Grafen-Demir Oksit Hibrit Nanoakışkanı Kullanılan Bir Isı Değiştirici Borusunun Entropi Üretim Analizi

Bu çalışmada, türbülanslı akış koşullarında bir ısı değiştirici borusunda % 0.5-1 aralığında altı farklı hacimsel karışım oranına sahip Grafen-Demir Oksit-Su hibrit nanoyakışkanın entropi üretim analizi sayısal olarak incelenmiştir. Boru üzerine sabir ısı akısı sınır şartı uygulanmış ve Reynolds sayısı çalışma aralığı 10000-50000 olarak belirlenmiştir. Sayısal analizde k − ε RNG çözüm metodu seçilmiş ve ağ bağımsızlığı çalışması gerçekleştirilmiştir. Boyutsuz entropi üretimini incelendiği sonuçlara göre, entropi üretimi, hibrit nanoakışkan hacimsel karışım oranının artmasıyla düşen bir eğilim göstermiştir. Artan Reynolds sayısı ile artış gösteren boyutsuz entropi üretim sayısı 0,5, 0,6, 0,7 ve 0,8 % hacimsel karışım oranında birim değer üzerinde daha fazla konfigürasyonda gerçekleşirken, 0,9 ve 1 % hacimsel karışım oranlasında entropi üretim sayısı için tüm değerler 40000 Reynolds sayısına kadar birim değerin altında gerçekleşmiştir. Bu sonuç, hibrit nanoakışkanın Grafen-Demir oksitinin ısı değiştiricilerde kullanılmasının termodinamik açıdan büyük avantajlar sağladığını göstermiştir.

Anahtar Kelimeler:

Nanoakışanlar, Entropi üretimi, Isı transferi

Entropy Generation Analysis of a Heat Exchanger Tube with Graphene-Iron Oxide Hybrid Nanofluid

In this study, the entropy generation analysis of the Graphene-Iron Oxide-Water hybrid nanofluid with six different volumetric fractions in the range of 0.5-1% in a heat exchanger tube under turbulent flow conditions was numerically investigated. The constant surface heat flux was applied to the tube and the Reynolds number was obtained in the range of 10000-50000. The k − ε RNG solver method was selected for the turbulence method and grid independence was checked. According to the results examining the dimensionless entropy production, entropy production showed a descending trend with the increment of hybrid nanofluid volume fraction. For the dimensionless entropy generation number, which increased with the increasing Reynolds number, configurations above unity were found at the volumetric fractions of 0.5, 0.6, 0.7 and 0.8 %, in addition, all values for entropy generation number with the volume fractions of 0.9 and 1 % were realized below unity up to the Reynolds number of 40000. This result showed that the use Graphene-Iron oxide of hybrid nanofluid in heat exchangers provides great advantages in terms of thermodynamics.

Keywords:

