The Effect of Windbreak Walls on the Thermal Performance of Natural Draft Dry Cooling Towers

A three-dimensional study using the standard k-ϵ turbulence model to simulate airflow in and around a natural draft dry cooling tower (NDDCT) has been conducted using a general-purpose CFD code. This investigation considered the location and the porosity of windbreak walls' structure on the NDDCT thermal performance. In addition, the effect of the windbreak walls on the thermal performance of two NDDCTs with different capacities has been investigated. Two parameters have been used to show the effect of the windbreak walls on the NDDCT thermal performance. At the reference heat exchanger temperature, the thermal effectiveness parameter has been employed. At the reference rejected heat from the NDDCT, the change in the cooling tower approach parameter has been employed. The results in this paper show an improvement in the NDDCT thermal performance due to the introduction of windbreak walls. Moreover, optimizing the location of the windbreak walls has been shown to have a more significant effect on the NDDCT thermal performance than the porosity of the walls. In addition, the effect of the windbreak walls on the thermal performance is similar for the two NDDCT with different capacities.

[1]  R. Blevins.  Applied Fluid Dynamics Handbook , 1984 .

[2]  J. Gandemer,et al.  The aerodynamic characteristics of windbreaks, resulting in empirical design rules , 1981 .

[3]  M. Perera,et al.  Shelter behind two-dimensional solid and porous fences , 1981 .

[4]  P. A. Sheppard.  Atmospheric Turbulence , 1947, Nature.

[5]  Detlev G. Kröger,et al.  Effect of wind on performance of a dry-cooling tower , 1993 .

[6]  D. C. Stevenson,et al.  Wind protection by model fences in a simulated atmospheric boundary layer , 1977 .

[7]  Boyin Zhang,et al.  A study of the unfavorable effects of wind on the cooling efficiency of dry cooling towers , 1995 .

[8]  M. D. Su,et al.  Numerical simulation of fluid flow and thermal performance of a dry-cooling tower under cross wind condition , 1999 .

[9]  Jinmei Shen,et al.  SHELTERBELTS AND WINDBREAKS: Mathematical Modeling and Computer Simulations of Turbulent Flows , 2001 .

[10]  Fuh-Min Fang,et al.  On the flow around a vertical porous fence , 1997 .

[11]  Detlev G. Kröger,et al.  The effect of the heat exchanger arrangement and wind-break walls on the performance of natural draft dry-cooling towers subjected to cross-winds , 1995 .

[12]  Donald J. Bergstrom,et al.  A study on the effects of wind on the air intake flow rate of a cooling tower: Part 2. Wind wall study , 1996 .

[13]  Detlev G. Kröger,et al.  Effect of the Shape of the Tower Supports and Walls on the Performance of a Dry-Cooling Tower Subjected to Cross Winds , 1995 .