Transient cooling potential of Vertical Ground Heat Exchanger

Vertical U-tube ground heat exchangers are one of the most important parts of geothermal utilization systems. Most of the previous numerical and analytical models were interested to predict the steady state behavior of a Vertical Ground Heat Exchanger (VGHX) instead of the transient behavior of VGHX. Their models are mostly valid few hours after starting operation time. It is clear that when design procedures are based on the steady state behavior of VGHX automatically the transient cooling potential of ground is neglected and if the transient cooling potential of ground is neglected it caused to increasing the number of boreholes and also the total capital costs. In this study at the first stage, a three dimensional computational fluid dynamics simulation of VGHX was carried out then based on the transient CFD results the transient cooling potential of ground is computed and compared with steady state based borehole design

Keywords:

Vertical Ground Heat Exchanger (VGHX) , Computational Fluid Dynamics (CFD) , Transient behavior , Steady state behavior