Buildings.Fluid.Geothermal.Borefields.BaseClasses.HeatTransfer.Validation
Validation models for GroundHeatTransfer
Information
This package contains validation models for the classes in Buildings.Fluid.Geothermal.Borefields.BaseClasses.HeatTransfer.
Extends from Modelica.Icons.ExamplesPackage (Icon for packages containing runnable examples).
Package Content
Name | Description |
---|---|
Analytic_20Years | Long term validation of ground temperature response model |
Cylindrical | Comparison of the Cylindrical with the GroundTemperatureResponse |
FiniteDifference_1Week | Short term validation of ground temperature response model |
Measured_SmallScale | Long term validation of ground temperature response model using the small scale experiment of Cimmino and Bernier (2015) |
BaseClasses | Package with base classes for Buildings.Fluid.Geothermal.Borefields.BaseClasses.HeatTransfer.Validation |
Buildings.Fluid.Geothermal.Borefields.BaseClasses.HeatTransfer.Validation.Analytic_20Years
Long term validation of ground temperature response model
Information
This validation case applies the asymetrical synthetic load profile developed
by Pinel (2003) over a 20 year period by directly injecting the heat at the
borehole wall in the ground temperature response model. The difference between
the resulting borehole wall temperature and the same temperature precalculated
by using a fast Fourier transform is calculated with the add
component. The fast Fourier transform calculation was done using the same
g-function as was calculated by
Buildings.Fluid.Geothermal.Borefields.BaseClasses.HeatTransfer.ThermalResponseFactors.gFunction.
References
Pinel, P. 2003. Amélioration, validation et implantation d’un algorithme de calcul pour évaluer le transfert thermique dans les puits verticaux de systèmes de pompes à chaleur géothermiques, M.A.Sc. Thesis, École Polytechnique de Montréal.
Extends from Modelica.Icons.Example (Icon for runnable examples).
Parameters
Type | Name | Default | Description |
---|---|---|---|
Template | borFieDat | borFieDat(conDat(borCon=Type... | Borefield parameters |
Modelica definition
Buildings.Fluid.Geothermal.Borefields.BaseClasses.HeatTransfer.Validation.Cylindrical
Comparison of the Cylindrical with the GroundTemperatureResponse
Information
This example demonstrates the use of Buildings.Fluid.Geothermal.Borefields.BaseClasses.HeatTransfer.Cylindrical.
After a short delay, a constant heat flow rate is applied to the inner surface of a cylindrical ground layer while the outer surface is kept at a constant temperature.
Extends from Modelica.Icons.Example (Icon for runnable examples).
Parameters
Type | Name | Default | Description |
---|---|---|---|
Temperature | T_start | 295.15 | Initial soil temperature [K] |
Template | borFieDat | Buildings.Fluid.Geothermal.B... |
Modelica definition
Buildings.Fluid.Geothermal.Borefields.BaseClasses.HeatTransfer.Validation.FiniteDifference_1Week
Short term validation of ground temperature response model
Information
This example validates the implementation of Buildings.Fluid.Geothermal.Borefields.BaseClasses.HeatTransfer.GroundTemperatureResponse for the evaluation of the borehole wall temperature at a short time scale.
After a short delay, a sinusoidal heat flow rate is applied to borehole heat exchanger. The temperature at the borehole wall evaluated with Buildings.Fluid.Geothermal.Borefields.BaseClasses.HeatTransfer.GroundTemperatureResponse is compared to the temperature obtained with Buildings.Fluid.Geothermal.Borefields.BaseClasses.HeatTransfer.Cylindrical
Extends from Modelica.Icons.Example (Icon for runnable examples).
Parameters
Type | Name | Default | Description |
---|---|---|---|
Temperature | T_start | 283.15 | Initial soil temperature [K] |
Template | borFieDat | borFieDat(soiDat(kSoi=1, cSo... | Borefield parameters |
Modelica definition
Buildings.Fluid.Geothermal.Borefields.BaseClasses.HeatTransfer.Validation.Measured_SmallScale
Long term validation of ground temperature response model using the small scale experiment of Cimmino and Bernier (2015)
Information
This validation case simulates the experiment of Cimmino and Bernier (2015). The experiment consists in the injection of heat at an average rate of 8.67 W in a 0.40 m long borehole over a period of 168 h. Borehole wall tempratures were measured by a series of 22 thermocouples welded to the stainless steel pipe that contains the borehole and acts as the borehole wall.
Since the model is not adapted to the simulation of small scale boreholes, the borehole dimensions are multiplied by a factor 375 to obtain a scaled-up 150.0 m long borehole. The time values of the experimental data are then multiplied by a factor 3752. The predicted borehole wall temperature is compared to the experimental data.
A sharp increase in the rate of change of the borehole wall temperature is observed at t=500 years. This is caused by a sudden change in the rate of heat injected to the fluid at the same moment. The simulated borehole wall temperature is more affected the measured borehole wall temperature since the validation model does not consider the dynamics of the borehole and the fluid, and that heat is directly injected at the borehole wall. In the experiment, the sudden change in heat injection rate was dampened by the circulating fluid, the borehole filling material, and the measurement apparatus.
References
Cimmino, M. and Bernier, M. 2015. Experimental determination of the g-functions of a small-scale geothermal borehole. Geothermics 56: 60-71.
Extends from Modelica.Icons.Example (Icon for runnable examples).
Parameters
Type | Name | Default | Description |
---|---|---|---|
Real | sizFac | 375.0 | Scaling factor of the experiment |
SmallScale_Borefield | borFieDat | Borefield parameters |