Thesis (PhD (Mechanical and Mechatronic Engineering))--Stellenbosch University, 2008. / ENGLISH ABSTRACT: The power conversion unit of a large solar chimney power plant converts the fluid power, first into mechanical power, and then into electrical power. In this
dissertation a tool is developed to determine the layout and the number of turbines
of the solar chimney power conversion unit providing the lowest cost of
electricity.
First, the history of the solar chimney concept and the related fields of research
are presented. Potential features and configurations of the power conversion
unit are introduced, and it is shown how the solar chimney power conversion
unit compares to those of other applications. An outline of the dissertation
is given, and its potential impact is discussed.
An analytical turbine model is developed. Several modelling approaches and
the performance of single rotor and counter rotating turbine layouts are compared.
Preliminary turbine designs are investigated, experimentally and numerically.
The main aim of the experimental investigation is to verify the applicability
of the loss model used in the analytical turbine model. The aim of the numerical
investigation is to evaluate a commercial software package as a tool in context
with solar chimney turbines.
For each component of the power conversion unit an analytical performance
model is introduced. Using these models, the single vertical axis, multiple vertical
axis and multiple horizontal axis turbine configurations are compared from
an efficiency and energy yield point of view, and the impact of the various losses
on the overall performance is highlighted. A detailed cost model for the power
conversion unit is also presented. To optimize for cost of electricity this cost
model is then linked to the performance models, and the resulting optimization
scheme is applied to several plant configurations.
It is shown that for a large solar chimney power plant the power conversion
unit providing minimal cost of electricity consists of multiple horizontal axis turbines
using a single rotor layout including inlet guide vanes. / AFRIKAANSE OPSOMMING: Die drywingsomsettingseenheid van ’n groot sonskoorsteenaanleg sit die vloeidrywing om, eers in meganiese drywing en dan in elektriese drywing. In hierdie
proefskrif word ’n gereedskapstuk ontwikkel om die uitleg en aantal turbines van
die sonskoorsteen-drywingsomsettingseenheid te bepaal wat die laagste koste
van elektrisiteit lewer. Eerstens word die geskiedenis van die sonskoorsteen en verwante navorsingsvelde
behandel. Moontlike eienskappe en konfigurasies vir die drywingsomsettingseenheid word
voorgestel, en daar word aangetoon hoe die sonskoorsteendrywingsomsettings-
eenheid vergelyk met ander toepassings. ’n Raamwerk van
die proefskrif word gegee, en die potensiële trefkrag daarvan word bespreek.
’n Analitiese turbine-model word ontwikkel. Verskeie nabootsingsbenaderings
en die vertoning van ’n enkelrotor en teenroterende turbine-uitlegte word
vergelyk. Voorlopige turbine-ontwerpe word ondersoek, eksperimenteel en numeries.
Die hoofdoel van die eksperimentele ondersoek is om die toepaslikheid
van die verliesmodel in die analitiese turbine-model te bevestig. Die doel van die
numeriese ondersoek is om kommersiële sagteware op te weeg as ’n gereedskapstuk
in die konteks van sonskoorsteenturbines.
Vir elke onderdeel van die drywingsomsettingseenheid word ’n analitiese model
voorgestel. Met gebruik van hierdie modelle word die enkele vertikale-as, die
veelvoudige vertikale-as an die veelvoudige horisontale-as turbinekonfigurasies
vergelyk vanuit ’n benuttingsgraad- en energie-opbrengsoogpunt,en die uitwerking
van die verskillende verliese op die algehele gedrag word uitgewys. ’n Kostemodel
in besonderhede word vir die drywingsomsettingseenheid aangebied. Om
vir die koste van elektrisiteit te optimeer word hierdie kostemodel dan gekoppel
aan die vertoningsmodelle, en die gevolglike optimeringskema word toegepas op
verskeie aanlegkonfigurasies.
Daar word aangetoon dat vir ’n groot sonskoorsteenaanleg die drywingsomsettingseenheid wat
die minimumkoste van elektrisiteit gee, bestaan uit veelvoudige
horisontale-as turbines met enkelrotoruitleg en inlaatleilemme. / Centre for Renewable and Sustainable Energy Studies
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:sun/oai:scholar.sun.ac.za:10019.1/4402 |
| Date | 12 1900 |
| Creators | Fluri, Thomas Peter |
| Contributors | Von Backstrom, T. W., Stellenbosch University. Faculty of Engineering. Dept. of Mechanical and Mechatronic Engineering. |
| Publisher | Stellenbosch : Stellenbosch University |
| Source Sets | South African National ETD Portal |
| Language | en_ZA |
| Detected Language | Unknown |
| Type | Thesis |
| Rights | Stellenbosch University |
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