HAVUZ KAYNAMA ISI TRANSFERİNDE MEKANİK ÇALKALAMA ETKİLERİNİN DENEYSEL İNCELENMESİ

Abstract

Bu çalışmada, havuz kaynamada ısı transferini iyileştirme metotlarından biri olan mekanik çalkalamanın ısı transfer katsayısına etkisi deneysel olarak araştırılmıştır. Deneysel çalışma kapsamında bir deney düzeneği kurulmuştur. Deney akışkanı olarak saf su kullanılmıştır. Deneylerde havuz içerisinde mekanik çalkantı oluşturmak amacıyla farklı devir hızlarında çalışan bir adet 100 mm çapında aksiyel fan kanadı kullanılmıştır. Deneylerde 100 mm uzunluğunda 20 mm çapında silindirik çelik ısıtıcı kullanılmıştır. Deneyler havuz kaynamada en yüksek ısı transfer katsayılarının elde edildiği kabarcıklı kaynama bölgesinde (su için ∆T 5-30 ºC) gerçekleştirilmiştir. Deneyler 9 farklı ısıtıcı gücünde (17, 23, 29, 38, 47, 58, 70, 83 ve 94 kW/m2) ve 5 farklı mekanik karıştırıcı devrinde (0, 55, 139, 205 ve 212 d/d) gerçekleştirilmiştir. Isı transferi katsayısının, ısıtıcı gücün ve mekanik karıştırıcının devir sayısının artmasıyla arttığı tespit edilmiştir. Isıtıcı gücün 17 kW/m2 den 94 kW/m2 ye yükseltilmesiyle (mekanik karıştırıcının 55 d/d da sabit tutulmuştur), ısı transferi katsayının yaklaşık %10 oranında arttığı belirlenmiştir. Düşük ısıtıcı gücünde (17 kW/m2’de), devir sayısının 0 d/d’dan 212 d/d’ya çıkartılmasıyla, ısı transferi katsayısının %190 oranında iyileştiği tespit edilmiştir.

Keywords

• Buhar
• Havuz kaynama
• Mekanik karıştırma
• Isı transfer katsayısı

EXPERIMENTAL INVESTIGATION OF HEAT TRANSFER EFFECTS OF MECHANICAL AGITATION IN POOL BOILING

Abstract

In this study, the effect of mechanical agitation, which is one of the methods of improving the heat transfer in pool boiling, on the heat transfer coefficient has been investigated experimentally. Pure water has been used as the test fluid. In the experiments, a 100 mm diameter axial fan blade operating at different rotational speeds have been used to create mechanical agitation in the pool. In the experiments, 100 mm long, 20 mm diameter cylindrical steel heater has been used. Experiments have been carried out in nucleate boiling regime region (for water ∆T 5-30 ºC), where the highest heat transfer coefficients have been obtained in pool boiling. Experiments have been carried out at 9 different heating power (17, 23, 29, 38, 47, 58, 70, 83 and 94 kW/m2) and at 5 different mechanical agitator speeds (0, 55, 139, 205 and 212 rpm). It has been determined that the heat transfer coefficient (HTC) increases with the increase of the heater power and the speed of the mechanical agitator. Increasing the heater power from 17 kW / m2 to 94 kW / m2 (the mechanical agitator has been kept constant at 55 rpm), it has been determined that the heat transfer coefficient increased by approximately 10%. It has been determined that the HTC improved by 190% by increasing the number of revolutions from 0 rpm to 212 rpm at low heater power (at 17 kW/m2).

