Abstract
This paper represents an investigation on geothermal cooling/heating systems based on a numerical study of a Ground-Air Heat Exchanger (GAHE) in order to improve the performance of air conditioning system and minimize the area occupied by the GAHE. A new configuration of the GAHE (Horizontal Spiral) was evaluated. The Finite Volume Method was used to discretize the calculation's domain. On each control volume, the fundamental differential conservation equations were applied and integrated, for this purpose, a commercial CFD software (ANSYS FLUENT) has been used. A transient three-dimensional model for predicting the distribution temperature in the soil and in the GAHE was carried out. Preliminary validation of the numerical model was carried out and the obtained results agreed well with the experiments and numerical results cited in the literature. Next, a comparison between spirals shaped and other geometry was carried out to find the more suitable the more compact configuration occupying less soil's space. Finally, we studied and discussed the effect of the pitch (distance between axis centers of tubes) on the outlet temperature of the GAHE.