Comparative Analysis on Thermal Performance of Different Natural-draft Dry Cooling Towers under Crosswind Condition

Goodarzi, M.; Mohammadi, P.

doi:10.22060/mej.2017.12314.5310

Comparative Analysis on Thermal Performance of Different Natural-draft Dry Cooling Towers under Crosswind Condition

Document Type : Research Article

Authors

M. Goodarzi ¹
P. Mohammadi ²

¹ Department of Mechanical Engineering, Bu Ali Sina University, Hamedan, Iran

² Department of Mechanical Engineering, Takestan Branch of Islamic Azad University, Takestan, Iran

10.22060/mej.2017.12314.5310

Abstract

This article aims to study the thermal performances of four different natural draft cooling
towers under crosswind condition. The windbreakers and the oblique exit plane have been simultaneously
included in the structure of the new cooling tower. A finite volume method using SIMPLE algorithm was
used to simulate the flow field around each cooling tower. The thermal performance of the new geometry
has been compared with those of others for the generally investigated wind velocity profile for 10 m/s,
and also two uniform wind velocities for 3 and 7 m/s. The cooling capacity of the cooling tower utilizing
windbreakers and the oblique exit plane was predicted as 98.3% of the design value in the presence of
generally studied wind velocity profile of 10 m/s, while that of the cooling tower utilizing windbreakers
was predicted as 93.5%. Of course, the percentage of the thermal improvements of the different restoring
strategies are sensitive to the profile of an approaching wind. The uniform wind velocity decreases the
thermal efficiency of the cooling tower more than the distributed one, while the restoring strategies using
windbreakers provide a higher percentage of thermal improvements in the presence of uniform wind
velocity.

Highlights

[1] N. Kapas, Behavior of natural draught cooling towers in wind, CMFF, Budapest, Hungary, 30 (2003).

[2] W. Rodi, hree-Dimensional Numerical Calculations of Flow and Plume Spreading Past Cooling Towers, Journal of Heat Transfer, 109 (1987) 113.

[3] T. Bender, D. Bergstrom, K. Rezkallah, A study on the effects of wind on the air intake flow rate of a cooling tower: Part 3. Numerical study, Journal of Wind Engineering and Industrial Aerodynamics, 64(1) (1996) 73-88.

[4] D. Bergstrom, D. Derksen, K. Rezkallah, Numerical study of wind flow over a cooling tower, Journal of wind engineering and industrial aerodynamics, 46 (1993) 657-664.

[5] A. Du Preez, D. Kröger, Effect of wind on performance of a dry-cooling tower, Heat Recovery Systems and CHP, 13(2) (1993) 139-146.

[6] Q.-d. Wei, B.-y. Zhang, K.-q. Liu, X.-d. Du, X.-z. Meng, A study of the unfavorable effects of wind on the cooling efficiency of dry cooling towers, Journal of wind engineering and industrial aerodynamics, 54 (1995) 633-643.

[7] M. Su, G. Tang, S. Fu, Numerical simulation of fluid flow and thermal performance of a dry-cooling tower under cross wind condition, Journal of Wind Engineering and Industrial Aerodynamics, 79(3) (1999) 289-306.

[8] R. Al‐Waked, M. Behnia, The performance of natural draft dry cooling towers under crosswind: CFD study, International journal of energy research, 28(2) (2004) 147-161.

[9] A. Du Preez, D. Kröger, The effect of the heat exchanger arrangement and wind-break walls on the performance of natural draft dry-cooling towers subjected to cross-winds, Journal of wind engineering and industrial aerodynamics, 58(3) (1995) 293-303.

[10] Z. Zhai, S. Fu, Improving cooling efficiency of dry-cooling towers under cross-wind conditions by using wind-break methods, Applied Thermal Engineering, 26(10) (2006) 1008-1017.

[11] M. Goodarzi, R. Keimanesh, Heat rejection enhancement in natural draft cooling tower using radiator-type windbreakers, Energy Conversion and Management, 71 (2013) 120-125.

[12] M. Goodarzi, R. Keimanesh, Numerical analysis on overall performance of Savonius turbines adjacent to a natural draft cooling tower, Energy Conversion and Management, 99 (2015) 41-49.

[13] W. Wang, H. Zhang, P. Liu, Z. Li, J. Lv, W. Ni, The cooling performance of a natural draft dry cooling tower under crosswind and an enclosure approach to cooling efficiency enhancement, Applied Energy, 186 (2017) 336-346.

[14] M. Goodarzi, R. Ramezanpour, Alternative geometry for cylindrical natural draft cooling tower with higher cooling efficiency under crosswind condition, Energy Conversion and Management, 77 (2014) 243-249.

[15] Y. Kong, W. Wang, L. Yang, X. Du, Y. Yang, A novel natural draft dry cooling system with bilaterally arranged air-cooled heat exchanger, International Journal of Thermal Sciences, 112 (2017) 318-334.

[16] M. Goodarzi, A proposed stack configuration for dry cooling tower to improve cooling efficiency under

crosswind, Journal of Wind Engineering and Industrial Aerodynamics, 98(12) (2010) 858-863.

[17] M. Goodarzi, H. Amooie, Heat transfer enhancement in a natural draft dry cooling tower under crosswind operation with heterogeneous water distribution, Atw. Internationale Zeitschrift fuer Kernenergie, 61(4) (2016) 252-259.

[18] W. Wang, L. Yang, X. Du, Y. Yang, Anti-freezing water flow rates of various sectors for natural draft dry cooling system under wind conditions, International Journal of Heat and Mass Transfer, 102 (2016) 186-200.

[19] B. Gebhart, Y. Jaluria, R.L. Mahajan, B. Sammakia, Buoyancy-induced flows and transport, (1988).

[20] B.E. Launder, D.B. Spalding, The numerical computation of turbulent flows, Computer methods in applied mechanics and engineering, 3(2) (1974) 269- 289.

[21] EGI, The Heller System, EGI, 1984.

[22] EGI, Thermo Technical and Aerodynamic Design/ Calculation/ Characteristics of the Dry Cooling Plant System Heater, Budapest Institute of Engineering, 1985.

[23] S. Patankar, Numerical heat transfer and fluid flow, CRC press, 1980.

Keywords

References