Keywords

• Pool boiling
• Mechanical agitation
• Heat transfer coefficient
• Vapor

References

1. Abadi, S. M. A. N. R., & Meyer, J. P. (2018). Numerical investigation into the inclination effect on conjugate pool boiling and the condensation of steam in a passive heat removal system. International Journal of Heat and Mass Transfer, 122, 1366–1382.
2. Ahmadreza Zahedipoor, M. F., & , Shahab Eslami, A. M. (2017). 10.22104/JPST.2017.2098.1076. 3, 63–69. https://doi.org/10.22104/JPST.2017.2098.1076
3. Akbari, A., Mohammadian, E., Alavi Fazel, S. A., Shanbedi, M., Bahreini, M., Heidari, M., Babakhani Dehkordi, P., & Che Mohamed Hussein, S. N. (2019). Natural Convection from the Outside Surface of an Inclined Cylinder in Pure Liquids at Low Flux. ACS Omega, 4(4), 7038–7046. https://doi.org/10.1021/acsomega.9b00176
4. Alavi Fazel, S. A., Arabi Shamsabadi, A., Sarafraz, M. M., & Peyghambarzadeh, S. M. (2011). Artificial boiling heat transfer in the free convection to carbonic acid solution. Experimental Thermal and Fluid Science, 35(4), 645–652. https://doi.org/10.1016/j.expthermflusci.2010.12.014
5. Alavi Fazel, S. Ali. (2017). A genetic algorithm-based optimization model for pool boiling heat transfer on horizontal rod heaters at isolated bubble regime. Heat and Mass Transfer/Waerme- Und Stoffuebertragung, 53(9), 2731–2744. https://doi.org/10.1007/s00231-017-2013-8
6. Alıç, E., Kaska, Ö., & Tokgöz, N. (2018). Measuring the formation of the bubble occuring in pool boiling with an image processing technique. 521–529.
7. Atherton, T. J., & Kerbyson, D. J. (1999). Size invariant circle detection. Image and Vision Computing, 17(11), 795–803. https://doi.org/10.1016/s0262-8856(98)00160-7
8. Babu, K., & Prasanna Kumar, T. S. (2011). Effect of CNT concentration and agitation on surface heat flux during quenching in CNT nanofluids. International Journal of Heat and Mass Transfer, 54(1–3), 106–117. https://doi.org/10.1016/j.ijheatmasstransfer.2010.10.003

