Time dependent thermal behavior of geothermal energy pile (GEP) for summer and winter periods using CFD analysis

This study investigates the thermomechanical behavior of geothermal energy piles, which serve the dual function of providing structural support and facilitating heat exchange with the surrounding ground. The thermal energy transfer is achieved by circulating a working fluid through U-shaped heat exchanger pipes embedded in the pile, enabling cooling during summer and heating in winter. Unlike conventional piles, the thermomechanical coupling in energy piles alters their load transfer mechanisms, with distinct responses during summer (cooling) and winter (heating) periods that require separate evaluation. While energy pile modeling is relatively new compared to borehole systems, both share operational similarities. To explore this, a numerical simulation was conducted using ANSYS Fluent, incorporating a polyethylene tube, concrete, and surrounding soil. The analysis was performed under various Reynolds numbers (500, 1000, 1500, and 2000) and time intervals (60 min, 360 min, and 720 min) to capture the time-dependent thermal behavior for both cooling and heating periods. The simulations demonstrated satisfactory outcomes, suggesting promising potential for geothermal energy applications in Algerian residential buildings.