Energy degradation
can be calculated
by
the
quantification
of
entropy and loss
of work
and
is a common approach in
power plant performance analysis. Information about the
location, amount and
sourc
es of system deficiencies are
determined by
the
exergy analysis, which
quantifies the
exergy
destruction.
Micro
-
gas turbines are
prime movers
that are
ideally suited for cogeneration applications due to their
flexibility in providing stable and reliable power. This paper
presents
an
exergy analysis
by means of a
numerical
simulation
of a
regenerative
micro
-
gas turbine
for cogeneration
applications
. The main objective is
to study
the best
configuration of each system component
,
considering the minimization of the
system irreversibilities
. Each component of
the system was evaluated
considering the quantitative exergy
balance
.
Subsequently the optimization
procedure
was applied
to the mathematical model that
describes the
full
system.
The rate of irreversibility, efficiency and flaws are
highlighted for each system component and for
the
whole
system.
The effect
of turbine inlet temperature
change
on plant
exergy destruction
was also evaluated
. The results disclose that
considerable exergy destruction occurs in the combustion
chamber. Also, it
was revealed that the exergy
efficiency is
expressively
dependent on the
changes
of
the turbine inlet
temperature
and increases with
the
latter
.The authors would like to express their acknowledgments for the support given by the Portuguese F01mdation for Science and Technology (FCT) through the PhD grant SFRH/BD/62287/2009. This work was financed by National Funds-Portuguese Foundation for Science and Technology, under Strategic Project and PEst-OE/EME/UI0252/2011 and also the PEst-C/EME/UI4077/2011