9. Bergman, T. L., Lavine, A. S., Incropera, F. P., & Dewitt, D. P. (2015). Fundamentals of heat and mass transfer. 2011. In ISBN (Vol. 13, pp. 470–978). John Wiley & Sons.
10. Bovard, S., Asadinia, H., Hosseini, G., & Alavi Fazel, S. A. (2017). Investigation and experimental analysis of the bubble departure diameter in pure liquids on horizontal cylindrical heater. Heat and Mass Transfer/Waerme- Und Stoffuebertragung, 53(4), 1199–1210. https://doi.org/10.1007/s00231-016-1885-3
11. Cengel, Y. (2014). Heat and mass transfer: fundamentals and applications. McGraw-Hill Higher Education.
12. Chen, H., Chen, G., Zou, X., Yao, Y., & Gong, M. (2017). Experimental investigations on bubble departure diameter and frequency of methane saturated nucleate pool boiling at four different pressures. International Journal of Heat and Mass Transfer, 112, 662–675. https://doi.org/10.1016/j.ijheatmasstransfer.2017.05.031
13. Çiloglu, D., Bölükbaşi, A., & Çifci, H. (2015). Experimental investigation of pool boiling heat transfer in nanofluids around spherical surfaces. Journal of the Faculty of Engineering and Architecture of Gazi University, 30(3), 405–415.
14. Das, P., Khan, M. M. K., Rasul, M. G., Wu, J., & Youn, I. (2018). Experimental investigation of hydrodynamic and heat transfer effects on scaling in an agitated tank. Chemical Engineering and Processing - Process Intensification, 128(April), 245–256. https://doi.org/10.1016/j.cep.2018.04.019
15. Dikici, B., Eno, E., & Compere, M. (2014). Pool boiling enhancement with environmentally friendly surfactant additives. Journal of Thermal Analysis and Calorimetry, 116(3), 1387–1394. https://doi.org/10.1007/s10973-013-3634-x
16. Durmaz, U., & Ozdemir, M. (2012). An experimental investigation on heat transfer for different parameters in centripetally located boiling agitation vessels. SAÜ Fen Bilimleri Enstitüsü Dergisi, 16(2), 99–105. https://doi.org/10.5505/saufbe.2012.04127
17. Esonye, C. (2019). The Development of Standard Agitator Conditions for Effective Performance of a Batch Crutcher in the Frame of Semi-Boiled Process. International Journal of Chemical Reactor Engineering, 17(9), 1–12. https://doi.org/10.1515/ijcre-2018-0248
18. Gates, L. E., Morton, J., & Pl, F. (1976). Selecting agitator systems to suspend solids in liquids.
19. Gheitaghy, A. M., Samimi, A., & Saffari, H. (2017). Surface structuring with inclined minichannels for pool boiling improvement. Applied Thermal Engineering, 126, 892–902. https://doi.org/10.1016/j.applthermaleng.2017.07.200
20. Guan, C. K., Klausner, J. F., & Mei, R. (2011). A new mechanistic model for pool boiling CHF on horizontal surfaces. International Journal of Heat and Mass Transfer, 54(17–18),3960–3969. https://doi.org/10.1016/j.ijheatmasstransfer.2011.04.029
21. Holman, J. P. (2001). Experimental methods for engineers.
22. Hu, Y., Wang, H., Song, M., Huang, J., Babu, K., Prasanna Kumar, T. S., Rahimian, A., Kazeminejad, H., Khalafi, H., Mirvakili, S. M., & Akhavan, A. (2020). An Experimental Study of the Steel Cylinder Quenching in Water-based Nanofluids. International Journal of Heat and Mass Transfer, 134(1–3), 106–117. https://doi.org/10.1016/j.ijheatmasstransfer.2010.10.003
23. Image Processing Toolbox User’s Guide Revised for Version 11.1 (Release 2020a). (n.d.). The MathWorks, Inc.
24. Jm, S., & An, K. (1993). Impeller Power Demand in Mechanically Agitated Boiling Systems. Chemical Engineering Research & Design, 71(2), 145–152. https://www.cheric.org/research/tech/periodicals/view.php?seq=51438
25. Jung, S., & Kim, H. (2016). Effects of surface orientation on nucleate boiling heat transfer in a pool of water under atmospheric pressure. Nuclear Engineering and Design, 305, 347–358. https://doi.org/10.1016/j.nucengdes.2016.06.013
26. Kamel, M. S., & Lezsovits, F. (2020). Enhancement of pool boiling heat transfer performance using dilute cerium oxide/water nanofluid: An experimental investigation. International Communications in Heat and Mass Transfer, 114(April), 104587. https://doi.org/10.1016/j.icheatmasstransfer.2020.104587
27. Kamel, M. S., Lezsovits, F., Hussein, A. M., Mahian, O., & Wongwises, S. (2018). Latest developments in boiling critical heat flux using nanofluids: A concise review. International Communications in Heat and Mass Transfer, 98(September), 59–66. https://doi.org/10.1016/j.icheatmasstransfer.2018.08.009
28. Kim, J. (2003). Heater Size and Gravity Effects on Pool Boiling Heat Transfer. AIP Conference Proceedings, 654(2003), 132–141. https://doi.org/10.1063/1.1541287
29. Kumar, N., Raza, M. Q., & Raj, R. (2018). Surfactant aided bubble departure during pool boiling. International Journal of Thermal Sciences, 131(April), 105–113. https://doi.org/10.1016/j.ijthermalsci.2018.05.025
