Kabuk ve Sarmal Bobin Isı Eşanjörünün Termal Performansının İyileştirilmesi

Yıl 2021, Cilt: 5 Sayı: 2, 237 - 259, 31.12.2021

Tareq Abed , İbrahim Koç

https://doi.org/10.53600/ajesa.985556

Öz

Günümüzde enerji tüketimi arttığı için ısı enerjisi geçişinin verimliliğini ve performansını artırmak gerekmektedir. Delikli bükümlü bandın ısı transfer katsayısı, etkinlik, Nusselt sayısı ve basınç düşüşü üzerindeki etkileri sayısal olarak incelenmiştir. Kurulumu gerçekleştirmek ve çözümü tamamlamak için sonlu hacim yönteminin kullanıldığı ısı eşanjörünün delikli bükümlü bant ile modellenmesi uygulanmıştır. Sayısal sonuçlar önceki deneysel sonuçlarla doğrulanmıştır ve sayısal ve deneysel sonuçlar arasında aşırı bir uyum vardır. Reynolds sayılarının aralığı 3800 ila 18000 arasındadır. Sonuçlar, genel ısı aktarım katsayısının U’nun, Reynolds sayısının artmasıyla arttığını göstermiştir; burada delikli bükümlü bant, 965 ila 1250 W/ sayılarına ulaşarak ısı aktarım katsayısında maksimum artış sağlar. m2K. Delikli bükümlü bant, 65’ten 115’e kadar olan sayıların ardından Nusselt sayısını arttırma oranı en yüksek olanıdır ve bu, hız arttıkça türbülans seviyesi arttıkça açıklanabilir. Isı eşanjörünün etkinliği, delikli bükümlü bandın 0.35’ten 0.85’e ulaşan sayılara ulaşan üstün etkinlik geliştirmesine ulaştığı Reynolds sayısının büyümesiyle artar. Bükümlü bandın karmaşıklığı basınç düşüşünü artırdıkça, bükümlü bant konfigürasyonunun maksimum basınç düşüşü artış oranına sahip olduğu belirtilmektedir. Isı eşanjöründen geçen sıcak ve soğuk suyun hatları ve akış çizgileri sıcaklık, hız ve basınç dağılımlarını açıklar.

Anahtar Kelimeler

Eşanjör, Delikli bükümlü bant, Termal performans

Thermal Performance Improvement of Shell and Helical Coil Heat Exchanger

Öz

Nowadays, energy consumption increases so it is necessary to enhance the efficiency and performance of heat energy transition. The effects of perforated twisted tape on heat transfer coefficient, effectiveness, Nusselt number, and pressure drop are studied numerically. Modeling of heat exchanger with the perforated twisted tape is applied where finite volume method is utilized to perform the setup and complete the solution. The numerical results are validated with previous experimental results and there is an excessive agreement between the numerical and experimental results. The range of Reynolds numbers is from 3800 to 18000. The results showed that the overall heat transfer coefficient U increases with the rise of Reynolds number where the perforated twisted tape achieves the maximum enhancement of heat transfer coefficient achieving the numbers from 965 to 1250 W/m2K. The perforated twisted tape has the highest ratio of enhancing Nusselt number following the numbers from 65 to 115 and this can be explained as the velocity rises, the turbulence level increases. Heat exchanger effectiveness increases with the growth of Reynolds number where the perforated twisted tape attained the supreme enhancement of effectiveness reaching the numbers from 0.35 to 0.85. It is indicated that the twisted tape configuration has the maximum ratio of pressure drop increase as the complicity of twisted tape rise the pressure drop. Contours and streamlines of hot and cold water cross the heat exchanger explains the distributions of temperature, velocity, and pressure.

