Problem:

There is recently been an increased interest in understanding geothermal energy. These types of applications focus on setting the conductive and convective movement of heat beneath the ground. There is also interest in exploring the use of underground aquifers as heat storage systems in borehole thermal extraction systems (BTES). The numerical modeling of these systems must include both conductive and convective processes. The buoyant action of the heated fluid must also be accounted for in the numerical model. Adding to the complexity is the fact that many underground aquifers are of irregular geometry and therefore must be modeled in three dimensions.

Solution:

A coupled SVFlux/SVHeat numerical model allows full coupling of the relevant processes such as to be ideal for geothermal numerical modeling. Conductive and convective heat flow as well as thermal buoyancy can be modeled in the software. Full irregular aquifers can be modeled in 3-D or simplified to 2-D models. The numerical model also allows simulation of geothermal heating systems. The amount of influence a geothermal heating system can have on the surrounding region can be computed. The numerical model can also be used to optimize the design of the boreholes for a geothermal system.

Additional Articles

• Geothermal Newsletter

This is a shorter version of the CanalBankFreezingThawing model presented in the Example Manual. Example is to illustrate hydrothermal coupling in the simulation of soil and ice freeze-thaw behavior on a canal bank. The water in the canal is also included in the analysis. The model simulation time is 50 hours, The canal bank is freezing in the first 25 hours, and after that time, the thawing process happens.

Model filename: GeoThermal > CanalBankFreezingThawing_50h.svm

This example demonstrates the implementation of a thermosyphon boundary condition. Reference: Cold Regions Science and Technology 53 (2008) 283–297

Model filename: Thermosyphon > HairpinThermosyphon.svm

Heated strip extended across permafrost conditions.

Model filename: GeoThermal > HeatedStrip.svm

This example illustrates a 3D model of highway embankment cooling.

Model filename: GeoThermal > Ventilated_Pipe_RailwayEmbankmentCooling.svm

Solution of Laplacian equation for two dimensional heat flow. Analytical results obtained from Harlan and Nixon 1978 (see verification manual).

Model filename: GeoThermal > Verification01.svm