ايمان عواد حمود الشمريالأستاذ الدكتور مشتاق إسماعيل حسن2025-01-212025-01-212024-07-21https://dspace.utq.edu.iq/handle/123456789/590Abstract This research undertakes both numerical and experimental analyses of a ground-air heat exchanger system designed to cool air supply compressors used in oil pipeline operations. Any deviation from these conditions can lead to station shutdowns, halting production. The primary objective of this study is to establish optimal operating conditions by ensuring sufficient cooling for this equipment. The investigation primarily focuses on the impact of different design configurations on heat transfer rates, including coil design (0.152) m, grid design (0.1016, 0.152) m, and grid design (0.152) m. Computational Fluid Dynamics (CFD) modeling is utilized for the numerical analysis, leading to the practical proposition of a preferred type (grid design (0.152 m)). This system involves an 11.88 m PVC pipe with a 0.0508 m diameter buried approximately 3.5 m deep in the ground, utilizing the earth as a heat sink. The research encompasses numerical and experimental simulations to compare non-finned tubes with various finned tubes, such as annular fin tubes, circular perforated annular fin tubes, and square perforated annular fin tubes. The system incorporates a 1.5 m long, 0.152 m diameter PVC pipe buried approximately 3.5 m deep in the ground. The ground temperature remains relatively constant at around 30°C at a depth of 3 m in Nassriyah city, southern Iraq, throughout the year. This consistency enables the ground to function efficiently as a heat sink, cooling the system in the summer and providing warmth in the winter. To evaluate the reliability of the experimental model, a comparison was conducted between the numerical findings and the experimental data, resulting in an average percentage max difference of 7%, signifying their acceptability. The results from the system, which was monitored at a constant velocity (V = 4.52 m/s) from the end of August 2023 to the end of September 2023, indicate distinct patterns. At the onset of August, there was an initial increase in temperatures attributed to high ambient temperatures (51.6 °C). The peak outlet air temperature, recorded on August 21, 2023, reached 36.1°C, while the lowest temperature occurred on September 30, 2023, at (33.1 °C). During this period, there was a notable rise in heat transfer rate and a decrease in pressure drop, resulting in an enhanced performance factor. However, in the subsequent days of August and September, as the heat transfer rate decreased and pressure drop increased, there was a slight reduction in the performance factor. Regarding the comparison between finned and non-finned tubes to assess the reliability of the numerical model, an evaluation was conducted, resulting in an average percentage error of 16% for the non-finned tube and 14% for finned tube 1, affirming their satisfactory agreement. Practical experiments conducted from July to August 2023 revealed that despite high inlet temperatures (53.6 °C), The temperature contrast between the finned tube outlet and the ambient temperature is roughly 10 °C, whereas the variance between the non-finned tube and ambient temperature is comparatively smaller (4 °C), annularly finned tubes exhibited superior heat transfer rates and higher pressure drops in both theoretical simulations and practical experiments compared to non-finned tubes. The consistent low outlet temperatures contributed to efficient system cooling. Theoretical simulations also indicated that finned tubes, particularly those in annular shapes, outperformed non-finned tubes in terms of heat transfer rates. Among various fin shapes and non-finned tubes, the annularly finned tube demonstrated the most effective cooling performance despite challenging external conditions, generating the highest pressure drop.text::thesis::master thesis