Estimation of In Situ Heat Capacity and Thermal Diffusivity from Undisturbed Ground Temperature Profile Measured in Ground Heat Exchangers
Undisturbed ground temperature (UGT), thermal conductivity (TC) and heat capacity (HC) are essential parameters to design geothermal heat pumps and underground thermal energy storage systems, particularly borehole heat exchangers (BHE). However, field methods to assess the thermal state and properti...
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| Format: | Article |
| Language: | English |
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MDPI AG
2022-04-01
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| Series: | Geosciences |
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| Online Access: | https://www.mdpi.com/2076-3263/12/5/180 |
| _version_ | 1827668806546227200 |
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| author | Claude Hugo K. Pambou Jasmin Raymond Mafalda M. Miranda Nicolò Giordano |
| author_facet | Claude Hugo K. Pambou Jasmin Raymond Mafalda M. Miranda Nicolò Giordano |
| author_sort | Claude Hugo K. Pambou |
| collection | DOAJ |
| description | Undisturbed ground temperature (UGT), thermal conductivity (TC) and heat capacity (HC) are essential parameters to design geothermal heat pumps and underground thermal energy storage systems, particularly borehole heat exchangers (BHE). However, field methods to assess the thermal state and properties of the subsurface are costly and time consuming. Moreover, HC is often not evaluated in situ but arbitrarily selected from literature considering the geological materials intercepted by boreholes. This work proposes an original empirical approach to reproduce a UGT profile and estimate in situ thermal diffusivity (TD) and HC in the scope of conventional thermal response tests (TRTs). Empirical equations were developed to reproduce a UGT profile measured along a BHE. Experimental coefficients are found with a non-linear least square solver optimization and used to calculate the damping depth, TD and HC. The suggested heat tracing method was verified and validated against other field methods demonstrating to be fast and reliable. The novelty of this new empirical approach relies on the use of a single temperature profile providing a simple way to better assess subsurface thermal properties. |
| first_indexed | 2024-03-10T03:49:46Z |
| format | Article |
| id | doaj.art-e8abca6e9bc3409ba8943ba6332f2cfa |
| institution | Directory Open Access Journal |
| issn | 2076-3263 |
| language | English |
| last_indexed | 2024-03-10T03:49:46Z |
| publishDate | 2022-04-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Geosciences |
| spelling | doaj.art-e8abca6e9bc3409ba8943ba6332f2cfa2023-11-23T11:11:51ZengMDPI AGGeosciences2076-32632022-04-0112518010.3390/geosciences12050180Estimation of In Situ Heat Capacity and Thermal Diffusivity from Undisturbed Ground Temperature Profile Measured in Ground Heat ExchangersClaude Hugo K. Pambou0Jasmin Raymond1Mafalda M. Miranda2Nicolò Giordano3INRS—Institut National de la Recherche Scientifique, 490 rue de la Couronne, Quebec City, QC G1K 9A9, CanadaINRS—Institut National de la Recherche Scientifique, 490 rue de la Couronne, Quebec City, QC G1K 9A9, CanadaINRS—Institut National de la Recherche Scientifique, 490 rue de la Couronne, Quebec City, QC G1K 9A9, CanadaGéotherma Solutions Inc., 13-2528 Avenue de Monceaux, Quebec City, QC G1T 2N7, CanadaUndisturbed ground temperature (UGT), thermal conductivity (TC) and heat capacity (HC) are essential parameters to design geothermal heat pumps and underground thermal energy storage systems, particularly borehole heat exchangers (BHE). However, field methods to assess the thermal state and properties of the subsurface are costly and time consuming. Moreover, HC is often not evaluated in situ but arbitrarily selected from literature considering the geological materials intercepted by boreholes. This work proposes an original empirical approach to reproduce a UGT profile and estimate in situ thermal diffusivity (TD) and HC in the scope of conventional thermal response tests (TRTs). Empirical equations were developed to reproduce a UGT profile measured along a BHE. Experimental coefficients are found with a non-linear least square solver optimization and used to calculate the damping depth, TD and HC. The suggested heat tracing method was verified and validated against other field methods demonstrating to be fast and reliable. The novelty of this new empirical approach relies on the use of a single temperature profile providing a simple way to better assess subsurface thermal properties.https://www.mdpi.com/2076-3263/12/5/180heat conductionthermal propertiesgeothermal heat pumpdamping depth |
| spellingShingle | Claude Hugo K. Pambou Jasmin Raymond Mafalda M. Miranda Nicolò Giordano Estimation of In Situ Heat Capacity and Thermal Diffusivity from Undisturbed Ground Temperature Profile Measured in Ground Heat Exchangers Geosciences heat conduction thermal properties geothermal heat pump damping depth |
| title | Estimation of In Situ Heat Capacity and Thermal Diffusivity from Undisturbed Ground Temperature Profile Measured in Ground Heat Exchangers |
| title_full | Estimation of In Situ Heat Capacity and Thermal Diffusivity from Undisturbed Ground Temperature Profile Measured in Ground Heat Exchangers |
| title_fullStr | Estimation of In Situ Heat Capacity and Thermal Diffusivity from Undisturbed Ground Temperature Profile Measured in Ground Heat Exchangers |
| title_full_unstemmed | Estimation of In Situ Heat Capacity and Thermal Diffusivity from Undisturbed Ground Temperature Profile Measured in Ground Heat Exchangers |
| title_short | Estimation of In Situ Heat Capacity and Thermal Diffusivity from Undisturbed Ground Temperature Profile Measured in Ground Heat Exchangers |
| title_sort | estimation of in situ heat capacity and thermal diffusivity from undisturbed ground temperature profile measured in ground heat exchangers |
| topic | heat conduction thermal properties geothermal heat pump damping depth |
| url | https://www.mdpi.com/2076-3263/12/5/180 |
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