: Kylteknik / [ed] Energi- och Miljötekniska Föreningen, Stockholm: EMTF Förlag , 2016, p. 10-32Chapter in book (Other academic)
  • 7.
    Claesson, Joachim
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Chapter 5 - Aggregat2016In: VVS 2000 TABELLER & DIAGRAM: Kylteknik / [ed] Energi- och Miljötekniska Föreningen, Stockholm: EMTF Förlag , 2016, p. 48-52Chapter in book (Other academic)
  • 8.
    Claesson, Joachim
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Chapter 7 - Energieffektivitet2016In: VVS 2000 TABELLER & DIAGRAM: Kylteknik / [ed] Energi- och Miljötekniska Föreningen, Stockholm: EMTF Förlag , 2016, p. 59-70Chapter in book (Other academic)
  • 9.
    Claesson, Joachim
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Chapter 9 – Miljö- och livscykelaspekter2016In: VVS 2000 TABELLER & DIAGRAM: Kylteknik / [ed] Energi- och Miljötekniska Föreningen, Stockholm: EMTF Förlag , 2016, p. 111-114Chapter in book (Other academic)
  • 10.
    Claesson, Joachim
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Correction of Logarithmic Mean Temperature Difference in a compact brazed plate evaporator assuming heat flux governed flow boiling heat transfer coefficient2005In: International journal of refrigeration, ISSN 0140-7007, E-ISSN 1879-2081, Vol. 28, no 4, p. 573-578Article in journal (Refereed)
    Abstract [en]

    The heat transfer in heat exchangers is commonly calculated using the concept of Logarithmic Mean Temperature Difference (LMTD). As is well known this approach is only valid for counter-current and co-current heat exchanger configurations. For other configurations, corrections for the deviation from pure counter-current are introduced. From any standard text book in heat transfer it may be found that the LMTD approach may also be used if condensation and evaporation occurs in the heat exchanger. The purpose of the present paper is to investigate if the LMTD approach can be used in a compact brazed plate evaporator. It will be shown through integration of the governing equations that the LMTD approach indeed may be used for practical cases, even though deviations occur at small logarithmic mean temperature differences. The article presents suggestions on the correction factor (F) needed under some simplified assumptions in a compact brazed plate heat exchanger operating as an evaporator for heat pump and refrigeration applications.

  • 11.
    Claesson, Joachim
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration. KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Sustainable Building Systems.
    En litteraturstudie om klimatets inverkan på kyleffekt och avfrostningsbehov i livsmedelsbutiker2005Report (Other academic)
  • 12.
    Claesson, Joachim
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Kombisystem: uthållig uppvärmning av mindre fastigheter2008In: Energi & Miljö, ISSN 1101-0568, no 12, p. 68-72Article in journal (Other academic)
  • 13.
    Claesson, Joachim
    KTH, Superseded Departments (pre-2005), Energy Technology.
    Literature Survey, relevant to compact brazed plate heat exchangers as evaporators in heat pump system2004Report (Other academic)
  • 14.
    Claesson, Joachim
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration. KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Sustainable Building Systems.
    Local flow boiling experiments with refrigerant R134a in compact brazed plate heat exchanger2007Conference paper (Other academic)
  • 15.
    Claesson, Joachim
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration. KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Sustainable Building Systems.
    Performance Evaluation of Combined Heat Sources for Innovative Heat Pumps: Ground Source Combined With an Air Coil, Paper ID 6502013Conference paper (Refereed)
    Abstract [en]

