Parametric Study of the Performance Efficiency of a Single Oil Cooler Section

The paper presents the results of numerical investigation of the influence of the design parameter - the gap between the cooling plates of the convective heat exchanger for oil cooling on its efficiency. A single cooling section of an oil cooler consisting of cooling plates separated by a certain distance is considered. Each single plate of the oil cooler has 6 internal channels of complex geometry and row external fins, each row of which includes 11 elements of two standard sizes, and the number of rows is determined by the length of the plate. The efficiency of the device is evaluated on the basis of analyzing the change of heat transfer coefficients at the boundaries of working media from the increase of the distance between the plates. The problem of conjugate heat exchange between heated hydraulic oil, oil cooler plates and cold turbulent flow of air blown by a fan is considered. The mathematical model of fluid media motion is based on the Navier-Stokes equations. Modelling of heat transfer processes in the oil cooler plate is based on the heat conduction equation. To close the averaged system of conservation equations, the Menter SST turbulence model is applied. The numerical solution of the obtained system of equations is constructed by the method of control volumes using the chtMultiRegionFoam solver of the freely distributed OpenFOAM software. Numerical modelling of the working processes occurring in a single section of the oil cooler was performed using the establishment method. For discretization of non-viscous flows (in oil and air), a counter flow scheme of 2nd order of accuracy is applied, and for viscous flows, total variation minimization (TVD) schemes and the limitedLinear method were applied. The gradients were approximated based on the linear Gaussian method. The conjugate gradient method was used to accelerate convergence. As a result of numerical modelling, the fields of physical quantities, air and oil flow structure in the corresponding channels of the device were obtained. The influence of the plate gap size on the internal and external aerodynamics of the unit section of the oil cooler is identified and shown.  Non-uniform heating of the cooling section body with localization of the temperature maximum in the area of internal central channels has been revealed, described and substantiated. The analysis of the obtained thermophysical characteristics allowed to reveal the optimum distance between the plates of the oil cooler of 22 mm.

1. Зиннатуллин Н.Х., Ильин В.К., Хайбуллина А.И. З-63 Нагнетатели и тепловые двигатели, Казань: Казан. гос. энерг. ун-т, 2016. – 158 с.

2. Du Toit C.G., Kroger D.G. Modelling of the recirculation in mechanical-draught heat exchangers // R&D Journal, 1993, vol. 9, No. 1, pp. 2-8.

3. Zhao W., Wang Q., Liu P. The experimental investigation of recirculation of air-cooled system for a large power plant // Energy and Power Engineering, 2010, No. 2, pp. 291-297.

4. Xing Xuea, Xianming Fenga, Junmin Wanga, Fang Liu, Modeling and Simulation of an Air-cooling Condenser under Transient Conditions // Procedia Engineering, 2012, № 31, pp. 817 – 822.

5. Чернов Н.С. Технико-экономическая оценка эффективности теплообменных аппаратов // Автомобильная промышленность, 2011, № 3, с. 33-35.

6. Леонтьев А. И., Олимпиев В. В.Теплофизика и теплотехника перспективных интенсификаторов теплообмена (обзор) // Известия Российской академии наук. Энергетика. 2011. № 1. с. 7-31.

7. Попов И.А., Махянов Х.М., Гуреев В.М. Интенсификация теплообмена. Физические основы и промышленное применение интенсификации теплообмена. Казань: Центр инновационных технологий, 2009. 560 c.

8. Жукаускас А.А. Конвективный перенос в теплообменниках / А.А. Жукаускас. М.: Наука, 1982. 472 с.

9. Глухарев А.С., Навасардян Е.С. Повышение эффективности теплообменных аппаратов за счет оребрения внутритрубного пространства // Молодежный научно-технический вестник ФС77-51038, 2017, №1, http://sntbul.bmstu.ru/doc/854258.html.

10. Lambert T. Automated Boundary Layer Mesh Generation for Simulation of Convective Cooling, Bachelor Thesis Defense, MathCCES Lunch Seminar, RWTH Aachen University, 10 April, 2018, 90 p.

