Ground Heat Exchanger model validation through software comparison

Abstract

Experimental data are obtained for a Borehole Ground Heat Exchanger (GHE) with a single U-tube configuration, at a depth of 160m, with underwater flow. The monitored inlet and outlet temperatures of the circulating fluid (water) are recorded by a Thermal Response Test. Two similar numerical models, one constructed in the Flex PDE and another in the COMSOL Multiphysics environment, are then validated for the experimental regime described above. The time-dependent convection-diffusion equation of heat transfer was used in both models with the same boundary conditions representing the actual parameters of the installed column. The results obtained by both models, in good agreement with the experimental data, are discussed and assessed. Furthermore, the two computational model responses to various design aspects of GHE are studied and inter-compared.