Coupling Subsurface and Above-Surface Models for Optimizing the Design of Borefields and District Heating and Cooling Systems
Accurate dynamic energy simulation is important for the design and sizing of district heating and cooling systems with geothermal heat exchange for seasonal energy storage. Current modeling approaches in building and district energy simulation tools typically consider heat conduction through the ground between boreholes without flowing groundwater. While detailed simulation tools for subsurface heat and mass transfer exist, these fall short in simulating above-surface energy systems.
To support the design and operation of such systems, the study developed a coupled model including a software package for building and district energy simulation, and software for detailed heat and mass transfer in the subsurface. For the first, it uses the open-source Modelica Buildings Library, which includes dynamic simulation models for building and district energy and control systems. For the heat and mass transfer in the soil, it uses the TOUGH simulator. The TOUGH family of codes can model heat and multi-phase, multi-component mass transport for a variety of fluid systems, as well as chemical reactions, in fractured porous media.
The study validated the coupled modeling approach by comparing the simulation results with one from the g-function based ground response model. It then looked into effects when the water table and the regional groundwater flow are considered in the ground, from the perspective of heat exchange between borehole and ground, and the electrical consumption of the district heating and cooling systems.
To access the simulation models, please find the links in the submission:
-- For coupled approach validation: see model Buildings.Fluid.Geothermal.Borefields.Examples.BorefieldsWithTough and Buildings.Examples.DistrictReservoirNetworks.Examples.Reservoir3Variable_TOUGH from the "Modelica Building Library" resource, branch issue1495_tough_interface, commit a2667c0.
-- For the study of the effect of water table: see model Buildings.Examples.DistrictReservoirNetworks.Examples.Reservoir3Variable_TOUGH from he "Modelica Building Library" resource, branch issue1495_tough_interface_moreIO, commit 760de49.
The coupling interface script "GrounResponse.py" can be found from the above links in the folder Buildings/Resources/Python-Sources. Also, the needed files for TOUGH simulation are in the folder Buildings/Resources/Python-Sources/ToughFiles that can be accessed through the above links. A brief description of these files is given below; detailed specifications for the first three files may be found in the TOUGH3 Users Guide (Jung et al., 2018) https://tough.lbl.gov/documentation/tough-manuals/.
(1) INCON - initial conditions for each grid block
(2) INFILE - main input file with material properties and control parameters
(3) MESH - description of the computational grid
(4) readsave - Modelica/TOUGH interface program: read the final output of TOUGH simulation after TOUGH time step and prepare for transfer to Modelica for next Modelica time step
(5) readsave.inp - input parameters for program readsave
(6) writeincon - Modelica/TOUGH interface program: write the output of Modelica after Modelica time step and prepare for transfer to TOUGH as initial conditions for the next TOUGH step
(7) writeincon.inp - input parameters for program writeincon
Citation Formats
TY - DATA
AB - Accurate dynamic energy simulation is important for the design and sizing of district heating and cooling systems with geothermal heat exchange for seasonal energy storage. Current modeling approaches in building and district energy simulation tools typically consider heat conduction through the ground between boreholes without flowing groundwater. While detailed simulation tools for subsurface heat and mass transfer exist, these fall short in simulating above-surface energy systems.
To support the design and operation of such systems, the study developed a coupled model including a software package for building and district energy simulation, and software for detailed heat and mass transfer in the subsurface. For the first, it uses the open-source Modelica Buildings Library, which includes dynamic simulation models for building and district energy and control systems. For the heat and mass transfer in the soil, it uses the TOUGH simulator. The TOUGH family of codes can model heat and multi-phase, multi-component mass transport for a variety of fluid systems, as well as chemical reactions, in fractured porous media.
The study validated the coupled modeling approach by comparing the simulation results with one from the g-function based ground response model. It then looked into effects when the water table and the regional groundwater flow are considered in the ground, from the perspective of heat exchange between borehole and ground, and the electrical consumption of the district heating and cooling systems.