    A significant amount of the Swedish single family houses have installed a ground source heat pump as primary energy source. Many of these installed heat pumps are due for replacement and the new installed heat pumps are generally more efficient. Thus, they extract more heat from the ground at a given heat load of the building. This fact combined with the early “rule of thumb” used by Swedish installers for sizing the borehole length means that many boreholes now are slightly undersized in terms of length.One obvious remedy is to drill some additional meters to the existing borehole. Other alternatives exist to offset this situation as well and two of these are that the borehole is assisted by either a solar collector or an outside air heat collector, similar type used for air-to-air heat pumps. The effect of such a measure is that less energy is extracted from the ground during the heating season, and the heat pump may operate at higher heat source temperatures. In addition, it may prevent or at least delay freezing of the borehole, which may occur late of the heating season for some installations.The present paper investigates the performance of such system and to compare the outcome of these three systems in terms of annual energy extraction rate from the ground. The results indicate that the proposed system indeed may offset the additional heat extraction that a new more efficient heat pump would otherwise cause.

  • 16.
    Claesson, Joachim
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration. KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Sustainable Building Systems.
    Performance of compact brazed plate heat exchanger operating as condenser in domestic heat pump system: An experimental investigation2005In: International Energy Agency Heat Pump Conference: Global Advances in Heat Pump Technology, Applications, and Markets, 2005Conference paper (Refereed)
  • 17.
    Claesson, Joachim
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration. KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Sustainable Building Systems.
    Plattvärmeväxlare: Hur kan jag räkna enfasvärmeövergångstal i dessa?2005Report (Other academic)
  • 18.
    Claesson, Joachim
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration. KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Sustainable Building Systems.
    Plattvärmeväxlare som förångare, jämförelse mellan förångare med och utan fördelningsanordning2002In: Kyla, no 3, p. 41-43Article in journal (Other academic)
  • 19.
    Claesson, Joachim
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Slutrapport Etapp 1: Energieffektiv Kyla – Effektivare Styrning, Övervakning och Systemlösningar2006Report (Other academic)
  • 20.
    Claesson, Joachim
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration. KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Sustainable Building Systems.
    The influence of brine flow on the flow boiling refrigerant heat transfer coefficient in a compact brazed plate heat exchanger2005In: International Journal of Heat Exchangers, ISSN 1524-5608, Vol. 6, no 1, p. 35-54Article in journal (Refereed)
    Abstract [en]

    The present article investigates the heat transfer coefficient on the refrigerant side in an compact brazed plate heat exchanger used as evaporator with different brine flows. The experimental equipment consisted of a test rig, simulating a domestic heat pump. Two different heat loads were tested, 5 kW and 10 kW, which corresponds to approx. 2.5 kW/m2 and 5.0 kW/m 2. The inlet quality to the evaporator was kept within 0.18 - 0.20. The pressure was kept within 2.93 - 2.97 bar(a) and R134a was used as refrigerant. The experiment showed for both heat loads a significant increase in the refrigerant area averaged heat transfer coefficient with increasing brine flow. It may be concluded that the temperature profile on the brine side has a significant influence on the refrigerant area averaged heat transfer coefficient. It is suggested that the higher wall superheat on the refrigerant side near the inlet of refrigerant is enhancing the heat transfer.

  • 21.
    Claesson, Joachim
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology.
    Thermal and hydraulic characteristics of brazed plate heat exchangers - Part I: Review of single-phase and two-phase adiabatic and flow boiling characteristics2005In: ASHRAE Transactions 2005, Vol 111, Pt 1, 2005, Vol. 111, p. 822-833Conference paper (Refereed)
    Abstract [en]

    This paper reviews the status of research reported in the open literature on plate heat exchangers, operating in single-phase and two-phase adiabatic and flow boiling applications. The review has been made as apart of an ongoing study aimed at enhancing the efficiency of heat transfer in plate heat exchangers used as evaporators in small heat pumps. It constitutes the background for the report of the activities within the project, given in part two of the present article. In order to obtain a complete picture of the performance of a plate heat exchanger operating as an evaporator, it is as important to have knowledge of the single-phase characteristics as it is to have knowledge of the flow boiling characteristics. The review shows that single-phase flow is quite well understood, even if the influence of the many geometric parameters is still under discussion. It also shows that there is still a controversy concerning which mechanism is dominant in flow boiling: convective evaporation or nucleate boiling.

