Analyses of Thermoactive Piles Considering Surface Radiation and Wind Convection Effects

Abstract

Energy piles present a promising avenue for harnessing shallow geothermal energy, attracting significant attention in recent years, resulting in a surge of studies including field and model tests and numerical analyses. While numerical analyses are valuable for their adaptability, their reliability hinges upon rigorous validation against field or model data. This endeavor is challenging due to the intricate interplay of mechanical, thermal, and hydrological phenomena. Factors such as cyclic thermal loading, seasonal temperature variations, and intermittent operational patterns further complicate the validation process. Nonetheless, it is worth noting that most verification studies employ adiabatic thermal boundary conditions, overlooking atmospheric temperature fluctuations and wind effects, which significantly influence the thermal behavior of energy piles, especially near the surface. This study addresses this gap by incorporating atmospheric and solar effects into numerical analysis, utilizing a thermal loading test on a single continuous flight auger pile in Houston, Texas. By accounting for surface solar radiation, this study enhances the understanding of soil and pile thermal responses, yielding results closely aligned with field-measured values. By considering atmospheric and solar effects, this research contributes to advancing the accuracy and applicability of numerical models in simulating energy pile behavior, crucial for optimizing their energy efficiency and performance.