A Numerical Study on the Thermal Conductivity of Geothermal Energy Piles Installed in Godavari River Basin

Increased use of fossil fuel for energy generation releases the greenhouse gases like N₂O, CO₂, etc. at an alarming rate, which causes a significant alteration in the environment. As an alternative, the geothermal energy pile (GEP) can be utilized as a sustainable source of energy for heating and cooling of buildings. In this direction, an attempt is made to study the thermo-mechanical behavior of GEPs installed in Godavari River basin soil which falls under the effective geothermal zone. Finite element analysis using PLAXIS 2D was carried out on an axially loaded energy pile of 1 m diameter to find out stress distribution and thermal conductivity of the pile by varying the length to diameter ratio (L/d) of pile (i.e., 10, 15, and 20) and considering stratified soil conditions. The constitutive models used in analysis for soil and pile are Mohr–coulomb model and linear elastic model, respectively. The behavior of the pile has been studied under seasonal variation by changing the temperature combined under mechanical loading. The results show that the above-mentioned parameters have minimal impact on the load carrying capacity of GEPs. Due to the impact of thermo-mechanical load, maximum displacement is observed in the soil near to the pile surface. Moreover, GEPs under higher temperature conditions have shown more displacement than under normal temperature conditions. From these studies, it was found that the GEP is an effective technique to control the temperature inside the buildings by utilizing the earth’s energy.