DOI QR코드

DOI QR Code

Effects of different wind deflectors on wind loads for extra-large cooling towers

  • Ke, S.T. (Department of Civil Engineering, Nanjing University of Aeronautics and Astronautics) ;
  • Zhu, P. (Tower college, China Information Consulting & Designing Institude Co, LTD) ;
  • Ge, Y.J. (State Key Laboratory for Disaster Reduction in Civil Engineering, Tongji University)
  • Received : 2018.04.11
  • Accepted : 2018.09.25
  • Published : 2019.05.25

Abstract

In order to examine the effects of different wind deflectors on the wind load distribution characteristics of extra-large cooling towers, a comparative study of the distribution characteristics of wind pressures on the surface of three large cooling towers with typical wind deflectors and one tower without wind deflector was conducted using wind tunnel tests. These characteristics include aerodynamic parameters such as mean wind pressures, fluctuating wind pressures, peak factors, correlation coefficients, extreme wind pressures, drag coefficients and vorticity distribution. Then distribution regularities of different wind deflectors on global and local wind pressure of extra-large cooling towers was extracted, and finally the fitting formula of extreme wind pressure of the cooling towers with different wind deflectors was provided. The results showed that the large eddy simulation (LES) method used in this article could be used to accurately simulate wind loads of such extra-large cooling towers. The three typical wind deflectors could effectively reduce the average wind pressure of the negative pressure extreme regions in the central part of the tower, and were also effective in reducing the root of the variance of the fluctuating wind pressure in the upper-middle part of the windward side of the tower, with the curved air deflector showing particularly. All the different wind deflectors effectively reduced the wind pressure extremes of the middle and lower regions of the windward side of the tower and of the negative pressure extremes region, with the best effect occurring in the curved wind deflector. After the wind deflectors were installed the drag coefficient values of each layer of the middle and lower parts of the tower were significantly higher than that without wind deflector, but the effect on the drag coefficients of layers above the throat was weak. The peak factors for the windward side, the side and leeward side of the extra-large cooling towers with different wind deflectors were set as 3.29, 3.41 and 3.50, respectively.

Keywords

Acknowledgement

Supported by : National Natural Science Foundation, Postdoctoral Science Foundation