  • 22.
    Claesson, Joachim
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology.
    Thermal and hydraulic characteristics of brazed plate heat exchangers - Part II: Current research on evaporators at KTH2005In: ASHRAE Transactions 2005, Vol 111, Pt 1, 2005, Vol. 111, p. 834-845Conference paper (Refereed)
    Abstract [en]

    This paper summarizes recent research on plate heat exchangers used as evaporators in domestic heat pumps and refrigeration systems, carried out at the Royal Institute Of Technology, Sweden. The investigations have been focusing on issues relevant to the performance and to parameters influencing the performance for the application in mind. Thus, the adiabatic pressure drop in a plate heat exchanger has been investigated and a new correlation is suggested, based on the classical approach by Lockhart-Martinelli and the correlation by Chisholm. The boiling section heat transfer coefficient was experimentally determined using TLC measurements. The resulting heat transfer coefficient was then plotted against mass flux and heat flux in order to investigate the relative importance of the two parameters. As it was found that the heat flux correlated the data much better than the mass flux, the applicability of using the LMTD assuming a heat flux-governed flow boiling correlation was investigated next. In addition, since the heat transfer coefficient seemed dependent on heat flux (wall superheat) the impact of different brine mass flow rates and brine temperature profiles was investigated. Further the possible improvement of running the evaporator in co-current configuration was investigated. The influence of geometry (chevron angle) and of using different inlet refrigerant flow distributor devices on the performance of a plate heat exchanger was also investigated.

  • 23.
    Claesson, Joachim
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology.
    Thermal and hydraulic performance of compact brazed plate heat exchangers operating as evaporators in domestic heat pumps2005Doctoral thesis, monograph (Other scientific)
    Abstract [en]

    This thesis investigates the performance of compact brazed plate heat exchangers (CBE) operating as evaporator in heat pump applications. The thesis, and the performances investigated, has been divided into three main sections; One zone evaporator performance; Two zone evaporator performance; and finally Local performance.

    The 'One zone evaporator performance' section considers the evaporator as one "black box". It was found that "approaching terminal temperatures" were obtained as low overall heat flux is employed. It was also found that the total area averaged film heat transfer coefficient was affected by changes of the brine mass flow rate. This indicates that the widespread Wilson plot method may not be used to determine flow boiling heat transfer coefficients. Further, it seems that co- and counter-current flow configuration performs equally well if the superheat is kept low. A numerical simulation of the above investigations indicates that a nucleate boiling model better predicts the performance compared to a convective evaporation model. Finally, the significant impact of the refrigerant inlet distributor design was illustrated using several CBEs with different inlet geometries but with identical heat transfer surfaces.

    The 'Two zone evaporator performance section' considers the evaporator as two "black boxes", i.e. the boiling and superheating boxes. Thermochromic liquid crystals (TLC) was used to determine the boiling heat transfer area. The resulting flow boiling heat transfer coefficient was found to correlate with heat flux. The superheated heat transfer area was then estimated using single phase correlations. It was observed that the TLC measurements and the predicted superheating area did not agree. Possible causes for this deviation were discussed. The most likely explanation found was the presence of mist flow at the higher vapor quality range in the boiling section of the evaporator.

    The 'Local Performance' section considers local pressure drop and flow boiling heat transfer. The Chisholm parameter was found not to be a constant and was found to correlate well with the kinetic energy per volume. The resulting predictions of the pressure drop were better than ± 10%.

    The resulting local flow boiling heat transfer coefficient, at different vapor quality, mass flux and heat flux, was compared to flow boiling correlations available in the literature. It was found that the saturated nucleate pool boiling correlation by Cooper (1984) and narrow channel flow boiling correlations (Tran 1999, Lazarek and Black 1982) predicted the experimental data better than several traditional flow boiling correlations, developed for larger tubes.

