0
Research Papers

Simulating the Effect of Wind on the Performance of Axial Flow Fans in Air-Cooled Steam Condenser Systems

[+] Author and Article Information
Neil Fourie

Department of Mechanical
and Mechatronic Engineering,
Stellenbosch University,
Stellenbosch 7600, South Africa

S. J. van der Spuy

Department of Mechanical
and Mechatronic Engineering,
Stellenbosch University,
Stellenbosch 7600, South Africa
e-mail: 15355640@sun.ac.za

T. W. von Backström

Professor
Department of Mechanical
and Mechatronic Engineering,
Stellenbosch University,
Stellenbosch 7600, South Africa

Contributed by the Heat Transfer Division of ASME for publication in the JOURNAL OF THERMAL SCIENCE AND ENGINEERING APPLICATIONS. Manuscript received July 16, 2014; final manuscript received December 23, 2014; published online February 10, 2015. Assoc. Editor: W. J. Marner.

J. Thermal Sci. Eng. Appl 7(2), 021011 (Jun 01, 2015) (12 pages) Paper No: TSEA-14-1166; doi: 10.1115/1.4029597 History: Received July 16, 2014; Revised December 23, 2014; Online February 10, 2015

The use of air-cooled steam condensers (ACSCs) is preferred in the chemical and power industry due to their ability to adhere to stringent environmental and water use regulations. ACSC performance is, however, highly dependent on the prevailing wind conditions. Research has shown that the presence of wind reduces the performance of ACSCs. It has been found that cross-winds (wind perpendicular to the longest side of the ACSC) cause distorted inlet flow conditions, particularly at the upstream peripheral fans near the symmetry plane of the ACSC. These fans are subjected to what is referred to as “two-dimensional” wind conditions, which are characterized by flow separation on the upstream edge of the fan inlets. Experimental investigations into inlet flow distortion have simulated these conditions by varying the fan platform height. Low platform heights resulted in higher levels of inlet flow distortion, as also found to exist with high cross-wind velocities. The similarity between platform height and cross-wind velocity is investigated in this study by conducting experimental and numerical investigations into the effect of distorted inlet flow conditions on the performance of various fan configurations (representative of configurations used in the South-African power industry). A correlation between system volumetric effectiveness, platform height, and cross-wind velocity is derived which provides a means to compare platform height and cross-wind velocity effects.

Copyright © 2015 by ASME
Your Session has timed out. Please sign back in to continue.

References

Kröger, D. G., 2004, Air-Cooled Heat Exchangers and Cooling Towers, PenWell, Tulsa, OK.
Goldschagg, H., 1993, “Winds of Change at Eskom's Matimba Plant,” Mod. Power Syst., 19(1), p. 43.
Salta, C. A., and Kröger, D. G., 1995, “Effect of Inlet Flow Distortions on Fan Performance in Forced Draught Air-Cooled Heat Exchangers,” Heat Recovery Syst. CHP, 15(6), pp. 555–561. [CrossRef]
van der Spuy, S. J., 2011, “Perimeter Fan Performance in Forced Draught Air-Cooled Steam Condensers,” Ph.D. thesis, University of Stellenbosch, Stellenbosch, South Africa.
Duvenhage, K., Vermeulen, J. A., Meyer, C. J., and Kröger, D. G., 1996, “Flow Distortions at the Fan Inlet of Forced-Draught Air-Cooled Heat Exchangers,” Appl. Therm. Eng., 16(8–9), pp. 741–752. [CrossRef]
Bredell, J. R., Kröger, D. G., and Thiart, G. D., 2006, “Numerical Investigation of Fan Performance in a Forced Draft Air-Cooled Steam Condenser,” Appl. Therm. Eng., 26(8), pp. 846–852. [CrossRef]
Louw, F. G., 2011, “Performance Trends of a Large Air-Cooled Steam Condenser During Windy Conditions,” Master's thesis, University of Stellenbosch, Stellenbosch, South Africa.
Bruneau, P. R. P., 1994, “The Design of a Single Rotor Axial Flow Fan for a Cooling Tower Application,” Master's thesis, University of Stellenbosch, Stellenbosch, South Africa.
Conradie, P. J. F., 2010, “Edge Fan Performance in Air-Cooled Condensers,” Master's thesis, University of Stellenbosch, Stellenbosch, South Africa.
British Standards Institute, 2007, “Methods for Testing Performance: Fans for General Purposes, Part 1,” British Standards Institute, London.
Shih, T.-H., Liou, W. W., Shabbir, A., Yang, Z., and Zhu, J., 1995, “A New k-ε Eddy-Viscosity Model for High Reynolds Number Turbulent Flows: Model Development and Validation,” Comput. Fluids, 24(3), pp. 227–238. [CrossRef]
Yang, L. J., Du, X. Z., and Yang, Y. P., 2012, “Wind Effect on the Thermo-Flow Performances and Its Decay Characteristics for Air-Cooled Condensers in a Power Plant,” Int. J. Therm. Sci., 53, pp. 175–187. [CrossRef]
Gao, X. F., Zhang, C. W., Wei, J. J., and Yu, B., 2010, “Performance Prediction of an Improved Air-Cooled Steam Condenser With Deflector Under Strong Wind,” Appl. Therm. Eng., 30(17), pp. 2663–2669. [CrossRef]
Owen, M. T. F., 2010, “A Numerical Investigation of Air-Cooled Steam Condenser Performance Under Windy Conditions,” Master's thesis, University of Stellenbosch, Stellenbosch, South Africa.
Joubert, R., 2010, “Influence of Geometric and Environmental Parameters on Air-Cooled Steam Condenser Performance,” Master's thesis, University of Stellenbosch, Stellenbosch, South Africa.
van Rooyen, J. A., 2007, “Performance Trends of an Air-Cooled Steam Condenser Under Windy Conditions,” Master’s thesis, University of Stellenbosch, Stellenbosch, South Africa.
Fluent, 2009, “ansysfluent 12.0 User's Guide,” ANSYS, Inc., Canonsburg, PA.
VDI, 1978, VDI Guidelines, VDI 2049, Thermal Acceptance and Performance Tests on Dry-Cooling Towers, VDI-Verlag, Dusseldorf.
Stinnes, W. H., and von Backström, T. W., 2002, “Effect of Cross-Flow on the Performance of Air-Cooled Heat Exchanger Fans,” Appl. Therm. Eng., 22(12), pp. 1403–1415. [CrossRef]

