A Numerical Approach to Correlate Energy Performance of Prototype and Model-Scale Geothermal Piles

Ground source heat pump (GSHP) technology offers several advantages over conventional space heating and cooling systems. Long-term performance evaluation of GSHP systems is crucial for technical, economic, and environmental sustainability assessment of this technology. Nevertheless, it is often challenging to acquire good quality performance data over a long duration of operation under variable field boundary conditions. This paper correlates, through numerical analysis, thermal performance of a laboratory-scale model pile with that of a prototype pile. Results show that a constant fluid circulation velocity with different diameters of fluid circulation tube produces nearly the same power output per unit length of a geothermal pile. The size of the material domain and the time duration of laboratory thermal performance tests can be decided by carefully selecting the materials with appropriate thermal properties.