Heat Transfer in Borehole Heat Exchangers from Laminar to Turbulent Conditions

E. Holzbecher[1], H. Räuschel[1]
[1]Georg-August Universität Göttingen, Göttingen, Germany
Veröffentlicht in 2014

Borehole heat exchangers (BHE) in connection with heat pumps and floor heating in many countries are becoming an alternative to conventional heating or cooling systems using fossil resources. We describe how 1D components for heat transport in pipes can be coupled with a 2D or 3D component for the ground. Thermal conductances are derived for laminar, transitory and turbulent flow conditions in the pipes. We describe applications for two sites of geothermal production from a sub-surface salt formation. We use the model to estimate the heat capacity for the projected facilities. The presented concept enables the simulation of coupled hydraulic and thermal processes. It can be applied for 2D/3D models in cartesian/axisymmetric coordinates, for steady-state and for transient problems.