To access the simulation models, please find the links in the submission:
-- For coupled approach validation: see model Buildings.Fluid.Geothermal.Borefields.Examples.BorefieldsWithTough and Buildings.Examples.DistrictReservoirNetworks.Examples.Reservoir3Variable_TOUGH from the "Modelica Building Library" resource, branch issue1495_tough_interface, commit a2667c0.
-- For the study of the effect of water table: see model Buildings.Examples.DistrictReservoirNetworks.Examples.Reservoir3Variable_TOUGH from he "Modelica Building Library" resource, branch issue1495_tough_interface_moreIO, commit 760de49.
The coupling interface script "GrounResponse.py" can be found from the above links in the folder Buildings/Resources/Python-Sources. Also, the needed files for TOUGH simulation are in the folder Buildings/Resources/Python-Sources/ToughFiles that can be accessed through the above links. A brief description of these files is given below; detailed specifications for the first three files may be found in the TOUGH3 Users Guide (Jung et al., 2018) https://tough.lbl.gov/documentation/tough-manuals/.
(1) INCON - initial conditions for each grid block
(2) INFILE - main input file with material properties and control parameters
(3) MESH - description of the computational grid
(4) readsave - Modelica/TOUGH interface program: read the final output of TOUGH simulation after TOUGH time step and prepare for transfer to Modelica for next Modelica time step
(5) readsave.inp - input parameters for program readsave
(6) writeincon - Modelica/TOUGH interface program: write the output of Modelica after Modelica time step and prepare for transfer to TOUGH as initial conditions for the next TOUGH step
(7) writeincon.inp - input parameters for program writeincon
AU - Hu, Jianjun
A2 - Doughty, Christine
A3 - Dobson, Patrick
A4 - Nico, Peter
A5 - Wetter, Michael
DB - Geothermal Data Repository
DP - Open EI | National Renewable Energy Laboratory
DO - 10.15121/1843793
KW - Geothermal Bofield
KW - Energy
KW - Modelica Buildings Library
KW - TOUGH
KW - Coupling
KW - District Energy System
KW - district heating
KW - district cooling
KW - Geothermal
KW - borefield
KW - simulation
KW - model
KW - modeling
KW - optimization
KW - energy storage
KW - seasonal energy storage
KW - geothermal heat exchange
KW - ground source heat pump
KW - gshp
KW - code
KW - python
KW - Modelica
LA - English
DA - 2022/01/31
PY - 2022
PB - Lawrence Berkeley National Laboratory
T1 - Coupling Subsurface and Above-Surface Models for Optimizing the Design of Borefields and District Heating and Cooling Systems
UR - https://doi.org/10.15121/1843793
ER -
Hu, Jianjun, et al. Coupling Subsurface and Above-Surface Models for Optimizing the Design of Borefields and District Heating and Cooling Systems. Lawrence Berkeley National Laboratory, 31 January, 2022, Geothermal Data Repository. https://doi.org/10.15121/1843793.
Hu, J., Doughty, C., Dobson, P., Nico, P., & Wetter, M. (2022). Coupling Subsurface and Above-Surface Models for Optimizing the Design of Borefields and District Heating and Cooling Systems. [Data set]. Geothermal Data Repository. Lawrence Berkeley National Laboratory. https://doi.org/10.15121/1843793
Hu, Jianjun, Christine Doughty, Patrick Dobson, Peter Nico, and Michael Wetter. Coupling Subsurface and Above-Surface Models for Optimizing the Design of Borefields and District Heating and Cooling Systems. Lawrence Berkeley National Laboratory, January, 31, 2022. Distributed by Geothermal Data Repository. https://doi.org/10.15121/1843793
@misc{GDR_Dataset_1365,
title = {Coupling Subsurface and Above-Surface Models for Optimizing the Design of Borefields and District Heating and Cooling Systems},
author = {Hu, Jianjun and Doughty, Christine and Dobson, Patrick and Nico, Peter and Wetter, Michael},
abstractNote = {Accurate dynamic energy simulation is important for the design and sizing of district heating and cooling systems with geothermal heat exchange for seasonal energy storage. Current modeling approaches in building and district energy simulation tools typically consider heat conduction through the ground between boreholes without flowing groundwater. While detailed simulation tools for subsurface heat and mass transfer exist, these fall short in simulating above-surface energy systems.
