Thesis (MEng) -- Stellenbosch University, 2014. / ENGLISH ABSTRACT: The use of air-cooled steam condensers (ACSCs) is the preferred cooling
method in the chemical and power industry due to stringent environmental and
water use regulations. The performance of ACSCs is however highly dependent
on the influence of windy 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 '2-D' wind
conditions, which are characterised 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 speeds. This investigation determines the performance of
various fan configurations (representative of configurations used in the South-
African power industry) subjected to distorted inlet flow conditions through
experimental and numerical investigations. The similarity between platform
height and cross-wind effects is also investigated and a correlation between
system volumetric effectiveness, platform height and cross-wind velocity is
found. / AFRIKAANSE OPSOMMING: Die gebruik van lugverkoelde stoom kondensors (LVSK's) word verkies as
'n verkoelingsmetode in die chemiese- en kragvoorsieningsindustrie as gevolg
van streng omgewings- en waterverbruiksregulasies. Die werkverrigting van
LVSK's word egter grootliks beïnvloed deur die teenwoordigheid van wind.
Navorsing het gewys dat die teenwoordigheid van wind die werkverrigting van
LVSK's verminder. Daar was gevind dat kruiswinde (wind loodreg tot die
langste sy van die LVSK) versteurde inlaat vloeitoestande veroorsaak, veral
by waaiers wat aan die stroomop kant van die LVSK naby die simmetrievlak
geleë is. Hierdie waaiers word blootgestel aan na wat verwys word as
'2-D' windtoestande wat gekenmerk word deur vloeiwegbreking wat plaasvind
by die stroomop rand van die waaierinlate. Eksperimentele ondersoeke van
inlaat vloeiversteurings het hierdie toestande gesimuleer deur die waaier platformhoogte
te verstel. Lae platform hoogtes het gelei tot hoër vlakke van
inlaat vloeiversteuring, soortgelyk aan wat gevind word met hoë kruiswindsnelhede.
Hierdie ondersoek gebruik numeriese en eksperimentele metodes om die
werkverrigting van verskeie waaierkon gurasies (verteenwoordigend van kon-
gurasies wat gebruik word in die Suid-Afrikaanse kragvoorsieningsindustrie)
wat blootgestel word aan versteurde inlaat vloeitoestande te bepaal. Die ooreenkoms
tussen platformhoogte en kruiswind e ekte word ook ondersoek en
'n korrelasie tussen die sisteem volumetriese e ektiwiteit, platformhoogte en
kruiswindsnelheid word bepaal.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:sun/oai:scholar.sun.ac.za:10019.1/95977 |
| Date | 12 1900 |
| Creators | Fourie, Neil |
| Contributors | Van Der Spuy, S. J., Von Backstrom, T. W., Stellenbosch University. Faculty of Engineering. Department of Mechanical and Mechatronic Engineering. |
| Publisher | Stellenbosch : Stellenbosch University |
| Source Sets | South African National ETD Portal |
| Language | en_ZA |
| Detected Language | Unknown |
| Type | Thesis |
| Format | xv, 135 p. : ill. |
| Rights | Stellenbosch University |
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