THE THREE DIMENSIONAL NUMERICAL INVESTIGATION OF THE EFFECT OF FIN GEOMETRY ON THE HEAT TRANSFER IN PLATE FIN HEAT EXCHANGERS

Yıl 2017, Cilt: 19 Sayı: 56, 346 - 363, 01.05.2017

Ertan Buyruk Koray Karabulut

Öz

In the present study, the effects of two different types of rectangular fins with zigzag (B type) and inner-outer zigzag (C type) for heat transfer enhancement with the use of a conjugated heat transfer approach and pressure drops are numerically evaluated in plate fin heat exchangers. The numerical computations are performed by solving a steady, threedimensional Navier-Stokes equation and an energy equation by using Fluent software program. Air is taken as a working fluid. On heat transfer enhancement the effect of different values of Reynolds number and fin heights and also temperature distributions of the hot and cold fluids are investigated for parallel and counter flow in the study. The results show that cold fluid temperature is enhanced by 8.4 % at the exit of the channel with inner-outer zigzag fin for counter flow, it is increased by 7.6 % at the exit of the channel with zigzag fin for parallel flow when compared to channel without fin

Anahtar Kelimeler

Plate heat exchanger, Numerical heat transfer, Fin

PLAKALI KANATÇIKLI ISI DEĞİŞTİRİCİLERDE KANAT GEOMETRİSİNİN ISI TRANSFERİNE OLAN ETKİSİNİN ÜÇ BOYUTLU SAYISAL OLARAK İNCELENMESİ

Öz

Bu çalışmada, plakalı kanatçıklı ısı değiştiricilerde ısı transferini artırmak için birleşik ısı transferi yaklaşımıyla zikzak (B tipi) ve iç-dış zikzak (C tipi) olmak üzere iki farklı dikdörtgensel kanatçık tipinin ısı transferine olan etkileri ve basınç hesaplamalar, üç boyutlu Navier-Stokes ve enerji denkleminin FLUENT programı kullanılarak çözülmesiyle zamandan bağımsız olarak elde edilmiştir. Çalışma akışkanı olarak hava kullanılmıştır. Çalışmada, paralel ve ters akış şartlarında Reynolds sayısının farklı değerlerinin ve kanatçık yüksekliğinin ısı transfer artışı üzerindeki etkisi ve ayrıca soğuk ve sıcak akışkanların sıcaklık dağılımları da incelenmiştir. Sonuçlar soğuk akışkan sıcaklığının ters akış durumunda iç-dış zikzak kanatçıklı kanalda düz kanala göre kanal çıkışında % 8.4, paralel akış durumunda ise zikzak kanatçıklı kanalda yine düz kanalla karşılaştırıldığında % 7.6’ lık artış elde edildiğini göstermektedir

