تأثير مادة أنابيب المبادل الحراري هواء_أرض على أداء المبادل المستخدم في تدفئة البيوت المحمية في محافظة طرطوس

Abstract

Because of the orientation towards the natural and sustainable methods for temperature control in greenhouses, earth-to-air heat exchangers have been among the most prominent technologies adopted. In order to improve the efficiency of heat exchangers and utilize them optimally, many experiments must be conducted to determine the optimal parameters. The current study aims to  determine the extent to which the heat exchanger tube material affects performance.

Experiments were conducted on four earth-to-air heat exchanger systems in four greenhouses of dimensions (2,3,12)m. Tubes were buried at depth of 1.5m in a U-shape in the greenhouse. Two of the tubes used were made of iron and the other two were made of PVC with diameters of 15.24cm and 5.08cm, with a tube wall thickness of 2.8mm, and the air velocity within the tubes was 1sm.s^-1.

The results showed that the material of the exchanger tubes had an effect on performance, where the metal-tube system outperformed the plastic-tube system by 0.9% for the diameter of 15.24cm, and by 1.8% for the diameter of 5.08 cm. It was also found that the tube diameter had the greatest effect compared to the type of material. The system with the largest diameter for PVC tubes had outperformed by 32.79%, and  31.84 % for metal tubes.