Increasing the efficiency of heat exchanger devices


Аuthors

Nasirov S. N.1, Abdullayev A. P.2, Dilara M. K.2

1. Azerbaijan State University of Oil and Industry,
2. Azerbaijan University of Architecture and Construction, Baku, Republic of Azerbaijan

Abstract

The article presents the improvement of the efficiency of heat exchangers by increasing the heat transfer inside the heat exchange tubes. To achieve this improvement and enhance the heat exchange process, profiled tubes are used. Experiments were conducted using toluene as the working fluid in both smooth and profiled tubes. The study presents a detailed comparison of the data obtained from these two types of tubes to determine the heat transfer efficiency in profiled tubes. The results demonstrate the advantages of using profiled tubes in the optimization.

Enhancing heat transfer is a key strategy for optimizing the heating of liquids to the desired temperature while minimizing the size and weight of heat exchanger systems. This process requires artificially increasing turbulence in the near-wall region of the fluid flow. The research examines ways to intensify heat transfer in flows with variable thermal properties and analyzes the temperature distribution and heat exchange mechanisms in heat exchanger tubes.

Experiments were conducted on a test setup to investigate heat transfer enhancement in both single-phase flow and toluene boiling processes. The experiments used toluene at subcritical pressures, measu-ring the temperature of both the tube wall and the liquid inside for smooth and profiled tubes. Additionally, parameters such as fluid flow rate, pressure, electrical current, and supplied voltage were recorded.

The study determined the heat transfer coefficient based on heat flux density, with experimental data comparing smooth and profiled tubes. The following key relationships were established. The correlation between tube wall temperature and liquid temperature along the tube's relative length, showing that tubes with turbulence-enhancing elements exhibit a significantly smaller temperature in according with the difference between the wall and the fluid compared to smooth tubes. The relationship between the tube wall temperature and the heat transfer coefficient along the tube's relative length, demonstrating that heat transfer efficiency is considerably higher in tubes with turbulizers than in smooth ones. The effect of heat flux density on the heat transfer coefficient, indicating that, despite similar heat flux va-lues, also tubes with turbulizers show significantly higher heat transfer coefficients. The dependence of the heat transfer coefficient on the ratio of heat flux density to mass velocity, proving that even when mass heat flux values are comparable, heat transfer is markedly more efficient in turbulized tubes than in smooth ones.

The results indicate that the heat transfer coefficient in profiled tubes is between 2,0 and 4,0 times greater than that of smooth tubes.

Keywords:

efficiency, heat exchange, surface, artificial turbulence, heat transfer, pipes with turbulazors, efficiency, temperature, heat flux density

References

  1. Popov IA, Makhyanov KhM, Gureev VM. (ed.) Physical fundamentals and industrial applications of heat transfer intensification. Heat transfer intensification. Kazan: Tsentr innovatsionnykh tekhnologii, 2009. 560 p. (In Russ.).

  2. Kalinin EK, Dreitser GA, Yarkho SA. Intensification of heat exchange in channels. Moscow: Mashinostroenie, 1990. 200 p. (In Russ.).

  3. Dreitser GA. Heat exchangers. Moscow Aviation Institute. 23 p. (In Russ.).

  4. Gortyshov YuF, Olimpiev VV, Popov IA. The effectiveness of industrially promising heat transfer intensifiers. Izv. RAN. Energetika. 2002;(3):102–118. (In Russ.).

  5. Leont'ev AI, Gortyshov YuF, Olimpiev VV et al. Effective heat transfer intensifiers for laminar (turbulent) flows in power plant channels. Izv. RAN. Energetika. 2005;(1): 75–91. (In Russ.).

  6. Yuncu H, Kakac S. Temel isi transferi. Ankara, 1999. 454 p.

  7. Bordov YuM, Ryabchikov AYu, Aronson KE. Research on a number of methods for intensifying heat exchange in energy heat exchange devices. Trudy tret'ei rossiĭskoi natsional'noĭ konferentsii po teploobmenu. Мoscow: MEI. 2002;6:49–52. (In Russ.).

  8. Laptev AG, Nikolaev NA, Basharov MM. Methods for intensifying and modeling heat and mass transfer processes. Moscow: 2011. 335 p. (In Russ.).

  9. Kaffarov VV, Meshalkin VP, Gur'eva LV. Optimization of heat exchange processes and systems. Мoscow: Energoatomizdat; 1988. 192 p. (In Russ.).

  10. Manglik RM, Bergles AE. Swirl Flow Heat Transfer and Pressure Drop with Twisted-Tape Inserts. Advances Heat Transfer. 2002. С. 183–266. DOI: 10.1016/s0065-2717(02)80007-7

  11. Surtaev AS, Pavlenko AN, Kalita VI et al. The Influence of Three-Dimensional Capillary-Porous Coatings on Heat Transfer at Liquid Boiling. Tech. Phys. Lett. 2016:42(4). DOI: 10.1134/s106378501604026x

  12. Surtaev AS, Serdyukov VS, Safonov AI. Enhancement of Boiling Heat Transfer on Hydrophobic Fluoropolymer Coatings. Interfacial Phenomena and Heat Transfer. 2018;(6(3)):269. DOI:10.1615/InterfacPhenomHeatTransfer.2019030504

  13. He H, Yamada M, Hidaka S et al. Enhanced Boiling Surface with Hydrophobic Circle Spots Evaporator of Looped Thermosiphon. Proc. 13th Int. Conf. on Heat Transfer, Fluid Mechanics and Thermodynamics. 2017. July. P. 365.

  14. Betz AR, Jenkins J, Kim C-J et al. Boiling Heat Transfer on Superhydrophilic, Superhydrophobic, and Superbiphilic Surfaces. Int. J. Heat Mass Transfer. 2013;57(2):733. DOI: 10.1016/j.ijheatmasstransfer.2012.10.080

  15. Motezakker AR, Sadaghiani AK, Çelik S et al. Optimum Ratio of Hydrophobic to Hydrophilic Areas of Biphilic Surfaces in Thermal Fluid Systems Involving Boiling. Int. J. Heat Mass Transfer. 2019. P. 164. DOI: 10.1016/ j.ijheatmasstransfer.2019.01.139

  16. Kalinin EK, Dreitser GA, Yarkho SA. Intensification of heat exchange in channels. Moscow: Mashinostroenie; 1990. 199 p. (In Russ.).

  17. Kalinin EK, Dreitser GA, Yarkho SA. Intensification of heat exchange in channels. Мoscow: Mashinostroenie; 1990. 208 с. (In Russ.).

  18. Kalinin EK, Dreitser GA, Kopp IZ et al. Efficient heat exchange surfaces. Мoscow: Energoatomizdat, 1998. 408 p. (In Russ.).

  19. Kelbaliev RF. Heat transfer during liquid boiling at pressures close to the critical pressure. Teploenergetika. 2002; (3):39–42. (In Russ.).

  20. Rzaev MA. Heat transfer in steam-generating pipes at su-percritical pressures of aromatic hydrocarbons. PhD. thesis. Baku; 1992. 167 p. (In Russ.).

  21. Rzaev MA, Kelbaliev RF, Bairamov NM et al. Methods for determining the deterioration of heat transfer in turbulent flow and supercritical fluid pressures. Trudy XIV Shkoly-seminara molodykh uchenykh i spetsialistov pod rukovodstvom akademika RAN A.I. Leont'eva. Rybinsk: Russia, 2003. Т. 1. С. 109–112. (In Russ.).

  22. Bairamov NM. Intensification of heat transfer during boiling in the near-critical pressure region. Problemy Energetiki. 2004;(3):76–79. (In Russ.).

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