Figures

Grahic Jump Location
Fig. 4

Layout of three-fan unit in ACSC [4]

Grahic Jump Location
Fig. 3

Axial flow fans performance curves

Grahic Jump Location
Fig. 1

ACSC flow conditions associated with low platform heights and cross-winds

Grahic Jump Location
Fig. 5

Three-fan experimental setup

Grahic Jump Location
Fig. 6

Hex-core mesh pressure drop measurements [4]

Grahic Jump Location
Fig. 7

Single fan CFD model geometry and boundary conditions

Grahic Jump Location
Fig. 8

Three-fan facility CFD model geometry

Grahic Jump Location
Fig. 9

Three-fan facility CFD model computational grid

Grahic Jump Location
Fig. 10

Conventional A-frame fan-unit and corresponding numerical model

Grahic Jump Location
Fig. 18

N-fan system variable platform height CFD results comparison with experimental results

Grahic Jump Location
Fig. 12

ACSC numerical model computational grid (5.57 × 106 cells)

Grahic Jump Location
Fig. 11

ACSC numerical model domain

Grahic Jump Location
Fig. 13

Experimental platform height investigation repeatability with the N-fan system

Grahic Jump Location
Fig. 14

Effect of platform height on the volumetric effectiveness of the N-fan system

Grahic Jump Location
Fig. 15

Effect of platform height on the system volumetric effectiveness of the N-, N9-, and 630 L-fan systems

Grahic Jump Location
Fig. 16

Effect of platform height on the system volumetric effectiveness of the 630 L-, N9-, and 630 L–N9–N9 fan systems

Grahic Jump Location
Fig. 17

N-fan static pressure CFD results comparison

Grahic Jump Location
Fig. 19

Comparison between analytical and numerical ACSC fan unit outlet temperature results

Grahic Jump Location
Fig. 20

N-fan ACSC street 1 temperature contours

Grahic Jump Location
Fig. 21

ACSC street 1 volumetric effectiveness results

Grahic Jump Location
Fig. 22

Definition of cross flow and wind velocity variables

Grahic Jump Location
Fig. 23

Variable platform height and cross-wind velocity results for each fan system

Grahic Jump Location
Fig. 25

Effect of nondimensional wind number, vw/vx, on the wind factor, fwind

Grahic Jump Location
Fig. 26

Combined platform height and cross-wind velocity results for all fan systems

Grahic Jump Location
Fig. 27

3D plot of volumetric effectiveness as a function of platform height and dimensionless wind velocity

Grahic Jump Location
Fig. 28

Volumetric effectiveness curves at constant dimensionless wind velocities

Grahic Jump Location
Fig. 29

Dimensionless platform height curves at constant volumetric effectiveness values

Grahic Jump Location
Fig. 24

Perimeter fan flow field comparison of coinciding experimental and numerical data points at (a) in Fig. 23

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In