Analyses of thermo-active piles considering surface radiation and wind convection effects

Energy piles are emerging as a promising technology for utilizing shallow geothermal energy, garnering considerable interest recently. This has led to an increase in studies, including field tests, model tests, and numerical analyses. While numerical analyses are advantageous due to their flexibility, their accuracy depends on thorough validation with field or model data. This task is complex because of the intricate interactions between mechanical, thermal, and hydrological processes. The validation process is further complicated by factors such as cyclic thermal loading, seasonal temperature changes, and intermittent operation. It's important to note that many verification studies use adiabatic thermal boundary conditions, which ignore atmospheric temperature fluctuations and wind effects that significantly impact the thermal behavior of energy piles, particularly near the surface. This study addresses this limitation by incorporating atmospheric and solar effects into the numerical analysis, using a thermal loading test on a continuous flight auger pile in Houston, Texas. By considering surface solar radiation, this study improves the understanding of the thermal responses of soil and piles, producing results that closely match field measurements. Incorporating atmospheric and solar effects advances the accuracy and relevance of numerical models in simulating energy pile behavior, which is crucial for optimizing their energy efficiency and performance.