ABSTRACT
The paper presents the results of a series of 3-Dimensional (3D), Finite Element (FE) analyses, conducted to investigate the effects of the heating cycles on innovative energy foundations of small diameter (Energy Micro-Piles, EMP) installed in fine-grained soils. This study has been performed during the design stage of a full-scale prototype EMP currently under development at the University of Perugia for the exploitation of low-enthalpy geothermal energy in the retrofitting of existing buildings. The FE simulation program has been focused mainly on the evaluation of the heat flux variations of the prototype during functioning of the system, by varying thermal properties of the soil, the inlet fluid rate, and the primary circuit pipe material. The results of the numerical analyses showed a major influence given by the thermal properties of the soil surrounding the micro-pile and a limited effect provided by the material used for the circulation pipes.
