The Effect of Shank-Space on the Thermal Performance of Shallow Vertical U-Tube Ground Heat Exchangers
One parameter that may affect the performance of a ground source heat pump is the shank-space, the center-to-center distance between the two branches of a vertical U-tube used in a ground heat exchanger. A 3D steady-state computational fluid dynamics (CFD) model of a U-tube ground heat exchanger was...
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| Format: | Article |
| Language: | English |
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MDPI AG
2020-01-01
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| Series: | Energies |
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| Online Access: | https://www.mdpi.com/1996-1073/13/3/602 |
| _version_ | 1811303257784451072 |
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| author | Christopher Vella Simon Paul Borg Daniel Micallef |
| author_facet | Christopher Vella Simon Paul Borg Daniel Micallef |
| author_sort | Christopher Vella |
| collection | DOAJ |
| description | One parameter that may affect the performance of a ground source heat pump is the shank-space, the center-to-center distance between the two branches of a vertical U-tube used in a ground heat exchanger. A 3D steady-state computational fluid dynamics (CFD) model of a U-tube ground heat exchanger was used to investigate the influence of varying shank-space on the thermal performance of two isolated vertical shallow U-tubes, one 20 m deep and the other 40 m deep, given that most existing research focuses on systems making use of deeper boreholes. The models adopt an innovative approach, whereby the U-junction at the bottom of the U-tube is eliminated, thus facilitating the computational process. The results obtained show that, although the temperature drop across the U-tube varies for different shank-spaces and is lowest and highest for the closest and the widest shank-spaces, respectively, this temperature drop is not linear with increases in shank-space, and the thermal performance improvement drastically diminishes with increasing shank-space. This indicates that, for shallow U-tubes, the temperature drop is more dependent on the length of the pipework. |
| first_indexed | 2024-04-13T07:44:44Z |
| format | Article |
| id | doaj.art-54a5a80e54dd4932ab8d3ceaeae2f4e0 |
| institution | Directory Open Access Journal |
| issn | 1996-1073 |
| language | English |
| last_indexed | 2024-04-13T07:44:44Z |
| publishDate | 2020-01-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Energies |
| spelling | doaj.art-54a5a80e54dd4932ab8d3ceaeae2f4e02022-12-22T02:55:45ZengMDPI AGEnergies1996-10732020-01-0113360210.3390/en13030602en13030602The Effect of Shank-Space on the Thermal Performance of Shallow Vertical U-Tube Ground Heat ExchangersChristopher Vella0Simon Paul Borg1Daniel Micallef2Department of Environmental Design, Faculty for the Built Environment, University of Malta, L-Imsida MSD 2080, MaltaDepartment of Environmental Design, Faculty for the Built Environment, University of Malta, L-Imsida MSD 2080, MaltaDepartment of Environmental Design, Faculty for the Built Environment, University of Malta, L-Imsida MSD 2080, MaltaOne parameter that may affect the performance of a ground source heat pump is the shank-space, the center-to-center distance between the two branches of a vertical U-tube used in a ground heat exchanger. A 3D steady-state computational fluid dynamics (CFD) model of a U-tube ground heat exchanger was used to investigate the influence of varying shank-space on the thermal performance of two isolated vertical shallow U-tubes, one 20 m deep and the other 40 m deep, given that most existing research focuses on systems making use of deeper boreholes. The models adopt an innovative approach, whereby the U-junction at the bottom of the U-tube is eliminated, thus facilitating the computational process. The results obtained show that, although the temperature drop across the U-tube varies for different shank-spaces and is lowest and highest for the closest and the widest shank-spaces, respectively, this temperature drop is not linear with increases in shank-space, and the thermal performance improvement drastically diminishes with increasing shank-space. This indicates that, for shallow U-tubes, the temperature drop is more dependent on the length of the pipework.https://www.mdpi.com/1996-1073/13/3/602ground source heat pumpground heat exchangerthermal performanceshallow vertical u-tubeshank-spacecfdvalidation |
| spellingShingle | Christopher Vella Simon Paul Borg Daniel Micallef The Effect of Shank-Space on the Thermal Performance of Shallow Vertical U-Tube Ground Heat Exchangers Energies ground source heat pump ground heat exchanger thermal performance shallow vertical u-tube shank-space cfd validation |
| title | The Effect of Shank-Space on the Thermal Performance of Shallow Vertical U-Tube Ground Heat Exchangers |
| title_full | The Effect of Shank-Space on the Thermal Performance of Shallow Vertical U-Tube Ground Heat Exchangers |
| title_fullStr | The Effect of Shank-Space on the Thermal Performance of Shallow Vertical U-Tube Ground Heat Exchangers |
| title_full_unstemmed | The Effect of Shank-Space on the Thermal Performance of Shallow Vertical U-Tube Ground Heat Exchangers |
| title_short | The Effect of Shank-Space on the Thermal Performance of Shallow Vertical U-Tube Ground Heat Exchangers |
| title_sort | effect of shank space on the thermal performance of shallow vertical u tube ground heat exchangers |
| topic | ground source heat pump ground heat exchanger thermal performance shallow vertical u-tube shank-space cfd validation |
| url | https://www.mdpi.com/1996-1073/13/3/602 |
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