    Download full text (pdf)
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  • 24.
    Claesson, Joachim
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Thermal Comfort and Indoor Climate2021 (ed. 6)Book (Other academic)
  • 25.
    Claesson, Joachim
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Thermal Comfort and Indoor Climate2020 (ed. 5)Book (Other academic)
  • 26.
    Claesson, Joachim
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Thermal Comfort and Indoor Climate2019 (ed. 4)Book (Other academic)
  • 27.
    Claesson, Joachim
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Thermal Comfort and Indoor Climate2018 (ed. 3)Book (Other academic)
  • 28.
    Claesson, Joachim
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Thermal Comfort and Indoor Climate2017 (ed. 2)Book (Other academic)
  • 29.
    Claesson, Joachim
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Thermal Comfort and Indoor Climate2016 (ed. 1)Book (Other academic)
  • 30.
    Claesson, Joachim
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    TriGen: Uthållig förnybar uppvärmning av små och medelstora hus2008Report (Other academic)
    Abstract [sv]

    Föreliggande projekt var en förstudie för utvärdering av uthålligt uppvärmningssystem för småoch medelstora bostadsfastigheter. Uppvärmningssystemen som undersöktes innehöll ettkombisystem bestående av en värmemotor från ComPower för produktion av värme, för drivningav värmepump samt generering av elektricitet. Ett annat alternativ bestod av en värmemotor förelgenerering där motorns spillvärme driver en värmedriven värmepump. Tre typer avvärmepumpar undersöktes. En av dess är en mekanisk värmepump med uteluft som värmekälla,en annan använder IVTs ytjordsstaketlösning som värmekälla. Den värmedrivna värmepumpenär en konstruktion av ClimateWell.Resultaten från projektet visar att föreslaget system med kombinerat minielkraftverk eldad medpellets kombinerat med en mekanisk värmepump utnyttjar bränslet mest effektivt. Vid balansmellan producerad el i minikraftverket och förbrukad energi i kompressorn utnyttjas bränslet tillmer än 155 %. Anledningen till det är, som för alla värmepumpssystem, att gratis energi frånomgivningen utnyttjas.Undersökning kring tillgänglig teknik för realisering av systemet visar att alla ingåendekomponenter som krävs finns att tillgå (Pelleteldad stirlingmaskin), alternativt finns påprototypstadiet (pelleteldad mikrogasturbin). Avseende värmepumpen är den mest ekonomiskatypen att använda en s.k. uteluft/vatten-värmepump, d.v.s. att värmepumpen tar sin energi frånuteluften och avger den till ett vattenburet radiatorsystem inne i byggnaden. Det finns fleratillgängliga fabrikat att välja bland.Vad gäller minielkraftverk finns det ett svenskt företag som inom kort ämnar serietillverka enpelleteldad mikrogasturbin avsedd för småhus, som då kan producera både elektricitet ochvärme. Det finns även alternativ till detta internationellt, t.ex. säljs pelleteldade mikroelkraftverkbaserat på en stirlingmotor på den europeiska marknaden. Utöver detta finns mängder medförbränningsmotorer som åtminstone i några fall torde gå att elda med ”biodiesel”. Se Tabell 1 för typiska data för pelleteldade mikroelkraftverk.

  • 31.
    Claesson, Joachim
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Värmeövergång och tryckfall vid förångning i små plattvärmeväxlare2001Report (Other (popular science, discussion, etc.))
    Abstract [sv]

    Detta projekt har behandlat kokning av köldmedier i kompakta lödda plattvärmeväxlare. Experiment har utförts dels på kommersiella produkter och dels på värmeväxlare med speciell utformning. Vid sidan av experimenten har en omfattande litteraturstudie utförts. Plattvärmeväxlare i den internationella litteraturen är sällsynt, speciellt som förångare. 

