Numerical modeling of an earth air heat exchanger under the local conditions of Laghouat City, Algeria

In this work, a numerical simulation of the air-flow through an earth-air heat exchanger was carried out using the CFD platform ANSYS FLUENT 2020 R2 to examine the reliability of the 3-D numerical model. The results were compared with experimental data from the literature for two flow regimes: steady and transient. The main objective of this numerical study was to evaluate the performance of the earth-air heat exchanger under local seasonal climatic conditions (summer and winter seasons in Laghouat City, Algeria). For this purpose, a parametric analysis was performed to study the effects of inlet air velocity and pipe diameter for both winter and summer seasons on the air temperature at the exchanger outlet. Promising outcomes were demonstrated, with system efficiency reaching 85% in the summer for an inlet air temperature of 43?C and 84% in the winter for an inlet air temperature of ?2?C. These results were obtained at an optimal inlet air velocity of 2.5 m/s and a pipe diameter of 0.11 m. It was also found that the earth-air heat exchanger could operate continuously.