Hi,
I am currently simulating an open-loop thermal groundwater use scenario in Feflow using Heat nodal sink/source BC with a prescribed thermal power in kWh/d.
Model setup (test case for understanding the system):
- Two injection wells with constant discharge (total 115 L/s).
- Seasonal operation: Cooling mode (May–October) and Heating mode (November–April)
- Equal absolute thermal energy input/output in both modes (+5 K / - 5 K).
- No additional thermal sources or sinks in the model domain
- Initial groundwater temperature: 11.5 °C
- Injection and abstraction wells are hydraulically separated (no storage/ATES behaviour)
Observed behaviour:
Despite prescribing equal thermal energy, the simulated temperature response is not symmetric:
- Cooling leads to groundwater temperatures of roughly 5 °C (≈ −6.5 K deviation).
- Heating reaches only about 15 °C (≈ +3.5 K deviation).
- Therefore, the maximum cooling effect is significantly stronger than the maximum warming, although the absolute thermal power is identical.
Is such an asymmetric thermal response expected in Feflow?
Can anyone recommend literature for such a setting?
Many thanks,
Leander