To support the design and operation of such systems, the study developed a coupled model including a software package for building and district energy simulation, and software for detailed heat and mass transfer in the subsurface. For the first, it uses the open-source Modelica Buildings Library, which includes dynamic simulation models for building and district energy and control systems. For the heat and mass transfer in the soil, it uses the TOUGH simulator. The TOUGH family of codes can model heat and multi-phase, multi-component mass transport for a variety of fluid systems, as well as chemical reactions, in fractured porous media.
The study validated the coupled modeling approach by comparing the simulation results with one from the g-function based ground response model. It then looked into effects when the water table and the regional groundwater flow are considered in the ground, from the perspective of heat exchange between borehole and ground, and the electrical consumption of the district heating and cooling systems.
To access the simulation models, please find the links in the submission:
-- For coupled approach validation: see model Buildings.Fluid.Geothermal.Borefields.Examples.BorefieldsWithTough and Buildings.Examples.DistrictReservoirNetworks.Examples.Reservoir3Variable_TOUGH from the "Modelica Building Library" resource, branch issue1495_tough_interface, commit a2667c0.
-- For the study of the effect of water table: see model Buildings.Examples.DistrictReservoirNetworks.Examples.Reservoir3Variable_TOUGH from he "Modelica Building Library" resource, branch issue1495_tough_interface_moreIO, commit 760de49.
The coupling interface script "GrounResponse.py" can be found from the above links in the folder Buildings/Resources/Python-Sources. Also, the needed files for TOUGH simulation are in the folder Buildings/Resources/Python-Sources/ToughFiles that can be accessed through the above links. A brief description of these files is given below; detailed specifications for the first three files may be found in the TOUGH3 Users Guide (Jung et al., 2018) https://tough.lbl.gov/documentation/tough-manuals/.
(1) INCON - initial conditions for each grid block
(2) INFILE - main input file with material properties and control parameters
(3) MESH - description of the computational grid
(4) readsave - Modelica/TOUGH interface program: read the final output of TOUGH simulation after TOUGH time step and prepare for transfer to Modelica for next Modelica time step
(5) readsave.inp - input parameters for program readsave
(6) writeincon - Modelica/TOUGH interface program: write the output of Modelica after Modelica time step and prepare for transfer to TOUGH as initial conditions for the next TOUGH step
(7) writeincon.inp - input parameters for program writeincon},
url = {https://gdr.openei.org/submissions/1365},
year = {2022},
howpublished = {Geothermal Data Repository, Lawrence Berkeley National Laboratory, https://doi.org/10.15121/1843793},
note = {Accessed: 2025-04-29},
doi = {10.15121/1843793}
}
https://dx.doi.org/10.15121/1843793
Details
Data from Jan 31, 2022
Last updated Feb 17, 2025
Submitted Feb 1, 2022
Organization
Lawrence Berkeley National Laboratory
Contact
Peter Nico
510.486.7118
Authors
Keywords
Geothermal Bofield, Energy, Modelica Buildings Library, TOUGH, Coupling, District Energy System, district heating, district cooling, Geothermal, borefield, simulation, model, modeling, optimization, energy storage, seasonal energy storage, geothermal heat exchange, ground source heat pump, gshp, code, python, ModelicaDOE Project Details
Project Name Community Resilience through Low-Temperature Geothermal Reservoir Thermal Energy Storage
Project Lead Arlene Anderson
Project Number FY21 AOP 2.7.1.4