The simulation performance analysis of the EAHE open system with finned iron pipes

Abstract

Abstract This study focuses on the Eart-Air Heat Exchanger (EAHE) which serves to reduce the energy consumption of air conditioning units, and analyze the thermal performance of air-ground heat exchangers using computational fluid dynamics modeling and validated against experimental observations. The simulation used is for flow-resisting, incompressible, turbulent, and 3-dimensional. Simulations were carried out using finned iron and PVC 3.0 “with a thickness of 2 mm and a length of 6.7 m. The simulation conditions were limited to the fluid flow with variations of the velocity of 1 m/s, 2 m/s, and 3 m/s. The average air temperature outlet from 3D simulation using Ansys 17.0 software was obtained 25.45 °C for the velocity of inlet air of 1 m/s, 25.73 °C for a velocity of 2 m/s, and 25.84°C for the velocity of inlet air of 3 m/s. The experimental results obtained of 25.99 °C for a velocity of 1 m/s, 26.33 °C for a velocity of 2 m/s, and 26.0 °C for the velocity of inlet air of 3 m/s. The highest deviations between the simulation and experimental results were obtained at -3.04% for the velocity of 3 m/s, and the lowest deviation is -10.28% for the velocity of 1 m/s. The average of COP value of the simulation results is 0.703 for the velocity of 1 m/s, 0.624 for the velocity of 2 m/s, and 0.774 for the velocity of 3 m/s, while the experimental results are obtained 0.6307 for the velocity of 1 m/s, 0.5417 for the velocity of 2 m/s, and 0.7504 for the velocity of 3 m/s. For the average effectiveness value of the simulation results were obtained of 0.956 for the velocity of 1 m/s, 0.940 for the velocity of 2 m/s and 0.960 for the velocity of 3 m/s, while the experimental results were obtained of 0.8590 for the velocity of 1 m/s, 0.8164 for the velocity of 2 m/s, and 0.8970 for the velocity of 3 m/s.