     Experimenten visade inledningsvis att värmeövergångstalet vid kokning är en funktion av yteffekten, vilket är ett karaktäristiskt drag hos kärlkokning. Detta experiment utfördes med hjälp av termokroma flytande kristaller (TLC). Dessa ändrar färg med temperaturen. Dessutom visades att redan vid måttlig överhettning används stor del av värmeväxlarytan till att överhetta köldmediet. 

     

    Utifrån detta utvecklades en (iterativ) metod att beräkna prestanda hos en förångare i ett kylsystem med en termostatiskt expansionsventil. Preliminära resultat från denna modell uppvisar god överrensstämmelse med utförda experiment.  

    Visualisering av kokning inuti en plattvärmeväxlare har också utförts. Det visade sig att kokningen skedde med en viss pulsation. En viss intensivare kokning kunde också observeras på en halvan av ytan. Detta kan bero på en viss snedfördelning av flödet inom respektive kanal. Vi kunde inte observera någon ”mist-flow” efter det att ytan blivit torr, d.v.s. inga fria vätskedroppar. 

     

    Sammanfattningsvis har en god insyn i kokning av köldmedier i plattvärmeväxlare erhållits. Kärlkokning är den dominerande kokregimen och värmeövergångstalen kan predikteras genom att använda en korrelation framtagen för kärlkokning.

  • 32.
    Claesson, Joachim
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration. KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Sustainable Building Systems.
    Afghani, Mohsen
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology.
    Palm, Björn
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Influence of large temperature difference in a compact brazed plate evaporator with low overall heat flux2003In: / [ed] J.M. Corberán, R. Royo, 2003, p. 33-37Conference paper (Refereed)
  • 33.
    Claesson, Joachim
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration. KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Sustainable Building Systems.
    Antin, Karina
    Arias, Jaime
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration. KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Sustainable Building Systems.
    Wallin, Jörgen
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Sustainable Building Systems.
    Utvärdering av värmepumpar som attraktivt del i åtgärder i 50-, 60-, 70-tals inklusive även miljonprogrammet sett ur ett tekno-ekonomiskt perspektiv2010Report (Other academic)
  • 34.
    Claesson, Joachim
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration. KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Sustainable Building Systems.
    Forsén, Martin
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Capacity control of a domestic heat pump: Part 1 – Performance of the heat pump and its components2002Conference paper (Refereed)
  • 35.
    Claesson, Joachim
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration. KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Sustainable Building Systems.
    Hill, Peter
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Björk, Folke
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering.
    Slutrappport - Värmestugan – effektiviseringskoncept av bergvärme/solpanel/energilager - Utvärdering KTH: Diarienummer: 2013-0066552016Report (Other academic)
    Abstract [sv]

    Föreliggande projekt syftar till att utvärdera funktionen på ett bergvärmepumpsbaserat uppvärmningssystem för småhus med korta borrhål. För att kompensera för det korta borrhålet när en ny större och effektivare värmepump installeras har kollektorsystemet (dvs. borrhålssystemet) kompletterats med en solfångare kombinerad luftkonvektor, ”energikollektor”. Energikollektorns syfte är att tillföra energi till värmepumpens kalla sida, så att energiuttaget ur borrhålet inte ökar mot tidigare med den ersatta värmepumpen.

    Systemet har utrustats med flertalet energimätare samt en värmepumpsanalysator som samlar in och lagrar driftdata för systemet. Dessa driftdata visar för en dag i april, 2016, att energiuttaget ur kollektorsystemet via värmepumpen helt har kompensats av tillförd energi från energikollektorn. Dygnets medeltemperatur för detta dygn var 8.6 °C. Detta tyder på att syftet med systemet är uppfyllt och funktionen är den som initialt efterfrågades.

    Långtidsmätningar har inte gått att genomföra än, då installation av själva energisystemet, dvs. Värmestugan, försenats. Det intressantaste för en framtida studie är att se hur mycket energi, på årsbasis, som energikollektorn tillför kollektorsystemet, i förhållande till bortförd energi via värmepumpen. Det kunde noteras för undersökt dygn att temperaturen av vätskan in i värmepumpen signifikant ökade då energikollektorn tillförde energi. Kan detta även noteras sett över en årscykel? Solenergi som tillförs under varma tiden på året måste finnas kvar under uppvärmningssäsongen (dvs. ge en höge kollektorsystemtemperatur).

