“Performance
and optimisation of gas turbines with real gas effects”,
Guha
A.,
IMechE
Proc., Part A, J. Power and Energy, vol 215, no A4, 2001, p
507-512.
The influence of various
levels of mathematical
modelling on gas turbine performance is systematically analysed.
It is shown that real gas effects give rise to an optimum turbine entry
temperature which does not arise in a perfect gas analysis and has not
been described previously in the literature. At any pressure
ratio,
the maximum possible efficiency with real gas effects is significantly
lower (15-20%) than the maximum possible value predicted by a perfect
gas
analysis. An explicit equation has been derived for determining
the
optimum pressure ratio as a function of turbine entry temperature and
component
efficiencies. It is shown that the optimum design depends very
strongly
on turbine and compressor efficiencies. It is demonstrated that
the
optimum relation between pressure ratio and turbine entry temperature
depends
strongly on whether the optimisation is carried out at fixed pressure
ratios
or at fixed temperatures. All previous references seem to have
considered
only the latter method.
