Computational fluid dynamics simulation of enhanced heat transfer in ground-air heat exchangers using turbulators in PVC pipe systems
Payam Jalili, Bahram Jalili
Abstract
This study investigates heat transfer enhancement in a ground-air heat exchanger (GAHE) system by incorporating turbulators within the pipe, aiming to address seasonal heating demands in residential and industrial settings. Initially, simulations were conducted without turbulators, providing baseline heat transfer rates across flow velocities and inlet temperatures. Subsequently, turbulators were introduced to examine their influence on heat transfer performance. The model incorporated airflow velocities ranging from 0.1 to 5 m per second alongside inlet air temperatures from 0 to 16 °C to capture realistic environmental variations. The simulation maintained a constant surrounding soil temperature of 18.8 °C, reflecting typical subsurface conditions. The results reveal that adding turbulators significantly increases the heat transfer rate, with an improvement of approximately 15.22 % at a flow velocity of 5 m/s, where the heat transfer rate rose from 2253.135 W to 2596.305 W. At lower velocities, the impact was even more pronounced; for instance, at 2 m/s, the rate increased by 17.31 %, from 841.386 W to 987.128 W. This study highlights the effectiveness of turbulators in boosting the GAHE system's efficiency, especially at lower velocities, which could be advantageous for energy conservation in heating applications.