    Download full text (pdf)
    Värmestugan – effektiviseringskoncept av bergvärme/solpanel/energilager - Utvärdering KTH
  • 36.
    Claesson, Joachim
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration. KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Sustainable Building Systems.
    Palm, Björn
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Boiling mechanism in a small compact brazed plate heat exchanger (CBE) determined by using thermochromic liquid crystals (TLC)1999Conference paper (Refereed)
  • 37.
    Claesson, Joachim
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration. KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Sustainable Building Systems.
    Palm, Björn
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Discrepancy between calculated and measured superheated area in an evaporator plate heat exchanger2002Conference paper (Refereed)
  • 38.
    Claesson, Joachim
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration. KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Sustainable Building Systems.
    Palm, Björn
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Performance of a compact brazed plate heat exchanger evaporator run in co-current and counter-current2003Conference paper (Other academic)
  • 39.
    Claesson, Joachim
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration. KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Sustainable Building Systems.
    Palm, Björn
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Pelletier, Olivier
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    On the influence of geometry on evaporation in compact brazed plate heat exchangers2001Conference paper (Other academic)
  • 40.
    Claesson, Joachim
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration. KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Sustainable Building Systems.
    Rogstam, Jörgen
    Den fullskaliga testbutiken i miniatyr har öppnat2006In: Kyla+, no 8, p. 41-43Article in journal (Other academic)
  • 41.
    Claesson, Joachim
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration. KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Sustainable Building Systems.
    Simanic, Branko
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology.
    Pressure drop and visualization of adiabatic R134a two-phase flow inside a chevron type plate heat exchanger2003Conference paper (Refereed)
  • 42.
    Claesson, Joachim
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration. KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Sustainable Building Systems.
    Stare, Johan
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration. KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Sustainable Building Systems.
    Bergvärme kombinerat med uteluftkonvektor – Förbättrad SPF i stadsdelar med hög andel bergvärme2014In: KYLA+ Värmepumpar, ISSN 1100-343XArticle in journal (Other (popular science, discussion, etc.))
    Abstract [sv]

    Att använda en uteluftkonvektor som kompletteringskälla är intressant för de installationer som finns i stadsdelar där avståndet till grannhål är kort. Genom återladdning kan ett nästan balanserat energiuttag ur berget erhållas och därmed nästan ett ”hållbart” energisystem. Projektet har visat att även om det (även för enskilda hål) ges mer gynnsamma förhållanden för konvektorn äts nyttan upp av de ökande driveffekterna för pump och fläkt. Noggrann analys behöver alltså göras innan dylikt system implementeras. För stadsdelar som Bromma kan det dock vara intressant för att dels undvika oväntade stopp av värmepumpen pga. för kalla brinetemperaturer, dels få ett balanserat energiuttag ur berget genom återladdning.

  • 43.
    Fasci, Maria Letizia
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Lazzarotto, Alberto
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology.
    Acuña, José
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Claesson, Joachim
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Analysis of the thermal interference between ground source heat pump systems in dense neighborhoods2019In: Science and Technology for the Built Environment, ISSN 2374-4731, E-ISSN 2374-474X, Vol. 25, no 8, p. 1069-1080Article in journal (Refereed)
    Abstract [en]

