modelMultipoleThermalResistances_TwoUTube

Validation of the thermal resitances for a double U-tube borehole

Extends from Modelica.Icons.Example (Icon for runnable examples).

Information

This example validates the implementation of AixLib.Fluid.Geothermal.Borefields.BaseClasses.Boreholes.BaseClasses.Functions.multipoleThermalResistances for the evaluation of the borehole thermal resistances.

The multipole method is used to evaluate thermal resistances for a double U-tube borehole with symmetrically positionned pipes. Results are compared to reference values given in Claesson (2012).

References

Claesson, J. (2012). Multipole method to calculate borehole thermal resistances. Mathematical report. Department of Building Physics, Lund University, Box 118, SE-221 00 Lund, Sweden. 128 pages.

Parameters

TypeNameDefaultDescription
IntegernPip4Number of pipes
IntegerJ3Number of multipoles
Modelica.Units.SI.PositionxPip{0.03, -0.03, -0.03, 0.03}x-Coordinates of pipes
Modelica.Units.SI.PositionyPip{0.03, 0.03, -0.03, -0.03}y-Coordinates of pipes
Modelica.Units.SI.RadiusrBor0.07Borehole radius
Modelica.Units.SI.RadiusrPipfill(0.02, nPip)Outter radius of pipes
Modelica.Units.SI.ThermalConductivitykFil1.5Thermal conductivity of grouting material
Modelica.Units.SI.ThermalConductivitykSoi2.5Thermal conductivity of soil material
RealRFluPipfill(1.2/(2*Modelica.Constants.pi*kFil), nPip)Fluid to pipe wall thermal resistances
Modelica.Units.SI.TemperatureTBor0Average borehole wall temperature
RealRDelta_Ref{{1/3.61, 1/0.35, -1/0.25, 1/0.35}, {1/0.35, 1/3.61, 1/0.35, -1/0.25}, {-1/0.25, 1/0.35, 1/3.61, 1/0.35}, {1/0.35, -1/0.25, 1/0.35, 1/3.61}}Reference delta-circuit thermal resistances
RealR_Ref{{0.2509, 0.0192, -0.0122, 0.0192}, {0.0192, 0.2509, 0.0192, -0.0122}, {-0.0122, 0.0192, 0.2509, 0.0192}, {0.0192, -0.0122, 0.0192, 0.2509}}Reference internal thermal resistances

Components

TypeNameDefaultDescription
RealRDeltaDelta-circuit thermal resistances
RealRInternal thermal resistances

Revisions

  • June 21, 2018, by Massimo Cimmino:
    First implementation.