Ändra sökning
RefereraExporteraLänk till posten
Permanent länk

Direktlänk
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
Improvements of U-pipe Borehole Heat Exchangers
KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Tillämpad termodynamik och kylteknik. (Energiteknik)ORCID-id: 0000-0002-3490-1777
2010 (Engelska)Licentiatavhandling, monografi (Övrigt vetenskapligt)
Abstract [en]

The sales of Ground Source Heat Pumps in Sweden and many other countries are having a rapid growth in the last decade. Today, there are approximately 360 000 systems installed in Sweden, with a growing rate of about 30 000 installations per year. The most common way to exchange heat with the bedrock in ground source heat pump applications is circulating a secondary fluid through a Borehole Heat Exchanger (BHE), a closed loop in a vertical borehole. The fluid transports the heat from the ground to a certain heating and/or cooling application. A fluid with one degree higher or lower temperature coming out from the borehole may represent a 2-3% change in the COP of a heat pump system. It is therefore of great relevance to design cost effective and easy to install borehole heat exchangers. U-pipe BHEs consisting of two equal cylindrical pipes connected together at the borehole bottom have dominated the market for several years in spite of their relatively poor thermal performance and, still, there exist many uncertainties about how to optimize them. Although more efficient BHEs have been discussed for many years, the introduction of new designs has been practically lacking. However, the interest for innovation within this field is increasing nowadays and more effective methods for injecting or extracting heat into/from the ground (better BHEs) with smaller temperature differences between the heat secondary fluid and the surrounding bedrock must be suggested for introduction into the market.

This report presents the analysis of several groundwater filled borehole heat exchangers, including standard and alternative U-pipe configurations (e.g. with spacers, grooves), as well as two coaxial designs. The study embraces measurements of borehole deviation, ground water flow, undisturbed ground temperature profile, secondary fluid and groundwater temperature variations in time, theoretical analyses with a FEM software, Distributed Thermal Response Test (DTRT), and pressure drop. Significant attention is devoted to distributed temperature measurements using optic fiber cables along the BHEs during heat extraction and heat injection from and to the ground.

Ort, förlag, år, upplaga, sidor
Stockholm: KTH , 2010. , s. 97
Serie
TRITA-REFR, ISSN 1102-0245 ; 10/01
Nyckelord [en]
Borehole Heat Exchanger, Distributed Thermal Response Test, Ground Source Heat Pumps
Nationell ämneskategori
Annan naturresursteknik Geovetenskap och miljövetenskap Samhällsbyggnadsteknik
Identifikatorer
URN: urn:nbn:se:kth:diva-12749ISBN: 978-91-7415-660-7 (tryckt)OAI: oai:DiVA.org:kth-12749DiVA, id: diva2:318637
Presentation
2010-05-25, M3, Brinellvägen 64, Stockholm, 10:00 (Engelska)
Opponent
Handledare
Projekt
EFFSYS2Efficient Use of Energy Wells for Heat Pumps
Anmärkning

QC 20100517

Tillgänglig från: 2010-05-17 Skapad: 2010-05-10 Senast uppdaterad: 2015-05-11Bibliografiskt granskad

Open Access i DiVA

fulltext(3420 kB)2931 nedladdningar
Filinformation
Filnamn FULLTEXT01.pdfFilstorlek 3420 kBChecksumma SHA-512
ffb1ef0f46a9834e2cac63567eacf91ce9726095fc5eba0434a91bf439abbcab63d4b1f40743a39c90235b9b3cb4a26f79ae532ff002e5deae36597f62d33d2d
Typ fulltextMimetyp application/pdf

Övriga länkar

Energibrunnar

Sök vidare i DiVA

Av författaren/redaktören
Acuña, José
Av organisationen
Tillämpad termodynamik och kylteknik
Annan naturresursteknikGeovetenskap och miljövetenskapSamhällsbyggnadsteknik

Sök vidare utanför DiVA

GoogleGoogle Scholar
Totalt: 2931 nedladdningar
Antalet nedladdningar är summan av nedladdningar för alla fulltexter. Det kan inkludera t.ex tidigare versioner som nu inte längre är tillgängliga.

isbn
urn-nbn

Altmetricpoäng

isbn
urn-nbn
Totalt: 5432 träffar
RefereraExporteraLänk till posten
Permanent länk

Direktlänk
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