Anahtar Kelimeler

Plakalı ısı değiştirici, Sayısal ısı transferi, Kanat

Kaynakça

• Sunden, B. 1999. Heat Transfer and Fluid Flow in Rib-Roughened Rectangular Ducts. ss 123-140. Kakaç, S., Bergles, A.E., Mayinger, F., Yüncü, H., ed. 1999. Heat Transfer Enhancement of Heat Exchangers, Kluwer Netherlands, 675s.
• Publishers, [2] Tauscher, R., Mayinger, F. 1999. Heat Transfer Enchancement in a Plate Heat Exchanger with Rib- Roughened Surfaces. ss 207-221. Kakaç, S., Bergles, A.E., Mayinger, F., Yüncü, H., ed. 1999. Heat Transfer Enhancement of Heat Exchangers, Kluwer Netherlands, 675s.
• Publishers, [3] Lee, C.K., Abdel-Moneim, S.A. 2001. Computational Analysis of Heat Transfer in Turbulent Flow Past a Horizontal Surface with Two- Dimensional Ribs, International Communications in Heat and Mass Transfer, Cilt. 28, No.2, s. 161-170.
• Acharya, S., Dutta, S., Myrum, T.A., Baker, R.S. 1993. Periodically Developed Flow and Heat Transfer in a Ribbed Duct, International Journal of Heat and Mass Transfer, Cilt. 36, No. 8, s. 2069-2082.
• Liou, T.M., Chang, Y., Hwang, D.W. 1990.
• Computational Study of Turbulent Flows in a Channel with Two Pairs of Turbulence Promoters in Tandem, ASME Journal of Fluids Engineering, Cilt. 112, No.3, s. 302- 310.
• and [6] Liou, T.M., Hwang, J.J. 1992. Developing Heat Transfer and Friction in a Ribbed Rectangular Duct with Flow Separation at Inlet, ASME Journal of
• Fluids Engineering, Cilt. 114, No.3, s. 565- 573.
• Kaya, D., Buyruk, E., Can, A., Fertelli, A. 2007. Numerical Study of Heat Transfer Characteristics of Extended Surfaces, Strojarstvo, Cilt. 49, No. 2, s. 137-144. [8] Buyruk, E., Karabulut,
• K., Karabulut, Ö.O. 2013. Three- Dimensional
• Investigation of Heat Transfer for Plate Fin Heat Exchangers, Heat and Mass Transfer, Cilt. 49, No. 6, s. 817-826.
• Numerical [9] Buyruk, E., Karabulut, K. 2013. Numerical Investigation Into Heat Transfer for Three-Dimensional Plate Fin Heat Exchangers with Fins Placed Perpendicular to Flow, Transactions of Famena, Cilt. 37, No.2, s. 87-102.
• Buyruk, E., Karabulut, K. 2015. Numerical Study of Heat Transfer Enhancement Characteristics Dimensional Exchangers,
• Research, Cilt. 46, No. 9, s. 819-837. Transfer [11] Karabulut, K., Buyruk, E., Kılınç, F., Karabulut, Ö.O. 2013. Farklı Geometrilerden Oluşan Kanatçıklı Plakalı Isı Değiştiricileri için Isı Transferinin Üç Boyutlu Sayısal Olarak İncelenmesi, 11. Ulusal Tesisat Müh. Kongresi, 17-20 Nisan, İzmir, 69-85.
• Ngo, T.L., Kato, Y., Nikitin, K., Ishizuka, T. 2007. Heat Transfer and Pressure Drop Correlations of Microchannel Heat Exchangers with S-shaped and Zigzag Fins for Carbon
• Experimental Thermal and Fluid Science, Cilt. 32, s. 560-570.
• Cycles, [13] Ganzarolli, M.M., Alternani, C.A.C. 2010. Optimum Fin Spacing and Thickness of a Finned Heat Exchanger Plate, Heat Transfer Engineering, Cilt. 31, No. 1, s. 25- 32.
• Wang, Y.Q., Dong, Q.W., Liu, M.S., Wang, D. 2009. Numerical Study on Plate Fin Heat Exchangers with Plain Fins and Serrated Fins at Low Reynolds
• Engineering&Technology, Cilt. 32, No. 8, s. 1219-1226.
• Chemical [15] Wen, J., Yang, H., Tong, X., Li, K., Wang, S., Li, Y. 2016. Optimization Investigation on Configuration Parameters of Serrated Fin in Plate-Fin Heat Exchanger Using Genetic Algorithm, International Journal of Thermal Sciences, Cilt. 101, s. 116-125.
• Masliyah, J.H., Nandakumar, K. 1976. Heat Transfer in Internally Finned Tubes, ASME Journal of Heat Transfer, Cilt. 98, No. 2, s. 257-261.
• Gupta, M., Kasana, K.S., Vasudevan, R. 2009. A Numerical Study of the Effect on Flow Structure and Heat Transfer of a Rectangular Winglet Pair in a Plate Fin Heat Exchangers, Journal of Mechanical Engineering Science, Cilt. 223, No. 9, s. 2109- 2215.
• Salehi, S., Afshin, H., Farhanieh, B. 2015. Numerical Investigation of the Inlet Baffle, Header Geometry and Triangular Fins Effects on Plate-Fin Performance,
• Engineering, Cilt. 36, No. 16, s. 1397-1408. Exchangers Heat
• Transfer [19] Zhu, Y.H., Li, Y.Z. 2008. Three Dimensional
• Investigation on the Laminar Flow and Heat Transfer in Four Basic Fins of Plate Fin Heat Exchangers, ASME Journal of Heat Transfer, Cilt. 130, s. 1-8.
• Numerical [20] Dixit, A., Patil, K. 2015. Heat Transfer Grooved Convection,
• Engineering, Cilt. 36, No. 16, s. 1409-1416. of Fin
• Forced Transfer Heat
• Wasewar, K.L., Hargunai, S., Atluri, P., Kumar, N. 2007. CFD Simulation of Flow Distribution in the Header of Plate Fin Heat Exchangers, Chemical Engineering&Technology, Cilt. 30, No. 10, s. 1340-1346.
• Bhutta, M.M.A., Hayat, N., Bashir, M.H., Khan, A.R., Ahmad, K.N., Khan, S. 2012. CFD Applications in Various Heat Exchangers Design: A Review,
• Engineering, Cilt. 32, s. 1-12.
• Thermal [23] FLUENT User's Guide. 2003. Fluent Inc. Lebanon, NH.
• Kayatas, N., Ilbas, M. 2005. İç İçe Borulu
• Değiştiricisinde Isı Transferinin İyileştirilmesinin Sayısal Olarak İncelenmesi, Erciyes Üniversitesi Fen Bilimleri Enstitüsü Dergisi, Cilt. 21, No. 1-2, s. 128-139. Bir Isı