A Numerical Investigation of the Condenser Coil Orientation Angle Effect on the Performance of an Air-Cooled Chiller
Subject Areas : Journal of New Applied and Computational Findings in Mechanical Systems
mohsen Talebzadegan
1
,
Amin Rabiepoor
2
1 - گروه مهندسی مکانیک، واحد اهواز، دانشگاه آزاد اسلامی، اهواز، ایران.
2 - Department of Mechanical Engineering, Ahvaz Branch, Islamic Azad University, Ahvaz, Iran
Keywords: Chiller, Convection, Heat transfer, Heat Exchanger,
Abstract :
Non-uniform air flow distribution can be regarded as a significant factor in condenser performance degradation. Air-cooled condensers are essentially finned-tube heat exchangers. Typically, condenser coils are arranged in a V-shaped configuration with a fan positioned above them. Due to this V-shaped coil arrangement, achieving uniform airflow over the entire coil surface is not possible, and consequently, the heat transfer rate is not consistent across the entire coil surface. As a result, the actual convective heat transfer rate becomes lower than the design value, leading to an increase in condensation temperature and a decrease in heat exchanger performance. Therefore, research focused on improving the symmetric distribution of airflow across condensers can, by itself, lead to more efficient condenser operation and overall system performance enhancement.
In this study, a numerical investigation of the effect of varying the finned-tube heat exchanger angle on the velocity field is conducted. The velocity field in flat, vertical, and angled heat exchangers with angles of 40°, 60°, 90°, 104°, 112°, and 120° is examined. The results indicate that, assuming an identical air flow rate, V-shaped condensers performed better than horizontal and vertical ones, with the best performance belonging to the condenser with a 120° angle, which increased the average velocity and heat transfer by 17.5% and 16.38%, respectively.
[1] Liu, J., Wei, W., Ding, G., Zhang, C., Zhang, C., Fukaya, M., Wang, K., Inagaki, T., (2004), A general steady state mathematical model for fin-and-tube heat exchanger based on graph theory, International Journal of Refrigeration, 27, pp 965–973.
[2] Ishaque, S., Kim, M.H., (2021),Numerical modeling of an outdoor unit heat exchanger for residential heat pump systems with nonuniform airflow and refrigerant distribution, International Journal of Heat and Mass Transfer, 175, p. 121323.
[3] Meyer, C.J., Kroger, D.G., (2001),Air-cooled heat exchanger inlet flow losses, Applied. Thermal Engineering, 21, pp. 771-786.
[4] Lee, T.S., Wu, W.C., Chuah, Y.K., Wang, S.K., (2010),An improvement of airflow and heat transfer performance of multi-coil condensers by different coil configurations. International Journal of Refrigeration, 33 , pp 1370-1376.
[5] Padhmanabhan, S., Yanik, M., (2016),Analysis of an Innovative Microchannel Condenser Design for Modular Chillers and Unitary Rooftop Air Conditioners, International Refrigeration and Air Conditioning Conference, No. 16, pp 1680-1690.
[6] Abu-Hamdeh, N.H., Bantan, R.A.R., Alimoradi, A., (2020), Heat transfer optimization through new form of pin type of finned tube heat exchangers using the exergy and energy analysis, International Journal of Refrigeration, 117, pp 12–22.
[7] Ishaque, S., Kim, M.H., (2022),Refrigerant circuitry optimization of finned tube heat exchangers using a dual-mode intelligent search algorithm, Applied Thermal Engineering, 212, p.118576.
[8]Aminian, E., Saffari, H., (2022),Experimental analysis of dropwise condensation heat transfer on a finned tube: Impact of pitch size, Part A: Journal of Power and Energy, 236(4), pp. 752–759.
[9] Hashemabadi, M., Hajian, R., Pirkandi, J., Mansoori, S., Sadrvaghefi, S., (2023), Experimental investigation and performance comparison of two types of microchannel and Fin-tube condensers with R407c refrigerant in compression refrigeration cycle, Amirkabir Journal Mechanical Engineering, 55(5), pp 577-594.
[10] Bin Hatrash, H.A.H, Mohd Tahir, I.N.I.B, W. Muhieldeen, M., (2021), Study on the effects of tube arrangements to the heat transfer performance of evaporator chiller system based on industrial standards, In International Conference on Mechanical Engineering Research, Springer Nature Singapore, pp 641–654.
[11] Afrand, M., (2018), Numerical study on thermal performance of an air-cooled heat exchanger: Effects of hybrid nanofluid, pipe arrangement and cross section. Energy Conversion and Management, 164, pp 615-628.
[12] Diana, L., Kusumawardani, F., Fadilah, W.N., Ariansyah, M.N., Irfianto, M.F., (2021), Numerical Analysis of the Effect of Serrated Fin to the Heat Transfer in the Condenser, Flywheel: Jurnal Teknik Mesin Untirta, 7(2), pp 1–8.
[13] Lee, T.S., Wu, W.C., Wang, S.K., (2012), Improved energy performance of air-cooled water chillers with innovative condenser coil configurations-Part I:CFD simulation, International Journal of Refrigeration, 35(8) , pp 2199-2211.
