BuildSysPro.IBPSA.Fluid.Geothermal.Borefields.BaseClasses.Boreholes.BaseClasses.InternalHEXTwoUTube

# .BuildSysPro.IBPSA.Fluid.Geothermal.Borefields.BaseClasses.Boreholes.BaseClasses.InternalHEXTwoUTube

Internal heat exchanger of a borehole for a double U-tube configuration. In loop 1, fluid 1 streams from a1 to b1 and comes back from a2 to b2. In loop 2: fluid 2 streams from a3 to b3 and comes back from a4 to b4.

## Information

Model for the heat transfer between the fluid and within the borehole filling. This model computes the dynamic response of the fluid in the tubes, the heat transfer between the fluid and the borehole filling, and the heat storage within the fluid and the borehole filling.

This model computes the different thermal resistances present in a single-U-tube borehole using the method of Bauer et al. (2011) and computing explicitely the fluid-to-ground thermal resistance Rb and the grout-to-grout resistance Ra as defined by Claesson and Hellstrom (2011) using the multipole method.

#### References

J. Claesson and G. Hellstrom. Multipole method to calculate borehole thermal resistances in a borehole heat exchanger. HVAC&R Research, 17(6): 895-911, 2011.

D. Bauer, W. Heidemann, H. Müller-Steinhagen, and H.-J. G. Diersch. Thermal resistance and capacity models for borehole heat exchangers . International Journal Of Energy Research, 35:312-320, 2011.

## Revisions

- March 7, 2022, by Michael Wetter:
  Removed `massDynamics`.
  This is for #1542.
- February 28, 2022, by Massimo Cimmino:
  Removed `printDebug` parameter from call to IBPSA.Fluid.Geothermal.Borefields.BaseClasses.Boreholes.BaseClasses.Functions.internalResistancesTwoUTube.
  This is for IBPSA, #1582.
- July 10, 2018, by Alex Laferrière:
  Updated documentation following major changes to the IBPSA.Fluid.HeatExchangers.Ground package. Additionally, implemented a partial InternalHex model.
- June 18, 2014, by Michael Wetter:
  Added initialization for temperatures and derivatives of `capFil1` and `capFil2` to avoid a warning during translation.
- February 14, 2014, by Michael Wetter:
  Removed unused parameters `B0` and `B1`.
- January 24, 2014, by Michael Wetter:
  Revised implementation, added comments, replaced `HeatTransfer.Windows.BaseClasses.ThermalConductor` with resistance models from the Modelica Standard Library.
- January 23, 2014, by Damien Picard:
  First implementation.

Generated at 2026-05-09T18:18:56Z by OpenModelicaOpenModelica 1.26.7 using GenerateDoc.mos