References

  1. Armitt, J. (1980), "Wind loading on cooling towers", J. Struct. Div., 106(3), 623-641. https://doi.org/10.1061/JSDEAG.0005384
  2. Bartoli, G., Borri, C., Hoeffer, R. and Orlando, M. (1997), "Wind induced pressures and interference effects on a group of cooling towers in a power plant arrangement", Proceedings of the 2nd European and African Conference on Wind Engineering, Genoa, Italy, Padua, SGE.
  3. Busch, D., Harte, R., Kratzig, W.B. and Montag, U. (2002), "New natural draught cooling tower of 200 m height", Eng. Struct., 24(12), 1509-1521. https://doi.org/10.1016/S0141-0296(02)00082-2.
  4. Davenport, A.G. (1967), "Gust loading factors", J. Struct. Div. - ASCE, 93(3), 11-34. https://doi.org/10.1061/JSDEAG.0001692
  5. Goudarzi, M.A. and Sabbagh-Yazdi, S.R. (2008), "Modeling wind ribs effects for numerical simulation external pressure load on a cooling tower of Kazerun power plant-Iran", Wind Struct., 11(6), 479-496. http://dx.doi.org/10.12989/was.2008.11.6.479.
  6. Goudarzi, M.A. and Sabbagh-Yazdi, S.R. (2008), "Modeling wind ribs effects for numerical simulation external pressure load on a cooling tower of KAZERUN power plant-IRAN", Wind Struct., 11(6), 479-496. http://dx.doi.org/10.12989/was.2008.11.6.479.
  7. Harte, R. and Wittek, U. (2009), "Recent developments of cooling tower design", Proceedings of the IASS Symposium, Valencia, Spain, Sept.-Oct.
  8. Holmes, J.D. (1992), "Optimized peak load distributions", J. Wind Eng. Ind. Aerod., 41(1), 267-276. https://doi.org/10.1016/0167-6105(92)90419-B
  9. Holmes, J.D. (2002), "Effective static load distributions in wind engineering", J. Wind Eng. Ind. Aerod., 90(2), 91-109. https://doi.org/10.1016/S0167-6105(01)00164-7.
  10. Isyumov, N. and Abu-Sitta, S.H. (1972), "Approaches to the design of hyperbolic cooling towers against the dynamic action of wind and earthquakes", Bull. Int. Assoc. Shell Struct., 48, 3-22.
  11. Ke, S.T., Liang, J., Zhao, L. and Ge, Y.J. (2015), "Influence of ventilation rate on the aerodynamic interference for two IDCTs by CFD", Wind Struct., 20(3), 449-468. http://dx.doi.org/10.12989/was.2015.20.3.449.
  12. Ke, S.T., Ge, Y.J., Zhao, L. and Tamura, Y. (2012), "A new methodology for analysis of equivalent static wind loads on super-large cooling towers", J. Wind Eng. Ind. Aerod., 111(3), 30-39. https://doi.org/10.1016/j.jweia.2012.08.001.
  13. Ke, S.T., Ge, Y.J., Zhao, L. and Tamura, Y. (2013), "Wind-induced responses characteristics on super-large cooling towers", J. Central South Univ. Technol., 20(11), 3216-3227. https://doi.org/10.1007/s11771-013-1846-7
  14. Ke, S.T. and Ge, Y.J. (2014), "The influence of self-excited forces on wind loads and wind effects for super-large cooling towers", J. Wind Eng. Ind. Aerod., 132, 125-135. https://doi.org/10.1016/j.jweia.2014.07.003.
  15. Ke, S.T. and Ge, Y.J. (2015), "Extreme wind pressures and non-Gaussian characteristics for super-large hyperbolic cooling towers considering aero-elastic effect", J. Eng. Mech., 141(7), 04015010. https://doi.org/10.1061/(ASCE)EM.1943-7889.0000922
  16. Niemann, H.J. and Kopper, H.D. (1998), "Influence of adjacent buildings on wind effects on cooling towers", Eng. Struct., 20(10), 874-880. https://doi.org/10.1016/S0141-0296(97)00131-4
  17. Qiao, Q., Guo, Z. and Wang, R. (2011), "Wind Tunnel Experimental Study on Effect of Nuclear Power Plant Cooling Tower on Radioactive Plume Dispersion", Bioinformatics and Biomedical Engineering,(iCBBE), Proceedings of the 5th International Conference on. IEEE.
  18. Ramakrishnan, R. and Arumugam, R. (2012), "Optimization of operating parameters and performance evaluation of forced draft cooling tower using response surface methodology (RSM) and artificial neural network (ANN)", J. Mech. Sci. Technol., 26(5), 1643-1650. https://doi.org/10.1007/s12206-012-0323-9
  19. Ruscheweyh, H. (1975), "Wind loadings on the television tower, Hamburg, Germany", J. Ind. Aerod., 1, 315-333. https://doi.org/10.1016/0167-6105(75)90026-4.
  20. Sageau, J.F. and Hamonou, M. (1979), "Application of data acquisition system for on site measurements of wind effects on structures",Von Karman Inst for Fluid Dyn Data Acquisition Systems & Data Analysis in Fluid Dyn 26 P. In Von Karman Inst. for Fluid Dyn. Data Acquisition Systems and Data Analysis in Fluid Dyn., SEE N80-12354 03-34.
  21. Sun, T.F. and Gu, Z.F. (1992), "Full-scale measurement and windtunnel testing of wind loading on two neighboring cooling towers", J. Wind Eng. Ind. Aerod., 43(1-3), 2213-2224. https://doi.org/10.1016/0167-6105(92)90660-3.
  22. Sun, T.F. and Gu, Z.F. (1995), "Interference between wind loading on group of structures", J. Wind Eng. Ind. Aerod., 54(55), 213-225. https://doi.org/10.1016/0167-6105(94)00051-E.
  23. VGB-Guideline (2005), "Structural design of cooling towertechnical guideline for the structural design, computation and execution of cooling towers", Standard Essen: BTR Bautechnik bei Kuhlturmen.
  24. Zhang, J.F., Ge, Y.J. and Zhao, L. (2011), "Effect of latitude wind pressure distribution on the load effects of hyperboloidal cooling tower shell", Proceedings of the 13th International Conference on Wind Engineering. Amsterdam, Netherlands.
  25. Zhao, L., Chen, X., Ke, S.T. and Ge, Y.J. (2014), "Aerodynamic and aero-elastic performances of super-large cooling towers", Wind Struct., 19(4), 443-465. http://dx.doi.org/10.12989/was.2014.19.4.443
  26. Zhao, L., Chen, X. and Ge, Y. (2016), "Investigations of adverse wind loads on a large cooling tower for the six-tower combination", Appl. Therm. Eng., 105, 988-999. https://doi.org/10.1016/j.applthermaleng.2016.02.038.