Change search

Cite
Citation style
• apa
• ieee
• modern-language-association-8th-edition
• vancouver
• Other style
More styles
Language
• de-DE
• en-GB
• en-US
• fi-FI
• nn-NO
• nn-NB
• sv-SE
• Other locale
More languages
Output format
• html
• text
• asciidoc
• rtf
Improvements on a Numerical Model of Borehole Heat Exchangers
KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
EnergyLab, Spain.
KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.ORCID iD: 0000-0002-5093-9070
2016 (English)In: Proceedins of the European Geothermal Congress 2016, 2016Conference paper, Poster (with or without abstract) (Other academic)
##### Abstract [en]

In the mathematical simulation of bore fields for ground coupled heat pump (GCHP) systems, it has become a common practice to consider the boreholes as having a uniform temperature. As a rule the boreholes are hydraulically connected in parallel and the small temperature difference between incoming and outgoing heat carrier fluid justifies the assumption that all boreholes have the same uniform temperature in operation. Two simultaneous boundary conditions usually apply: All borehole walls should have a uniform temperature and the heat flow from the bore field should equal the energy needed by the heat pump. This paper describes improvements applied to a previous numerical approach that employs the concept of a highly conductive material (HCM) embedded in the boreholes and connected to a HCM bar above the ground surface to impose a uniform temperature boundary condition at the borehole wall. The original boundary condition with the uniform fluid temperature comes in conflict with the concept of the uniform borehole wall temperature. Between the fluid and the borehole wall there is a thermal borehole resistance. The heat flux increases at the borehole ends and thus also the temperature changes between borehole wall and the fluid. The borehole wall temperature deviates from the uniform assumption and will cause an error in the simulations. This paper presents a correction to that error. Firstly, the improvements to the HCM model are validated for g-function generation, which presents a good agreement with reference solutions. Secondly, the improvements to the HCM model are illustrated to predict fluid temperatures for measured variable daily loads of a monitored GCHP installation. The predicted fluid temperatures are compared with monitored data for about four years. The predicted fluid temperatures deviate from the measured data by less than 1 K during the last monitored year.

2016.
##### Keywords [en]
Monitored installation, borehole heat exchanger, fluid temperature prediction
##### National Category
Energy Engineering
##### Identifiers
OAI: oai:DiVA.org:kth-192897DiVA, id: diva2:974357
##### Conference
European Geothermal Congress
##### Note

QC 20160928

Available from: 2016-09-26 Created: 2016-09-22 Last updated: 2016-09-28Bibliographically approved

#### Open Access in DiVA

##### File information
File name FULLTEXT02.pdfFile size 675 kBChecksum SHA-512
706abfd4ab7d7235bdbc5976eee59e5cfbdce059479d358510340edd049396a49954bc24d36923857b5c838ff8ac0375baf31902b7cbf467d47d5ced957e0f6d
Type fulltextMimetype application/pdf

http://europeangeothermalcongress.eu/

#### Search in DiVA

##### By author/editor
Puttige, Anjan RaoMonzó, Patricia
##### By organisation
Applied Thermodynamics and Refrigeration
##### On the subject
Energy Engineering

#### Search outside of DiVA

The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available
urn-nbn

#### Altmetric score

urn-nbn
Total: 194 hits

Cite
Citation style
• apa
• ieee
• modern-language-association-8th-edition
• vancouver
• Other style
More styles
Language
• de-DE
• en-GB
• en-US
• fi-FI
• nn-NO
• nn-NB
• sv-SE
• Other locale
More languages
Output format
• html
• text
• asciidoc
• rtf
v. 2.35.7
|