Numerical modelling of a geothermal pile in tropical environment based on a TRT Test

¹ Polytechnic School of University of São Paulo, Av. Prof. Luciano Gualberto, 380 - Butantã, São Paulo, SP, Brazil.
² Polytechnic School of University of São Paulo, Av. Prof. Luciano Gualberto, 380 - Butantã, SP, Brazil.
³ FEI University Center, Av. Humberto de Alencar Castelo Branco, 3972, São Bernardo do Campo, SP, Brazil.
⁴ Engineering School of São Carlos of University of São Paulo, Av. Trabalhador São Carlense 400, SC, SP, Brazil.

^* Corresponding author: crdealme@usp.br

Abstract

The continuous search for sustainable renewable energy sources has motivated the use of geothermal piles to heat or cool buildings, resulting in lower electric energy consumption. Geothermal piles are foundation elements used to provide structural support and thermal comfort. In countries with tropical climate, geothermal piles dissipate heat from the internal environment of the building to the foundation soil. This paper presents a numerical model of a geothermal pile inserted in a saturated sandy soil in São Paulo City, Brazil. The model was developed with ANSYS CFX version 19.2 program, a high performance CFD (Computational Fluid Dynamics) tool. Data from a Thermal Response Test (TRT) carried out for 10 days in the campus of São Paulo University was used to calibrate the model. The development of the model comprised experimental data, geometry, mesh, boundary conditions and simplifying assumptions. The calibration was carried out as back-analysis of experimental data. The obtained numerical results are considerably close to the experimental results, showing that the model is consistent. The validated model will be used to study the influence of geotechnical, hydraulic, thermal, and geometrical parameters on heat transfer, involving water, pipes, concrete and soil.