| Summary: | The
objective of this thesis is to determine if an advanced gas turbine cycle exists,
which can
compete with the simple and the combined cycles in the intermediate load
electricity generation market; defined as the market with annual utilisation between
3,000 to 6,000 operating hours.
Several
thermodynamic cycles in the 100MW and 200MW power output range are
investigated and compared to base reference simple and combined cycles that have
been defined
by a survey of existing models in the market.
For the
investigation of these cycles, gt-ETA (gas turbine - Economic and Technical
Analysis) has been developed; a software for the design and off-design
thermodynamic performance and the economic evaluation of gas turbine cycles.
A new method is
proposed for calculating the total capital investment of a advanced
cycle engine project. This is based on deriving empirical relations linking the
purchased equipment cost to power output and thermal efficiency, based on published
data for
simple cycle engines. Standardised values are used for the specific costs of
different
performance improvement' packages.
A
optimisation process is developed for the determination of the optimum split
between the
capital investment of a baseline' simple cycle engine and a 'performance
improvement package.
For accurate
performance calculations a cooling air model has been created based on
either the direct definition of
cooling air amounts or the required hot gas path
component metal temperatures. The model is able to select the optimum cooling
configuration considering the temperature and pressure of mixing streams.
The advanced
cycles are competitive against base reference cycles only in the power
range of l00MW. From the configurations considered, the recuperated cycle with
spray intercooling seems to be the most promising option with a wide range of
competitiveness at both design and off-design operating conditions and along the
sensitivity range of changing fuel prices.
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