modelSandbox

Validation of BorefieldOneUTube based on the experiment of Beier et al. (2011)
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Information

This validation case simulates the experiment of Beier et al. (2011). Measured experimental data is taken from the reference.

The experiment consists in the injection of heat at an average rate of 1142 W in a 18 m long borehole over a period 52 h. Dimensions and thermal properties reported by Beier et al. (2011) are used in the model. The authors conducted multiple independent measurements of soil thermal conductivity. The average of reported values (2.88 W/m-K) is used here. Finally, the filling material thermal capacity and density was not reported. Values were chosen from the estimated volumetric heat capacity used by Pasquier and Marcotte (2014).

The construction of the borehole is non-conventional: the borehole is contained within an aluminum pipe that acts as the borehole wall. As this modifies the thermal resistances inside the borehole, the values evaluated by the multipole method are modified to obtain the effective borehole thermal resistance reported by Beier et al. (2011).

References

Beier, R.A., Smith, M.D. and Spitler, J.D. 2011. Reference data sets for vertical borehole ground heat exchanger models and thermal response test analysis. Geothermics 40: 79-85.

Pasquier, P., and Marcotte, D. 2014. Joint use of quasi-3D response model and spectral method to simulate borehole heat exchanger. Geothermics 51: 281-299.

Parameters

TypeNameDefaultDescription
Modelica.Units.SI.TemperatureT_start273.15 + 22.09Initial temperature of the sandbox
RealmSenFac1.59186Scaling factor for the borehole capacitances, modified to account for the thermal mass of the pipes and the borehole casing
Buildings.Fluid.Geothermal.Borefields.Validation.BaseClasses.SandBox_BorefieldborFieDatBorefield data

Components

TypeNameDefaultDescription
Buildings.Fluid.Geothermal.Borefields.OneUTubeborHolBorehole
Buildings.Fluid.Movers.FlowControlled_m_flowpumCirculation pump
Buildings.Fluid.Sensors.TemperatureTwoPortTBorFieInInlet temperature of the borefield
Buildings.Fluid.Sensors.TemperatureTwoPortTBorFieOutOutlet temperature of the borefield
Buildings.Fluid.Sources.Boundary_phsinSink
Modelica.Blocks.Sources.CombiTimeTablesandBoxMea
Buildings.Fluid.HeatExchangers.HeaterCooler_uheaHeater

Contents

NameDescription
Medium

Revisions

  • April 29, 2026, by Michael Wetter:
    Changed configuration of table to cause the parameters to be evaluated, as this leads to more efficient code.
    This is for IBPSA, #2111.
  • November 15, 2022, by Michael Wetter:
    Set proper head for pump.
    This is for IBPSA, issue 1659.
  • April 8, 2021, by Michael Wetter:
    Added missing parameter keyword.
    For IBPSA, issue 1464.
  • July 18, 2018, by Massimo Cimmino:
    First implementation.