Investigation of the effects of using hexagonal boron nitride-water nanofluid on thermal performance in solar collectors

Öz

In this study, the effects of adding a rectangular spiral fin inside a collector pipe used in a parabolic solar collector and the use of nanofluids on thermal performance were numerically investigated. Four model geometries were created by changing the number of spiral turns along the tube length of the fin. It is assumed that Hexagonal Boron Nitride-Water (hBN-water) nanofluid passes through the collector pipe. The volumetric mixing ratios of the nanofluid were changed between 0% and 4%. The flow is laminar and the Reynolds number is taken at a constant 1500. Analyzes were made with the help of Computational Fluid Dynamics for different parameters. As a result of the study, it was observed that the heat transfer increased as the volumetric mixing ratio of the hBN particle in the nanofluid was increased. In addition, increasing the number of turns of the fin added in the collector pipe also increased the heat transfer. With the addition of fins to the collector tube and the use of hBN nanofluid, the value of the heat transfer coefficient increased by approximately 284% and the value of the Nusselt number increased by approximately 256% compared to a collector tube without fins and only water flowing through it.

Anahtar Kelimeler

• Nanofluid
• Hexagonal Boron Nitride
• hBN
• Thermal performance

Güneş kolektörlerinde hegzagonal bor nitrür-su nanoakışkanının kullanımının ısıl performans üzerindeki etkilerinin incelenmesi

Öz

Bu çalışmada parabolik güneş kolektöründe kullanılan toplayıcı bir borunun içine dikdörtgen spiral bir kanatçık eklenilmesi ve nanoakışkan kullanımının ısıl performansa olan etkileri sayısal olarak incelenmiştir. Kanatçığın boru uzunluğu boyunca spiral sarım sayısı değiştirilerek dört adet model geometri oluşturulmuştur. Toplayıcı borunun içinden Hegzagonal Bor Nitrür-Su (hBN-su) nanoakışkanının geçtiği kabul edilmiştir. Nano akışkanın hacimsel karışım oranları %0 ile %4 aralığında değiştirilmiştir. Akış laminer bir akıştır ve Reynolds sayısı sabit 1500 değerinde alınmıştır. Farklı parametreler için Hesaplamalı akışkanlar Dinamiği yardımı ile analizler yapılmıştır. Çalışmanın sonucunda, nanoakışkan içindeki hBN partikülünün hacimsel karışım oranı artırıldıkça ısı transferinin arttığı gözlemlenmiştir. Ayrıca toplayıcı boru içerisine eklenen kanatçığın sarım sayısının artırılması da ısı transferini artırmıştır. Toplayıcı boruya kanatçık eklenmesi ve hBN nanoakışkanının kullanımı ile, kanatçıksız ve içinden sadece su akan bir toplayıcı boruya göre, ısı taşınım katsayısının değeri yaklaşık %284 Nusselt sayısının değeri ise yaklaşık %256 artış göstermiştir.

Anahtar Kelimeler

• Nanoakışkan
• Hegzagonal Bor Nitrür
• hBN
• Isıl performans

Kaynakça

1. [1] Koçak Soylu, Sezgi. (2018). Investigation of the effect of TiO2 based nanofluid usage on heat transfer performance in automobile radiator [PhD. thesis, Akdeniz University]. Institute of Science.
2. [2] Aytac, İ. (2021). Investigation of the effect of CuO/water and ZnO/water nanofluids on heat pipe performance. Polytechnic Journal, 24(3), 963-971.
3. [3] Çiftçi, E., Sözen, A., & Karaman, E. (2016). Experimental investigation of nano fluid usage including TiO2 on the effect of heat pipe performance. Polytechnic Journal, 19(3), 367-376.
4. [4] Veeramanikandan, K., Vignesh, S., Pitchia Krishnan, B., Mathanbabu, M., & Ashokkumar, M. (2021). Investigation of Al2O3-water nano fluid flow through the circular tube. Materials Today: Proceedings, 46, 8288-8295.
5. [5] Dawood, H., Mohammed, H., Sidik, N. A., Munisamy, K., & Alawi, O. A. (2017). Heat transfer augmentation in concentric elliptic annular by ethylene glycol based nanofluids. International Communications in Heat and Mass Transfer, 82, 29-39.
6. [6] Ijaz, H., Raza, H., Gohar, G., Ullah, S., Akhtar, A., & Imran, M. (2020). Effect of graphene oxide doped nano coolant on temperature drop across the tube length and effectiveness of car radiator – a CFD study. Thermal Science and Engineering Progress, 20, 100689.
7. [7] Gnanavel, C., Saravanan, R., & Chandrasekaran, M. (2020). Heat transfer augmentation by nano-fluids and circular fin insert in double tube heat exchanger – A numerical exploration. Materials Today: Proceedings, 21, 934-939.
8. [8] Tokgoz, N., Avci, M., Erdinc, M. T., & Kaska, O. (2021). Numerical investigation of flow characteristics of nanofluid usage in L and T. Cukurova University Journal of the Faculty of Engineering, 23(67), 457 - 472.

9. [9] Naik, B., Hosmani, A., Kerur, S., Jadhav, C. C., Benni, S., Annigeri, S., . . . Aralikatti, P. (2021). Numerical analysis of two tube helical heat exchanger using various nano-fluids. Materials Today Proceedings, 47, 3137-3143.
10. [10] Huminic, G., & Huminic, A. (2011). Heat transfer characteristics in double tube helical heat exchangers using nanofluids. International Journal of Heat and Mass Transfer, 54, 4280-4287.
11. [11] Heris, S. Z., Esfahany, M. N., & Etemad, S. G. (2007). Experimental investigation of convective heat transfer of Al2O3/water nanofluid in circular tube. International Journal of Heat and Fluid Flow, 28(2), 203-210.
12. [12] Salman, B. H., Mohammed, H. A., & Kherbeet, A. S. (2014). Numerical and experimental investigation of heat transfer enhancement in a microtube using nanofluids. International Communications in Heat and Mass Transfer, 59, 88-100.
13. [13] Tuzun, A. H. (2019). Numerıcal method of thermal – hydraulic performance nanofluids in different concentrations [Master's thesis, Pamukkale University]. Institute of Science Mechanical Engineering.
14. [14] Demir, U. (2019). Experimental and numerical investigation of the effect of nanofluid use on heat transfer in a Mini-Channel [Master's thesis, Zonguldak Bulent Ecevit University]. Council of Higher Education Thesis Center.
15. [15] Çağlar, Ç. (2010). Investigation of the properties of hot-pressed hexagonal boron nitride - titanium diboride composites with titanium diboride doped in nano-size [Master's thesis, Istanbul Technical University]. Institute of Science.
16. [16] Dal, A. R. (2019). Numerıcal analysıs of the optımum fın pıtch of a plaın plate tube heat exchanger. Omer Halisdemir University Journal of Engineering Sciences, 8(1), 479-501.
17. [17] Kaya, M., Demircan, T., & Gemicioglu, B. (2021). Effects of using Nanofluids on Heat Transfer Performance in Parabolic Solar Collectors. Dokuz Eylul University Journal of Science and Engineering, 23(67), 169-178.
18. [18] Ocal, S. (2019). Investigation of thermophysical characterıstics of various hybrid nanofluids for heat transfer applications [Master's thesis, Nigde Omer Halisdemir University]. Institute of Science.