30. Lee, H. C., Oh, B. Do, Bae, S. W., & Kim, M. H. (2003). Single bubble growth in saturated pool boiling on a constant wall temperature surface. International Journal of Multiphase Flow, 29(12), 1857–1874. https://doi.org/10.1016/j.ijmultiphaseflow.2003.09.003
31. Mehrotra, A. K., Nassar, N. N., & Kasumu, A. S. (2012). A novel laboratory experiment for demonstrating boiling heat transfer. Education for Chemical Engineers, 7(4), e210–e218. https://doi.org/10.1016/j.ece.2012.09.003
32. Minocha, N., Joshi, J. B., Nayak, A. K., & Vijayan, P. K. (2016). 3D CFD simulation of passive decay heat removal system under boiling conditions: Role of bubble sliding motion on inclined heated tubes. Chemical Engineering Science, 145, 245–265. https://doi.org/10.1016/j.ces.2016.02.015
33. Noori Rahim Abadi, S. M. A., Ahmadpour, A., & Meyer, J. P. (2018). Numerical simulation of pool boiling on smooth, vertically aligned tandem tubes. International Journal of Thermal Sciences, 132(March), 628–644. https://doi.org/10.1016/j.ijthermalsci.2018.07.005
34. Nukiyama, S. (1934). Maximum and minimum values of heat q transmitted from metal to water under atmospheric pressure.[J]. Soc. Mech. Eng. Jpn. L934 (37), 354(367), 2.
35. Ozdemir, M., & Durmaz, U. (2015). An approach to obtain the heat transfer coefficient of aqueous sucrose solutions in agitated boiling vessels. Thermal Science, 19(3), 1025–1036. https://doi.org/10.2298/TSCI130111143O
36. Price, D. C. (1966). The effect of surface vibration on nucleate pool boiling at low heat fluxes. In Doctoral Thesis (pp. 68–77).
37. Rajasekaran, E., Kumar, B., Muruganandhan, R., Raman, S. V., & Antony, U. (2018). Determination of forced convection heat transfer coefficients and development of empirical correlations for milk in vessel with mechanical agitators. Journal of Food Science and Technology, 55(7), 2514–2522. https://doi.org/10.1007/s13197-018-3169-z
38. Rashidi, S., Hormozi, F., & Sarafraz, M. M. (2020). Fundamental and subphenomena of boiling heat transfer. Journal of Thermal Analysis and Calorimetry, February. https://doi.org/10.1007/s10973-020-09468-3
39. Rohsenow, W. M. (1951). A method of correlating heat transfer data for surface boiling of liquids. Cambridge, Mass.: MIT Division of Industrial Cooporation,[1951].
40. Saha, S. K., Ranjan, H., Emani, M. S., & Bharti, A. K. (2020). Two-Phase Heat Transfer Enhancement. https://doi.org/10.1007/978-3-030-20755-7
41. Sarafraz, M. M., Peyghambarzadeh, S. M., & Alavifazel, S. A. (2012). Enhancement of nucleate pool boiling heat transfer to dilute binary mixtures using endothermic chemical reactions around the smoothed horizontal cylinder. Heat and Mass Transfer/Waerme- Und Stoffuebertragung, 48(10), 1755–1765. https://doi.org/10.1007/s00231-012-1019-5
42. Sarafraz, M. M., Pourmehran, O., Yang, B., Arjomandi, M., & Ellahi, R. (2020). Pool boiling heat transfer characteristics of iron oxide nano-suspension under constant magnetic field. International Journal of Thermal Sciences, 147(October 2019), 106131. https://doi.org/10.1016/j.ijthermalsci.2019.106131
43. Sathyabhama, A., & Dinesh, A. (2017). Augmentation of heat transfer coefficient in pool boiling using compound enhancement techniques. Applied Thermal Engineering, 119, 176–188. https://doi.org/10.1016/j.applthermaleng.2017.03.029
44. Schuster, G. M., & Katsaggelos, A. K. (2004). Robust circle detection using a weighted MSB estimator. Proceedings - International Conference on Image Processing, ICIP, 3, 2111–2114. https://doi.org/10.1109/ICIP.2004.1421502
45. Smith, J. M., Gao, Z., & Middleton, J. C. (2001). The unsparged power demand of modern gas dispersing impeller in boiling liquids. Chemical Engineering Journal, 84(1), 15–21. https://doi.org/10.1016/S1385-8947(00)00267-9
46. Suriyawong, A., Saisorn, S., & Wongwises, S. (2017). Pool boiling heat transfer enhancement of distilled water with passive rotating blades installed above the heating surface. Experimental Thermal and Fluid Science, 87, 109–116. https://doi.org/10.1016/j.expthermflusci.2017.04.025
47. Takahashi, T., Tagawa, A., Atsumi, N., Dohi, N., & Kawase, Y. (2006). Liquid-phase mixing time in boiling stirred tank reactors with large cross-section impellers. Chemical Engineering and Processing: Process Intensification, 45(4), 303–311. https://doi.org/10.1016/j.cep.2005.06.012
48. Yagov, V. V. (2009). Nucleate boiling heat transfer: Possibilities and limitations of theoretical analysis. Heat and Mass Transfer/Waerme- Und Stoffuebertragung, 45(7), 881–892. https://doi.org/10.1007/s00231-007-0253-8