Air Velocity Effect on Geothermal Helicoidally Water-Air Heat Exchanger under El Oued Climate -Algeria

Abstract In the region of El Oued southeast of Algeria, a PVC pipe is used as a water-air helical heat exchanger (HWAHE), with 30 m long and 0.06 m in diameter. The exchanger is emerged 5 m to the bottom of a well of water. The results showed that the maximum heat exchange has reached nearly to 80 kW at 10 m/s of air velocity while the maximum of temperature gap between the inlet and the outlet air has got to 13 C°. The HWAHE efficiency has decreased with the increase of the air velocity. At the average velocity values have used in this study (10, 15 and 20 m/s), the HWAHE efficiency has been 92%, 91% and 90%, respectively. According to the obtained results, this HWAHE may be used for cooling and heating of buildings or greenhouses in southeastern Algeria.