Thesis (MScEng (Civil Engineering))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: This investigation focused on the marine components of large direct seawater intake and brine
discharge systems for seawater desalination plants, with the main aim to provide an overall design
approach for these components.
Due to its complexity, an overall and systematic design approach, addressing all the components
(feedwater requirements, plant technology, marine structures and environmental issues) is required to
ensure an optimum design. A literature review was done on the various desalination technologies,
the main components of a seawater desalination plant, as well as the physical, hydraulic, operational
and environmental issues regarding seawater extraction facilities, marine pipelines and discharge
structures (diffuser).
In order to obtain practical input to the development of an overall design approach, information
regarding the marine structures of ten of the largest existing seawater desalination plants throughout
the world were obtained and compared with each other and the available technologies.
By way of example, the recently designed marine components of a new seawater reverse osmosis
desalination plant in Namibia were reviewed and, as part of this thesis, alternative conceptual
concepts which will include two additional components (sump and brine reservoir) were designed.
The alternative design was compared with the actual design in order to determine the feasibility of the
alternative in terms of operation and cost and subsequently provide input to the overall design
recommendations.
Furthermore, from the literature review it seems that there are still significant uncertainties regarding
the required performance of a brine (dense) outfall and this required more attention in terms of
environmental and hydraulic performance. Based on the Namibian plant, the diffuser configuration
was analysed in terms of its hydraulic and environmental performance and subsequently some
general guidance with specific respect to a brine diffuser was developed, which in turn formed part of
the overall design approach for the marine components.
Finally, the design approach for seawater intake structures, brine outfalls and the connecting marine
pipelines is provided in the form of flow diagrams. / AFRIKAANSE OPSOMMING: Hierdie ondersoek handel oor die mariene komponente van groot en direkte toevoer van seewater en
die sout-uitvloeisisteme van ontsoutingsaanlegte van seewater. Die doel is om ‘n oorsigtelike
ontwerpbenadering vir hierdie component te verskaf.
As gevolg van die kompleksiteit, is ‘n oorsigtelike en sistimatiese benadering, wat al die komponente
(vereistes vir toevoerwater, tehnologie by die aanleg, mariene omstandighede en omgewingsfaktore)
in ag neem noodsaaklik om die beste ontwerp te verseker.
‘n Literêre oorsig is gedoen ten opsigte van die tegnologie van verskeie ontsoutingsmetodes, die
hoofkomponente van ‘n seewater-ontsoutingsaanleg, asook die fisiese, hidrouliese, operasionele en
omgewingskwessies rakende die fasiliteite om die seewater te onttrek, die mariene pyplyne en die
strukture vir die afvloei.
Ten einde die optimum ontwerp te ontwikkel, is inligting oor die tegnologie en strukture van tien van
die grootste bestaande onsoutingsaanlegte in die wêreld bekom, bestudeer en vergelyk Hulle is met
mekaar vergelyk, asook met beskikbare tegnologie.
As ‘n voorbeeld is die nuut ontwerpte mariene komponente van die nuwe ontsoutingsaanleg in
Namibië, waar ontsouting d.m.v. omgekeerde osmose gedoen word ondersoek en as deel van hierdie
tesis, is ‘n alternatiewe konsep, wat twee bykomende komponente – ‘n opvangput en reservoir vir die
afloop – ontwerp. Hierdie alternatiewe ontwerp is met die werklike aanleg vergelyk om die
uitvoerbaarheid van die onderneming en die koste daaraan verbonde te toets. Dit is gebruik as
aanbeveling vir die oorhoofse ontwerp.
Uit die literêre oorsig blyk dit dar daar nog groot onsekerheid is oor die vereistes van die (digte)
waterafloop en dat meer aandag aan die omgewings- en hidrouliese aspekte gegee moet word. Met
die Namibiese aanleg as voorbeeld, is die struktuur van die spreiers t.o.v. hidrouliese werkverrigting
en die omgewing ontleed. Voortspruitend daaruit is algemene riglyne vir ‘n spesifieke spreier vir
afloopwater ontwikkel, wat op sy beurt weer deel vorm van die oorhoofse ontwerp vir mariene
komponente.
Laastens is die ontwerp vir die strukture vir seewater-invloei, die afloopwater en die mariene
verbindingspyplyne as vloeidigramme aangetoon.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:sun/oai:scholar.sun.ac.za:10019.1/4177 |
| Date | 03 1900 |
| Creators | Le Roux, Maria |
| Contributors | Bosman, D. E., Toms, G., University of Stellenbosch. Faculty of Engineering. Dept. of Civil Engineering. |
| Publisher | Stellenbosch : University of Stellenbosch |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | Unknown |
| Type | Thesis |
| Format | 139 p. : ill. |
| Rights | University of Stellenbosch |
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