Dynamic Heat Transfer Modeling and Validation of Super-Long Flexible Thermosyphons for Shallow Geothermal Applications
In comparison to borehole heat exchangers that rely on forced convection, super-long thermosyphons offer a more efficient approach to extracting shallow geothermal energy. This work conducted field tests on a super-long flexible thermosyphon (SFTS) to evaluate its heat transfer characteristics. The...
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| Format: | Article |
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2025-01-01
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| Series: | Energies |
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| Online Access: | https://www.mdpi.com/1996-1073/18/2/433 |
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| author | Jianhua Liu Yanghuiqin Ding Hao Liu Liying Zheng Xiaoyuan Wang Yuezhao Zhu |
| author_facet | Jianhua Liu Yanghuiqin Ding Hao Liu Liying Zheng Xiaoyuan Wang Yuezhao Zhu |
| author_sort | Jianhua Liu |
| collection | DOAJ |
| description | In comparison to borehole heat exchangers that rely on forced convection, super-long thermosyphons offer a more efficient approach to extracting shallow geothermal energy. This work conducted field tests on a super-long flexible thermosyphon (SFTS) to evaluate its heat transfer characteristics. The tests investigated the effects of cooling water temperature and the inclination angle of the condenser on the start-up characteristics and steady-state heat transfer performance. Based on the field test results, the study proposed a dynamic heat transfer modeling method for SFTSs using the equivalent thermal conductivity (ETC) model. Furthermore, a full-scale 3D CFD model for geothermal extraction via SFTS was developed, taking into account weather conditions and groundwater advection. The modeling validation showed that the simulation results aligned well with the temperature and heat transfer power variations observed in the field tests when the empirical coefficient in the ETC model was specified as 2. This work offers a semi-empirical dynamic heat transfer modeling method for geothermal thermosyphons, which can be readily incorporated into the overall simulation of a geothermal system that integrates thermosyphons. |
| format | Article |
| id | doaj-art-1fb536db539b441caf5b8029a98d7d94 |
| institution | Kabale University |
| issn | 1996-1073 |
| language | English |
| publishDate | 2025-01-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Energies |
| spelling | doaj-art-1fb536db539b441caf5b8029a98d7d942025-01-24T13:31:28ZengMDPI AGEnergies1996-10732025-01-0118243310.3390/en18020433Dynamic Heat Transfer Modeling and Validation of Super-Long Flexible Thermosyphons for Shallow Geothermal ApplicationsJianhua Liu0Yanghuiqin Ding1Hao Liu2Liying Zheng3Xiaoyuan Wang4Yuezhao Zhu5JOYOU Chemical Technology & Engineering Co., Ltd., Beijing 100025, ChinaJOYOU Chemical Technology & Engineering Co., Ltd., Beijing 100025, ChinaSchool of Energy and Environment, Zhongyuan University of Technology, Zhengzhou 451191, ChinaSchool of Mechanical and Power Engineering, Nanjing Tech University, Nanjing 211816, ChinaSchool of Mechanical and Power Engineering, Nanjing Tech University, Nanjing 211816, ChinaSchool of Mechanical and Power Engineering, Nanjing Tech University, Nanjing 211816, ChinaIn comparison to borehole heat exchangers that rely on forced convection, super-long thermosyphons offer a more efficient approach to extracting shallow geothermal energy. This work conducted field tests on a super-long flexible thermosyphon (SFTS) to evaluate its heat transfer characteristics. The tests investigated the effects of cooling water temperature and the inclination angle of the condenser on the start-up characteristics and steady-state heat transfer performance. Based on the field test results, the study proposed a dynamic heat transfer modeling method for SFTSs using the equivalent thermal conductivity (ETC) model. Furthermore, a full-scale 3D CFD model for geothermal extraction via SFTS was developed, taking into account weather conditions and groundwater advection. The modeling validation showed that the simulation results aligned well with the temperature and heat transfer power variations observed in the field tests when the empirical coefficient in the ETC model was specified as 2. This work offers a semi-empirical dynamic heat transfer modeling method for geothermal thermosyphons, which can be readily incorporated into the overall simulation of a geothermal system that integrates thermosyphons.https://www.mdpi.com/1996-1073/18/2/433shallow geothermal energytwo-phase closed thermosyphonsuper-long flexible thermosyphonCFDdynamic heat transfer modeling |
| spellingShingle | Jianhua Liu Yanghuiqin Ding Hao Liu Liying Zheng Xiaoyuan Wang Yuezhao Zhu Dynamic Heat Transfer Modeling and Validation of Super-Long Flexible Thermosyphons for Shallow Geothermal Applications Energies shallow geothermal energy two-phase closed thermosyphon super-long flexible thermosyphon CFD dynamic heat transfer modeling |
| title | Dynamic Heat Transfer Modeling and Validation of Super-Long Flexible Thermosyphons for Shallow Geothermal Applications |
| title_full | Dynamic Heat Transfer Modeling and Validation of Super-Long Flexible Thermosyphons for Shallow Geothermal Applications |
| title_fullStr | Dynamic Heat Transfer Modeling and Validation of Super-Long Flexible Thermosyphons for Shallow Geothermal Applications |
| title_full_unstemmed | Dynamic Heat Transfer Modeling and Validation of Super-Long Flexible Thermosyphons for Shallow Geothermal Applications |
| title_short | Dynamic Heat Transfer Modeling and Validation of Super-Long Flexible Thermosyphons for Shallow Geothermal Applications |
| title_sort | dynamic heat transfer modeling and validation of super long flexible thermosyphons for shallow geothermal applications |
| topic | shallow geothermal energy two-phase closed thermosyphon super-long flexible thermosyphon CFD dynamic heat transfer modeling |
| url | https://www.mdpi.com/1996-1073/18/2/433 |
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