Anahtar Kelimeler

Heat exchanger, Perforated twisted tape, Thermal performance

Kaynakça

• Abu-Hamdeh, N.H., K.H. Almitani, and A. Alimoradi. 2021. Exergetic performance of the helically coiled tube heat exchangers: Comparison the sector-by-sector with tube in tube types. Alexandria Engineering Journal, 60(1), 979-993.
• Abu-Hamdeh, N.H., R.A.R Bantan, and I. Tlili. 2020. Analysis of the thermal and hydraulic performance of the sector-by-sector helically coiled tube heat exchangers as a new type of heat exchangers. International Journal of Thermal Sciences, 150, 106229.
• Agbossou, A., B. Souyri, and B. Stutz. 2018. Modeling of helical coil heat exchangers for heat pump applications: Analysis of operating modes and distance between heat exchangers. Applied Thermal Engineering, 129, 1068-1078.
• Alimoradi, A., and F. Veysi. 2017. Optimal and critical values of geometrical parameters of shell and helically coiled tube heat exchangers. Case Studies in Thermal Engineering, 10, 73-78.
• Chagny, C., C. Castelain, and H. Peerhossaimi. 2000. Chaotic heat transfer for heat exchanger design and comparison with a regular regime for a large range of Reynolds numbers. Applied Thermal Engineering, 20(17), 1615-1648.
• Eiamsa-Ard, S., and P. Promvonge. 2017. Heat transfer characteristics in a tube fitted with helical screw-tape with/without core-rod inserts. International Communications in Heat and Mass Transfer, 34(2), 176-185.
• Farmam, M., M. Khoshvaght-Aliabadi, and M.J. Asadollahzadeh. 2021. Intensified single-phase forces convective heat transfer with helical-twisted tube in coil heat exchangers. Annals of Nuclear Energy, 154, 108108.
• Galeazzo, F.C.C., R.Y. Miura, J.A.W. Gut, and C.C. Tadini. 2006. Experimental and numerical heat transfer in a plate heat exchanger. Chemical Engineering Science, 61(21), 7133-7138.
• Jean, A., M.K. Nyein, J.Q. Zheng, D.F. Moore, J.D. Joannopoulos, and R. Radovitzky. 2014. An animal-to-human scaling law for blast-induced traumatic brain injury risk assessment. Proceedings of the National Academy of Sciences, 111(43), 15310-15315.
• Manglik, R.M., and A.E. Bergles. 2003. Swirl flow heat transfer and pressure drop with twisted-tape inserts. In Advances in Heat Transfer (Vol. 36, pp. 182-266). Elsevier.
• Marzouk, S.A., M.M. Abou Al-Sood, M.K. El-Fakharany, and E.M.S. El-Said. 2021. Thermo-hydraulic study in a shell and tube heat exchanger using rod inserts consisting of wire-nails with air injection: Experimental study. International Journal of Thermal Sciences, 161, 106742.
• Moawed, M. 2011. Experimental study of forced convection from helical coiled tubes with different parameters. Enerhy Conversion and Management, 52(2), 1150-1156.
• Niwalkar, A.F., J.M. Kshirsagar, and K. Kulkarni. 2019. Experimental investigation of heat transfer enhancement in shell and helically coiled tube heat exchaner using SiO2/water nanofluids. Materials Today: Proceedings, 18, 947-962.
• Palanisamy, K., and P.C.M. Kumar. 2019. Experimental investigation on convective heat transfer and pressure drop of cone helically coiled tube heat exchanger using carbon nanotubes/water nanofluids. Heliyon. 5(5), e01705.
• Panahi, D., and K. Zamzamian. 2017. Heat transfer enhancement of shell-and-coiled tube heat exchanger utilizing helical wire turbulator. Applied Thermal Engineering, 115, 607-615.
• Rasheed, A.H., H.B. Alias, and S.D. Salman. 2021. Experimental and numerical investigations of heat transfer enhancement in shell and helically microtube heat exchanger using nanofluids. International Journal of Thermal Sciences, 159, 106547.
• Salimpour, M.R. 2009. Heat transfer coefficients of shell and coiled tube heat exchangers. Experimental Thermal and Fluid Science, 33(2), 203-207.
• Sepehr, M., S.S. Hashemi, M. Rahjoo, V. Farhangmehr, and A. Alimoradi. 2018. Prediction of heat transfer, pressure drop and entropy generation in shell and helically coiled finned tube heat exchangers. Chemical Engineering Research and Design, 134, 277-291.
• Sharifi, K., M. Sabeti, M. Rafiei, A.H. Mohammadi, and L. Shirazi. 2018. Computational fluid dynamics (CFD) technique to study the effects of helical wire inserts on heat transfer and pressure drop in a double pipe heat exchanger. Applied Thermal Engineering, 128, 898-910.
• Wang, G., T. Dbouk, D. Wang, Y. Pei, X. Peng, H. Yuan, and S. Xiang. 2020. Experimental and numerical investigation on hydraulic and thermal performance in the tube-side of helically coiled-twisted trilobal tube heat exchanger. International Journal of Thermal Sciences, 153, 106328.
• Wang, J., S.S. Hashemi, S. Alahgholi, M. Mehri, M. Safarzadeh, and A. Alimoradi. 2018. Analysis of exergy and energy in shell and helically coiled finned tube heat exchangers and design optimizations. International Journal of Refrigeration, 94, 11-23.