Behavior of Reinforced Concrete Cooling Tower Type Structures Under Wind and Thermal Loads

Öz

Cooling towers are structures mainly used in industrial zones such as natural gas facilities, nuclear energy plants, power plants and petrol refineries for supplying cooling water and designed accordingly. The need for industrial facilities in our country has been increasing every passing day. Cooling towers are quite tall and have a big diameter which is why they are exposed to wind loads due to their wide surface area. Considering different seasonal conditions and the hot water circulation, it can be said that thermal effects also have an impact for the cooling towers. In this study that is within this context, as model parameters; 120 m, 160 m, 200 m of heights for concrete shell, 18 m steel columns, 37.5 m s-1 wind speed and temperatures of +20 °C, +40 °C, -40 °C, 30-60 °C are chosen for analyses. Analysis results are evaluated for the chosen parameters. As a result, it was observed that the temperature loads combined with the wind load had a significant effect on the tower shell.

Anahtar Kelimeler

• Cooling Tower
• Wind Loading
• Thermal Loading
• Axisymmetric Structures

Betonarme Soğutma Kulesi Tipi Yapıların Rüzgâr ve Sıcaklık Yükleri Etkisi Altındaki Davranışı

Öz

Soğutma kuleleri, başta doğalgaz işletme tesisleri, nükleer enerji ve elektrik santralleri, petrol rafinerileri olmak üzere endüstriyel tesislere soğutma suyu sağlamak amacıyla tasarlanan yapılardır. Ülkemizin ekonomik ve siyasi durumu dikkate alındığında endüstriyel tesislere duyulan ihtiyaç her geçen gün artmaktadır. Çok yüksek ve büyük çapa sahip yapılar oldukları için rüzgâr kuvvetine maruz kalan büyük bir yüzey alanına sahiptir. Farklı iklim koşulları ve soğutma kulesinin içinde dolaşan sıcak su dikkate alındığında termal etki de soğutma kulelerinde etkin bir rol oynar. Bu bağlamda yapılan bu çalışmada soğutma kulesi model parametresi olarak 120, 160, 200 m yüksekliğe sahip beton kabuğa 18 m olarak seçilen çelik kolonlar 37.5 m s-1 rüzgâr hızıyla birlikte tüm kabuğa +20 °C, +40 °C, -40 °C ve hava akışına bağlı olarak 30-60 °C arasında değişen sıcaklıklar kullanılarak analiz edilmiştir. Sonuç olarak rüzgâr yükü ile kombine edilen sıcaklık yüklerinin kule kabuğunda kayda değer bir etkiye sahip olduğu görülmüştür.

Anahtar Kelimeler

• Soğutma kulesi
• Rüzgâr Yükü
• Sıcaklık Yükü
• Eksenel Simetrik Yapılar

Kaynakça

1. Abedi-Nik F, Sabouri-Ghomi S, 2008. The damaging effects of earthquake excitation on concrete cooling towers. AIP Konferansı, Reggio Calabria.
2. Cheng X X, Zhao L, Ge Y J, 2013. Multıple loadıng effects on wınd-induced static performance of super-large cooling towers. International Journal of Structural Stability and Dynamics, 13 (8): 1-21.
3. Ge W, Jun L, Chuan X, Li W G, Zhao Y, 2019. Critical impact factors on the cooling performance design of natural draft dry cooling tower and relevant optimization strategies. Applied Thermal Engineering, 154: 614-627.
4. Jahangiri A, Borzooee A, Armoudli E, 2019. Thermal performance improvement of the three aligned natural draft dry cooling towers by wind breaking walls and flue gas injection under different crosswind conditions. International Journal of Thermal Sciences, 137: 288-298.
5. Ke S, Yu W, Zhu, P, Ge Y, Hou X, 2018. Full-scale measurements and damping ratio properties of cooling towers with typical heights and configurations. Thin-Walled Structures, 124: 437-448.
6. Li X, Gurgenci H, Guan Z, Wang X, Xia L, 2015. A review of the crosswind effect on the natural draft cooling towers. Applied Thermal Engineering, 150: 250-270.
7. Lin F, Li Y, Gu X, Zhao X, Tang D, 2013. Prediction of ground vibration due to the collapse of a 235 m high cooling tower under accidental loads. Nuclear Engineering and Design, 258: 89-101.
8. Lin F, Ji H, Li Y, Zuo Z, Gu X, Li Y, 2014. Prediction of ground motion due to the collapse of a large-scale cooling tower under strong earthquakes. Soil Dynamics and Earthquake Engineering, 65: 43-54.

9. Liu, Z, Zhang C, Ishihara T, 2018. Numerical study of the wind loads on a cooling tower by a stationary tornado-like vortex through LES. Journal of Fluids and Structures, 81: 656-672.
10. Ma H, Li Z, Fan F, 2019. Static performance analysis of single-layer steel cooling tower. Structures, 19: 322-332.
11. Noh C, 2006. Nonlinear behavior and ultimate load bearing capacity of reinforced concrete natural draught cooling tower shell. Engineering Structures, 28(3): 399-410.
12. Sabouri-Ghomi S, Abedi-Nik F, Roufegarinejad A, Bradford M A, 2006. Numerical study of the nonlinear dynamic behaviour of reinforced concrete cooling towers under earthquake excitation. Advances in Structural Engineering, 9(3): 433-442.
13. TS EN 1991-1-4, 2007. Yapılar Üzerindeki Etkiler Bölüm 1-4: Genel Etkiler-Rüzgâr Etkileri Ankara: Türk Standartları Enstitüsü.
14. TS EN IEC 61400-1, 2019. Rüzgâr Enerjisi jeneratör sistemleri- Bölüm 1: Tasarım kuralları Ankara: Türk Standartları Enstitüsü.
15. Wang H, Ke S T, Ge Y J, 2019. Research on non-stationary wind-induced effects and the working mechanism of full scale super-large cooling tower based on field measurement. Journal of Wind Engineering and Industrial Aerodynamics, 184: 61-76.
16. Ye F, 2015. Local buckling analysis of thin-wall shell structures. Hollanda: Delft University of Technology, Yüksek Lisans Tezi (Basılmış)
17. Yu Q-Q, Gu X-L, Li Y, Lin F, 2016. Collapse-resistant performance of super-large cooling towers subjected to seismic actions. Engineering Structures, 108: 77-89.
18. Zhang J.-F, Ge Y-J, Zhao L, Zhu B, 2017. Wind induced dynamic responses on hyperbolic cooling tower shells and the equivalent static wind load. Journal of Wind Engineering and Industrial Aerodynamics, 169: 280-289.