nanofluids, entropy generation, heat transfer,

PDF

___

Ozerinç, S., Kakaç, S., Yazıcıoğlu, A.G. (2010). Enhanced Thermal Conductivity of Nano-Fluids: A State-of-the-Art Review. Microfluid Nanofluid, 8(2), 145-170.
Ahammed, N., Asirvatham, L.G., Wongwises, S. (2016). Entropy generation analysis of graphene–alumina hybrid nanofluid in multiport minichannel heat exchanger coupled with thermoelectric cooler. Int. J. Heat Mass Transf., 103, 1084–1097.
Hussain, S., Ahmed, S.E., Akbar, T. (2017). Entropy generation analysis in MHD mixed convection of hybrid nanofluid in an open cavity with a horizontal channel containing an adiabatic obstacle, Int. J. Heat Mass Transf., 114, 1054–1066.
Rahimi, A., Sepehr, M., Lariche, M.J., Mesbah, M., Kasaeipoor, A., Malekshah, E.H. (2018). Analysis of natural convection in nanofluid-filled H-shaped cavity by entropy generation and heatline visualization using lattice Boltzmann method, Physica E: LowDimensional Systems and Nanostructures. 97, 347–362.
Kasaeipoor, A., Malekshah, E.H., Kolsi, L. (2017). Free convection heat transfer and entropy generation analysis of MWCNT-MgO (15% −85%)/water nanofluid using lattice Boltzmann method in cavity with refrigerant solid body-experimental thermophysical properties, Powder Technol., 322,9–23.
Mehrali, M., Sadeghinezhad, E., Akhiani, A.R., Latibari, S.T., Metselaar, H.S.C., Kherbeet, A.S., Mehrali, M. (2017). Heat transfer and entropy generation analysis of hybrid graphene/Fe3O4 ferro-nanofluid flow under the influence of a magnetic field, Powder Technol., 308, 149–157.
Askari, S., Koolivand, H., Pourkhalil, M., Lotfi, R., Rashidi, A. (2017). Investigation of Fe3O4/Graphene nanohybrid heat transfer properties: Experimental approach. International Communications in Heat and Mass Transfer, 87, 30-39.
Shahsavar, A., Rahimi, Z., Bahiraei, M. (2017). Optimization of irreversibility and thermal characteristics of a mini heat exchanger operated with a new hybrid nanofluid containing carbon nanotubes decorated with magnetic nanoparticles, Energy Convers. Manag., 150, 37–47.
Shahsavar, A., Ansarian, R., Bahiraei, M. (2018). Effect of line dipole magnetic field on entropy generation of Mn-Zn ferrite ferrofluid flowing through a minichannel using twophase mixture model, Powder Technol., 340, 370–379.
Bahiraei, M., Heshmatian, S. (2018). Thermal performance and second law characteristics of two new microchannel heat sinks operated with hybrid nanofluid containing graphene–silver nanoparticles, Energy Convers. Manag., 168, 357–370.
Bahiraei, M., Mazaheri, N. (2018). Second law analysis for flow of a nanofluid containing graphene–platinum nanoparticles in a minichannel enhanced with chaotic twisted perturbations, Chem. Eng. Res. Des., 136, 230–241.
Potenza, M., Cataldo, A., Bovesecchi, G., Corasaniti, S., Coppa, P., Bellucci, S. (2017). Graphene nanoplatelets: Thermal diffusivity and thermal conductivity by the flash method. AIP Advances, 7, 1-15.
Manikandan, S. P., Baskar, R. (2018). Assessment of the Inﬂuence of Graphene Nanoparticles on Thermal Conductivity of Graphene/Water Nanoﬂuids Using Factorial Design of Experiments. Periodica Polytechnica Chemical Engineering, 62(3), 317-322.
Yongsheng, F., Haiqun, C., Xiaoqiang, S., Xin, W., (2012). Combination of cobalt ferrite and graphene: High-performance and recyclable visible-light photocatalysis. Applied Catalysis B: Environmental, 111, 280–287.
Fluent (2016). ANSYS Fluent V.17.0 User Guide, Fluent Corporation, Lebanon, New Hampshire.
Keklikcioglu, O., (2020). İçerisinde Grafen katkılı nanoakışkan ve konik iç eleman kullanılan boruda termohidrolik performans ve entropi üretiminin incelenmesi. Erciyes Üniversitesi, Fen Bilimleri Enstitüsü, Doktora Tezi, 191s, Kayseri.
Krishna V., K.P.V., Kishore, P.S., Durga Prasad, P.V., (2017). Enhancement of Heat Transfer Using Fe3O4 / Water Nanofluid with Varying Cut-Radius Twisted Tape Inserts. International Journal of Applied Engineering Research, 12, 7088-7095.
Salim, S.M., Cheah, S.C. (2009). Wall y+ Strategy for Dealing with Wall-bounded Turbulent Flows. International MultiConference of Engineers and Computer Scientists, 18-20 Mart, Hong Kong, 2165-2170.
Anjali Devi, S.P., Suriya U.D.S. (2016). Numerical investigation of hydromagnetic hybrid Cu–Al2O3/water nanofluid flow over a permeable stretching sheet with suction. International Journal of Nonlinear Sciences and Numerical Simulation, 17, 249–257.
Bejan, A., (2001). Thermodynamic optimization of geometry in engineering flow systems, Exergy, An International Journal, 1(4), 269 – 277.
Ventsislav D. Zimparov, Nikolai L. Vulchanov, (1994). Performance evaluation criteria for enhanced heat transfer surfaces, International Journal of Heat and Mass Transfer, 37, 1807-1816.
Haddad, O., Abuzaid, M., ve Al-Nimr, M. (2004). Entropy generation due to laminar incompressible forced convection flow through parallel-plates microchannel, Entropy, 6, 413–426.