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A platform for research: civil engineering, architecture and urbanism
Thermal behavior and performance of shallow-deep-mixed borehole heat exchanger array for sustainable building cooling and heating
https://orcid.org/0000-0001-6896-8622
https://orcid.org/0000-0002-6559-0094
Highlights An integrated model is established for deep-shallow borehole heat exchanger array. Heat extraction capacity translation between deep and shallow tubes is identified. Effect of load distribution and operation pattern is analyzed for the system. The optimal matching between cooling/heating load ratio and system layout is identified.
Abstract Geothermal energy system is a renewable, sustainable and clean source for building heating and cooling, which is important for reducing both building energy use and carbon emissions. Currently, both shallow borehole heat exchangers (SBHEs) and deep borehole heat exchangers (DBHEs) are popular in applications. However, SBHEs and DBHEs have inherit limitations when used alone. SBHEs suffer from lower heating/cooling capacities and ground imbalance problems in long run, while DBHEs are mainly used for building heating. In this study, combining both SBHEs and DBHEs is proposed as a shallow-deep-mixed borehole heat exchanger (SD-BHE) array, and more importantly a new scheme is proposed that the DBHE tube could be switched to SBHE tube in summer. SD-BHE is a new design, focusing on the combination of DBHE and shallow tube group. Its heat transfer model is established on the basis of single tube heat transfer model and tube group heat transfer model. In the analysis, the heat extraction capacity per linear meter of DBHE and SBHE is compared and analyzed for various parameters. It is found that when the cooling load of a building is greater than the heating load, the shallow-deep-mixed borehole heat exchanger (SD-BHE) array has less influence on ground temperature and provides better stability of the outlet water temperature than the SBHE array. The present study can offer a new paradigm for geothermal energy-based building cooling/heating.
Thermal behavior and performance of shallow-deep-mixed borehole heat exchanger array for sustainable building cooling and heating
https://orcid.org/0000-0001-6896-8622
https://orcid.org/0000-0002-6559-0094
Highlights An integrated model is established for deep-shallow borehole heat exchanger array. Heat extraction capacity translation between deep and shallow tubes is identified. Effect of load distribution and operation pattern is analyzed for the system. The optimal matching between cooling/heating load ratio and system layout is identified.
Abstract Geothermal energy system is a renewable, sustainable and clean source for building heating and cooling, which is important for reducing both building energy use and carbon emissions. Currently, both shallow borehole heat exchangers (SBHEs) and deep borehole heat exchangers (DBHEs) are popular in applications. However, SBHEs and DBHEs have inherit limitations when used alone. SBHEs suffer from lower heating/cooling capacities and ground imbalance problems in long run, while DBHEs are mainly used for building heating. In this study, combining both SBHEs and DBHEs is proposed as a shallow-deep-mixed borehole heat exchanger (SD-BHE) array, and more importantly a new scheme is proposed that the DBHE tube could be switched to SBHE tube in summer. SD-BHE is a new design, focusing on the combination of DBHE and shallow tube group. Its heat transfer model is established on the basis of single tube heat transfer model and tube group heat transfer model. In the analysis, the heat extraction capacity per linear meter of DBHE and SBHE is compared and analyzed for various parameters. It is found that when the cooling load of a building is greater than the heating load, the shallow-deep-mixed borehole heat exchanger (SD-BHE) array has less influence on ground temperature and provides better stability of the outlet water temperature than the SBHE array. The present study can offer a new paradigm for geothermal energy-based building cooling/heating.
Thermal behavior and performance of shallow-deep-mixed borehole heat exchanger array for sustainable building cooling and heating
https://orcid.org/0000-0001-6896-8622
https://orcid.org/0000-0002-6559-0094
Highlights An integrated model is established for deep-shallow borehole heat exchanger array. Heat extraction capacity translation between deep and shallow tubes is identified. Effect of load distribution and operation pattern is analyzed for the system. The optimal matching between cooling/heating load ratio and system layout is identified.
Abstract Geothermal energy system is a renewable, sustainable and clean source for building heating and cooling, which is important for reducing both building energy use and carbon emissions. Currently, both shallow borehole heat exchangers (SBHEs) and deep borehole heat exchangers (DBHEs) are popular in applications. However, SBHEs and DBHEs have inherit limitations when used alone. SBHEs suffer from lower heating/cooling capacities and ground imbalance problems in long run, while DBHEs are mainly used for building heating. In this study, combining both SBHEs and DBHEs is proposed as a shallow-deep-mixed borehole heat exchanger (SD-BHE) array, and more importantly a new scheme is proposed that the DBHE tube could be switched to SBHE tube in summer. SD-BHE is a new design, focusing on the combination of DBHE and shallow tube group. Its heat transfer model is established on the basis of single tube heat transfer model and tube group heat transfer model. In the analysis, the heat extraction capacity per linear meter of DBHE and SBHE is compared and analyzed for various parameters. It is found that when the cooling load of a building is greater than the heating load, the shallow-deep-mixed borehole heat exchanger (SD-BHE) array has less influence on ground temperature and provides better stability of the outlet water temperature than the SBHE array. The present study can offer a new paradigm for geothermal energy-based building cooling/heating.
Thermal behavior and performance of shallow-deep-mixed borehole heat exchanger array for sustainable building cooling and heating
Cheng, Nan (author) / Zhou, Chaohui (author) / Luo, Yongqiang (author) / Shen, Junhao (author) / Tian, Zhiyong (author) / Sun, Deyu (author) / Fan, Jianhua (author) / Zhang, Ling (author) / Deng, Jie (author) / Rosen, Marc A. (author)
Energy and Buildings ; 291
2023-04-23
Article (Journal)
Electronic Resource
English
| UB Braunschweig | 2022