International Scientific Journal


Cross-flow heat exchangers with elliptical tubes are often used in industrial application. In comparison with round tubes, the elliptical tubes have a better aero-dynamic shape, which results in a lower pressure drop of working fluid flowing through the inter-tubular space of heat exchanger. Also, a higher heat flux is transferred from gas to the wall of such a tube due to the more intense heat exchange process. To prove this thesis, the values of the heat transfer coefficient from the wall of the elliptical pipe to the water flowing inside were determined, using the data from the conducted measurements. This study presents also research stand with a vertically positioned tube. In order to obtain a constant heat flux through the wall of elliptical tube, a resistance wire is used, evenly wound on the external surface of tube measuring section. The use of thermal insulation minimized heat loss to the environment to a negligible value. Installed K-type thermocouples allowed one to obtain, for various measurement conditions, the temperature distribution within the elliptical tube wall (for a given cross-section) and the water flowing inside it (in a given cross-section, at different depths, for both axes of the ellipse). The design of the stand allows such measurements in several locations along the length of the measurement section. The measurement results were used to verify numerical calculations. The relative error of the heat transfer coefficient value determined on the basis of CFD calculations using the SST-TR turbulence model in relation to the one determined on the basis of the measurement data is about 11%.
PAPER REVISED: 2019-04-20
PAPER ACCEPTED: 2019-05-17
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THERMAL SCIENCE YEAR 2019, VOLUME 23, ISSUE Supplement 4, PAGES [S1323 - S1332]
  1. Nagatha, H., The Development of Heat Exchanger with Elliptic Tubes for High Viscous Liquid (in Japanise), Mitsui Zosen Technical Review, 183 (2004), 1, pp. 29-33
  2. Ibrahim, T. A., Gomaa, A., Thermal Performance Criteria of Elliptic Tube Bundle in Crossflow, International Journal of Thermal Sciences, 48 (2009), 11, pp. 2148-2158
  3. Matos, R. S., et al., Optimally Staggered Finned Circular and Elliptic Tubes in Forced Convection, International Journal of Heat and Mass Transfer, 47 (2004), 6-7, pp. 1347-1359
  4. Jang, J. Y., Yang, J. Y., Experimental and Numerical Analysis of the Thermal-Hydraulic Characteristics of Elliptic Finned-Tube Heat Exchangers, Heat Transfer Engineering, 19 (1998), 4, pp. 55-67
  5. Li, B., et al., Experimental Study on Friction Factor and Numerical Simulation on Flow and Heat Transfer in an Alternating Elliptical Axis Tube, Applied Thermal Engineering, 26 (2006), 17-18, pp. 2336-2344
  6. Lopata, S., Oclon, P., Investigation of the Flow Conditions in a High-Performance Heat Exchanger. Archives of Thermodynamics, 31 (2010), 3, pp. 37-53
  7. Oclon, P., Lopata, S., Modelling of the Flow Distribution Inside the Collectors of the High Performance Heat Exchanger, Technical Transactions, Mechanics, 4-M/2011/B (2011), 7, pp. 393-400
  8. Oclon, P., Analiza przeplywowo-cieplna i wytrzymalosciowa warunkow pracy wymiennika ciepla z ozebrowanymi rurami eliptycznymi (in Polish) (Coupled Flow-Thermal and Structural Analysis of Operating Conditions for Heat Exchanger with Finned Elliptical Tubes), Ph. D. thesis, Cracow University of Technology, Cracow, Poland, 2013
  9. Oclon, P., et al., Experimental and Numerical Investigation of Flow Distribution within the Heat Exchanger with Elliptical Tubes, Procedia Engineering, 157 (2016), Dec., pp. 428-435
  10. Lopata, S., et al., Experimental Stand for Investigation of Fluid Flow in Heat Exchangers with Cross-Flow Arrangement, E3S Web of Conferences, 13 (2017), 02001
  11. Lopata, S., Oclon, P., Modelling and Optimizing Operating Conditions of Heat Exchanger with Finned Elliptical Tubes, in: Fluid Dynamics. Computational Modeling and Applications (Ed. L. H. Juarez), InTech, Rijeka, Croatia, 2012, pp. 327-356
  12. Lopata, S., Oclon, P.: Sprzezona cieplno-wytrzymalosciowa analiza wysokosprawnego wymiennika ciepla z ozebrowanymi rurami eliptycznymi (in Polish) (Coupled Thermal-Structural Analysis of High Performance Heat Exchange with Finned Eliptical Tubes), in: Systemy, Technologie i Urządzenia Energetyczne (in Polish) (Systems, Technologies and Energy Equipment), II (Ed. J. Taler), Cracow University of Technology Press, Cracow, Poland, 2010, pp. 825-839
  13. Lopata, S., Oclon, P., The Stress State Analysis of the High Performance Heat Exchanger, Technical Transactions, Mechanics, 4-M/2011/B (2011), 7, pp. 359-368
  14. Lopata, S., Oclon, P., Analysis of Operating Conditions for High Performance Heat Exchanger with the Finned Elliptical Tube, Rynek Energii, 102 (2012), 5, pp. 112-124
  15. Lopata, S., Oclon, P., Numerical Study of the Effect of Fouling on Local Heat Transfer Conditions in a High-Temperature Fin-and-Tube Heat Exchanger, Energy, 92 (2015), Part 1, pp. 100-116
  16. Oclon, P., at al., Numerical Study on the Effect of Inner Tube Fouling on the Thermal Performance of High-Temperature Fin-and-Tube Heat Exchanger, Progress in Computational Fluid Dynamics - An International Journal, 15 (2015), 5, pp. 290-306
  17. Oclon, P., Lopata, S., Study of the Effect of Fin-and-Tube Heat Exchanger Fouling on its Structural Performance, Heat Transfer Engineering, 39 (2018), 13-14, pp. 1139-1155
  18. Taler, D., A New Heat Transfer Correlation for Transition and Turbulent Fluid Flow in Tubes, International Journal of Thermal Sciences, 108 (2016), Oct., pp. 108-122
  19. Lopata, S., Oclon, P., Verification of the Applicability of the Two-Equation Turbulence Models for Temperature Distribution in Transitional Flow in an Elliptical Tube, Thermal Science, 23 (2019), Suppl. 4, pp.????-????
  20. ***, ANSYS INC, CFX Solver Theory Guide, CFX-International, Canonsburg, Penn., USA, 2011
  21. Menter, F. R., et al., Transition Modelling for General Purpose CFD Codes, Flow, Turbulence and Combustion, 77 (2006), 1-4, pp. 277-303
  22. Bergman, T. L., et al., Fundamentals of Heat and Mass Transfer, 7 ed., John Wiley and Sons Inc., New York, USA, 2011

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