11. Shoji Y., Sato K., Oliver D. R. Heat Transfer Enhancement in Round Tube Using Coiled Wire: Influence of Length and Segmentation // Heat Transf. Asian Res, 2003, vol. 32, pp. 99–107.

12. Garcia A., Vicente P. G., Viedma A. Experimental Study of Heat Transfer Enhancement with Wire Coil Inserts in Laminar-Transition-Turbulent Regimes at Different Prandtl Numbers // Int. J Heat Mass Transf., 2005, vol. 48, pp. 4640–4651.

13. Liu S., Sakr M. A Comprehensive Review on Passive Heat Transfer Enhancements in Pipe Exchangers // Renew. Sustain. Energy Rev., 2013, vol. 19, pp. 64–81.

14. Rahai H. R., Wong T. W. Velocity Field Characteristics of Turbulent Jets from Round Tubes with Coil Inserts // Appl. Therm. Eng., 2002, vol. 22, pp. 1037–1045.

15. Армянин А. Ю., Байметова Е. С., Хвалько М. Е. Особенности теплового режима маслоохладителя с развитой внешней поверхностью // Химическая физика и мезоскопия. 2022, т. 24, № 1. С.93 – 103. https://doi.org/10.15350/17270529.2022.1.8.

16. Baymetova E. S., Chernova A. A., Koroleva M. R., Kelemen M. Optimization of the developed outer surface of an industrial oil cooler // MM Science Journal, 2021, vol. 2021, No. June, pp. 4764-4768. https://doi.org/10.17973/MMSJ.2021_10_2021027.

17. Байметова Е. С. Определение оптимальных конструктивных параметров теплообменной секции путем численного моделирования // Diagnostics, Resourceand Mechanicso fMaterials and Structures. 2022. № 2. с. 45-54. https://doi.org/10.17804/2410-9908.2022.2.045-054.

18. Байметова Е.С., Чернова А.А., Шигапова А.Р. Аэродинамика плохообтекаемых тел на примере конвективного теплообменного аппарата // Химическая физика и мезоскопия. 2024, т. 26, № 2, с. 143-154.

19. Байметова Е. С. Численное моделирование гидродинамических процессов в многоканальном коллекторе // Труды МАИ. 2023. № 130, 8. https://doi.org/10.34759/trd-2023-130-08.

20. Байметова Е.С., Митрюкова Е.А. Численное и экспериментальное исследование гидродинамики теплообменного аппарата // Труды Института системного программирования РАН. 2023, т. 35, № 6, с. 235-246. https://doi.org/10.15514/ISPRAS-2023-35(6)-15.

21. Королева М. Р., Терентьев А. Н., Чернова А. А. Гидродинамика коллектора сложной формы // Вестник РГАТА имени П.А. Соловьева. 2021. № 3 (58), с. 50-55.

22. Байметова Е.С., Хвалько М.Е., Армянин А.Ю. Моделирование сопряженного теплообмена в микроканалах в среде openFOAM // Труды Института системного программирования РАН. 2022, т. 34. № 5. с. 205-214. https://doi.org/10.15514/ISPRAS-2022-34(5)-14.

23. Гарбарук А.В., Стрелец М.Х., Шур М.Л. Моделирование турбулентности в расчетах сложных течений: Учебное пособие. СПб: Изд-во Политехн. ун-та, 2012. - 88 с.

24. Menter F. R., Kuntz M., Langtry R. Ten years of industrial experience with the SST turbulence model // Proceedings of the Fourth International Symposium on Turbulence, Heat and Mass Transfer. Antalya, Turkey, 12-17 October, 2003, pp. 625-632.

25. Finned ChtMultiRegionFoamOpenFoam. Solver for steady or transient fluid flow and solid heat conduction, with conjugate heat transfer between regions, buoyancy effects, turbulence, reactions and radiation modelling. URL: https://openfoamwiki.net/index.php/ChtMultiRegionFoam (дата обращения 21.02.2023).