    Ground source heat pumps (GSHPs) are a state-of-the-art technology for heating, cooling, and hot water production. They are already common in several countries and represent a promising technology for others. As the technology penetrates the market, the number of ground heat exchangers in densely populated areas may increase significantly. Therefore, it becomes important to consider the thermal influence of neighboring GSHPs while designing these systems in such areas. This question has become more frequent in some Swedish residential areas where the use of GSHPs is very common. This article proposes an easy-to-implement methodology to evaluate the thermal influence between borehole heat exchangers (BHEs) in areas with a high number of GSHPs installed. It also suggests two mitigation strategies to decrease the thermal interference so that the given limit for the ground temperature change is respected. The methodologies proposed are implemented using the programming language Julia and applied to fictional scenarios relevant for Sweden. It is found that neglecting the presence of neighboring systems might lead to an overexploitation of the underground heat. This can be avoided if, during the design phase, the presence of neighboring BHEs is taken into account and mitigation strategies are applied.

  • 44.
    Fasci, Maria Letizia
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration. KTH.
    Lazzarotto, Alberto
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology.
    Acuña, José
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Claesson, Joachim
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Shallow Geothermal Heat Pumps: a study of the resource potential at a neighbourhood scale.2018Conference paper (Refereed)
    Abstract [en]

    The residential sector accounts for a relevant share of global energy use; therefore it is important to use as much renewable energy as possible to satisfy its demand. Geothermal energy, among others, is nowadays used for this scope: more and more buildings in several countries are exploiting the underground to satisfy domestic heating, cooling and hot water demand by means of ground-source heat pumps. On the long run heat extraction/injection can lead to depletion of the ground as heat source/sink. Current tools only allow a designer to take into account the depletion of the ground caused by the system she or he is designing. However, the actual total heat depletion is also influenced by the surrounding systems. With the growing diffusion of ground-source heat pumps the ability of estimating the total underground heat depletion is of paramount importance. The aim of the article is to give an insight of the problem: the goal is to show what will happen in the underground if residential ground source heat pump systems are designed without taking into account the presence of neighbouring installations. The study is performed for different types of soil and borehole heat exchangers designs.

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  • 45.
    Fasci, Maria Letizia
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Lazzarotto, Alberto
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology.
    Acuña, José
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Claesson, Joachim
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Simulation of thermal influence between independent geothermal boreholes in densely populated areas2021In: Applied Thermal Engineering, ISSN 1359-4311, E-ISSN 1873-5606, Vol. 196, article id 117241Article in journal (Refereed)
    Abstract [en]

    Ground Source Heat Pumps (GSHPs) connected to Borehole Heat Exchangers (BHEs) are a fast-growing technology for thermally efficient buildings. Therefore, areas with several independent GSHP installations close to each other are becoming more and more common. To guarantee an optimal operation of these systems, it is necessary to design them considering the influence of the neighbouring installations. However, a tailored model for this scope has not been found in the literature. In this paper, we aim at filling this gap by proposing and validating a methodology to calculate the thermal influence between neighbouring independent boreholes. It is based on the Finite Line Source (FLS) model and prescribes novel boundary conditions, tailored to hydraulically independent boreholes. The methodology allows to prescribe different thermal loads to different BHEs and imposes uniform temperature boundary condition on each borehole wall. We also show how to implement and apply the model. Our application shows a thermal influence of up to 1.5 K during the lifetime of a GSHP and of up to 0.8 K during the first year of operation in an area with a relatively low number of installations, underlying the importance of considering the thermal influence and the usefulness of our proposed model. Finally, a sensitivity study on the ground thermal conductivity shows the importance of a correct estimation of this property for accurate simulation results.

  • 46.
    Fasci, Maria Letizia
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Mazzotti, Willem
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Lazzarotto, Alberto
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Claesson, Joachim
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Temperature of energy boreholes accounting for climate change and the built environment - A new model for its estimation2023In: Renewable energy, ISSN 0960-1481, E-ISSN 1879-0682, Vol. 202, p. 1479-1496Article in journal (Refereed)
    Abstract [en]

