Modeling neighborhood-scale shallow geothermal energy utilization: a case study in Berlin
Abstract Nowadays, utilizing shallow geothermal energy for heating and cooling buildings has received increased interest in the building sector. Among different technologies, large borehole heat exchanger arrays are widely employed to supply heat to various types of buildings. Recently, a 16-borehol...
| Main Authors: | , , , , , , , , , |
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| Format: | Article |
| Language: | English |
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SpringerOpen
2022-02-01
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| Series: | Geothermal Energy |
| Subjects: | |
| Online Access: | https://doi.org/10.1186/s40517-022-00211-9 |
| _version_ | 1828135794909380608 |
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| author | Jakob Randow Shuang Chen Katrin Lubashevsky Steve Thiel Tom Reinhardt Karsten Rink Rüdiger Grimm Anke Bucher Olaf Kolditz Haibing Shao |
| author_facet | Jakob Randow Shuang Chen Katrin Lubashevsky Steve Thiel Tom Reinhardt Karsten Rink Rüdiger Grimm Anke Bucher Olaf Kolditz Haibing Shao |
| author_sort | Jakob Randow |
| collection | DOAJ |
| description | Abstract Nowadays, utilizing shallow geothermal energy for heating and cooling buildings has received increased interest in the building sector. Among different technologies, large borehole heat exchanger arrays are widely employed to supply heat to various types of buildings. Recently, a 16-borehole array was constructed to extract shallow geothermal energy to provide heat to a newly-developed public building in Berlin. To guarantee the quality of the numerical model and reveal its sensitivity to different subsurface conditions, model simulations were conducted for 25 years with two finite element simulators, namely the open-source code OpenGeoSys and the widely applied commercial software FEFLOW. Given proper numerical settings, the simulation results from OpenGeoSys and FEFLOW are in good agreement. However, further analysis reveals differences with respect to borehole inflow temperature calculation implemented in the two software. It is found that FEFLOW intrinsically uses the outflow temperature from the previous time step to determine the current inflow temperature, which makes it capable of much faster simulation by avoiding iterations within a single time step. In comparison, OpenGeoSys always updates the inflow and outflow temperature based on their current time step values. Because the updates are performed after each iteration, it delivers more accurate results with the expense of longer simulation time. Based on this case study, OpenGeoSys is a valid alternative to FEFLOW for modeling ground source heat pump systems. For modellers working in this field, it is thus recommended to adopt small enough time step size, so that potential numerical error can be avoided. |
| first_indexed | 2024-04-11T17:52:50Z |
| format | Article |
| id | doaj.art-1c4e95a09fcf41e487a1ea9b7efd2836 |
| institution | Directory Open Access Journal |
| issn | 2195-9706 |
| language | English |
| last_indexed | 2024-04-11T17:52:50Z |
| publishDate | 2022-02-01 |
| publisher | SpringerOpen |
| record_format | Article |
| series | Geothermal Energy |
| spelling | doaj.art-1c4e95a09fcf41e487a1ea9b7efd28362022-12-22T04:10:59ZengSpringerOpenGeothermal Energy2195-97062022-02-0110112610.1186/s40517-022-00211-9Modeling neighborhood-scale shallow geothermal energy utilization: a case study in BerlinJakob Randow0Shuang Chen1Katrin Lubashevsky2Steve Thiel3Tom Reinhardt4Karsten Rink5Rüdiger Grimm6Anke Bucher7Olaf Kolditz8Haibing Shao9Faculty of Engineering, Leipzig University of Applied Sciences - HTWKDepartment of Environmental Informatics, Helmholtz Centre for Environmental Research - UFZFaculty of Engineering, Leipzig University of Applied Sciences - HTWKgeoENERGIE Konzept GmbHgeoENERGIE Konzept GmbHDepartment of Environmental Informatics, Helmholtz Centre for Environmental Research - UFZgeoENERGIE Konzept GmbHFaculty of Engineering, Leipzig University of Applied Sciences - HTWKDepartment of Environmental Informatics, Helmholtz Centre for Environmental Research - UFZDepartment of Environmental Informatics, Helmholtz Centre for Environmental Research - UFZAbstract Nowadays, utilizing shallow geothermal energy for heating and cooling buildings has received increased interest in the building sector. Among different technologies, large borehole heat exchanger arrays are widely employed to supply heat to various types of buildings. Recently, a 16-borehole array was constructed to extract shallow geothermal energy to provide heat to a newly-developed public building in Berlin. To guarantee the quality of the numerical model and reveal its sensitivity to different subsurface conditions, model simulations were conducted for 25 years with two finite element simulators, namely the open-source code OpenGeoSys and the widely applied commercial software FEFLOW. Given proper numerical settings, the simulation results from OpenGeoSys and FEFLOW are in good agreement. However, further analysis reveals differences with respect to borehole inflow temperature calculation implemented in the two software. It is found that FEFLOW intrinsically uses the outflow temperature from the previous time step to determine the current inflow temperature, which makes it capable of much faster simulation by avoiding iterations within a single time step. In comparison, OpenGeoSys always updates the inflow and outflow temperature based on their current time step values. Because the updates are performed after each iteration, it delivers more accurate results with the expense of longer simulation time. Based on this case study, OpenGeoSys is a valid alternative to FEFLOW for modeling ground source heat pump systems. For modellers working in this field, it is thus recommended to adopt small enough time step size, so that potential numerical error can be avoided.https://doi.org/10.1186/s40517-022-00211-9Shallow Geothermal ExploitationBorehole Heat ExchangerGround Source Heat PumpNumerical ModelingFEFLOWOpenGeoSys |
| spellingShingle | Jakob Randow Shuang Chen Katrin Lubashevsky Steve Thiel Tom Reinhardt Karsten Rink Rüdiger Grimm Anke Bucher Olaf Kolditz Haibing Shao Modeling neighborhood-scale shallow geothermal energy utilization: a case study in Berlin Geothermal Energy Shallow Geothermal Exploitation Borehole Heat Exchanger Ground Source Heat Pump Numerical Modeling FEFLOW OpenGeoSys |
| title | Modeling neighborhood-scale shallow geothermal energy utilization: a case study in Berlin |
| title_full | Modeling neighborhood-scale shallow geothermal energy utilization: a case study in Berlin |
| title_fullStr | Modeling neighborhood-scale shallow geothermal energy utilization: a case study in Berlin |
| title_full_unstemmed | Modeling neighborhood-scale shallow geothermal energy utilization: a case study in Berlin |
| title_short | Modeling neighborhood-scale shallow geothermal energy utilization: a case study in Berlin |
| title_sort | modeling neighborhood scale shallow geothermal energy utilization a case study in berlin |
| topic | Shallow Geothermal Exploitation Borehole Heat Exchanger Ground Source Heat Pump Numerical Modeling FEFLOW OpenGeoSys |
| url | https://doi.org/10.1186/s40517-022-00211-9 |
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