    Changes in the ground surface temperature, as it can occur in built-up areas or due to climate change, affect the temperatures of geothermal boreholes. Analytical models for the thermal simulation of boreholes and consid-ering this factor have been proposed. However, they all impose a uniform heat extraction boundary condition along the borehole walls. This boundary condition overestimates the temperature change in the underground caused by the borehole heat extraction and underestimates it in case of rejection. More accurate results are most often obtained by imposing a uniform temperature boundary condition.In this paper, we propose a new model to calculate the boreholes wall temperature taking into account both the heat extractions/rejections from all the boreholes in the area and the change in ground surface temperature. The model is tailored for areas with independent ground source heat pumps and imposes a uniform temperature boundary condition along the borehole walls, overcoming the limitation of the existing models.We apply the new model to a real Swedish neighbourhood and show that existing systems may already be significantly affected by the increased ground surface temperature due to urbanization. We also compare our new model with an existing similar model and show that while the two models provide similar results for smaller areas, their difference tends to be relevant for bigger areas - including the real Swedish neighbourhood analysed -thus making the application of our model important for neighbourhood-and city-scale studies.

  • 47.
    Forsén, Martin
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Claesson, Joachim
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration. KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Sustainable Building Systems.
    Capacity control of a domestic heat pump: Part 2 System modelling and Simulation2002Conference paper (Refereed)
  • 48.
    Havtun, Hans
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Bohdanowicz, Paulina
    Claesson, Joachim
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Sustainable Energy Utilization2021Book (Other academic)
  • 49.
    Madani, Hatef
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Acuña, José
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Claesson, Joachim
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Lundqvist, Per
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    The Ground Source Heat Pump: A System Analysis With a Particular Focus on The U-Pipe Borehole Heat Exchanger2010In: 2010 14th International Heat Transfer Conference, Volume 4, 2010, p. 395-402Conference paper (Refereed)
    Abstract [en]

    The mass flow rate of the secondary refrigerant flowing in the borehole heat exchanger of a ground source heat pump is an influential system parameter whose variation can influence the pumping power, efficiency of the pump, heat distribution in the borehole, heat pump heat capacity, and above all, the system Overall Coefficient Of Performance (COP). The present paper uses both in-situ field measurements and modeling to evaluate these effects. From the field measurements, it can be concluded that the thermal contact between U-pipe channels increases as the brine mass flow rate decreases. Furthermore, the modeling results show that there is a certain optimum brine mass flow rate which gives a maximum overall system COP. Different optimum mass flow rates are obtained for different compressor speed and it is shown that their relation is almost linear. However, concerning system COP maximization, it can be concluded that a constant but carefully-selected brine mass flow rate can still be an appropriate option for the variable capacity heat pump unit studied in the present paper where the compressor frequency changes between 30Hz and 75Hz. Concerning the heat capacity maximization in the system, a variable speed brine pump can be used to help the insufficiently-sized compressor to cover the peak heat demand of the building.

  • 50.
    Madani, Hatef
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Ahmadi, Navid
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Claesson, Joachim
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Lundqvist, Per
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Experimental Analysis of a Variable Capacity Heat Pump System Focusing on the Compressor and Inverter Loss Behavior2010In: Proceeding International Refrigeration and Air Conditioning Conference, Academic Conferences Publishing, 2010Conference paper (Refereed)
    Abstract [en]

    Capacity control with variable speed compressors in heat pump systems is one of the techniques having a potentialfor efficiency improvement in heat pump systems. It is anticipated that the compressor and inverter efficiency areinfluenced by changes of the compressor speed. The present experimental study evaluates these losses in a variablespeed heat pump system.The experimental results show that increasing the compressor speed reduces the heat pump COP up to 30%. Theinverter loss increases as the compressor speed is increased, although the inverter loss as the percentage of the totalcompressor power decreases. Increasing the compressor speed increases the pressure ratio from 2.7 to 5.8,increasing the loss due to the pressure ratio mismatch drastically. Finally, the highest total isentropic efficiency ofthe compressor is obtained when the compressor frequency is close to 50Hz.

12 1 - 50 of 72
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